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authorMatthew Garrett <mjg@redhat.com>2012-09-04 08:28:06 +0000
committerRafael J. Wysocki <rjw@sisk.pl>2012-09-09 22:05:02 +0200
commitf594065faf4f9067c2283a34619fc0714e79a98d (patch)
treec4648afdda2ad77d5ec116855525bbe0aec684db /drivers/acpi
parenta2060958569a8e8e36202c373a55c458ff84856d (diff)
downloadlinux-linaro-stable-f594065faf4f9067c2283a34619fc0714e79a98d.tar.gz
ACPI: Add fixups for AMD P-state figures
Some AMD systems may round the frequencies in ACPI tables to 100MHz boundaries. We can obtain the real frequencies from MSRs, so add a quirk to fix these frequencies up on AMD systems. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/processor_perflib.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index a093dc163a42..836bfe069042 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -324,6 +324,34 @@ static int acpi_processor_get_performance_control(struct acpi_processor *pr)
return result;
}
+#ifdef CONFIG_X86
+/*
+ * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding
+ * in their ACPI data. Calculate the real values and fix up the _PSS data.
+ */
+static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
+{
+ u32 hi, lo, fid, did;
+ int index = px->control & 0x00000007;
+
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
+ return;
+
+ if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
+ || boot_cpu_data.x86 == 0x11) {
+ rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
+ fid = lo & 0x3f;
+ did = (lo >> 6) & 7;
+ if (boot_cpu_data.x86 == 0x10)
+ px->core_frequency = (100 * (fid + 0x10)) >> did;
+ else
+ px->core_frequency = (100 * (fid + 8)) >> did;
+ }
+}
+#else
+static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {};
+#endif
+
static int acpi_processor_get_performance_states(struct acpi_processor *pr)
{
int result = 0;
@@ -379,6 +407,8 @@ static int acpi_processor_get_performance_states(struct acpi_processor *pr)
goto end;
}
+ amd_fixup_frequency(px, i);
+
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
i,