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

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/*
* 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.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/semaphore.h>
#include <linux/irqdomain.h>
#include <asm/irqdomain.h>
#include <asm/apic.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) | (major)))
#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16)
#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff)
enum {
PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1),
PCI_PROTOCOL_VERSION_CURRENT = PCI_PROTOCOL_VERSION_1_1
};
#define CPU_AFFINITY_ALL -1ULL
#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
/*
* 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_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;
/**
* 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 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[0];
};
/*
* 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;
enum pci_message_type 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[0];
} __packed;
struct pci_q_res_req_response {
struct vmpacket_descriptor hdr;
s32 status; /* negative values are failures */
u32 probed_bar[6];
} __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_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_delete_interrupt {
struct pci_message message_type;
union win_slot_encoding wslot;
struct tran_int_desc int_desc;
} __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);
/*
* Definitions or interrupt steering hypercall.
*/
#define HV_PARTITION_ID_SELF ((u64)-1)
#define HVCALL_RETARGET_INTERRUPT 0x7e
struct retarget_msi_interrupt {
u64 partition_id; /* use "self" */
u64 device_id;
u32 source; /* 1 for MSI(-X) */
u32 reserved1;
u32 address;
u32 data;
u64 reserved2;
u32 vector;
u32 flags;
u64 vp_mask;
} __packed;
/*
* Driver specific state.
*/
enum hv_pcibus_state {
hv_pcibus_init = 0,
hv_pcibus_probed,
hv_pcibus_installed,
hv_pcibus_removed,
hv_pcibus_maximum
};
struct hv_pcibus_device {
struct pci_sysdata sysdata;
enum hv_pcibus_state state;
atomic_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 semaphore enum_sem;
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;
struct retarget_msi_interrupt retarget_msi_interrupt_params;
spinlock_t retarget_msi_interrupt_lock;
};
/*
* 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_dr_state {
struct list_head list_entry;
u32 device_count;
struct pci_function_description func[0];
};
enum hv_pcichild_state {
hv_pcichild_init = 0,
hv_pcichild_requirements,
hv_pcichild_resourced,
hv_pcichild_ejecting,
hv_pcichild_maximum
};
enum hv_pcidev_ref_reason {
hv_pcidev_ref_invalid = 0,
hv_pcidev_ref_initial,
hv_pcidev_ref_by_slot,
hv_pcidev_ref_packet,
hv_pcidev_ref_pnp,
hv_pcidev_ref_childlist,
hv_pcidev_irqdata,
hv_pcidev_ref_max
};
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_function_description desc;
bool reported_missing;
struct hv_pcibus_device *hbus;
struct work_struct wrk;
/*
* 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[6];
};
struct hv_pci_compl {
struct completion host_event;
s32 completion_status;
};
/**
* 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 *hv_pcidev,
enum hv_pcidev_ref_reason reason);
static void put_pcichild(struct hv_pci_dev *hv_pcidev,
enum hv_pcidev_ref_reason reason);
static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus);
static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus);
/**
* 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 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 read beyond a function's config space.\n");
}
}
/**
* _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, hv_pcidev_ref_by_slot);
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, hv_pcidev_ref_by_slot);
return PCIBIOS_SUCCESSFUL;
}
/* PCIe operations */
static struct pci_ops hv_pcifront_ops = {
.read = hv_pcifront_read_config,
.write = hv_pcifront_write_config,
};
/* 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, hv_pcidev_ref_by_slot);
}
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 retarget_msi_interrupt *params;
struct hv_pcibus_device *hbus;
struct cpumask *dest;
struct pci_bus *pbus;
struct pci_dev *pdev;
int cpu;
unsigned long flags;
dest = irq_data_get_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->source = 1; /* MSI(-X) */
params->address = msi_desc->msg.address_lo;
params->data = msi_desc->msg.data;
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->vector = cfg->vector;
for_each_cpu_and(cpu, dest, cpu_online_mask)
params->vp_mask |= (1ULL << vmbus_cpu_number_to_vp_number(cpu));
hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, params, NULL);
spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);
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);
}
/**
* 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 hv_pci_dev *hpdev;
struct pci_bus *pbus;
struct pci_dev *pdev;
struct pci_create_interrupt *int_pkt;
struct compose_comp_ctxt comp;
struct tran_int_desc *int_desc;
struct cpumask *affinity;
struct {
struct pci_packet pkt;
u8 buffer[sizeof(struct pci_create_interrupt)];
} ctxt;
int cpu;
int ret;
pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data));
pbus = pdev->bus;
hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
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.pkt.completion_func = hv_pci_compose_compl;
ctxt.pkt.compl_ctxt = &comp;
int_pkt = (struct pci_create_interrupt *)&ctxt.pkt.message;
int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
int_pkt->int_desc.vector = cfg->vector;
int_pkt->int_desc.vector_count = 1;
int_pkt->int_desc.delivery_mode =
(apic->irq_delivery_mode == dest_LowestPrio) ? 1 : 0;
/*
* This bit doesn't have to work on machines with more than 64
* processors because Hyper-V only supports 64 in a guest.
