From 05131ecc99ea9da7f45ba3058fe8a2c1d0ceeab8 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Sun, 23 Oct 2005 16:31:00 -0400 Subject: [ACPI] Avoid BIOS inflicted crashes by evaluating _PDC only once 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 Signed-off-by: Len Brown --- arch/x86_64/kernel/acpi/Makefile | 5 +++ arch/x86_64/kernel/acpi/processor.c | 72 +++++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+) create mode 100644 arch/x86_64/kernel/acpi/processor.c (limited to 'arch/x86_64/kernel/acpi') diff --git a/arch/x86_64/kernel/acpi/Makefile b/arch/x86_64/kernel/acpi/Makefile index 7da9ace890b..4fe97071f29 100644 --- a/arch/x86_64/kernel/acpi/Makefile +++ b/arch/x86_64/kernel/acpi/Makefile @@ -1,3 +1,8 @@ obj-y := boot.o boot-y := ../../../i386/kernel/acpi/boot.o obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup.o + +ifneq ($(CONFIG_ACPI_PROCESSOR),) +obj-y += processor.o +endif + diff --git a/arch/x86_64/kernel/acpi/processor.c b/arch/x86_64/kernel/acpi/processor.c new file mode 100644 index 00000000000..3bdc2baa5bb --- /dev/null +++ b/arch/x86_64/kernel/acpi/processor.c @@ -0,0 +1,72 @@ +/* + * arch/x86_64/kernel/acpi/processor.c + * + * Copyright (C) 2005 Intel Corporation + * Venkatesh Pallipadi + * - Added _PDC for platforms with Intel CPUs + */ + +#include +#include +#include +#include + +#include +#include + +static void init_intel_pdc(struct acpi_processor *pr, struct cpuinfo_x86 *c) +{ + 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_EST_CAPABILITY_SMP; + + obj->type = ACPI_TYPE_BUFFER; + obj->buffer.length = 12; + obj->buffer.pointer = (u8 *) buf; + obj_list->count = 1; + obj_list->pointer = obj; + pr->pdc = obj_list; + + return; +} + +/* Initialize _PDC data based on the CPU vendor */ +void arch_acpi_processor_init_pdc(struct acpi_processor *pr) +{ + unsigned int cpu = pr->id; + struct cpuinfo_x86 *c = cpu_data + cpu; + + pr->pdc = NULL; + if (c->x86_vendor == X86_VENDOR_INTEL && cpu_has(c, X86_FEATURE_EST)) + init_intel_pdc(pr, c); + + return; +} + +EXPORT_SYMBOL(arch_acpi_processor_init_pdc); -- cgit v1.2.3