X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=drivers%2Fcpufreq%2Fcppc_cpufreq.c;h=99db4227ae38785bbaf2d59fd506ed0f96a4dece;hb=f89f4147f76f91bfff6f32890fc34148178f144d;hp=8882b8e2ecd0d0fe82ddd8cbb1bf8c4e29f4b886;hpb=d011a4d861ce583466a8ae72a0c8e7f51c8cba4e;p=cascardo%2Flinux.git

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 8882b8e2ecd0..99db4227ae38 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -19,10 +19,19 @@
 #include <linux/delay.h>
 #include <linux/cpu.h>
 #include <linux/cpufreq.h>
+#include <linux/dmi.h>
 #include <linux/vmalloc.h>
 
+#include <asm/unaligned.h>
+
 #include <acpi/cppc_acpi.h>
 
+/* Minimum struct length needed for the DMI processor entry we want */
+#define DMI_ENTRY_PROCESSOR_MIN_LENGTH	48
+
+/* Offest in the DMI processor structure for the max frequency */
+#define DMI_PROCESSOR_MAX_SPEED  0x14
+
 /*
  * These structs contain information parsed from per CPU
  * ACPI _CPC structures.
@@ -32,6 +41,39 @@
  */
 static struct cpudata **all_cpu_data;
 
+/* Capture the max KHz from DMI */
+static u64 cppc_dmi_max_khz;
+
+/* Callback function used to retrieve the max frequency from DMI */
+static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private)
+{
+	const u8 *dmi_data = (const u8 *)dm;
+	u16 *mhz = (u16 *)private;
+
+	if (dm->type == DMI_ENTRY_PROCESSOR &&
+	    dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) {
+		u16 val = (u16)get_unaligned((const u16 *)
+				(dmi_data + DMI_PROCESSOR_MAX_SPEED));
+		*mhz = val > *mhz ? val : *mhz;
+	}
+}
+
+/* Look up the max frequency in DMI */
+static u64 cppc_get_dmi_max_khz(void)
+{
+	u16 mhz = 0;
+
+	dmi_walk(cppc_find_dmi_mhz, &mhz);
+
+	/*
+	 * Real stupid fallback value, just in case there is no
+	 * actual value set.
+	 */
+	mhz = mhz ? mhz : 1;
+
+	return (1000 * mhz);
+}
+
 static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
 		unsigned int target_freq,
 		unsigned int relation)
@@ -42,7 +84,7 @@ static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
 
 	cpu = all_cpu_data[policy->cpu];
 
-	cpu->perf_ctrls.desired_perf = target_freq;
+	cpu->perf_ctrls.desired_perf = (u64)target_freq * policy->max / cppc_dmi_max_khz;
 	freqs.old = policy->cur;
 	freqs.new = target_freq;
 
@@ -94,8 +136,10 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		return ret;
 	}
 
-	policy->min = cpu->perf_caps.lowest_perf;
-	policy->max = cpu->perf_caps.highest_perf;
+	cppc_dmi_max_khz = cppc_get_dmi_max_khz();
+
+	policy->min = cpu->perf_caps.lowest_perf * cppc_dmi_max_khz / cpu->perf_caps.highest_perf;
+	policy->max = cppc_dmi_max_khz;
 	policy->cpuinfo.min_freq = policy->min;
 	policy->cpuinfo.max_freq = policy->max;
 	policy->shared_type = cpu->shared_type;
@@ -112,7 +156,8 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	cpu->cur_policy = policy;
 
 	/* Set policy->cur to max now. The governors will adjust later. */
-	policy->cur = cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf;
+	policy->cur = cppc_dmi_max_khz;
+	cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf;
 
 	ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
 	if (ret)