*/
affinity = irq_data_get_affinity_mask(data);
if (cpumask_weight(affinity) >= 32) {
int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL;
} else {
for_each_cpu_and(cpu, affinity, cpu_online_mask) {
int_pkt->int_desc.cpu_mask |=
(1ULL << vmbus_cpu_number_to_vp_number(cpu));
}
}
ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt,
sizeof(*int_pkt), (unsigned long)&ctxt.pkt,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
goto free_int_desc;
wait_for_completion(&comp.comp_pkt.host_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, hv_pcidev_ref_by_slot);
return;
free_int_desc:
kfree(int_desc);
drop_reference:
put_pcichild(hpdev, hv_pcidev_ref_by_slot);
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 list_head *iter;
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(iter, &hbus->children) {
hpdev = container_of(iter, struct hv_pci_dev, list_entry);
for (i = 0; i < 6; 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;
struct list_head *iter;
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);
/* Pick addresses for the BARs. */
do {
list_for_each(iter, &hbus->children) {
hpdev = container_of(iter, struct hv_pci_dev,
list_entry);
for (i = 0; i < 6; 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);
}
/**
* 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);
pci_bus_assign_resources(hbus->pci_bus);
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 < 6; i++) {
completion->hpdev->probed_bar[i] =
q_res_req->probed_bar[i];
}
}
complete(&completion->host_event);
}
static void get_pcichild(struct hv_pci_dev *hpdev,
enum hv_pcidev_ref_reason reason)
{
refcount_inc(&hpdev->refs);
}
static void put_pcichild(struct hv_pci_dev *hpdev,
enum hv_pcidev_ref_reason reason)
{
if (refcount_dec_and_test(&hpdev->refs))
kfree(hpdev);
}
/**
* 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 pci_function_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_ATOMIC);
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;
wait_for_completion(&comp_pkt.host_event);
hpdev->desc = *desc;
refcount_set(&hpdev->refs, 1);
get_pcichild(hpdev, hv_pcidev_ref_childlist);
spin_lock_irqsave(&hbus->device_list_lock, flags);
/*
* When a device is being added to the bus, we set the PCI domain
* number to be the device serial number, which is non-zero and
* unique on the same VM. The serial numbers start with 1, and
* increase by 1 for each device. So device names including this
* can have shorter names than based on the bus instance UUID.
* Only the first device serial number is used for domain, so the
* domain number will not change after the first device is added.
*/
if (list_empty(&hbus->children))
hbus->sysdata.domain = desc->ser;
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, hv_pcidev_ref_by_slot);
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 a work item, and it may not be
* invoked in the order that it was queued. Back to back
* updates of the list of present devices may involve queuing
* multiple work items, and this one may run before ones that
* were sent later. As such, this function only does something
* if is the last one in the queue.
