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linux/drivers/pci/controller/pci-hyperv.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) Microsoft Corporation.
*
* Author:
* Jake Oshins <jakeo@microsoft.com>
*
* This driver acts as a paravirtual front-end for PCI Express root buses.
* When a PCI Express function (either an entire device or an SR-IOV
* Virtual Function) is being passed through to the VM, this driver exposes
* a new bus to the guest VM. This is modeled as a root PCI bus because
* no bridges are being exposed to the VM. In fact, with a "Generation 2"
* VM within Hyper-V, there may seem to be no PCI bus at all in the VM
* until a device as been exposed using this driver.
*
* Each root PCI bus has its own PCI domain, which is called "Segment" in
* the PCI Firmware Specifications. Thus while each device passed through
* to the VM using this front-end will appear at "device 0", the domain will
* be unique. Typically, each bus will have one PCI function on it, though
* this driver does support more than one.
*
* In order to map the interrupts from the device through to the guest VM,
* this driver also implements an IRQ Domain, which handles interrupts (either
* MSI or MSI-X) associated with the functions on the bus. As interrupts are
* set up, torn down, or reaffined, this driver communicates with the
* underlying hypervisor to adjust the mappings in the I/O MMU so that each
* interrupt will be delivered to the correct virtual processor at the right
* vector. This driver does not support level-triggered (line-based)
* interrupts, and will report that the Interrupt Line register in the
* function's configuration space is zero.
*
* The rest of this driver mostly maps PCI concepts onto underlying Hyper-V
* facilities. For instance, the configuration space of a function exposed
* by Hyper-V is mapped into a single page of memory space, and the
* read and write handlers for config space must be aware of this mechanism.
* Similarly, device setup and teardown involves messages sent to and from
* the PCI back-end driver in Hyper-V.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/semaphore.h>
#include <linux/irqdomain.h>
#include <asm/irqdomain.h>
#include <asm/apic.h>
#include <linux/irq.h>
#include <linux/msi.h>
#include <linux/hyperv.h>
#include <linux/refcount.h>
#include <asm/mshyperv.h>
/*
* Protocol versions. The low word is the minor version, the high word the
* major version.
*/
#define PCI_MAKE_VERSION(major, minor) ((u32)(((major) << 16) | (minor)))
#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16)
#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff)
enum pci_protocol_version_t {
PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), /* Win10 */
PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2), /* RS1 */
PCI_PROTOCOL_VERSION_1_3 = PCI_MAKE_VERSION(1, 3), /* Vibranium */
};
#define CPU_AFFINITY_ALL -1ULL
/*
* Supported protocol versions in the order of probing - highest go
* first.
*/
static enum pci_protocol_version_t pci_protocol_versions[] = {
PCI_PROTOCOL_VERSION_1_3,
PCI_PROTOCOL_VERSION_1_2,
PCI_PROTOCOL_VERSION_1_1,
};
#define PCI_CONFIG_MMIO_LENGTH 0x2000
#define CFG_PAGE_OFFSET 0x1000
#define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET)
#define MAX_SUPPORTED_MSI_MESSAGES 0x400
#define STATUS_REVISION_MISMATCH 0xC0000059
/* space for 32bit serial number as string */
#define SLOT_NAME_SIZE 11
/*
* Message Types
*/
enum pci_message_type {
/*
* Version 1.1
*/
PCI_MESSAGE_BASE = 0x42490000,
PCI_BUS_RELATIONS = PCI_MESSAGE_BASE + 0,
PCI_QUERY_BUS_RELATIONS = PCI_MESSAGE_BASE + 1,
PCI_POWER_STATE_CHANGE = PCI_MESSAGE_BASE + 4,
PCI_QUERY_RESOURCE_REQUIREMENTS = PCI_MESSAGE_BASE + 5,
PCI_QUERY_RESOURCE_RESOURCES = PCI_MESSAGE_BASE + 6,
PCI_BUS_D0ENTRY = PCI_MESSAGE_BASE + 7,
PCI_BUS_D0EXIT = PCI_MESSAGE_BASE + 8,
PCI_READ_BLOCK = PCI_MESSAGE_BASE + 9,
PCI_WRITE_BLOCK = PCI_MESSAGE_BASE + 0xA,
PCI_EJECT = PCI_MESSAGE_BASE + 0xB,
PCI_QUERY_STOP = PCI_MESSAGE_BASE + 0xC,
PCI_REENABLE = PCI_MESSAGE_BASE + 0xD,
PCI_QUERY_STOP_FAILED = PCI_MESSAGE_BASE + 0xE,
PCI_EJECTION_COMPLETE = PCI_MESSAGE_BASE + 0xF,
PCI_RESOURCES_ASSIGNED = PCI_MESSAGE_BASE + 0x10,
PCI_RESOURCES_RELEASED = PCI_MESSAGE_BASE + 0x11,
PCI_INVALIDATE_BLOCK = PCI_MESSAGE_BASE + 0x12,
PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13,
PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14,
PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15,
PCI_RESOURCES_ASSIGNED2 = PCI_MESSAGE_BASE + 0x16,
PCI_CREATE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x17,
PCI_DELETE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x18, /* unused */
PCI_BUS_RELATIONS2 = PCI_MESSAGE_BASE + 0x19,
PCI_MESSAGE_MAXIMUM
};
/*
* Structures defining the virtual PCI Express protocol.
*/
union pci_version {
struct {
u16 minor_version;
u16 major_version;
} parts;
u32 version;
} __packed;
/*
* Function numbers are 8-bits wide on Express, as interpreted through ARI,
* which is all this driver does. This representation is the one used in
* Windows, which is what is expected when sending this back and forth with
* the Hyper-V parent partition.
*/
union win_slot_encoding {
struct {
u32 dev:5;
u32 func:3;
u32 reserved:24;
} bits;
u32 slot;
} __packed;
/*
* Pretty much as defined in the PCI Specifications.
*/
struct pci_function_description {
u16 v_id; /* vendor ID */
u16 d_id; /* device ID */
u8 rev;
u8 prog_intf;
u8 subclass;
u8 base_class;
u32 subsystem_id;
union win_slot_encoding win_slot;
u32 ser; /* serial number */
} __packed;
enum pci_device_description_flags {
HV_PCI_DEVICE_FLAG_NONE = 0x0,
HV_PCI_DEVICE_FLAG_NUMA_AFFINITY = 0x1,
};
struct pci_function_description2 {
u16 v_id; /* vendor ID */
u16 d_id; /* device ID */
u8 rev;
u8 prog_intf;
u8 subclass;
u8 base_class;
u32 subsystem_id;
union win_slot_encoding win_slot;
u32 ser; /* serial number */
u32 flags;
u16 virtual_numa_node;
u16 reserved;
} __packed;
/**
* struct hv_msi_desc
* @vector: IDT entry
* @delivery_mode: As defined in Intel's Programmer's
* Reference Manual, Volume 3, Chapter 8.
* @vector_count: Number of contiguous entries in the
* Interrupt Descriptor Table that are
* occupied by this Message-Signaled
* Interrupt. For "MSI", as first defined
* in PCI 2.2, this can be between 1 and
* 32. For "MSI-X," as first defined in PCI
* 3.0, this must be 1, as each MSI-X table
* entry would have its own descriptor.
* @reserved: Empty space
* @cpu_mask: All the target virtual processors.
*/
struct hv_msi_desc {
u8 vector;
u8 delivery_mode;
u16 vector_count;
u32 reserved;
u64 cpu_mask;
} __packed;
/**
* struct hv_msi_desc2 - 1.2 version of hv_msi_desc
* @vector: IDT entry
* @delivery_mode: As defined in Intel's Programmer's
* Reference Manual, Volume 3, Chapter 8.
* @vector_count: Number of contiguous entries in the
* Interrupt Descriptor Table that are
* occupied by this Message-Signaled
* Interrupt. For "MSI", as first defined
* in PCI 2.2, this can be between 1 and
* 32. For "MSI-X," as first defined in PCI
* 3.0, this must be 1, as each MSI-X table
* entry would have its own descriptor.
* @processor_count: number of bits enabled in array.
* @processor_array: All the target virtual processors.
*/
struct hv_msi_desc2 {
u8 vector;
u8 delivery_mode;
u16 vector_count;
u16 processor_count;
u16 processor_array[32];
} __packed;
/**
* struct tran_int_desc
* @reserved: unused, padding
* @vector_count: same as in hv_msi_desc
* @data: This is the "data payload" value that is
* written by the device when it generates
* a message-signaled interrupt, either MSI
* or MSI-X.
* @address: This is the address to which the data
* payload is written on interrupt
* generation.
*/
struct tran_int_desc {
u16 reserved;
u16 vector_count;
u32 data;
u64 address;
} __packed;
/*
* A generic message format for virtual PCI.
* Specific message formats are defined later in the file.
*/
struct pci_message {
u32 type;
} __packed;
struct pci_child_message {
struct pci_message message_type;
union win_slot_encoding wslot;
} __packed;
struct pci_incoming_message {
struct vmpacket_descriptor hdr;
struct pci_message message_type;
} __packed;
struct pci_response {
struct vmpacket_descriptor hdr;
s32 status; /* negative values are failures */
} __packed;
struct pci_packet {
void (*completion_func)(void *context, struct pci_response *resp,
int resp_packet_size);
void *compl_ctxt;
struct pci_message message[];
};
/*
* Specific message types supporting the PCI protocol.
*/
/*
* Version negotiation message. Sent from the guest to the host.
* The guest is free to try different versions until the host
* accepts the version.
*
* pci_version: The protocol version requested.
* is_last_attempt: If TRUE, this is the last version guest will request.
* reservedz: Reserved field, set to zero.
*/
struct pci_version_request {
struct pci_message message_type;
u32 protocol_version;
} __packed;
/*
* Bus D0 Entry. This is sent from the guest to the host when the virtual
* bus (PCI Express port) is ready for action.
*/
struct pci_bus_d0_entry {
struct pci_message message_type;
u32 reserved;
u64 mmio_base;
} __packed;
struct pci_bus_relations {
struct pci_incoming_message incoming;
u32 device_count;
struct pci_function_description func[];
} __packed;
struct pci_bus_relations2 {
struct pci_incoming_message incoming;
u32 device_count;
struct pci_function_description2 func[];
} __packed;
struct pci_q_res_req_response {
struct vmpacket_descriptor hdr;
s32 status; /* negative values are failures */
u32 probed_bar[PCI_STD_NUM_BARS];
} __packed;
struct pci_set_power {
struct pci_message message_type;
union win_slot_encoding wslot;
u32 power_state; /* In Windows terms */
u32 reserved;
} __packed;
struct pci_set_power_response {
struct vmpacket_descriptor hdr;
s32 status; /* negative values are failures */
union win_slot_encoding wslot;
u32 resultant_state; /* In Windows terms */
u32 reserved;
} __packed;
struct pci_resources_assigned {
struct pci_message message_type;
union win_slot_encoding wslot;
u8 memory_range[0x14][6]; /* not used here */
u32 msi_descriptors;
u32 reserved[4];
} __packed;
struct pci_resources_assigned2 {
struct pci_message message_type;
union win_slot_encoding wslot;
u8 memory_range[0x14][6]; /* not used here */
u32 msi_descriptor_count;
u8 reserved[70];
} __packed;
struct pci_create_interrupt {
struct pci_message message_type;
union win_slot_encoding wslot;
struct hv_msi_desc int_desc;
} __packed;
struct pci_create_int_response {
struct pci_response response;
u32 reserved;
struct tran_int_desc int_desc;
} __packed;
struct pci_create_interrupt2 {
struct pci_message message_type;
union win_slot_encoding wslot;
struct hv_msi_desc2 int_desc;
} __packed;
struct pci_delete_interrupt {
struct pci_message message_type;
union win_slot_encoding wslot;
struct tran_int_desc int_desc;
} __packed;
/*
* Note: the VM must pass a valid block id, wslot and bytes_requested.
*/
struct pci_read_block {
struct pci_message message_type;
u32 block_id;
union win_slot_encoding wslot;
u32 bytes_requested;
} __packed;
struct pci_read_block_response {
struct vmpacket_descriptor hdr;
u32 status;
u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
} __packed;
/*
* Note: the VM must pass a valid block id, wslot and byte_count.
