[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>

5 files changed, 76 insertions, 138 deletions

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-$(CONFIG_X86_IO_APIC)	+= earlyquirk.o
 obj-$(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_cpufreq_guess_freq (
 }
 
 
-/* 
- * 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 @@ acpi_cpufreq_cpu_init (
 	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_cpufreq_cpu_init (
 
 	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 struct acpi_processor_performance p;
  */
 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");