*/
static void pci_devices_present_work(struct work_struct *work)
{
u32 child_no;
bool found;
struct list_head *iter;
struct pci_function_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);
if (down_interruptible(&hbus->enum_sem)) {
put_hvpcibus(hbus);
return;
}
/* 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) {
up(&hbus->enum_sem);
put_hvpcibus(hbus);
return;
}
/* First, mark all existing children as reported missing. */
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_for_each(iter, &hbus->children) {
hpdev = container_of(iter, struct hv_pci_dev,
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(iter, &hbus->children) {
hpdev = container_of(iter, struct hv_pci_dev,
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(iter, &hbus->children) {
hpdev = container_of(iter, struct hv_pci_dev,
list_entry);
if (hpdev->reported_missing) {
found = true;
put_pcichild(hpdev, hv_pcidev_ref_childlist);
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);
put_pcichild(hpdev, hv_pcidev_ref_initial);
}
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);
pci_unlock_rescan_remove();
break;
case hv_pcibus_init:
case hv_pcibus_probed:
survey_child_resources(hbus);
break;
default:
break;
}
up(&hbus->enum_sem);
put_hvpcibus(hbus);
kfree(dr);
}
/**
* hv_pci_devices_present() - Handles list of new children
* @hbus: Root PCI bus, as understood by this driver
* @relations: Packet from host listing children
*
* This function is invoked 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;
struct hv_dr_work *dr_wrk;
unsigned long flags;
dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
if (!dr_wrk)
return;
dr = kzalloc(offsetof(struct hv_dr_state, func) +
(sizeof(struct pci_function_description) *
(relations->device_count)), GFP_NOWAIT);
if (!dr) {
kfree(dr_wrk);
return;
}
INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
dr_wrk->bus = hbus;
dr->device_count = relations->device_count;
if (dr->device_count != 0) {
memcpy(dr->func, relations->func,
sizeof(struct pci_function_description) *
dr->device_count);
}
spin_lock_irqsave(&hbus->device_list_lock, flags);
list_add_tail(&dr->list_entry, &hbus->dr_list);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
get_hvpcibus(hbus);
schedule_work(&dr_wrk->wrk);
}
/**
* 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_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);
if (hpdev->state != hv_pcichild_ejecting) {
put_pcichild(hpdev, hv_pcidev_ref_pnp);
return;
}
/*
* 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(hpdev->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(&hpdev->hbus->device_list_lock, flags);
list_del(&hpdev->list_entry);
spin_unlock_irqrestore(&hpdev->hbus->device_list_lock, flags);
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(hpdev->hbus->hdev->channel, ejct_pkt,
sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
VM_PKT_DATA_INBAND, 0);
put_pcichild(hpdev, hv_pcidev_ref_childlist);
put_pcichild(hpdev, hv_pcidev_ref_pnp);
put_hvpcibus(hpdev->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)
{
hpdev->state = hv_pcichild_ejecting;
get_pcichild(hpdev, hv_pcidev_ref_pnp);
INIT_WORK(&hpdev->wrk, hv_eject_device_work);
get_hvpcibus(hpdev->hbus);
schedule_work(&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_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 <
offsetof(struct pci_bus_relations, func) +
(sizeof(struct pci_function_description) *
(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_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,
hv_pcidev_ref_by_slot);
}
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)
{
struct pci_version_request *version_req;
struct hv_pci_compl comp_pkt;
struct pci_packet *pkt;
int ret;
/*
* 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;
version_req->protocol_version = PCI_PROTOCOL_VERSION_CURRENT;
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)
goto exit;
wait_for_completion(&comp_pkt.host_event);
if (comp_pkt.completion_status < 0) {
dev_err(&hdev->device,
"PCI Pass-through VSP failed version request %x\n",
comp_pkt.completion_status);
ret = -EPROTO;
goto exit;
}
ret = 0;
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);
}
/**
* 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)
goto exit;
wait_for_completion(&comp_pkt.host_event);
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)
return ret;
wait_for_completion(&comp);
return 0;
}
/**