*/
struct pci_write_block {
struct pci_message message_type;
u32 block_id;
union win_slot_encoding wslot;
u32 byte_count;
u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
} __packed;
struct pci_dev_inval_block {
struct pci_incoming_message incoming;
union win_slot_encoding wslot;
u64 block_mask;
} __packed;
struct pci_dev_incoming {
struct pci_incoming_message incoming;
union win_slot_encoding wslot;
} __packed;
struct pci_eject_response {
struct pci_message message_type;
union win_slot_encoding wslot;
u32 status;
} __packed;
static int pci_ring_size = (4 * PAGE_SIZE);
/*
* Driver specific state.
*/
enum hv_pcibus_state {
hv_pcibus_init = 0,
hv_pcibus_probed,
hv_pcibus_installed,
hv_pcibus_removing,
hv_pcibus_removed,
hv_pcibus_maximum
};
struct hv_pcibus_device {
struct pci_sysdata sysdata;
/* Protocol version negotiated with the host */
enum pci_protocol_version_t protocol_version;
enum hv_pcibus_state state;
refcount_t remove_lock;
struct hv_device *hdev;
resource_size_t low_mmio_space;
resource_size_t high_mmio_space;
struct resource *mem_config;
struct resource *low_mmio_res;
struct resource *high_mmio_res;
struct completion *survey_event;
struct completion remove_event;
struct pci_bus *pci_bus;
spinlock_t config_lock; /* Avoid two threads writing index page */
spinlock_t device_list_lock; /* Protect lists below */
void __iomem *cfg_addr;
struct list_head resources_for_children;
struct list_head children;
struct list_head dr_list;
struct msi_domain_info msi_info;
struct msi_controller msi_chip;
struct irq_domain *irq_domain;
spinlock_t retarget_msi_interrupt_lock;
struct workqueue_struct *wq;
/* Highest slot of child device with resources allocated */
int wslot_res_allocated;
/* hypercall arg, must not cross page boundary */
struct hv_retarget_device_interrupt retarget_msi_interrupt_params;
/*
* Don't put anything here: retarget_msi_interrupt_params must be last
*/
};
/*
* Tracks "Device Relations" messages from the host, which must be both
* processed in order and deferred so that they don't run in the context
* of the incoming packet callback.
*/
struct hv_dr_work {
struct work_struct wrk;
struct hv_pcibus_device *bus;
};
struct hv_pcidev_description {
u16 v_id; /* vendor ID */
u16 d_id; /* device ID */
u8 rev;
u8 prog_intf;
u8 subclass;
u8 base_class;
u32 subsystem_id;
union win_slot_encoding win_slot;
u32 ser; /* serial number */
u32 flags;
u16 virtual_numa_node;
};
struct hv_dr_state {
struct list_head list_entry;
u32 device_count;
struct hv_pcidev_description func[];
};
enum hv_pcichild_state {
hv_pcichild_init = 0,
hv_pcichild_requirements,
hv_pcichild_resourced,
hv_pcichild_ejecting,
hv_pcichild_maximum
};
struct hv_pci_dev {
/* List protected by pci_rescan_remove_lock */
struct list_head list_entry;
refcount_t refs;
enum hv_pcichild_state state;
struct pci_slot *pci_slot;
struct hv_pcidev_description desc;
bool reported_missing;
struct hv_pcibus_device *hbus;
struct work_struct wrk;
void (*block_invalidate)(void *context, u64 block_mask);
void *invalidate_context;
/*
* What would be observed if one wrote 0xFFFFFFFF to a BAR and then
* read it back, for each of the BAR offsets within config space.
*/
u32 probed_bar[PCI_STD_NUM_BARS];
};
struct hv_pci_compl {
struct completion host_event;
s32 completion_status;
};
static void hv_pci_onchannelcallback(void *context);
/**
* hv_pci_generic_compl() - Invoked for a completion packet
* @context: Set up by the sender of the packet.
* @resp: The response packet
* @resp_packet_size: Size in bytes of the packet
*
* This function is used to trigger an event and report status
* for any message for which the completion packet contains a
* status and nothing else.
*/
static void hv_pci_generic_compl(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct hv_pci_compl *comp_pkt = context;
if (resp_packet_size >= offsetofend(struct pci_response, status))
comp_pkt->completion_status = resp->status;
else
comp_pkt->completion_status = -1;
complete(&comp_pkt->host_event);
}
static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
u32 wslot);
static void get_pcichild(struct hv_pci_dev *hpdev)
{
refcount_inc(&hpdev->refs);
}
static void put_pcichild(struct hv_pci_dev *hpdev)
{
if (refcount_dec_and_test(&hpdev->refs))
kfree(hpdev);
}
static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus);
static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus);
/*
* There is no good way to get notified from vmbus_onoffer_rescind(),
* so let's use polling here, since this is not a hot path.
*/
static int wait_for_response(struct hv_device *hdev,
struct completion *comp)
{
while (true) {
if (hdev->channel->rescind) {
dev_warn_once(&hdev->device, "The device is gone.\n");
return -ENODEV;
}
if (wait_for_completion_timeout(comp, HZ / 10))
break;
}
return 0;
}
/**
* devfn_to_wslot() - Convert from Linux PCI slot to Windows
* @devfn: The Linux representation of PCI slot
*
* Windows uses a slightly different representation of PCI slot.
*
* Return: The Windows representation
*/
static u32 devfn_to_wslot(int devfn)
{
union win_slot_encoding wslot;
wslot.slot = 0;
wslot.bits.dev = PCI_SLOT(devfn);
wslot.bits.func = PCI_FUNC(devfn);
return wslot.slot;
}
/**
* wslot_to_devfn() - Convert from Windows PCI slot to Linux
* @wslot: The Windows representation of PCI slot
*
* Windows uses a slightly different representation of PCI slot.
*
* Return: The Linux representation
*/
static int wslot_to_devfn(u32 wslot)
{
union win_slot_encoding slot_no;
slot_no.slot = wslot;
return PCI_DEVFN(slot_no.bits.dev, slot_no.bits.func);
}
/*
* PCI Configuration Space for these root PCI buses is implemented as a pair
* of pages in memory-mapped I/O space. Writing to the first page chooses
* the PCI function being written or read. Once the first page has been
* written to, the following page maps in the entire configuration space of
* the function.
*/
/**
* _hv_pcifront_read_config() - Internal PCI config read
* @hpdev: The PCI driver's representation of the device
* @where: Offset within config space
* @size: Size of the transfer
* @val: Pointer to the buffer receiving the data
*/
static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where,
int size, u32 *val)
{
unsigned long flags;
void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where;
/*
* If the attempt is to read the IDs or the ROM BAR, simulate that.
*/
if (where + size <= PCI_COMMAND) {
memcpy(val, ((u8 *)&hpdev->desc.v_id) + where, size);
} else if (where >= PCI_CLASS_REVISION && where + size <=
PCI_CACHE_LINE_SIZE) {
memcpy(val, ((u8 *)&hpdev->desc.rev) + where -
PCI_CLASS_REVISION, size);
} else if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <=
PCI_ROM_ADDRESS) {
memcpy(val, (u8 *)&hpdev->desc.subsystem_id + where -
PCI_SUBSYSTEM_VENDOR_ID, size);
} else if (where >= PCI_ROM_ADDRESS && where + size <=
PCI_CAPABILITY_LIST) {
/* ROM BARs are unimplemented */
*val = 0;
} else if (where >= PCI_INTERRUPT_LINE && where + size <=
PCI_INTERRUPT_PIN) {
/*
* Interrupt Line and Interrupt PIN are hard-wired to zero
* because this front-end only supports message-signaled
* interrupts.
*/
*val = 0;
} else if (where + size <= CFG_PAGE_SIZE) {
spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
/* Choose the function to be read. (See comment above) */
writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
/* Make sure the function was chosen before we start reading. */
mb();
/* Read from that function's config space. */
switch (size) {
case 1:
*val = readb(addr);
break;
case 2:
*val = readw(addr);
break;
default:
*val = readl(addr);
break;
}
/*
* Make sure the read was done before we release the spinlock
* allowing consecutive reads/writes.
*/
mb();
spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
} else {
dev_err(&hpdev->hbus->hdev->device,
"Attempt to read beyond a function's config space.\n");
}
}
static u16 hv_pcifront_get_vendor_id(struct hv_pci_dev *hpdev)
{
u16 ret;
unsigned long flags;
void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET +
PCI_VENDOR_ID;
spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
/* Choose the function to be read. (See comment above) */
writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
/* Make sure the function was chosen before we start reading. */
mb();
/* Read from that function's config space. */
ret = readw(addr);
/*
* mb() is not required here, because the spin_unlock_irqrestore()
* is a barrier.
*/
spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
return ret;
}
/**
* _hv_pcifront_write_config() - Internal PCI config write
* @hpdev: The PCI driver's representation of the device
* @where: Offset within config space
* @size: Size of the transfer
* @val: The data being transferred
*/
static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where,
int size, u32 val)
{
unsigned long flags;
void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where;
if (where >= PCI_SUBSYSTEM_VENDOR_ID &&
where + size <= PCI_CAPABILITY_LIST) {
/* SSIDs and ROM BARs are read-only */
} else if (where >= PCI_COMMAND && where + size <= CFG_PAGE_SIZE) {
spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
/* Choose the function to be written. (See comment above) */
writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
/* Make sure the function was chosen before we start writing. */
wmb();
/* Write to that function's config space. */
switch (size) {
case 1:
writeb(val, addr);
break;
case 2:
writew(val, addr);
break;
default:
writel(val, addr);
break;
}
/*
* Make sure the write was done before we release the spinlock
* allowing consecutive reads/writes.
*/
mb();
spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
} else {
dev_err(&hpdev->hbus->hdev->device,
"Attempt to write beyond a function's config space.\n");
}
}
/**
* hv_pcifront_read_config() - Read configuration space
* @bus: PCI Bus structure
* @devfn: Device/function
* @where: Offset from base
* @size: Byte/word/dword
* @val: Value to be read
*
* Return: PCIBIOS_SUCCESSFUL on success
* PCIBIOS_DEVICE_NOT_FOUND on failure
*/
static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
struct hv_pcibus_device *hbus =
container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
struct hv_pci_dev *hpdev;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
if (!hpdev)
return PCIBIOS_DEVICE_NOT_FOUND;
_hv_pcifront_read_config(hpdev, where, size, val);
put_pcichild(hpdev);
return PCIBIOS_SUCCESSFUL;
}
/**
* hv_pcifront_write_config() - Write configuration space
* @bus: PCI Bus structure
* @devfn: Device/function
* @where: Offset from base
* @size: Byte/word/dword
* @val: Value to be written to device
*
* Return: PCIBIOS_SUCCESSFUL on success
* PCIBIOS_DEVICE_NOT_FOUND on failure
*/
static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
struct hv_pcibus_device *hbus =
container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
struct hv_pci_dev *hpdev;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
if (!hpdev)
return PCIBIOS_DEVICE_NOT_FOUND;
_hv_pcifront_write_config(hpdev, where, size, val);
put_pcichild(hpdev);
return PCIBIOS_SUCCESSFUL;
}
/* PCIe operations */
static struct pci_ops hv_pcifront_ops = {
.read = hv_pcifront_read_config,
.write = hv_pcifront_write_config,
};
/*
* Paravirtual backchannel
*
* Hyper-V SR-IOV provides a backchannel mechanism in software for
* communication between a VF driver and a PF driver. These
* "configuration blocks" are similar in concept to PCI configuration space,
* but instead of doing reads and writes in 32-bit chunks through a very slow
* path, packets of up to 128 bytes can be sent or received asynchronously.
*
* Nearly every SR-IOV device contains just such a communications channel in
* hardware, so using this one in software is usually optional. Using the
* software channel, however, allows driver implementers to leverage software
* tools that fuzz the communications channel looking for vulnerabilities.
*
* The usage model for these packets puts the responsibility for reading or
* writing on the VF driver. The VF driver sends a read or a write packet,
* indicating which "block" is being referred to by number.
