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[ACPI] Avoid BIOS inflicted crashes by evaluating _PDC only once

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Linux invokes the AML _PDC method (Processor Driver Capabilities)
to tell the BIOS what features it can handle.  While the ACPI
spec says nothing about the OS invoking _PDC multiple times,
doing so with changing bits seems to hopelessly confuse the BIOS
on multiple platforms up to and including crashing the system.

Factor out the _PDC invocation so Linux invokes it only once.

http://bugzilla.kernel.org/show_bug.cgi?id=5483

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Venkatesh Pallipadi
2005-10-23 16:31:00 -04:00
committed by Len Brown
parent d2149b5423
commit 05131ecc99
16 changed files with 243 additions and 231 deletions
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58
arch/i386/kernel/acpi/cstate.c
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@@ -14,64 +14,6 @@
#include <acpi/processor.h>
#include <asm/acpi.h>
static void acpi_processor_power_init_intel_pdc(struct acpi_processor_power
*pow)
{
struct acpi_object_list *obj_list;
union acpi_object *obj;
u32 *buf;
/* allocate and initialize pdc. It will be used later. */
obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
if (!obj_list) {
printk(KERN_ERR "Memory allocation error\n");
return;
}
obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
if (!obj) {
printk(KERN_ERR "Memory allocation error\n");
kfree(obj_list);
return;
}
buf = kmalloc(12, GFP_KERNEL);
if (!buf) {
printk(KERN_ERR "Memory allocation error\n");
kfree(obj);
kfree(obj_list);
return;
}
buf[0] = ACPI_PDC_REVISION_ID;
buf[1] = 1;
buf[2] = ACPI_PDC_C_CAPABILITY_SMP;
obj->type = ACPI_TYPE_BUFFER;
obj->buffer.length = 12;
obj->buffer.pointer = (u8 *) buf;
obj_list->count = 1;
obj_list->pointer = obj;
pow->pdc = obj_list;
return;
}
/* Initialize _PDC data based on the CPU vendor */
void acpi_processor_power_init_pdc(struct acpi_processor_power *pow,
unsigned int cpu)
{
struct cpuinfo_x86 *c = cpu_data + cpu;
pow->pdc = NULL;
if (c->x86_vendor == X86_VENDOR_INTEL)
acpi_processor_power_init_intel_pdc(pow);
return;
}
EXPORT_SYMBOL(acpi_processor_power_init_pdc);
/*
* Initialize bm_flags based on the CPU cache properties
* On SMP it depends on cache configuration