acpiphp_ibm.c

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/*
 * ACPI PCI Hot Plug IBM Extension
 *
 * Copyright (C) 2004 Vernon Mauery <[email protected]>
 * 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 <[email protected]>
 *
 */

#include <linux/init.h>
#include <linux/slab.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 <[email protected]>, Vernon Mauery <[email protected]>"
#define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension"

static bool 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 file *filp, 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,
};

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;
}

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;
}

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;
}

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;
}

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;
}

static ssize_t ibm_read_apci_table(struct file *filp, 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;
}

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, NULL,
            &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);