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authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>2005-10-23 16:31:00 -0400
committerLen Brown <len.brown@intel.com>2005-12-01 01:30:35 -0500
commit05131ecc99ea9da7f45ba3058fe8a2c1d0ceeab8 (patch)
treedec76975406874cf677d6391302f42a6da55ac38 /arch/ia64/kernel
parentd2149b542382bfc206cb28485108f6470c979566 (diff)
[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>
Diffstat (limited to 'arch/ia64/kernel')
-rw-r--r--arch/ia64/kernel/cpufreq/Makefile5
-rw-r--r--arch/ia64/kernel/cpufreq/acpi-cpufreq.c51
-rw-r--r--arch/ia64/kernel/cpufreq/acpi-processor.c67
3 files changed, 72 insertions, 51 deletions
diff --git a/arch/ia64/kernel/cpufreq/Makefile b/arch/ia64/kernel/cpufreq/Makefile
index f748d34c02f..642648361ed 100644
--- a/arch/ia64/kernel/cpufreq/Makefile
+++ b/arch/ia64/kernel/cpufreq/Makefile
@@ -1 +1,6 @@
obj-$(CONFIG_IA64_ACPI_CPUFREQ) += acpi-cpufreq.o
+
+ifneq ($(CONFIG_ACPI_PROCESSOR),)
+obj-y += acpi-processor.o
+endif
+
diff --git a/arch/ia64/kernel/cpufreq/acpi-cpufreq.c b/arch/ia64/kernel/cpufreq/acpi-cpufreq.c
index da4d5cf80a4..5a1bf815282 100644
--- a/arch/ia64/kernel/cpufreq/acpi-cpufreq.c
+++ b/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;
diff --git a/arch/ia64/kernel/cpufreq/acpi-processor.c b/arch/ia64/kernel/cpufreq/acpi-processor.c
new file mode 100644
index 00000000000..e683630c8ce
--- /dev/null
+++ b/arch/ia64/kernel/cpufreq/acpi-processor.c
@@ -0,0 +1,67 @@
+/*
+ * 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);