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linux/drivers/pci/hotplug/acpiphp_ibm.c

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/*
* ACPI PCI Hot Plug IBM Extension
*
* Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
* Copyright (C) 2004 IBM Corp.
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send feedback to <vernux@us.ibm.com>
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <acpi/acpi_bus.h>
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <asm/uaccess.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include "acpiphp.h"
#include "../pci.h"
#define DRIVER_VERSION "1.0.1"
#define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
#define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension"
static int debug;
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_VERSION(DRIVER_VERSION);
module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, " Debugging mode enabled or not");
#define MY_NAME "acpiphp_ibm"
#undef dbg
#define dbg(format, arg...) \
do { \
if (debug) \
printk(KERN_DEBUG "%s: " format, \
MY_NAME , ## arg); \
} while (0)
#define FOUND_APCI 0x61504349
/* these are the names for the IBM ACPI pseudo-device */
#define IBM_HARDWARE_ID1 "IBM37D0"
#define IBM_HARDWARE_ID2 "IBM37D4"
#define hpslot_to_sun(A) (((struct slot *)((A)->private))->acpi_slot->sun)
/* union apci_descriptor - allows access to the
* various device descriptors that are embedded in the
* aPCI table
*/
union apci_descriptor {
struct {
char sig[4];
u8 len;
} header;
struct {
u8 type;
u8 len;
u16 slot_id;
u8 bus_id;
u8 dev_num;
u8 slot_num;
u8 slot_attr[2];
u8 attn;
u8 status[2];
u8 sun;
u8 res[3];
} slot;
struct {
u8 type;
u8 len;
} generic;
};
/* struct notification - keeps info about the device
* that cause the ACPI notification event
*/
struct notification {
struct acpi_device *device;
u8 event;
};
static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
static int ibm_get_table_from_acpi(char **bufp);
static ssize_t ibm_read_apci_table(struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buffer, loff_t pos, size_t size);
static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
u32 lvl, void *context, void **rv);
static int __init ibm_acpiphp_init(void);
static void __exit ibm_acpiphp_exit(void);
static acpi_handle ibm_acpi_handle;
static struct notification ibm_note;
static struct bin_attribute ibm_apci_table_attr = {
.attr = {
.name = "apci_table",
.mode = S_IRUGO,
},
.read = ibm_read_apci_table,
.write = NULL,
};
static struct acpiphp_attention_info ibm_attention_info =
{
.set_attn = ibm_set_attention_status,
.get_attn = ibm_get_attention_status,
.owner = THIS_MODULE,
};
/**
* ibm_slot_from_id - workaround for bad ibm hardware
* @id: the slot number that linux refers to the slot by
*
* Description: This method returns the aCPI slot descriptor
* corresponding to the Linux slot number. This descriptor
* has info about the aPCI slot id and attention status.
* This descriptor must be freed using kfree when done.
*/
static union apci_descriptor *ibm_slot_from_id(int id)
{
int ind = 0, size;
union apci_descriptor *ret = NULL, *des;
char *table;
size = ibm_get_table_from_acpi(&table);
des = (union apci_descriptor *)table;
if (memcmp(des->header.sig, "aPCI", 4) != 0)
goto ibm_slot_done;
des = (union apci_descriptor *)&table[ind += des->header.len];
while (ind < size && (des->generic.type != 0x82 ||
des->slot.slot_num != id)) {
des = (union apci_descriptor *)&table[ind += des->generic.len];
}
if (ind < size && des->slot.slot_num == id)
ret = des;
ibm_slot_done:
if (ret) {
ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
memcpy(ret, des, sizeof(union apci_descriptor));
}
kfree(table);
return ret;
}
/**
* ibm_set_attention_status - callback method to set the attention LED
* @slot: the hotplug_slot to work with
* @status: what to set the LED to (0 or 1)
*
* Description: This method is registered with the acpiphp module as a
* callback to do the device specific task of setting the LED status.
