[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=5483Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

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
 

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

arch/i386/kernel/acpi/processor.c

+/*
+ * 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);

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;

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");

arch/ia64/kernel/cpufreq/Makefile

 obj-$(CONFIG_IA64_ACPI_CPUFREQ)		+= acpi-cpufreq.o
+
+ifneq ($(CONFIG_ACPI_PROCESSOR),)
+obj-y				+= acpi-processor.o
+endif
+

arch/ia64/kernel/cpufreq/acpi-cpufreq.c

@@ -269,48 +269,6 @@ acpi_cpufreq_verify (
 }
 
 
-/*
- * processor_init_pdc - 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. Actual call to _PDC is done in driver/acpi/processor.c
- */
-static void
-processor_init_pdc (
-		struct acpi_processor_performance *perf,
-		unsigned int cpu,
-		struct acpi_object_list *obj_list
-		)
-{
-	union acpi_object *obj;
-	u32 *buf;
-
-	dprintk("processor_init_pdc\n");
-
-	perf->pdc = NULL;
-	/* 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;
-}
-
-
 static int
 acpi_cpufreq_cpu_init (
 	struct cpufreq_policy   *policy)
@@ -320,14 +278,7 @@ acpi_cpufreq_cpu_init (
 	struct cpufreq_acpi_io	*data;
 	unsigned int		result = 0;
 
-	union acpi_object		arg0 = {ACPI_TYPE_BUFFER};
-	u32				arg0_buf[3];
-	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 = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
 	if (!data)
@@ -337,9 +288,7 @@ acpi_cpufreq_cpu_init (
 
 	acpi_io_data[cpu] = data;
 
-	processor_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;

arch/ia64/kernel/cpufreq/acpi-processor.c

+/*
+ * arch/ia64/kernel/cpufreq/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 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)
+{
+	pr->pdc = NULL;
+	init_intel_pdc(pr);
+	return;
+}
+
+EXPORT_SYMBOL(arch_acpi_processor_init_pdc);

arch/x86_64/kernel/acpi/Makefile

 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
+

arch/x86_64/kernel/acpi/processor.c

+/*
+ * arch/x86_64/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_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);

drivers/acpi/processor_core.c

@@ -253,31 +253,21 @@ static int acpi_processor_errata(struct acpi_processor *pr)
  * _PDC is required for a BIOS-OS handshake for most of the newer
  * ACPI processor features.
  */
-
-int acpi_processor_set_pdc(struct acpi_processor *pr,
-			   struct acpi_object_list *pdc_in)
+static int acpi_processor_set_pdc(struct acpi_processor *pr)
 {
+	struct acpi_object_list *pdc_in = pr->pdc;
 	acpi_status status = AE_OK;
-	u32 arg0_buf[3];
-	union acpi_object arg0 = { ACPI_TYPE_BUFFER };
-	struct acpi_object_list no_object = { 1, &arg0 };
-	struct acpi_object_list *pdc;
 
 	ACPI_FUNCTION_TRACE("acpi_processor_set_pdc");
 
-	arg0.buffer.length = 12;
-	arg0.buffer.pointer = (u8 *) arg0_buf;
-	arg0_buf[0] = ACPI_PDC_REVISION_ID;
-	arg0_buf[1] = 0;
-	arg0_buf[2] = 0;
-
-	pdc = (pdc_in) ? pdc_in : &no_object;
+	if (!pdc_in)
+		return_VALUE(status);
 
-	status = acpi_evaluate_object(pr->handle, "_PDC", pdc, NULL);
+	status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL);
 
-	if ((ACPI_FAILURE(status)) && (pdc_in))
+	if (ACPI_FAILURE(status))
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Error evaluating _PDC, using legacy perf. control...\n"));
+		    "Could not evaluate _PDC, using legacy perf. control...\n"));
 
 	return_VALUE(status);
 }
@@ -574,6 +564,10 @@ static int acpi_processor_start(struct acpi_device *device)
 				  "Error installing device notify handler\n"));
 	}
 