* 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 hv_pci_compl comp_pkt;
struct hv_pci_dev *hpdev;
struct pci_packet *pkt;
u32 wslot;
int ret;
pkt = kmalloc(sizeof(*pkt) + sizeof(*res_assigned), 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) + sizeof(*res_assigned));
init_completion(&comp_pkt.host_event);
pkt->completion_func = hv_pci_generic_compl;
pkt->compl_ctxt = &comp_pkt;
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;
put_pcichild(hpdev, hv_pcidev_ref_by_slot);
ret = vmbus_sendpacket(
hdev->channel, &pkt->message,
sizeof(*res_assigned),
(unsigned long)pkt,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
break;
wait_for_completion(&comp_pkt.host_event);
if (comp_pkt.completion_status < 0) {
ret = -EPROTO;
dev_err(&hdev->device,
"resource allocated returned 0x%x",
comp_pkt.completion_status);
break;
}
}
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;
u32 wslot;
int ret;
for (wslot = 0; wslot < 256; 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, hv_pcidev_ref_by_slot);
ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0,
VM_PKT_DATA_INBAND, 0);
if (ret)
return ret;
}
return 0;
}
static void get_hvpcibus(struct hv_pcibus_device *hbus)
{
atomic_inc(&hbus->remove_lock);
}
static void put_hvpcibus(struct hv_pcibus_device *hbus)
{
if (atomic_dec_and_test(&hbus->remove_lock))
complete(&hbus->remove_event);
}
/**
* 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;
int ret;
hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
if (!hbus)
return -ENOMEM;
hbus->state = hv_pcibus_init;
/*
* The PCI bus "domain" is what is called "segment" in ACPI and
* other specs. Pull it from the instance ID, to get something
* unique. Bytes 8 and 9 are what is used in Windows guests, so
* do the same thing for consistency. Note that, since this code
* only runs in a Hyper-V VM, Hyper-V can (and does) guarantee
* that (1) the only domain in use for something that looks like
* a physical PCI bus (which is actually emulated by the
* hypervisor) is domain 0 and (2) there will be no overlap
* between domains derived from these instance IDs in the same
* VM.
*/
hbus->sysdata.domain = hdev->dev_instance.b[9] |
hdev->dev_instance.b[8] << 8;
hbus->hdev = hdev;
atomic_inc(&hbus->remove_lock);
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);
sema_init(&hbus->enum_sem, 1);
init_completion(&hbus->remove_event);
ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
hv_pci_onchannelcallback, hbus);
if (ret)
goto free_bus;
hv_set_drvdata(hdev, hbus);
ret = hv_pci_protocol_negotiation(hdev);
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;
}
hbus->sysdata.fwnode = irq_domain_alloc_fwnode(hbus);
if (!hbus->sysdata.fwnode) {
ret = -ENOMEM;
goto unmap;
}
ret = hv_pcie_init_irq_domain(hbus);
if (ret)
goto free_fwnode;
ret = hv_pci_query_relations(hdev);
if (ret)
goto free_irq_domain;
ret = hv_pci_enter_d0(hdev);
if (ret)
goto free_irq_domain;
ret = hv_pci_allocate_bridge_windows(hbus);
if (ret)
goto free_irq_domain;
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);
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);
free_bus:
kfree(hbus);
return ret;
}
static void hv_pci_bus_exit(struct hv_device *hdev)
{
struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
struct {
struct pci_packet teardown_packet;
u8 buffer[sizeof(struct pci_message)];
} pkt;
struct pci_bus_relations relations;
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;
/* Delete any children which might still exist. */
memset(&relations, 0, sizeof(relations));
hv_pci_devices_present(hbus, &relations);
ret = hv_send_resources_released(hdev);
if (ret)
dev_err(&hdev->device,
"Couldn't send resources released packet(s)\n");
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)
wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ);
}
/**
* 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;
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);
pci_remove_root_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
hbus->state = hv_pcibus_removed;
}
hv_pci_bus_exit(hdev);
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);
kfree(hbus);
return 0;
}
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,
};
static void __exit exit_hv_pci_drv(void)
{
vmbus_driver_unregister(&hv_pci_drv);
}
static int __init init_hv_pci_drv(void)
{
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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