*/
static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
{
union acpi_object args[2];
struct acpi_object_list params = { .pointer = args, .count = 2 };
acpi_status stat;
unsigned long long rc;
union apci_descriptor *ibm_slot;
ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
dbg("%s: set slot %d (%d) attention status to %d\n", __func__,
ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
(status ? 1 : 0));
args[0].type = ACPI_TYPE_INTEGER;
args[0].integer.value = ibm_slot->slot.slot_id;
args[1].type = ACPI_TYPE_INTEGER;
args[1].integer.value = (status) ? 1 : 0;
kfree(ibm_slot);
stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
if (ACPI_FAILURE(stat)) {
err("APLS evaluation failed: 0x%08x\n", stat);
return -ENODEV;
} else if (!rc) {
err("APLS method failed: 0x%08llx\n", rc);
return -ERANGE;
}
return 0;
}
/**
* ibm_get_attention_status - callback method to get attention LED status
* @slot: the hotplug_slot to work with
* @status: returns what the LED is set to (0 or 1)
*
* Description: This method is registered with the acpiphp module as a
* callback to do the device specific task of getting the LED status.
*
* Because there is no direct method of getting the LED status directly
* from an ACPI call, we read the aPCI table and parse out our
* slot descriptor to read the status from that.
*/
static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
{
union apci_descriptor *ibm_slot;
ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
*status = 1;
else
*status = 0;
dbg("%s: get slot %d (%d) attention status is %d\n", __func__,
ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
*status);
kfree(ibm_slot);
return 0;
}
/**
* ibm_handle_events - listens for ACPI events for the IBM37D0 device
* @handle: an ACPI handle to the device that caused the event
* @event: the event info (device specific)
* @context: passed context (our notification struct)
*
* Description: This method is registered as a callback with the ACPI
* subsystem it is called when this device has an event to notify the OS of.
*
* The events actually come from the device as two events that get
* synthesized into one event with data by this function. The event
* ID comes first and then the slot number that caused it. We report
* this as one event to the OS.
*
* From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
* only re-enable the interrupt that causes this event AFTER this method
* has returned, thereby enforcing serial access for the notification struct.
*/
static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
{
u8 detail = event & 0x0f;
u8 subevent = event & 0xf0;
struct notification *note = context;
dbg("%s: Received notification %02x\n", __func__, event);
if (subevent == 0x80) {
dbg("%s: generationg bus event\n", __func__);
acpi_bus_generate_proc_event(note->device, note->event, detail);
acpi_bus_generate_netlink_event(note->device->pnp.device_class,
dev_name(&note->device->dev),
note->event, detail);
} else
note->event = event;
}
/**
* ibm_get_table_from_acpi - reads the APLS buffer from ACPI
* @bufp: address to pointer to allocate for the table
*
* Description: This method reads the APLS buffer in from ACPI and
* stores the "stripped" table into a single buffer
* it allocates and passes the address back in bufp.
*
* If NULL is passed in as buffer, this method only calculates
* the size of the table and returns that without filling
* in the buffer.
*
* Returns < 0 on error or the size of the table on success.
*/
static int ibm_get_table_from_acpi(char **bufp)
{
union acpi_object *package;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_status status;
char *lbuf = NULL;
int i, size = -EIO;
status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
if (ACPI_FAILURE(status)) {
err("%s: APCI evaluation failed\n", __func__);
return -ENODEV;
}
package = (union acpi_object *) buffer.pointer;
if (!(package) ||
(package->type != ACPI_TYPE_PACKAGE) ||
!(package->package.elements)) {
err("%s: Invalid APCI object\n", __func__);
goto read_table_done;
}
for(size = 0, i = 0; i < package->package.count; i++) {
if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
err("%s: Invalid APCI element %d\n", __func__, i);
goto read_table_done;
}
size += package->package.elements[i].buffer.length;
}
if (bufp == NULL)
goto read_table_done;
lbuf = kzalloc(size, GFP_KERNEL);
dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
__func__, package->package.count, size, lbuf);
if (lbuf) {
*bufp = lbuf;
} else {
size = -ENOMEM;
goto read_table_done;
}
size = 0;
for (i=0; i<package->package.count; i++) {
memcpy(&lbuf[size],
package->package.elements[i].buffer.pointer,
package->package.elements[i].buffer.length);
size += package->package.elements[i].buffer.length;
}
read_table_done:
kfree(buffer.pointer);
return size;
}
/**
* ibm_read_apci_table - callback for the sysfs apci_table file
* @kobj: the kobject this binary attribute is a part of
* @bin_attr: struct bin_attribute for this file
* @buffer: the kernel space buffer to fill
* @pos: the offset into the file
* @size: the number of bytes requested
*
* Description: Gets registered with sysfs as the reader callback
* to be executed when /sys/bus/pci/slots/apci_table gets read.
