129 lines
3.2 KiB
C
129 lines
3.2 KiB
C
/*
|
|
* ACPI watchdog table parsing support.
|
|
*
|
|
* Copyright (C) 2016, Intel Corporation
|
|
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "ACPI: watchdog: " fmt
|
|
|
|
#include <linux/acpi.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#include "internal.h"
|
|
|
|
/**
|
|
* Returns true if this system should prefer ACPI based watchdog instead of
|
|
* the native one (which are typically the same hardware).
|
|
*/
|
|
bool acpi_has_watchdog(void)
|
|
{
|
|
struct acpi_table_header hdr;
|
|
|
|
if (acpi_disabled)
|
|
return false;
|
|
|
|
return ACPI_SUCCESS(acpi_get_table_header(ACPI_SIG_WDAT, 0, &hdr));
|
|
}
|
|
EXPORT_SYMBOL_GPL(acpi_has_watchdog);
|
|
|
|
void __init acpi_watchdog_init(void)
|
|
{
|
|
const struct acpi_wdat_entry *entries;
|
|
const struct acpi_table_wdat *wdat;
|
|
struct list_head resource_list;
|
|
struct resource_entry *rentry;
|
|
struct platform_device *pdev;
|
|
struct resource *resources;
|
|
size_t nresources = 0;
|
|
acpi_status status;
|
|
int i;
|
|
|
|
status = acpi_get_table(ACPI_SIG_WDAT, 0,
|
|
(struct acpi_table_header **)&wdat);
|
|
if (ACPI_FAILURE(status)) {
|
|
/* It is fine if there is no WDAT */
|
|
return;
|
|
}
|
|
|
|
/* Watchdog disabled by BIOS */
|
|
if (!(wdat->flags & ACPI_WDAT_ENABLED))
|
|
return;
|
|
|
|
/* Skip legacy PCI WDT devices */
|
|
if (wdat->pci_segment != 0xff || wdat->pci_bus != 0xff ||
|
|
wdat->pci_device != 0xff || wdat->pci_function != 0xff)
|
|
return;
|
|
|
|
INIT_LIST_HEAD(&resource_list);
|
|
|
|
entries = (struct acpi_wdat_entry *)(wdat + 1);
|
|
for (i = 0; i < wdat->entries; i++) {
|
|
const struct acpi_generic_address *gas;
|
|
struct resource_entry *rentry;
|
|
struct resource res;
|
|
bool found;
|
|
|
|
gas = &entries[i].register_region;
|
|
|
|
res.start = gas->address;
|
|
if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
|
|
res.flags = IORESOURCE_MEM;
|
|
res.end = res.start + ALIGN(gas->access_width, 4);
|
|
} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
|
|
res.flags = IORESOURCE_IO;
|
|
res.end = res.start + gas->access_width;
|
|
} else {
|
|
pr_warn("Unsupported address space: %u\n",
|
|
gas->space_id);
|
|
goto fail_free_resource_list;
|
|
}
|
|
|
|
found = false;
|
|
resource_list_for_each_entry(rentry, &resource_list) {
|
|
if (rentry->res->flags == res.flags &&
|
|
resource_overlaps(rentry->res, &res)) {
|
|
if (res.start < rentry->res->start)
|
|
rentry->res->start = res.start;
|
|
if (res.end > rentry->res->end)
|
|
rentry->res->end = res.end;
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
rentry = resource_list_create_entry(NULL, 0);
|
|
if (!rentry)
|
|
goto fail_free_resource_list;
|
|
|
|
*rentry->res = res;
|
|
resource_list_add_tail(rentry, &resource_list);
|
|
nresources++;
|
|
}
|
|
}
|
|
|
|
resources = kcalloc(nresources, sizeof(*resources), GFP_KERNEL);
|
|
if (!resources)
|
|
goto fail_free_resource_list;
|
|
|
|
i = 0;
|
|
resource_list_for_each_entry(rentry, &resource_list)
|
|
resources[i++] = *rentry->res;
|
|
|
|
pdev = platform_device_register_simple("wdat_wdt", PLATFORM_DEVID_NONE,
|
|
resources, nresources);
|
|
if (IS_ERR(pdev))
|
|
pr_err("Device creation failed: %ld\n", PTR_ERR(pdev));
|
|
|
|
kfree(resources);
|
|
|
|
fail_free_resource_list:
|
|
resource_list_free(&resource_list);
|
|
}
|