*
* If the PF driver wishes to initiate communication, it can "invalidate" one or
* more of the first 64 blocks. This invalidation is delivered via a callback
* supplied by the VF driver by this driver.
*
* No protocol is implied, except that supplied by the PF and VF drivers.
*/
struct hv_read_config_compl {
struct hv_pci_compl comp_pkt;
void *buf;
unsigned int len;
unsigned int bytes_returned;
};
/**
* hv_pci_read_config_compl() - Invoked when a response packet
* for a read config block operation arrives.
* @context: Identifies the read config operation
* @resp: The response packet itself
* @resp_packet_size: Size in bytes of the response packet
*/
static void hv_pci_read_config_compl(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct hv_read_config_compl *comp = context;
struct pci_read_block_response *read_resp =
(struct pci_read_block_response *)resp;
unsigned int data_len, hdr_len;
hdr_len = offsetof(struct pci_read_block_response, bytes);
if (resp_packet_size < hdr_len) {
comp->comp_pkt.completion_status = -1;
goto out;
}
data_len = resp_packet_size - hdr_len;
if (data_len > 0 && read_resp->status == 0) {
comp->bytes_returned = min(comp->len, data_len);
memcpy(comp->buf, read_resp->bytes, comp->bytes_returned);
} else {
comp->bytes_returned = 0;
}
comp->comp_pkt.completion_status = read_resp->status;
out:
complete(&comp->comp_pkt.host_event);
}
/**
* hv_read_config_block() - Sends a read config block request to
* the back-end driver running in the Hyper-V parent partition.
* @pdev: The PCI driver's representation for this device.
* @buf: Buffer into which the config block will be copied.
* @len: Size in bytes of buf.
* @block_id: Identifies the config block which has been requested.
* @bytes_returned: Size which came back from the back-end driver.
*
* Return: 0 on success, -errno on failure
*/
static int hv_read_config_block(struct pci_dev *pdev, void *buf,
unsigned int len, unsigned int block_id,
unsigned int *bytes_returned)
{
struct hv_pcibus_device *hbus =
container_of(pdev->bus->sysdata, struct hv_pcibus_device,
sysdata);
struct {
struct pci_packet pkt;
char buf[sizeof(struct pci_read_block)];
} pkt;
struct hv_read_config_compl comp_pkt;
struct pci_read_block *read_blk;
int ret;
if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
return -EINVAL;
init_completion(&comp_pkt.comp_pkt.host_event);
comp_pkt.buf = buf;
comp_pkt.len = len;
memset(&pkt, 0, sizeof(pkt));
pkt.pkt.completion_func = hv_pci_read_config_compl;
pkt.pkt.compl_ctxt = &comp_pkt;
read_blk = (struct pci_read_block *)&pkt.pkt.message;
read_blk->message_type.type = PCI_READ_BLOCK;
read_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
read_blk->block_id = block_id;
read_blk->bytes_requested = len;
ret = vmbus_sendpacket(hbus->hdev->channel, read_blk,
sizeof(*read_blk), (unsigned long)&pkt.pkt,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
return ret;
ret = wait_for_response(hbus->hdev, &comp_pkt.comp_pkt.host_event);
if (ret)
return ret;
if (comp_pkt.comp_pkt.completion_status != 0 ||
comp_pkt.bytes_returned == 0) {
dev_err(&hbus->hdev->device,
"Read Config Block failed: 0x%x, bytes_returned=%d\n",
comp_pkt.comp_pkt.completion_status,
comp_pkt.bytes_returned);
return -EIO;
}
*bytes_returned = comp_pkt.bytes_returned;
return 0;
}
/**
* hv_pci_write_config_compl() - Invoked when a response packet for a write
* config block operation arrives.
* @context: Identifies the write config operation
* @resp: The response packet itself
* @resp_packet_size: Size in bytes of the response packet
*/
static void hv_pci_write_config_compl(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct hv_pci_compl *comp_pkt = context;
comp_pkt->completion_status = resp->status;
complete(&comp_pkt->host_event);
}
/**
* hv_write_config_block() - Sends a write config block request to the
* back-end driver running in the Hyper-V parent partition.
* @pdev: The PCI driver's representation for this device.
* @buf: Buffer from which the config block will be copied.
* @len: Size in bytes of buf.
* @block_id: Identifies the config block which is being written.
*
* Return: 0 on success, -errno on failure
*/
static int hv_write_config_block(struct pci_dev *pdev, void *buf,
unsigned int len, unsigned int block_id)
{
struct hv_pcibus_device *hbus =
container_of(pdev->bus->sysdata, struct hv_pcibus_device,
sysdata);
struct {
struct pci_packet pkt;
char buf[sizeof(struct pci_write_block)];
u32 reserved;
} pkt;
struct hv_pci_compl comp_pkt;
struct pci_write_block *write_blk;
u32 pkt_size;
int ret;
if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
return -EINVAL;
init_completion(&comp_pkt.host_event);
memset(&pkt, 0, sizeof(pkt));
pkt.pkt.completion_func = hv_pci_write_config_compl;
pkt.pkt.compl_ctxt = &comp_pkt;
write_blk = (struct pci_write_block *)&pkt.pkt.message;
write_blk->message_type.type = PCI_WRITE_BLOCK;
write_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
write_blk->block_id = block_id;
write_blk->byte_count = len;
memcpy(write_blk->bytes, buf, len);
pkt_size = offsetof(struct pci_write_block, bytes) + len;
/*
* This quirk is required on some hosts shipped around 2018, because
* these hosts don't check the pkt_size correctly (new hosts have been
* fixed since early 2019). The quirk is also safe on very old hosts
* and new hosts, because, on them, what really matters is the length
* specified in write_blk->byte_count.
*/
pkt_size += sizeof(pkt.reserved);
ret = vmbus_sendpacket(hbus->hdev->channel, write_blk, pkt_size,
(unsigned long)&pkt.pkt, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
return ret;
ret = wait_for_response(hbus->hdev, &comp_pkt.host_event);
if (ret)
return ret;
if (comp_pkt.completion_status != 0) {
dev_err(&hbus->hdev->device,
"Write Config Block failed: 0x%x\n",
comp_pkt.completion_status);
return -EIO;
}
return 0;
}
/**
* hv_register_block_invalidate() - Invoked when a config block invalidation
* arrives from the back-end driver.
* @pdev: The PCI driver's representation for this device.
* @context: Identifies the device.
* @block_invalidate: Identifies all of the blocks being invalidated.
*
* Return: 0 on success, -errno on failure
*/
static int hv_register_block_invalidate(struct pci_dev *pdev, void *context,
void (*block_invalidate)(void *context,
u64 block_mask))
{
struct hv_pcibus_device *hbus =
container_of(pdev->bus->sysdata, struct hv_pcibus_device,
sysdata);
struct hv_pci_dev *hpdev;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
if (!hpdev)
return -ENODEV;
hpdev->block_invalidate = block_invalidate;
hpdev->invalidate_context = context;
put_pcichild(hpdev);
return 0;
}
/* Interrupt management hooks */
static void hv_int_desc_free(struct hv_pci_dev *hpdev,
struct tran_int_desc *int_desc)
{
struct pci_delete_interrupt *int_pkt;
struct {
struct pci_packet pkt;
u8 buffer[sizeof(struct pci_delete_interrupt)];
} ctxt;
memset(&ctxt, 0, sizeof(ctxt));
int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message;
int_pkt->message_type.type =
PCI_DELETE_INTERRUPT_MESSAGE;
int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
int_pkt->int_desc = *int_desc;
vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt, sizeof(*int_pkt),
(unsigned long)&ctxt.pkt, VM_PKT_DATA_INBAND, 0);
kfree(int_desc);
}
/**
* hv_msi_free() - Free the MSI.
* @domain: The interrupt domain pointer
* @info: Extra MSI-related context
* @irq: Identifies the IRQ.
*
* The Hyper-V parent partition and hypervisor are tracking the
* messages that are in use, keeping the interrupt redirection
* table up to date. This callback sends a message that frees
* the IRT entry and related tracking nonsense.
*/
static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
unsigned int irq)
{
struct hv_pcibus_device *hbus;
struct hv_pci_dev *hpdev;
struct pci_dev *pdev;
struct tran_int_desc *int_desc;
struct irq_data *irq_data = irq_domain_get_irq_data(domain, irq);
struct msi_desc *msi = irq_data_get_msi_desc(irq_data);
pdev = msi_desc_to_pci_dev(msi);
hbus = info->data;
int_desc = irq_data_get_irq_chip_data(irq_data);
if (!int_desc)
return;
irq_data->chip_data = NULL;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
if (!hpdev) {
kfree(int_desc);
return;
}
hv_int_desc_free(hpdev, int_desc);
put_pcichild(hpdev);
}
static int hv_set_affinity(struct irq_data *data, const struct cpumask *dest,
bool force)
{
struct irq_data *parent = data->parent_data;
return parent->chip->irq_set_affinity(parent, dest, force);
}
static void hv_irq_mask(struct irq_data *data)
{
pci_msi_mask_irq(data);
}
/**
* hv_irq_unmask() - "Unmask" the IRQ by setting its current
* affinity.
* @data: Describes the IRQ
*
* Build new a destination for the MSI and make a hypercall to
* update the Interrupt Redirection Table. "Device Logical ID"
* is built out of this PCI bus's instance GUID and the function
* number of the device.
*/
static void hv_irq_unmask(struct irq_data *data)
{
struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
struct irq_cfg *cfg = irqd_cfg(data);
struct hv_retarget_device_interrupt *params;
struct hv_pcibus_device *hbus;
struct cpumask *dest;
cpumask_var_t tmp;
struct pci_bus *pbus;
struct pci_dev *pdev;
unsigned long flags;
u32 var_size = 0;
int cpu, nr_bank;
u64 res;
dest = irq_data_get_effective_affinity_mask(data);
pdev = msi_desc_to_pci_dev(msi_desc);
pbus = pdev->bus;
hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags);
params = &hbus->retarget_msi_interrupt_params;
memset(params, 0, sizeof(*params));
params->partition_id = HV_PARTITION_ID_SELF;
params->int_entry.source = 1; /* MSI(-X) */
hv_set_msi_entry_from_desc(&params->int_entry.msi_entry, msi_desc);
params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |
(hbus->hdev->dev_instance.b[4] << 16) |
(hbus->hdev->dev_instance.b[7] << 8) |
(hbus->hdev->dev_instance.b[6] & 0xf8) |
PCI_FUNC(pdev->devfn);
params->int_target.vector = cfg->vector;
/*
* Honoring apic->irq_delivery_mode set to dest_Fixed by
* setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a
* spurious interrupt storm. Not doing so does not seem to have a
* negative effect (yet?).
*/
if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
/*
* PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the
* HVCALL_RETARGET_INTERRUPT hypercall, which also coincides
* with >64 VP support.
* ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED
* is not sufficient for this hypercall.
*/
params->int_target.flags |=
HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) {
res = 1;
goto exit_unlock;
}
cpumask_and(tmp, dest, cpu_online_mask);
nr_bank = cpumask_to_vpset(&params->int_target.vp_set, tmp);
free_cpumask_var(tmp);
if (nr_bank <= 0) {
res = 1;
goto exit_unlock;
}
/*
* var-sized hypercall, var-size starts after vp_mask (thus
* vp_set.format does not count, but vp_set.valid_bank_mask
* does).
*/
var_size = 1 + nr_bank;
} else {
for_each_cpu_and(cpu, dest, cpu_online_mask) {
params->int_target.vp_mask |=
(1ULL << hv_cpu_number_to_vp_number(cpu));
}
}
res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17),
params, NULL);
exit_unlock:
spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);
if (res) {
dev_err(&hbus->hdev->device,
"%s() failed: %#llx", __func__, res);
return;
}
pci_msi_unmask_irq(data);
}
struct compose_comp_ctxt {
struct hv_pci_compl comp_pkt;
struct tran_int_desc int_desc;
};
static void hv_pci_compose_compl(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct compose_comp_ctxt *comp_pkt = context;
struct pci_create_int_response *int_resp =
(struct pci_create_int_response *)resp;
comp_pkt->comp_pkt.completion_status = resp->status;
comp_pkt->int_desc = int_resp->int_desc;
complete(&comp_pkt->comp_pkt.host_event);
}
static u32 hv_compose_msi_req_v1(
struct pci_create_interrupt *int_pkt, struct cpumask *affinity,
u32 slot, u8 vector)
{
int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
int_pkt->wslot.slot = slot;
int_pkt->int_desc.vector = vector;
int_pkt->int_desc.vector_count = 1;
int_pkt->int_desc.delivery_mode = dest_Fixed;
/*
* Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
* hv_irq_unmask().
