1 files changed, 74 insertions, 0 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 81e0062a6d2a..3b5c5359a44b 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);