+	/* _PDC call should be done before doing anything else (if reqd.). */
+	arch_acpi_processor_init_pdc(pr);
+	acpi_processor_set_pdc(pr);
+
 	acpi_processor_power_init(pr, device);
 
 	if (pr->flags.throttling) {

drivers/acpi/processor_idle.c

@@ -1014,8 +1014,6 @@ int acpi_processor_power_init(struct acpi_processor *pr,
 		}
 	}
 
-	acpi_processor_power_init_pdc(&(pr->power), pr->id);
-	acpi_processor_set_pdc(pr, pr->power.pdc);
 	acpi_processor_get_power_info(pr);
 
 	/*

drivers/acpi/processor_perflib.c

@@ -315,8 +315,6 @@ static int acpi_processor_get_performance_info(struct acpi_processor *pr)
 	if (!pr || !pr->performance || !pr->handle)
 		return_VALUE(-EINVAL);
 
-	acpi_processor_set_pdc(pr, pr->performance->pdc);
-
 	status = acpi_get_handle(pr->handle, "_PCT", &handle);
 	if (ACPI_FAILURE(status)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,

include/acpi/pdc_intel.h

@@ -15,9 +15,7 @@
 #define ACPI_PDC_C_C1_FFH		(0x0100)
 
 #define ACPI_PDC_EST_CAPABILITY_SMP	(ACPI_PDC_SMP_C1PT | \
-					 ACPI_PDC_C_C1_HALT)
-
-#define ACPI_PDC_EST_CAPABILITY_SMP_MSR	(ACPI_PDC_EST_CAPABILITY_SMP | \
+					 ACPI_PDC_C_C1_HALT | \
 					 ACPI_PDC_P_FFH)
 
 #define ACPI_PDC_C_CAPABILITY_SMP	(ACPI_PDC_SMP_C2C3 | \

include/acpi/processor.h

@@ -62,9 +62,6 @@ struct acpi_processor_power {
 	u32 bm_activity;
 	int count;
 	struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
-
-	/* the _PDC objects passed by the driver, if any */
-	struct acpi_object_list *pdc;
 };
 
 /* Performance Management */
@@ -96,8 +93,6 @@ struct acpi_processor_performance {
 	unsigned int state_count;
 	struct acpi_processor_px *states;
 
-	/* the _PDC objects passed by the driver, if any */
-	struct acpi_object_list *pdc;
 };
 
 /* Throttling Control */
@@ -151,6 +146,9 @@ struct acpi_processor {
 	struct acpi_processor_performance *performance;
 	struct acpi_processor_throttling throttling;
 	struct acpi_processor_limit limit;
+
+	/* the _PDC objects for this processor, if any */
+	struct acpi_object_list *pdc;
 };
 
 struct acpi_processor_errata {
@@ -178,22 +176,12 @@ int acpi_processor_notify_smm(struct module *calling_module);
 extern struct acpi_processor *processors[NR_CPUS];
 extern struct acpi_processor_errata errata;
 
-int acpi_processor_set_pdc(struct acpi_processor *pr,
-			   struct acpi_object_list *pdc_in);
+void arch_acpi_processor_init_pdc(struct acpi_processor *pr);
 
-#ifdef ARCH_HAS_POWER_PDC_INIT
-void acpi_processor_power_init_pdc(struct acpi_processor_power *pow,
-				   unsigned int cpu);
+#ifdef ARCH_HAS_POWER_INIT
 void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
 					unsigned int cpu);
 #else
-static inline void acpi_processor_power_init_pdc(struct acpi_processor_power
-						 *pow, unsigned int cpu)
-{
-	pow->pdc = NULL;
-	return;
-}
-
 static inline void acpi_processor_power_init_bm_check(struct
 						      acpi_processor_flags
 						      *flags, unsigned int cpu)

include/asm-i386/acpi.h

@@ -179,7 +179,7 @@ extern void acpi_reserve_bootmem(void);
 
 extern u8 x86_acpiid_to_apicid[];
 
-#define ARCH_HAS_POWER_PDC_INIT	1
+#define ARCH_HAS_POWER_INIT	1
 
 #endif /*__KERNEL__*/