*/
int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL;
return sizeof(*int_pkt);
}
static u32 hv_compose_msi_req_v2(
struct pci_create_interrupt2 *int_pkt, struct cpumask *affinity,
u32 slot, u8 vector)
{
int cpu;
int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE2;
int_pkt->wslot.slot = slot;
int_pkt->int_desc.vector = vector;
int_pkt->int_desc.vector_count = 1;
int_pkt->int_desc.delivery_mode = dest_Fixed;
/*
* Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten
* by subsequent retarget in hv_irq_unmask().
*/
cpu = cpumask_first_and(affinity, cpu_online_mask);
int_pkt->int_desc.processor_array[0] =
hv_cpu_number_to_vp_number(cpu);
int_pkt->int_desc.processor_count = 1;
return sizeof(*int_pkt);
}
/**
* hv_compose_msi_msg() - Supplies a valid MSI address/data
* @data: Everything about this MSI
* @msg: Buffer that is filled in by this function
*
* This function unpacks the IRQ looking for target CPU set, IDT
* vector and mode and sends a message to the parent partition
* asking for a mapping for that tuple in this partition. The
* response supplies a data value and address to which that data
* should be written to trigger that interrupt.
*/
static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
{
struct irq_cfg *cfg = irqd_cfg(data);
struct hv_pcibus_device *hbus;
struct vmbus_channel *channel;
struct hv_pci_dev *hpdev;
struct pci_bus *pbus;
struct pci_dev *pdev;
struct cpumask *dest;
struct compose_comp_ctxt comp;
struct tran_int_desc *int_desc;
struct {
struct pci_packet pci_pkt;
union {
struct pci_create_interrupt v1;
struct pci_create_interrupt2 v2;
} int_pkts;
} __packed ctxt;
u32 size;
int ret;
pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data));
dest = irq_data_get_effective_affinity_mask(data);
pbus = pdev->bus;
hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
channel = hbus->hdev->channel;
hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
if (!hpdev)
goto return_null_message;
/* Free any previous message that might have already been composed. */
if (data->chip_data) {
int_desc = data->chip_data;
data->chip_data = NULL;
hv_int_desc_free(hpdev, int_desc);
}
int_desc = kzalloc(sizeof(*int_desc), GFP_ATOMIC);
if (!int_desc)
goto drop_reference;
memset(&ctxt, 0, sizeof(ctxt));
init_completion(&comp.comp_pkt.host_event);
ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
ctxt.pci_pkt.compl_ctxt = &comp;
switch (hbus->protocol_version) {
case PCI_PROTOCOL_VERSION_1_1:
size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,
dest,
hpdev->desc.win_slot.slot,
cfg->vector);
break;
case PCI_PROTOCOL_VERSION_1_2:
case PCI_PROTOCOL_VERSION_1_3:
size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2,
dest,
hpdev->desc.win_slot.slot,
cfg->vector);
break;
default:
/* As we only negotiate protocol versions known to this driver,
* this path should never hit. However, this is it not a hot
* path so we print a message to aid future updates.
*/
dev_err(&hbus->hdev->device,
"Unexpected vPCI protocol, update driver.");
goto free_int_desc;
}
ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, &ctxt.int_pkts,
size, (unsigned long)&ctxt.pci_pkt,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret) {
dev_err(&hbus->hdev->device,
"Sending request for interrupt failed: 0x%x",
comp.comp_pkt.completion_status);
goto free_int_desc;
}
/*
* Prevents hv_pci_onchannelcallback() from running concurrently
* in the tasklet.
*/
tasklet_disable(&channel->callback_event);
/*
* Since this function is called with IRQ locks held, can't
* do normal wait for completion; instead poll.
*/
while (!try_wait_for_completion(&comp.comp_pkt.host_event)) {
unsigned long flags;
/* 0xFFFF means an invalid PCI VENDOR ID. */
if (hv_pcifront_get_vendor_id(hpdev) == 0xFFFF) {
dev_err_once(&hbus->hdev->device,
"the device has gone\n");
goto enable_tasklet;
}
/*
* Make sure that the ring buffer data structure doesn't get
* freed while we dereference the ring buffer pointer. Test
* for the channel's onchannel_callback being NULL within a
* sched_lock critical section. See also the inline comments
* in vmbus_reset_channel_cb().
*/
spin_lock_irqsave(&channel->sched_lock, flags);
if (unlikely(channel->onchannel_callback == NULL)) {
spin_unlock_irqrestore(&channel->sched_lock, flags);
goto enable_tasklet;
}
hv_pci_onchannelcallback(hbus);
spin_unlock_irqrestore(&channel->sched_lock, flags);
if (hpdev->state == hv_pcichild_ejecting) {
dev_err_once(&hbus->hdev->device,
"the device is being ejected\n");
goto enable_tasklet;
}
udelay(100);
}
tasklet_enable(&channel->callback_event);
if (comp.comp_pkt.completion_status < 0) {
dev_err(&hbus->hdev->device,
"Request for interrupt failed: 0x%x",
comp.comp_pkt.completion_status);
goto free_int_desc;
}
/*
* Record the assignment so that this can be unwound later. Using
* irq_set_chip_data() here would be appropriate, but the lock it takes
* is already held.
*/
*int_desc = comp.int_desc;
data->chip_data = int_desc;
/* Pass up the result. */
msg->address_hi = comp.int_desc.address >> 32;
msg->address_lo = comp.int_desc.address & 0xffffffff;
msg->data = comp.int_desc.data;
put_pcichild(hpdev);
return;
enable_tasklet:
tasklet_enable(&channel->callback_event);
free_int_desc:
kfree(int_desc);
drop_reference:
put_pcichild(hpdev);
return_null_message:
msg->address_hi = 0;
msg->address_lo = 0;
msg->data = 0;
}
/* HW Interrupt Chip Descriptor */
static struct irq_chip hv_msi_irq_chip = {
.name = "Hyper-V PCIe MSI",
.irq_compose_msi_msg = hv_compose_msi_msg,
.irq_set_affinity = hv_set_affinity,
.irq_ack = irq_chip_ack_parent,
.irq_mask = hv_irq_mask,
.irq_unmask = hv_irq_unmask,
};
static irq_hw_number_t hv_msi_domain_ops_get_hwirq(struct msi_domain_info *info,
msi_alloc_info_t *arg)
{
return arg->msi_hwirq;
}
static struct msi_domain_ops hv_msi_ops = {
.get_hwirq = hv_msi_domain_ops_get_hwirq,
.msi_prepare = pci_msi_prepare,
.set_desc = pci_msi_set_desc,
.msi_free = hv_msi_free,
};
/**
* hv_pcie_init_irq_domain() - Initialize IRQ domain
* @hbus: The root PCI bus
*
* This function creates an IRQ domain which will be used for
* interrupts from devices that have been passed through. These
* devices only support MSI and MSI-X, not line-based interrupts
* or simulations of line-based interrupts through PCIe's
* fabric-layer messages. Because interrupts are remapped, we
* can support multi-message MSI here.
*
* Return: '0' on success and error value on failure
*/
static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
{
hbus->msi_info.chip = &hv_msi_irq_chip;
hbus->msi_info.ops = &hv_msi_ops;
hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
MSI_FLAG_PCI_MSIX);
hbus->msi_info.handler = handle_edge_irq;
hbus->msi_info.handler_name = "edge";
hbus->msi_info.data = hbus;
hbus->irq_domain = pci_msi_create_irq_domain(hbus->sysdata.fwnode,
&hbus->msi_info,
x86_vector_domain);
if (!hbus->irq_domain) {
dev_err(&hbus->hdev->device,
"Failed to build an MSI IRQ domain\n");
return -ENODEV;
}
return 0;
}
/**
* get_bar_size() - Get the address space consumed by a BAR
* @bar_val: Value that a BAR returned after -1 was written
* to it.
*
* This function returns the size of the BAR, rounded up to 1
* page. It has to be rounded up because the hypervisor's page
* table entry that maps the BAR into the VM can't specify an
* offset within a page. The invariant is that the hypervisor
* must place any BARs of smaller than page length at the
* beginning of a page.
*
* Return: Size in bytes of the consumed MMIO space.
*/
static u64 get_bar_size(u64 bar_val)
{
return round_up((1 + ~(bar_val & PCI_BASE_ADDRESS_MEM_MASK)),
PAGE_SIZE);
}
/**
* survey_child_resources() - Total all MMIO requirements
* @hbus: Root PCI bus, as understood by this driver
*/
static void survey_child_resources(struct hv_pcibus_device *hbus)
{
struct hv_pci_dev *hpdev;
resource_size_t bar_size = 0;
unsigned long flags;
struct completion *event;
u64 bar_val;
int i;
/* If nobody is waiting on the answer, don't compute it. */
event = xchg(&hbus->survey_event, NULL);
if (!event)
return;
/* If the answer has already been computed, go with it. */
if (hbus->low_mmio_space || hbus->high_mmio_space) {
complete(event);
return;
}
spin_lock_irqsave(&hbus->device_list_lock, flags);
/*
* Due to an interesting quirk of the PCI spec, all memory regions
* for a child device are a power of 2 in size and aligned in memory,
* so it's sufficient to just add them up without tracking alignment.
*/
list_for_each_entry(hpdev, &hbus->children, list_entry) {
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
if (hpdev->probed_bar[i] & PCI_BASE_ADDRESS_SPACE_IO)
dev_err(&hbus->hdev->device,
"There's an I/O BAR in this list!\n");
if (hpdev->probed_bar[i] != 0) {
/*
* A probed BAR has all the upper bits set that
* can be changed.
*/
bar_val = hpdev->probed_bar[i];
if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
bar_val |=
((u64)hpdev->probed_bar[++i] << 32);
else
bar_val |= 0xffffffff00000000ULL;
bar_size = get_bar_size(bar_val);
if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
hbus->high_mmio_space += bar_size;
else
hbus->low_mmio_space += bar_size;
}
}
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
complete(event);
}
/**
* prepopulate_bars() - Fill in BARs with defaults
* @hbus: Root PCI bus, as understood by this driver
*
* The core PCI driver code seems much, much happier if the BARs
* for a device have values upon first scan. So fill them in.
* The algorithm below works down from large sizes to small,
* attempting to pack the assignments optimally. The assumption,
* enforced in other parts of the code, is that the beginning of
* the memory-mapped I/O space will be aligned on the largest
* BAR size.
*/
static void prepopulate_bars(struct hv_pcibus_device *hbus)
{
resource_size_t high_size = 0;
resource_size_t low_size = 0;
resource_size_t high_base = 0;
resource_size_t low_base = 0;
resource_size_t bar_size;
struct hv_pci_dev *hpdev;
unsigned long flags;
u64 bar_val;
u32 command;
bool high;
int i;
if (hbus->low_mmio_space) {
low_size = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
low_base = hbus->low_mmio_res->start;
}
if (hbus->high_mmio_space) {
high_size = 1ULL <<
(63 - __builtin_clzll(hbus->high_mmio_space));
high_base = hbus->high_mmio_res->start;
}
spin_lock_irqsave(&hbus->device_list_lock, flags);
/*
* Clear the memory enable bit, in case it's already set. This occurs
* in the suspend path of hibernation, where the device is suspended,
* resumed and suspended again: see hibernation_snapshot() and
* hibernation_platform_enter().
*
* If the memory enable bit is already set, Hyper-V sliently ignores
* the below BAR updates, and the related PCI device driver can not
* work, because reading from the device register(s) always returns
* 0xFFFFFFFF.
