[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 <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/arch/i386/kernel/acpi/Makefile b/arch/i386/kernel/acpi/Makefile
index 267ca48..d51c731 100644
--- a/arch/i386/kernel/acpi/Makefile
+++ b/arch/i386/kernel/acpi/Makefile
@@ -3,6 +3,6 @@
obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup.o
ifneq ($(CONFIG_ACPI_PROCESSOR),)
-obj-y += cstate.o
+obj-y += cstate.o processor.o
endif
diff --git a/arch/i386/kernel/acpi/cstate.c b/arch/i386/kernel/acpi/cstate.c
index 4c3036b..25db49e 100644
--- a/arch/i386/kernel/acpi/cstate.c
+++ b/arch/i386/kernel/acpi/cstate.c
@@ -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
diff --git a/arch/i386/kernel/acpi/processor.c b/arch/i386/kernel/acpi/processor.c
new file mode 100644
index 0000000..9f4cc02
--- /dev/null
+++ b/arch/i386/kernel/acpi/processor.c
@@ -0,0 +1,75 @@
+/*
+ * arch/i386/kernel/acpi/processor.c
+ *
+ * Copyright (C) 2005 Intel Corporation
+ * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ * - Added _PDC for platforms with Intel CPUs
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+
+#include <acpi/processor.h>
+#include <asm/acpi.h>
+
+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_C_CAPABILITY_SMP;
+
+ if (cpu_has(c, X86_FEATURE_EST))
+ 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)
+ init_intel_pdc(pr, c);
+
+ return;
+}
+
+EXPORT_SYMBOL(arch_acpi_processor_init_pdc);
diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
index 871366b..31ce890 100644
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -297,68 +297,6 @@
}
-/*
- * acpi_processor_cpu_init_pdc_est - let BIOS know about the SMP capabilities
- * of this driver
- * @perf: processor-specific acpi_io_data struct
- * @cpu: CPU being initialized
- *
- * To avoid issues with legacy OSes, some BIOSes require to be informed of
- * the SMP capabilities of OS P-state driver. Here we set the bits in _PDC
- * accordingly, for Enhanced Speedstep. Actual call to _PDC is done in
- * driver/acpi/processor.c
- */
-static void
-acpi_processor_cpu_init_pdc_est(
- struct acpi_processor_performance *perf,
- unsigned int cpu,
- struct acpi_object_list *obj_list
- )
-{
- union acpi_object *obj;
- u32 *buf;
- struct cpuinfo_x86 *c = cpu_data + cpu;
- dprintk("acpi_processor_cpu_init_pdc_est\n");
-
- if (!cpu_has(c, X86_FEATURE_EST))
- return;
-
- /* Initialize pdc. It will be used later. */
- if (!obj_list)
- return;
-
- if (!(obj_list->count && obj_list->pointer))
- return;
-
- obj = obj_list->pointer;
- if ((obj->buffer.length == 12) && obj->buffer.pointer) {
- buf = (u32 *)obj->buffer.pointer;
- buf[0] = ACPI_PDC_REVISION_ID;
- buf[1] = 1;
- buf[2] = ACPI_PDC_EST_CAPABILITY_SMP;
- perf->pdc = obj_list;
- }
- return;
-}
-
-
-/* CPU specific PDC initialization */
-static void
-acpi_processor_cpu_init_pdc(
- struct acpi_processor_performance *perf,
- unsigned int cpu,
- struct acpi_object_list *obj_list
- )
-{
- struct cpuinfo_x86 *c = cpu_data + cpu;
- dprintk("acpi_processor_cpu_init_pdc\n");
- perf->pdc = NULL;
- if (cpu_has(c, X86_FEATURE_EST))
- acpi_processor_cpu_init_pdc_est(perf, cpu, obj_list);
- return;
-}
-
-
static int
acpi_cpufreq_cpu_init (
struct cpufreq_policy *policy)
@@ -373,9 +311,6 @@
struct acpi_object_list arg_list = {1, &arg0};
dprintk("acpi_cpufreq_cpu_init\n");
- /* setup arg_list for _PDC settings */
- arg0.buffer.length = 12;
- arg0.buffer.pointer = (u8 *) arg0_buf;
data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
if (!data)
@@ -383,9 +318,7 @@
acpi_io_data[cpu] = data;
- acpi_processor_cpu_init_pdc(&data->acpi_data, cpu, &arg_list);
result = acpi_processor_register_performance(&data->acpi_data, cpu);
- data->acpi_data.pdc = NULL;
if (result)
goto err_free;
diff --git a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
index edb9873..d930234 100644
--- a/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
+++ b/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
@@ -364,22 +364,10 @@
*/
static int centrino_cpu_init_acpi(struct cpufreq_policy *policy)
{
- union acpi_object arg0 = {ACPI_TYPE_BUFFER};
- u32 arg0_buf[3];
- struct acpi_object_list arg_list = {1, &arg0};
unsigned long cur_freq;
int result = 0, i;
unsigned int cpu = policy->cpu;
- /* _PDC settings */
- arg0.buffer.length = 12;
- arg0.buffer.pointer = (u8 *) arg0_buf;
- arg0_buf[0] = ACPI_PDC_REVISION_ID;
- arg0_buf[1] = 1;
- arg0_buf[2] = ACPI_PDC_EST_CAPABILITY_SMP_MSR;
-
- p.pdc = &arg_list;
-
/* register with ACPI core */
if (acpi_processor_register_performance(&p, cpu)) {
dprintk(KERN_INFO PFX "obtaining ACPI data failed\n");