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path: root/drivers/cpufreq/intel_pstate.c
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Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
-rw-r--r--drivers/cpufreq/intel_pstate.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 81e0062a6d2..3b5c5359a44 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -25,6 +25,7 @@
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
+#include <linux/acpi.h>
#include <trace/events/power.h>
#include <asm/div64.h>
@@ -779,6 +780,72 @@ static void copy_cpu_funcs(struct pstate_funcs *funcs)
pstate_funcs.set = funcs->set;
}
+#if IS_ENABLED(CONFIG_ACPI)
+#include <acpi/processor.h>
+
+static bool intel_pstate_no_acpi_pss(void)
+{
+ int i;
+
+ for_each_possible_cpu(i) {
+ acpi_status status;
+ union acpi_object *pss;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_processor *pr = per_cpu(processors, i);
+
+ if (!pr)
+ continue;
+
+ status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ continue;
+
+ pss = buffer.pointer;
+ if (pss && pss->type == ACPI_TYPE_PACKAGE) {
+ kfree(pss);
+ return false;
+ }
+
+ kfree(pss);
+ }
+
+ return true;
+}
+
+struct hw_vendor_info {
+ u16 valid;
+ char oem_id[ACPI_OEM_ID_SIZE];
+ char oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
+};
+
+/* Hardware vendor-specific info that has its own power management modes */
+static struct hw_vendor_info vendor_info[] = {
+ {1, "HP ", "ProLiant"},
+ {0, "", ""},
+};
+
+static bool intel_pstate_platform_pwr_mgmt_exists(void)
+{
+ struct acpi_table_header hdr;
+ struct hw_vendor_info *v_info;
+
+ if (acpi_disabled
+ || ACPI_FAILURE(acpi_get_table_header(ACPI_SIG_FADT, 0, &hdr)))
+ return false;
+
+ for (v_info = vendor_info; v_info->valid; v_info++) {
+ if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE)
+ && !strncmp(hdr.oem_table_id, v_info->oem_table_id, ACPI_OEM_TABLE_ID_SIZE)
+ && intel_pstate_no_acpi_pss())
+ return true;
+ }
+
+ return false;
+}
+#else /* CONFIG_ACPI not enabled */
+static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
+#endif /* CONFIG_ACPI */
+
static int __init intel_pstate_init(void)
{
int cpu, rc = 0;
@@ -792,6 +859,13 @@ static int __init intel_pstate_init(void)
if (!id)
return -ENODEV;
+ /*
+ * The Intel pstate driver will be ignored if the platform
+ * firmware has its own power management modes.
+ */
+ if (intel_pstate_platform_pwr_mgmt_exists())
+ return -ENODEV;
+
cpu_info = (struct cpu_defaults *)id->driver_data;
copy_pid_params(&cpu_info->pid_policy);