*/
list_for_each_entry(hpdev, &hbus->children, list_entry) {
_hv_pcifront_read_config(hpdev, PCI_COMMAND, 2, &command);
command &= ~PCI_COMMAND_MEMORY;
_hv_pcifront_write_config(hpdev, PCI_COMMAND, 2, command);
}
/* Pick addresses for the BARs. */
do {
list_for_each_entry(hpdev, &hbus->children, list_entry) {
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
bar_val = hpdev->probed_bar[i];
if (bar_val == 0)
continue;
high = bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64;
if (high) {
bar_val |=
((u64)hpdev->probed_bar[i + 1]
<< 32);
} else {
bar_val |= 0xffffffffULL << 32;
}
bar_size = get_bar_size(bar_val);
if (high) {
if (high_size != bar_size) {
i++;
continue;
}
_hv_pcifront_write_config(hpdev,
PCI_BASE_ADDRESS_0 + (4 * i),
4,
(u32)(high_base & 0xffffff00));
i++;
_hv_pcifront_write_config(hpdev,
PCI_BASE_ADDRESS_0 + (4 * i),
4, (u32)(high_base >> 32));
high_base += bar_size;
} else {
if (low_size != bar_size)
continue;
_hv_pcifront_write_config(hpdev,
PCI_BASE_ADDRESS_0 + (4 * i),
4,
(u32)(low_base & 0xffffff00));
low_base += bar_size;
}
}
if (high_size <= 1 && low_size <= 1) {
/* Set the memory enable bit. */
_hv_pcifront_read_config(hpdev, PCI_COMMAND, 2,
&command);
command |= PCI_COMMAND_MEMORY;
_hv_pcifront_write_config(hpdev, PCI_COMMAND, 2,
command);
break;
}
}
high_size >>= 1;
low_size >>= 1;
} while (high_size || low_size);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
}
/*
* Assign entries in sysfs pci slot directory.
*
* Note that this function does not need to lock the children list
* because it is called from pci_devices_present_work which
* is serialized with hv_eject_device_work because they are on the
* same ordered workqueue. Therefore hbus->children list will not change
* even when pci_create_slot sleeps.
*/
static void hv_pci_assign_slots(struct hv_pcibus_device *hbus)
{
struct hv_pci_dev *hpdev;
char name[SLOT_NAME_SIZE];
int slot_nr;
list_for_each_entry(hpdev, &hbus->children, list_entry) {
if (hpdev->pci_slot)
continue;
slot_nr = PCI_SLOT(wslot_to_devfn(hpdev->desc.win_slot.slot));
snprintf(name, SLOT_NAME_SIZE, "%u", hpdev->desc.ser);
hpdev->pci_slot = pci_create_slot(hbus->pci_bus, slot_nr,
name, NULL);
if (IS_ERR(hpdev->pci_slot)) {
pr_warn("pci_create slot %s failed\n", name);
hpdev->pci_slot = NULL;
}
}
}
/*
* Remove entries in sysfs pci slot directory.
*/
static void hv_pci_remove_slots(struct hv_pcibus_device *hbus)
{
struct hv_pci_dev *hpdev;
list_for_each_entry(hpdev, &hbus->children, list_entry) {
if (!hpdev->pci_slot)
continue;
pci_destroy_slot(hpdev->pci_slot);
hpdev->pci_slot = NULL;
}
}
/*
* Set NUMA node for the devices on the bus
*/
static void hv_pci_assign_numa_node(struct hv_pcibus_device *hbus)
{
struct pci_dev *dev;
struct pci_bus *bus = hbus->pci_bus;
struct hv_pci_dev *hv_dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
hv_dev = get_pcichild_wslot(hbus, devfn_to_wslot(dev->devfn));
if (!hv_dev)
continue;
if (hv_dev->desc.flags & HV_PCI_DEVICE_FLAG_NUMA_AFFINITY)
set_dev_node(&dev->dev, hv_dev->desc.virtual_numa_node);
put_pcichild(hv_dev);
}
}
/**
* create_root_hv_pci_bus() - Expose a new root PCI bus
* @hbus: Root PCI bus, as understood by this driver
*
* Return: 0 on success, -errno on failure
*/
static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus)
{
/* Register the device */
hbus->pci_bus = pci_create_root_bus(&hbus->hdev->device,
0, /* bus number is always zero */
&hv_pcifront_ops,
&hbus->sysdata,
&hbus->resources_for_children);
if (!hbus->pci_bus)
return -ENODEV;
hbus->pci_bus->msi = &hbus->msi_chip;
hbus->pci_bus->msi->dev = &hbus->hdev->device;
pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
hv_pci_assign_numa_node(hbus);
pci_bus_assign_resources(hbus->pci_bus);
hv_pci_assign_slots(hbus);
pci_bus_add_devices(hbus->pci_bus);
pci_unlock_rescan_remove();
hbus->state = hv_pcibus_installed;
return 0;
}
struct q_res_req_compl {
struct completion host_event;
struct hv_pci_dev *hpdev;
};
/**
* q_resource_requirements() - Query Resource Requirements
* @context: The completion context.
* @resp: The response that came from the host.
* @resp_packet_size: The size in bytes of resp.
*
* This function is invoked on completion of a Query Resource
* Requirements packet.
*/
static void q_resource_requirements(void *context, struct pci_response *resp,
int resp_packet_size)
{
struct q_res_req_compl *completion = context;
struct pci_q_res_req_response *q_res_req =
(struct pci_q_res_req_response *)resp;
int i;
if (resp->status < 0) {
dev_err(&completion->hpdev->hbus->hdev->device,
"query resource requirements failed: %x\n",
resp->status);
} else {
for (i = 0; i < PCI_STD_NUM_BARS; i++) {
completion->hpdev->probed_bar[i] =
q_res_req->probed_bar[i];
}
}
complete(&completion->host_event);
}
/**
* new_pcichild_device() - Create a new child device
* @hbus: The internal struct tracking this root PCI bus.
* @desc: The information supplied so far from the host
* about the device.
*
* This function creates the tracking structure for a new child
* device and kicks off the process of figuring out what it is.
*
* Return: Pointer to the new tracking struct
*/
static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
struct hv_pcidev_description *desc)
{
struct hv_pci_dev *hpdev;
struct pci_child_message *res_req;
struct q_res_req_compl comp_pkt;
struct {
struct pci_packet init_packet;
u8 buffer[sizeof(struct pci_child_message)];
} pkt;
unsigned long flags;
int ret;
hpdev = kzalloc(sizeof(*hpdev), GFP_KERNEL);
if (!hpdev)
return NULL;
hpdev->hbus = hbus;
memset(&pkt, 0, sizeof(pkt));
init_completion(&comp_pkt.host_event);
comp_pkt.hpdev = hpdev;
pkt.init_packet.compl_ctxt = &comp_pkt;
pkt.init_packet.completion_func = q_resource_requirements;
res_req = (struct pci_child_message *)&pkt.init_packet.message;
res_req->message_type.type = PCI_QUERY_RESOURCE_REQUIREMENTS;
res_req->wslot.slot = desc->win_slot.slot;
ret = vmbus_sendpacket(hbus->hdev->channel, res_req,
sizeof(struct pci_child_message),
(unsigned long)&pkt.init_packet,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
goto error;
if (wait_for_response(hbus->hdev, &comp_pkt.host_event))
goto error;
hpdev->desc = *desc;
refcount_set(&hpdev->refs, 1);
get_pcichild(hpdev);
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_add_tail(&hpdev->list_entry, &hbus->children);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
return hpdev;
error:
kfree(hpdev);
return NULL;
}
/**
* get_pcichild_wslot() - Find device from slot
* @hbus: Root PCI bus, as understood by this driver
* @wslot: Location on the bus
*
* This function looks up a PCI device and returns the internal
* representation of it. It acquires a reference on it, so that
* the device won't be deleted while somebody is using it. The
* caller is responsible for calling put_pcichild() to release
* this reference.
*
* Return: Internal representation of a PCI device
*/
static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
u32 wslot)
{
unsigned long flags;
struct hv_pci_dev *iter, *hpdev = NULL;
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_for_each_entry(iter, &hbus->children, list_entry) {
if (iter->desc.win_slot.slot == wslot) {
hpdev = iter;
get_pcichild(hpdev);
break;
}
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
return hpdev;
}
/**
* pci_devices_present_work() - Handle new list of child devices
* @work: Work struct embedded in struct hv_dr_work
*
* "Bus Relations" is the Windows term for "children of this
* bus." The terminology is preserved here for people trying to
* debug the interaction between Hyper-V and Linux. This
* function is called when the parent partition reports a list
* of functions that should be observed under this PCI Express
* port (bus).
*
* This function updates the list, and must tolerate being
* called multiple times with the same information. The typical
* number of child devices is one, with very atypical cases
* involving three or four, so the algorithms used here can be
* simple and inefficient.
*
* It must also treat the omission of a previously observed device as
* notification that the device no longer exists.
*
* Note that this function is serialized with hv_eject_device_work(),
* because both are pushed to the ordered workqueue hbus->wq.
*/
static void pci_devices_present_work(struct work_struct *work)
{
u32 child_no;
bool found;
struct hv_pcidev_description *new_desc;
struct hv_pci_dev *hpdev;
struct hv_pcibus_device *hbus;
struct list_head removed;
struct hv_dr_work *dr_wrk;
struct hv_dr_state *dr = NULL;
unsigned long flags;
dr_wrk = container_of(work, struct hv_dr_work, wrk);
hbus = dr_wrk->bus;
kfree(dr_wrk);
INIT_LIST_HEAD(&removed);
/* Pull this off the queue and process it if it was the last one. */
spin_lock_irqsave(&hbus->device_list_lock, flags);
while (!list_empty(&hbus->dr_list)) {
dr = list_first_entry(&hbus->dr_list, struct hv_dr_state,
list_entry);
list_del(&dr->list_entry);
/* Throw this away if the list still has stuff in it. */
if (!list_empty(&hbus->dr_list)) {
kfree(dr);
continue;
}
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (!dr) {
put_hvpcibus(hbus);
return;
}
/* First, mark all existing children as reported missing. */
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_for_each_entry(hpdev, &hbus->children, list_entry) {
hpdev->reported_missing = true;
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
/* Next, add back any reported devices. */
for (child_no = 0; child_no < dr->device_count; child_no++) {
found = false;
new_desc = &dr->func[child_no];
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_for_each_entry(hpdev, &hbus->children, list_entry) {
if ((hpdev->desc.win_slot.slot == new_desc->win_slot.slot) &&
(hpdev->desc.v_id == new_desc->v_id) &&
(hpdev->desc.d_id == new_desc->d_id) &&
(hpdev->desc.ser == new_desc->ser)) {
hpdev->reported_missing = false;
found = true;
}
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (!found) {
hpdev = new_pcichild_device(hbus, new_desc);
if (!hpdev)
dev_err(&hbus->hdev->device,
"couldn't record a child device.\n");
}
}
/* Move missing children to a list on the stack. */
spin_lock_irqsave(&hbus->device_list_lock, flags);
do {
found = false;
list_for_each_entry(hpdev, &hbus->children, list_entry) {
if (hpdev->reported_missing) {
found = true;
put_pcichild(hpdev);
list_move_tail(&hpdev->list_entry, &removed);
break;
}
}
} while (found);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
/* Delete everything that should no longer exist. */
while (!list_empty(&removed)) {
hpdev = list_first_entry(&removed, struct hv_pci_dev,
list_entry);
list_del(&hpdev->list_entry);
if (hpdev->pci_slot)
pci_destroy_slot(hpdev->pci_slot);
put_pcichild(hpdev);
}
switch (hbus->state) {
case hv_pcibus_installed:
/*
* Tell the core to rescan bus
* because there may have been changes.
*/
pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
hv_pci_assign_numa_node(hbus);
hv_pci_assign_slots(hbus);
pci_unlock_rescan_remove();
break;
case hv_pcibus_init:
case hv_pcibus_probed:
survey_child_resources(hbus);
break;
default:
break;
}
put_hvpcibus(hbus);
kfree(dr);
}
/**
* hv_pci_start_relations_work() - Queue work to start device discovery
* @hbus: Root PCI bus, as understood by this driver
* @dr: The list of children returned from host
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
struct hv_dr_state *dr)
{
struct hv_dr_work *dr_wrk;
unsigned long flags;
bool pending_dr;
if (hbus->state == hv_pcibus_removing) {
dev_info(&hbus->hdev->device,
"PCI VMBus BUS_RELATIONS: ignored\n");
return -ENOENT;
}
dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
if (!dr_wrk)
return -ENOMEM;
INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
dr_wrk->bus = hbus;
spin_lock_irqsave(&hbus->device_list_lock, flags);
/*
* If pending_dr is true, we have already queued a work,
* which will see the new dr. Otherwise, we need to
* queue a new work.