*
* Since we don't get notified on open and close for this file,
* things get really tricky here...
* our solution is to only allow reading the table in all at once.
*/
static ssize_t ibm_read_apci_table(struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buffer, loff_t pos, size_t size)
{
int bytes_read = -EINVAL;
char *table = NULL;
dbg("%s: pos = %d, size = %zd\n", __func__, (int)pos, size);
if (pos == 0) {
bytes_read = ibm_get_table_from_acpi(&table);
if (bytes_read > 0 && bytes_read <= size)
memcpy(buffer, table, bytes_read);
kfree(table);
}
return bytes_read;
}
/**
* ibm_find_acpi_device - callback to find our ACPI device
* @handle: the ACPI handle of the device we are inspecting
* @lvl: depth into the namespace tree
* @context: a pointer to our handle to fill when we find the device
* @rv: a return value to fill if desired
*
* Description: Used as a callback when calling acpi_walk_namespace
* to find our device. When this method returns non-zero
* acpi_walk_namespace quits its search and returns our value.
*/
static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
u32 lvl, void *context, void **rv)
{
acpi_handle *phandle = (acpi_handle *)context;
acpi_status status;
struct acpi_device_info *info;
int retval = 0;
status = acpi_get_object_info(handle, &info);
if (ACPI_FAILURE(status)) {
err("%s: Failed to get device information status=0x%x\n",
__func__, status);
return retval;
}
if (info->current_status && (info->valid & ACPI_VALID_HID) &&
(!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
!strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
dbg("found hardware: %s, handle: %p\n",
info->hardware_id.string, handle);
*phandle = handle;
/* returning non-zero causes the search to stop
* and returns this value to the caller of
* acpi_walk_namespace, but it also causes some warnings
* in the acpi debug code to print...
*/
retval = FOUND_APCI;
}
kfree(info);
return retval;
}
static int __init ibm_acpiphp_init(void)
{
int retval = 0;
acpi_status status;
struct acpi_device *device;
struct kobject *sysdir = &pci_slots_kset->kobj;
dbg("%s\n", __func__);
if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX, ibm_find_acpi_device,
&ibm_acpi_handle, NULL) != FOUND_APCI) {
err("%s: acpi_walk_namespace failed\n", __func__);
retval = -ENODEV;
goto init_return;
}
dbg("%s: found IBM aPCI device\n", __func__);
if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
err("%s: acpi_bus_get_device failed\n", __func__);
retval = -ENODEV;
goto init_return;
}
if (acpiphp_register_attention(&ibm_attention_info)) {
retval = -ENODEV;
goto init_return;
}
ibm_note.device = device;
status = acpi_install_notify_handler(ibm_acpi_handle,
ACPI_DEVICE_NOTIFY, ibm_handle_events,
&ibm_note);
if (ACPI_FAILURE(status)) {
err("%s: Failed to register notification handler\n",
__func__);
retval = -EBUSY;
goto init_cleanup;
}
ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
return retval;
init_cleanup:
acpiphp_unregister_attention(&ibm_attention_info);
init_return:
return retval;
}
static void __exit ibm_acpiphp_exit(void)
{
acpi_status status;
struct kobject *sysdir = &pci_slots_kset->kobj;
dbg("%s\n", __func__);
if (acpiphp_unregister_attention(&ibm_attention_info))
err("%s: attention info deregistration failed", __func__);
status = acpi_remove_notify_handler(
ibm_acpi_handle,
ACPI_DEVICE_NOTIFY,
ibm_handle_events);
if (ACPI_FAILURE(status))
err("%s: Notification handler removal failed\n", __func__);
/* remove the /sys entries */
sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
}
module_init(ibm_acpiphp_init);
module_exit(ibm_acpiphp_exit);
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