*/
pending_dr = !list_empty(&hbus->dr_list);
list_add_tail(&dr->list_entry, &hbus->dr_list);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (pending_dr) {
kfree(dr_wrk);
} else {
get_hvpcibus(hbus);
queue_work(hbus->wq, &dr_wrk->wrk);
}
return 0;
}
/**
* hv_pci_devices_present() - Handle list of new children
* @hbus: Root PCI bus, as understood by this driver
* @relations: Packet from host listing children
*
* Process a new list of devices on the bus. The list of devices is
* discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS,
* whenever a new list of devices for this bus appears.
*/
static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
struct pci_bus_relations *relations)
{
struct hv_dr_state *dr;
int i;
dr = kzalloc(struct_size(dr, func, relations->device_count),
GFP_NOWAIT);
if (!dr)
return;
dr->device_count = relations->device_count;
for (i = 0; i < dr->device_count; i++) {
dr->func[i].v_id = relations->func[i].v_id;
dr->func[i].d_id = relations->func[i].d_id;
dr->func[i].rev = relations->func[i].rev;
dr->func[i].prog_intf = relations->func[i].prog_intf;
dr->func[i].subclass = relations->func[i].subclass;
dr->func[i].base_class = relations->func[i].base_class;
dr->func[i].subsystem_id = relations->func[i].subsystem_id;
dr->func[i].win_slot = relations->func[i].win_slot;
dr->func[i].ser = relations->func[i].ser;
}
if (hv_pci_start_relations_work(hbus, dr))
kfree(dr);
}
/**
* hv_pci_devices_present2() - Handle list of new children
* @hbus: Root PCI bus, as understood by this driver
* @relations: Packet from host listing children
*
* This function is the v2 version of hv_pci_devices_present()
*/
static void hv_pci_devices_present2(struct hv_pcibus_device *hbus,
struct pci_bus_relations2 *relations)
{
struct hv_dr_state *dr;
int i;
dr = kzalloc(struct_size(dr, func, relations->device_count),
GFP_NOWAIT);
if (!dr)
return;
dr->device_count = relations->device_count;
for (i = 0; i < dr->device_count; i++) {
dr->func[i].v_id = relations->func[i].v_id;
dr->func[i].d_id = relations->func[i].d_id;
dr->func[i].rev = relations->func[i].rev;
dr->func[i].prog_intf = relations->func[i].prog_intf;
dr->func[i].subclass = relations->func[i].subclass;
dr->func[i].base_class = relations->func[i].base_class;
dr->func[i].subsystem_id = relations->func[i].subsystem_id;
dr->func[i].win_slot = relations->func[i].win_slot;
dr->func[i].ser = relations->func[i].ser;
dr->func[i].flags = relations->func[i].flags;
dr->func[i].virtual_numa_node =
relations->func[i].virtual_numa_node;
}
if (hv_pci_start_relations_work(hbus, dr))
kfree(dr);
}
/**
* hv_eject_device_work() - Asynchronously handles ejection
* @work: Work struct embedded in internal device struct
*
* This function handles ejecting a device. Windows will
* attempt to gracefully eject a device, waiting 60 seconds to
* hear back from the guest OS that this completed successfully.
* If this timer expires, the device will be forcibly removed.
*/
static void hv_eject_device_work(struct work_struct *work)
{
struct pci_eject_response *ejct_pkt;
struct hv_pcibus_device *hbus;
struct hv_pci_dev *hpdev;
struct pci_dev *pdev;
unsigned long flags;
int wslot;
struct {
struct pci_packet pkt;
u8 buffer[sizeof(struct pci_eject_response)];
} ctxt;
hpdev = container_of(work, struct hv_pci_dev, wrk);
hbus = hpdev->hbus;
WARN_ON(hpdev->state != hv_pcichild_ejecting);
/*
* Ejection can come before or after the PCI bus has been set up, so
* attempt to find it and tear down the bus state, if it exists. This
* must be done without constructs like pci_domain_nr(hbus->pci_bus)
* because hbus->pci_bus may not exist yet.
*/
wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
pdev = pci_get_domain_bus_and_slot(hbus->sysdata.domain, 0, wslot);
if (pdev) {
pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(pdev);
pci_dev_put(pdev);
pci_unlock_rescan_remove();
}
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_del(&hpdev->list_entry);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
if (hpdev->pci_slot)
pci_destroy_slot(hpdev->pci_slot);
memset(&ctxt, 0, sizeof(ctxt));
ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
vmbus_sendpacket(hbus->hdev->channel, ejct_pkt,
sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
VM_PKT_DATA_INBAND, 0);
/* For the get_pcichild() in hv_pci_eject_device() */
put_pcichild(hpdev);
/* For the two refs got in new_pcichild_device() */
put_pcichild(hpdev);
put_pcichild(hpdev);
/* hpdev has been freed. Do not use it any more. */
put_hvpcibus(hbus);
}
/**
* hv_pci_eject_device() - Handles device ejection
* @hpdev: Internal device tracking struct
*
* This function is invoked when an ejection packet arrives. It
* just schedules work so that we don't re-enter the packet
* delivery code handling the ejection.
*/
static void hv_pci_eject_device(struct hv_pci_dev *hpdev)
{
struct hv_pcibus_device *hbus = hpdev->hbus;
struct hv_device *hdev = hbus->hdev;
if (hbus->state == hv_pcibus_removing) {
dev_info(&hdev->device, "PCI VMBus EJECT: ignored\n");
return;
}
hpdev->state = hv_pcichild_ejecting;
get_pcichild(hpdev);
INIT_WORK(&hpdev->wrk, hv_eject_device_work);
get_hvpcibus(hbus);
queue_work(hbus->wq, &hpdev->wrk);
}
/**
* hv_pci_onchannelcallback() - Handles incoming packets
* @context: Internal bus tracking struct
*
* This function is invoked whenever the host sends a packet to
* this channel (which is private to this root PCI bus).
*/
static void hv_pci_onchannelcallback(void *context)
{
const int packet_size = 0x100;
int ret;
struct hv_pcibus_device *hbus = context;
u32 bytes_recvd;
u64 req_id;
struct vmpacket_descriptor *desc;
unsigned char *buffer;
int bufferlen = packet_size;
struct pci_packet *comp_packet;
struct pci_response *response;
struct pci_incoming_message *new_message;
struct pci_bus_relations *bus_rel;
struct pci_bus_relations2 *bus_rel2;
struct pci_dev_inval_block *inval;
struct pci_dev_incoming *dev_message;
struct hv_pci_dev *hpdev;
buffer = kmalloc(bufferlen, GFP_ATOMIC);
if (!buffer)
return;
while (1) {
ret = vmbus_recvpacket_raw(hbus->hdev->channel, buffer,
bufferlen, &bytes_recvd, &req_id);
if (ret == -ENOBUFS) {
kfree(buffer);
/* Handle large packet */
bufferlen = bytes_recvd;
buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
if (!buffer)
return;
continue;
}
/* Zero length indicates there are no more packets. */
if (ret || !bytes_recvd)
break;
/*
* All incoming packets must be at least as large as a
* response.
*/
if (bytes_recvd <= sizeof(struct pci_response))
continue;
desc = (struct vmpacket_descriptor *)buffer;
switch (desc->type) {
case VM_PKT_COMP:
/*
* The host is trusted, and thus it's safe to interpret
* this transaction ID as a pointer.
*/
comp_packet = (struct pci_packet *)req_id;
response = (struct pci_response *)buffer;
comp_packet->completion_func(comp_packet->compl_ctxt,
response,
bytes_recvd);
break;
case VM_PKT_DATA_INBAND:
new_message = (struct pci_incoming_message *)buffer;
switch (new_message->message_type.type) {
case PCI_BUS_RELATIONS:
bus_rel = (struct pci_bus_relations *)buffer;
if (bytes_recvd <
struct_size(bus_rel, func,
bus_rel->device_count)) {
dev_err(&hbus->hdev->device,
"bus relations too small\n");
break;
}
hv_pci_devices_present(hbus, bus_rel);
break;
case PCI_BUS_RELATIONS2:
bus_rel2 = (struct pci_bus_relations2 *)buffer;
if (bytes_recvd <
struct_size(bus_rel2, func,
bus_rel2->device_count)) {
dev_err(&hbus->hdev->device,
"bus relations v2 too small\n");
break;
}
hv_pci_devices_present2(hbus, bus_rel2);
break;
case PCI_EJECT:
dev_message = (struct pci_dev_incoming *)buffer;
hpdev = get_pcichild_wslot(hbus,
dev_message->wslot.slot);
if (hpdev) {
hv_pci_eject_device(hpdev);
put_pcichild(hpdev);
}
break;
case PCI_INVALIDATE_BLOCK:
inval = (struct pci_dev_inval_block *)buffer;
hpdev = get_pcichild_wslot(hbus,
inval->wslot.slot);
if (hpdev) {
if (hpdev->block_invalidate) {
hpdev->block_invalidate(
hpdev->invalidate_context,
inval->block_mask);
}
put_pcichild(hpdev);
}
break;
default:
dev_warn(&hbus->hdev->device,
"Unimplemented protocol message %x\n",
new_message->message_type.type);
break;
}
break;
default:
dev_err(&hbus->hdev->device,
"unhandled packet type %d, tid %llx len %d\n",
desc->type, req_id, bytes_recvd);
break;
}
}
kfree(buffer);
}
/**
* hv_pci_protocol_negotiation() - Set up protocol
* @hdev: VMBus's tracking struct for this root PCI bus
*
* This driver is intended to support running on Windows 10
* (server) and later versions. It will not run on earlier
* versions, as they assume that many of the operations which
* Linux needs accomplished with a spinlock held were done via
* asynchronous messaging via VMBus. Windows 10 increases the
* surface area of PCI emulation so that these actions can take
* place by suspending a virtual processor for their duration.
*
* This function negotiates the channel protocol version,
* failing if the host doesn't support the necessary protocol
* level.
*/
static int hv_pci_protocol_negotiation(struct hv_device *hdev,
enum pci_protocol_version_t version[],
int num_version)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_version_request *version_req;
struct hv_pci_compl comp_pkt;
struct pci_packet *pkt;
int ret;
int i;
/*
* Initiate the handshake with the host and negotiate
* a version that the host can support. We start with the
* highest version number and go down if the host cannot
* support it.
*/
pkt = kzalloc(sizeof(*pkt) + sizeof(*version_req), GFP_KERNEL);
if (!pkt)
return -ENOMEM;
init_completion(&comp_pkt.host_event);
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
version_req = (struct pci_version_request *)&pkt->message;
version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION;
for (i = 0; i < num_version; i++) {
version_req->protocol_version = version[i];
ret = vmbus_sendpacket(hdev->channel, version_req,
sizeof(struct pci_version_request),
(unsigned long)pkt, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (!ret)
ret = wait_for_response(hdev, &comp_pkt.host_event);
if (ret) {
dev_err(&hdev->device,
"PCI Pass-through VSP failed to request version: %d",
ret);
goto exit;
}
if (comp_pkt.completion_status >= 0) {
hbus->protocol_version = version[i];
dev_info(&hdev->device,
"PCI VMBus probing: Using version %#x\n",
hbus->protocol_version);
goto exit;
}
if (comp_pkt.completion_status != STATUS_REVISION_MISMATCH) {
dev_err(&hdev->device,
"PCI Pass-through VSP failed version request: %#x",
comp_pkt.completion_status);
ret = -EPROTO;
goto exit;
}
reinit_completion(&comp_pkt.host_event);
}
dev_err(&hdev->device,
"PCI pass-through VSP failed to find supported version");
ret = -EPROTO;
exit:
kfree(pkt);
return ret;
}
/**
* hv_pci_free_bridge_windows() - Release memory regions for the
* bus
* @hbus: Root PCI bus, as understood by this driver
*/
static void hv_pci_free_bridge_windows(struct hv_pcibus_device *hbus)
{
/*
* Set the resources back to the way they looked when they
* were allocated by setting IORESOURCE_BUSY again.
*/
if (hbus->low_mmio_space && hbus->low_mmio_res) {
hbus->low_mmio_res->flags |= IORESOURCE_BUSY;
vmbus_free_mmio(hbus->low_mmio_res->start,
resource_size(hbus->low_mmio_res));
}
if (hbus->high_mmio_space && hbus->high_mmio_res) {
hbus->high_mmio_res->flags |= IORESOURCE_BUSY;
vmbus_free_mmio(hbus->high_mmio_res->start,
resource_size(hbus->high_mmio_res));
}
}
/**
* hv_pci_allocate_bridge_windows() - Allocate memory regions
* for the bus
* @hbus: Root PCI bus, as understood by this driver
*
* This function calls vmbus_allocate_mmio(), which is itself a
* bit of a compromise. Ideally, we might change the pnp layer
* in the kernel such that it comprehends either PCI devices
* which are "grandchildren of ACPI," with some intermediate bus
* node (in this case, VMBus) or change it such that it
* understands VMBus. The pnp layer, however, has been declared
* deprecated, and not subject to change.
*
* The workaround, implemented here, is to ask VMBus to allocate
* MMIO space for this bus. VMBus itself knows which ranges are
* appropriate by looking at its own ACPI objects. Then, after
* these ranges are claimed, they're modified to look like they
* would have looked if the ACPI and pnp code had allocated
* bridge windows. These descriptors have to exist in this form
* in order to satisfy the code which will get invoked when the
* endpoint PCI function driver calls request_mem_region() or
* request_mem_region_exclusive().
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus)
{
resource_size_t align;
int ret;
if (hbus->low_mmio_space) {
align = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
ret = vmbus_allocate_mmio(&hbus->low_mmio_res, hbus->hdev, 0,
(u64)(u32)0xffffffff,
hbus->low_mmio_space,
align, false);
if (ret) {
dev_err(&hbus->hdev->device,
"Need %#llx of low MMIO space. Consider reconfiguring the VM.\n",
hbus->low_mmio_space);
return ret;
}
/* Modify this resource to become a bridge window. */
hbus->low_mmio_res->flags |= IORESOURCE_WINDOW;
hbus->low_mmio_res->flags &= ~IORESOURCE_BUSY;
pci_add_resource(&hbus->resources_for_children,
hbus->low_mmio_res);
}
if (hbus->high_mmio_space) {
align = 1ULL << (63 - __builtin_clzll(hbus->high_mmio_space));
ret = vmbus_allocate_mmio(&hbus->high_mmio_res, hbus->hdev,
0x100000000, -1,
hbus->high_mmio_space, align,
false);
if (ret) {
dev_err(&hbus->hdev->device,
"Need %#llx of high MMIO space. Consider reconfiguring the VM.\n",
hbus->high_mmio_space);
goto release_low_mmio;
}
/* Modify this resource to become a bridge window. */
hbus->high_mmio_res->flags |= IORESOURCE_WINDOW;
hbus->high_mmio_res->flags &= ~IORESOURCE_BUSY;
pci_add_resource(&hbus->resources_for_children,
hbus->high_mmio_res);
}
return 0;
release_low_mmio:
if (hbus->low_mmio_res) {
vmbus_free_mmio(hbus->low_mmio_res->start,
resource_size(hbus->low_mmio_res));
}
return ret;
}
/**
* hv_allocate_config_window() - Find MMIO space for PCI Config
* @hbus: Root PCI bus, as understood by this driver
*
* This function claims memory-mapped I/O space for accessing
* configuration space for the functions on this bus.
*
* Return: 0 on success, -errno on failure
*/
static int hv_allocate_config_window(struct hv_pcibus_device *hbus)
{
int ret;
/*
* Set up a region of MMIO space to use for accessing configuration
* space.
*/
ret = vmbus_allocate_mmio(&hbus->mem_config, hbus->hdev, 0, -1,
PCI_CONFIG_MMIO_LENGTH, 0x1000, false);
if (ret)
return ret;
/*
* vmbus_allocate_mmio() gets used for allocating both device endpoint
* resource claims (those which cannot be overlapped) and the ranges
* which are valid for the children of this bus, which are intended
* to be overlapped by those children. Set the flag on this claim
* meaning that this region can't be overlapped.
*/
hbus->mem_config->flags |= IORESOURCE_BUSY;
return 0;
}
static void hv_free_config_window(struct hv_pcibus_device *hbus)
{
vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH);
}
static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs);
/**
* hv_pci_enter_d0() - Bring the "bus" into the D0 power state
* @hdev: VMBus's tracking struct for this root PCI bus
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_enter_d0(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_bus_d0_entry *d0_entry;
struct hv_pci_compl comp_pkt;
struct pci_packet *pkt;
int ret;
/*
* Tell the host that the bus is ready to use, and moved into the
* powered-on state. This includes telling the host which region
* of memory-mapped I/O space has been chosen for configuration space
* access.
*/
pkt = kzalloc(sizeof(*pkt) + sizeof(*d0_entry), GFP_KERNEL);
if (!pkt)
return -ENOMEM;
init_completion(&comp_pkt.host_event);
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
d0_entry = (struct pci_bus_d0_entry *)&pkt->message;
d0_entry->message_type.type = PCI_BUS_D0ENTRY;
d0_entry->mmio_base = hbus->mem_config->start;
ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry),
(unsigned long)pkt, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (!ret)
ret = wait_for_response(hdev, &comp_pkt.host_event);
if (ret)
goto exit;
if (comp_pkt.completion_status < 0) {
dev_err(&hdev->device,
"PCI Pass-through VSP failed D0 Entry with status %x\n",
comp_pkt.completion_status);
ret = -EPROTO;
goto exit;
}
ret = 0;
exit:
kfree(pkt);
return ret;
}
/**
* hv_pci_query_relations() - Ask host to send list of child
* devices
* @hdev: VMBus's tracking struct for this root PCI bus
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_query_relations(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_message message;
struct completion comp;
int ret;
/* Ask the host to send along the list of child devices */
init_completion(&comp);
if (cmpxchg(&hbus->survey_event, NULL, &comp))
return -ENOTEMPTY;
memset(&message, 0, sizeof(message));
message.type = PCI_QUERY_BUS_RELATIONS;
ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message),
0, VM_PKT_DATA_INBAND, 0);
if (!ret)
ret = wait_for_response(hdev, &comp);
return ret;
}
/**
* hv_send_resources_allocated() - Report local resource choices
* @hdev: VMBus's tracking struct for this root PCI bus
*
* The host OS is expecting to be sent a request as a message
* which contains all the resources that the device will use.
* The response contains those same resources, "translated"
* which is to say, the values which should be used by the
* hardware, when it delivers an interrupt. (MMIO resources are
* used in local terms.) This is nice for Windows, and lines up
* with the FDO/PDO split, which doesn't exist in Linux. Linux
* is deeply expecting to scan an emulated PCI configuration
* space. So this message is sent here only to drive the state
* machine on the host forward.
*
* Return: 0 on success, -errno on failure
*/
static int hv_send_resources_allocated(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_resources_assigned *res_assigned;
struct pci_resources_assigned2 *res_assigned2;
struct hv_pci_compl comp_pkt;
struct hv_pci_dev *hpdev;
struct pci_packet *pkt;
size_t size_res;
int wslot;
int ret;
size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2)
? sizeof(*res_assigned) : sizeof(*res_assigned2);
pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL);
if (!pkt)
return -ENOMEM;
ret = 0;
for (wslot = 0; wslot < 256; wslot++) {
hpdev = get_pcichild_wslot(hbus, wslot);
if (!hpdev)
continue;
memset(pkt, 0, sizeof(*pkt) + size_res);
init_completion(&comp_pkt.host_event);
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
if (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) {
res_assigned =
(struct pci_resources_assigned *)&pkt->message;
res_assigned->message_type.type =
PCI_RESOURCES_ASSIGNED;
res_assigned->wslot.slot = hpdev->desc.win_slot.slot;
} else {
res_assigned2 =
(struct pci_resources_assigned2 *)&pkt->message;
res_assigned2->message_type.type =
PCI_RESOURCES_ASSIGNED2;
res_assigned2->wslot.slot = hpdev->desc.win_slot.slot;
}
put_pcichild(hpdev);
ret = vmbus_sendpacket(hdev->channel, &pkt->message,
size_res, (unsigned long)pkt,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (!ret)
ret = wait_for_response(hdev, &comp_pkt.host_event);
if (ret)
break;
if (comp_pkt.completion_status < 0) {
ret = -EPROTO;
dev_err(&hdev->device,
"resource allocated returned 0x%x",
comp_pkt.completion_status);
break;
}
hbus->wslot_res_allocated = wslot;
}
kfree(pkt);
return ret;
}
/**
* hv_send_resources_released() - Report local resources
* released
* @hdev: VMBus's tracking struct for this root PCI bus
*
* Return: 0 on success, -errno on failure
*/
static int hv_send_resources_released(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct pci_child_message pkt;
struct hv_pci_dev *hpdev;
int wslot;
int ret;
for (wslot = hbus->wslot_res_allocated; wslot >= 0; wslot--) {
hpdev = get_pcichild_wslot(hbus, wslot);
if (!hpdev)
continue;
memset(&pkt, 0, sizeof(pkt));
pkt.message_type.type = PCI_RESOURCES_RELEASED;
pkt.wslot.slot = hpdev->desc.win_slot.slot;
put_pcichild(hpdev);
ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0,
VM_PKT_DATA_INBAND, 0);
if (ret)
return ret;
hbus->wslot_res_allocated = wslot - 1;
}
hbus->wslot_res_allocated = -1;
return 0;
}
static void get_hvpcibus(struct hv_pcibus_device *hbus)
{
refcount_inc(&hbus->remove_lock);
}
static void put_hvpcibus(struct hv_pcibus_device *hbus)
{
if (refcount_dec_and_test(&hbus->remove_lock))
complete(&hbus->remove_event);
}
#define HVPCI_DOM_MAP_SIZE (64 * 1024)
static DECLARE_BITMAP(hvpci_dom_map, HVPCI_DOM_MAP_SIZE);
/*
* PCI domain number 0 is used by emulated devices on Gen1 VMs, so define 0
* as invalid for passthrough PCI devices of this driver.
*/
#define HVPCI_DOM_INVALID 0
/**
* hv_get_dom_num() - Get a valid PCI domain number
* Check if the PCI domain number is in use, and return another number if
* it is in use.
*
* @dom: Requested domain number
*
* return: domain number on success, HVPCI_DOM_INVALID on failure
*/
static u16 hv_get_dom_num(u16 dom)
{
unsigned int i;
if (test_and_set_bit(dom, hvpci_dom_map) == 0)
return dom;
for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) {
if (test_and_set_bit(i, hvpci_dom_map) == 0)
return i;
}
return HVPCI_DOM_INVALID;
}
/**
* hv_put_dom_num() - Mark the PCI domain number as free
* @dom: Domain number to be freed
*/
static void hv_put_dom_num(u16 dom)
{
clear_bit(dom, hvpci_dom_map);
}
/**
* hv_pci_probe() - New VMBus channel probe, for a root PCI bus
* @hdev: VMBus's tracking struct for this root PCI bus
* @dev_id: Identifies the device itself
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_probe(struct hv_device *hdev,
const struct hv_vmbus_device_id *dev_id)
{
struct hv_pcibus_device *hbus;
u16 dom_req, dom;
char *name;
bool enter_d0_retry = true;
int ret;
/*
* hv_pcibus_device contains the hypercall arguments for retargeting in
* hv_irq_unmask(). Those must not cross a page boundary.
*/
BUILD_BUG_ON(sizeof(*hbus) > HV_HYP_PAGE_SIZE);
/*
* With the recent 59bb47985c1d ("mm, sl[aou]b: guarantee natural
* alignment for kmalloc(power-of-two)"), kzalloc() is able to allocate
* a 4KB buffer that is guaranteed to be 4KB-aligned. Here the size and
* alignment of hbus is important because hbus's field
* retarget_msi_interrupt_params must not cross a 4KB page boundary.
*
* Here we prefer kzalloc to get_zeroed_page(), because a buffer
* allocated by the latter is not tracked and scanned by kmemleak, and
* hence kmemleak reports the pointer contained in the hbus buffer
* (i.e. the hpdev struct, which is created in new_pcichild_device() and
* is tracked by hbus->children) as memory leak (false positive).
*
* If the kernel doesn't have 59bb47985c1d, get_zeroed_page() *must* be
* used to allocate the hbus buffer and we can avoid the kmemleak false
* positive by using kmemleak_alloc() and kmemleak_free() to ask
* kmemleak to track and scan the hbus buffer.
*/
hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
if (!hbus)
return -ENOMEM;
hbus->state = hv_pcibus_init;
hbus->wslot_res_allocated = -1;
/*
* The PCI bus "domain" is what is called "segment" in ACPI and other
* specs. Pull it from the instance ID, to get something usually
* unique. In rare cases of collision, we will find out another number
* not in use.
*
* Note that, since this code only runs in a Hyper-V VM, Hyper-V
* together with this guest driver can guarantee that (1) The only
* domain used by Gen1 VMs for something that looks like a physical
* PCI bus (which is actually emulated by the hypervisor) is domain 0.
* (2) There will be no overlap between domains (after fixing possible
* collisions) in the same VM.
*/
dom_req = hdev->dev_instance.b[5] << 8 | hdev->dev_instance.b[4];
dom = hv_get_dom_num(dom_req);
if (dom == HVPCI_DOM_INVALID) {
dev_err(&hdev->device,
"Unable to use dom# 0x%hx or other numbers", dom_req);
ret = -EINVAL;
goto free_bus;
}
if (dom != dom_req)
dev_info(&hdev->device,
"PCI dom# 0x%hx has collision, using 0x%hx",
dom_req, dom);
hbus->sysdata.domain = dom;
hbus->hdev = hdev;
refcount_set(&hbus->remove_lock, 1);
INIT_LIST_HEAD(&hbus->children);
INIT_LIST_HEAD(&hbus->dr_list);
INIT_LIST_HEAD(&hbus->resources_for_children);
spin_lock_init(&hbus->config_lock);
spin_lock_init(&hbus->device_list_lock);
spin_lock_init(&hbus->retarget_msi_interrupt_lock);
init_completion(&hbus->remove_event);
hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0,
hbus->sysdata.domain);
if (!hbus->wq) {
ret = -ENOMEM;
goto free_dom;
}
ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
hv_pci_onchannelcallback, hbus);
if (ret)
goto destroy_wq;
hv_set_drvdata(hdev, hbus);
ret = hv_pci_protocol_negotiation(hdev, pci_protocol_versions,
ARRAY_SIZE(pci_protocol_versions));
if (ret)
goto close;
ret = hv_allocate_config_window(hbus);
if (ret)
goto close;
hbus->cfg_addr = ioremap(hbus->mem_config->start,
PCI_CONFIG_MMIO_LENGTH);
if (!hbus->cfg_addr) {
dev_err(&hdev->device,
"Unable to map a virtual address for config space\n");
ret = -ENOMEM;
goto free_config;
}
name = kasprintf(GFP_KERNEL, "%pUL", &hdev->dev_instance);
if (!name) {
ret = -ENOMEM;
goto unmap;
}
hbus->sysdata.fwnode = irq_domain_alloc_named_fwnode(name);
kfree(name);
if (!hbus->sysdata.fwnode) {
ret = -ENOMEM;
goto unmap;
}
ret = hv_pcie_init_irq_domain(hbus);
if (ret)
goto free_fwnode;
retry:
ret = hv_pci_query_relations(hdev);
if (ret)
goto free_irq_domain;
ret = hv_pci_enter_d0(hdev);
/*
* In certain case (Kdump) the pci device of interest was
* not cleanly shut down and resource is still held on host
* side, the host could return invalid device status.
* We need to explicitly request host to release the resource
* and try to enter D0 again.
* Since the hv_pci_bus_exit() call releases structures
* of all its child devices, we need to start the retry from
* hv_pci_query_relations() call, requesting host to send
* the synchronous child device relations message before this
* information is needed in hv_send_resources_allocated()
* call later.
*/
if (ret == -EPROTO && enter_d0_retry) {
enter_d0_retry = false;
dev_err(&hdev->device, "Retrying D0 Entry\n");
/*
* Hv_pci_bus_exit() calls hv_send_resources_released()
* to free up resources of its child devices.
* In the kdump kernel we need to set the
* wslot_res_allocated to 255 so it scans all child
* devices to release resources allocated in the
* normal kernel before panic happened.
*/
hbus->wslot_res_allocated = 255;
ret = hv_pci_bus_exit(hdev, true);
if (ret == 0)
goto retry;
dev_err(&hdev->device,
"Retrying D0 failed with ret %d\n", ret);
}
if (ret)
goto free_irq_domain;
ret = hv_pci_allocate_bridge_windows(hbus);
if (ret)
goto exit_d0;
ret = hv_send_resources_allocated(hdev);
if (ret)
goto free_windows;
prepopulate_bars(hbus);
hbus->state = hv_pcibus_probed;
ret = create_root_hv_pci_bus(hbus);
if (ret)
goto free_windows;
return 0;
free_windows:
hv_pci_free_bridge_windows(hbus);
exit_d0:
(void) hv_pci_bus_exit(hdev, true);
free_irq_domain:
irq_domain_remove(hbus->irq_domain);
free_fwnode:
irq_domain_free_fwnode(hbus->sysdata.fwnode);
unmap:
iounmap(hbus->cfg_addr);
free_config:
hv_free_config_window(hbus);
close:
vmbus_close(hdev->channel);
destroy_wq:
destroy_workqueue(hbus->wq);
free_dom:
hv_put_dom_num(hbus->sysdata.domain);
free_bus:
kfree(hbus);
return ret;
}
static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct {
struct pci_packet teardown_packet;
u8 buffer[sizeof(struct pci_message)];
} pkt;
struct hv_dr_state *dr;
struct hv_pci_compl comp_pkt;
int ret;
/*
* After the host sends the RESCIND_CHANNEL message, it doesn't
* access the per-channel ringbuffer any longer.
*/
if (hdev->channel->rescind)
return 0;
if (!keep_devs) {
/* Delete any children which might still exist. */
dr = kzalloc(sizeof(*dr), GFP_KERNEL);
if (dr && hv_pci_start_relations_work(hbus, dr))
kfree(dr);
}
ret = hv_send_resources_released(hdev);
if (ret) {
dev_err(&hdev->device,
"Couldn't send resources released packet(s)\n");
return ret;
}
memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet));
init_completion(&comp_pkt.host_event);
pkt.teardown_packet.completion_func = hv_pci_generic_compl;
pkt.teardown_packet.compl_ctxt = &comp_pkt;
pkt.teardown_packet.message[0].type = PCI_BUS_D0EXIT;
ret = vmbus_sendpacket(hdev->channel, &pkt.teardown_packet.message,
sizeof(struct pci_message),
(unsigned long)&pkt.teardown_packet,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
return ret;
if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0)
return -ETIMEDOUT;
return 0;
}
/**
* hv_pci_remove() - Remove routine for this VMBus channel
* @hdev: VMBus's tracking struct for this root PCI bus
*
* Return: 0 on success, -errno on failure
*/
static int hv_pci_remove(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus;
int ret;
hbus = hv_get_drvdata(hdev);
if (hbus->state == hv_pcibus_installed) {
/* Remove the bus from PCI's point of view. */
pci_lock_rescan_remove();
pci_stop_root_bus(hbus->pci_bus);
hv_pci_remove_slots(hbus);
pci_remove_root_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
hbus->state = hv_pcibus_removed;
}
ret = hv_pci_bus_exit(hdev, false);
vmbus_close(hdev->channel);
iounmap(hbus->cfg_addr);
hv_free_config_window(hbus);
pci_free_resource_list(&hbus->resources_for_children);
hv_pci_free_bridge_windows(hbus);
irq_domain_remove(hbus->irq_domain);
irq_domain_free_fwnode(hbus->sysdata.fwnode);
put_hvpcibus(hbus);
wait_for_completion(&hbus->remove_event);
destroy_workqueue(hbus->wq);
hv_put_dom_num(hbus->sysdata.domain);
kfree(hbus);
return ret;
}
static int hv_pci_suspend(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
enum hv_pcibus_state old_state;
int ret;
/*
* hv_pci_suspend() must make sure there are no pending work items
* before calling vmbus_close(), since it runs in a process context
* as a callback in dpm_suspend(). When it starts to run, the channel
* callback hv_pci_onchannelcallback(), which runs in a tasklet
* context, can be still running concurrently and scheduling new work
* items onto hbus->wq in hv_pci_devices_present() and
* hv_pci_eject_device(), and the work item handlers can access the
* vmbus channel, which can be being closed by hv_pci_suspend(), e.g.
* the work item handler pci_devices_present_work() ->
* new_pcichild_device() writes to the vmbus channel.
*
* To eliminate the race, hv_pci_suspend() disables the channel
* callback tasklet, sets hbus->state to hv_pcibus_removing, and
* re-enables the tasklet. This way, when hv_pci_suspend() proceeds,
* it knows that no new work item can be scheduled, and then it flushes
* hbus->wq and safely closes the vmbus channel.
*/
tasklet_disable(&hdev->channel->callback_event);
/* Change the hbus state to prevent new work items. */
old_state = hbus->state;
if (hbus->state == hv_pcibus_installed)
hbus->state = hv_pcibus_removing;
tasklet_enable(&hdev->channel->callback_event);
if (old_state != hv_pcibus_installed)
return -EINVAL;
flush_workqueue(hbus->wq);
ret = hv_pci_bus_exit(hdev, true);
if (ret)
return ret;
vmbus_close(hdev->channel);
return 0;
}
static int hv_pci_resume(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
enum pci_protocol_version_t version[1];
int ret;
hbus->state = hv_pcibus_init;
ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
hv_pci_onchannelcallback, hbus);
if (ret)
return ret;
/* Only use the version that was in use before hibernation. */
version[0] = hbus->protocol_version;
ret = hv_pci_protocol_negotiation(hdev, version, 1);
if (ret)
goto out;
ret = hv_pci_query_relations(hdev);
if (ret)
goto out;
ret = hv_pci_enter_d0(hdev);
if (ret)
goto out;
ret = hv_send_resources_allocated(hdev);
if (ret)
goto out;
prepopulate_bars(hbus);
hbus->state = hv_pcibus_installed;
return 0;
out:
vmbus_close(hdev->channel);
return ret;
}
static const struct hv_vmbus_device_id hv_pci_id_table[] = {
/* PCI Pass-through Class ID */
/* 44C4F61D-4444-4400-9D52-802E27EDE19F */
{ HV_PCIE_GUID, },
{ },
};
MODULE_DEVICE_TABLE(vmbus, hv_pci_id_table);
static struct hv_driver hv_pci_drv = {
.name = "hv_pci",
.id_table = hv_pci_id_table,
.probe = hv_pci_probe,
.remove = hv_pci_remove,
.suspend = hv_pci_suspend,
.resume = hv_pci_resume,
};
static void __exit exit_hv_pci_drv(void)
{
vmbus_driver_unregister(&hv_pci_drv);
hvpci_block_ops.read_block = NULL;
hvpci_block_ops.write_block = NULL;
hvpci_block_ops.reg_blk_invalidate = NULL;
}
static int __init init_hv_pci_drv(void)
{
/* Set the invalid domain number's bit, so it will not be used */
set_bit(HVPCI_DOM_INVALID, hvpci_dom_map);
/* Initialize PCI block r/w interface */
hvpci_block_ops.read_block = hv_read_config_block;
hvpci_block_ops.write_block = hv_write_config_block;
hvpci_block_ops.reg_blk_invalidate = hv_register_block_invalidate;
return vmbus_driver_register(&hv_pci_drv);
}
module_init(init_hv_pci_drv);
module_exit(exit_hv_pci_drv);
MODULE_DESCRIPTION("Hyper-V PCI");
MODULE_LICENSE("GPL v2");
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