[PATCH 1/2 V4] intel_pstate: skip this driver if Sun server has _PPC method

From: Ethan Zhao
Date: Thu Nov 27 2014 - 03:36:28 EST


Oracle Sun X86 servers have dynamic power capping capability that works via
ACPI _PPC method etc, so skip loading this driver if Sun server has ACPI _PPC
enabled.

Signed-off-by: Ethan Zhao <ethan.zhao@xxxxxxxxxx>
Signed-off-by: Dirk Brandewie <dirk.brandewie@xxxxxxxxx>
Tested-by: Linda Knippers <linda.knippers@xxxxxx>
---
v2: fix break HP Proliant issue.
v3: expand the hardware vendor list.
v4: refine code.

drivers/cpufreq/intel_pstate.c | 45 ++++++++++++++++++++++++++++++++++++++----
1 file changed, 41 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 27bb6d3..1bb62ca 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -943,15 +943,46 @@ static bool intel_pstate_no_acpi_pss(void)
return true;
}

+static bool intel_pstate_has_acpi_ppc(void)
+{
+ int i;
+
+ for_each_possible_cpu(i) {
+ struct acpi_processor *pr = per_cpu(processors, i);
+
+ if (!pr)
+ continue;
+ if (acpi_has_method(pr->handle, "_PPC"))
+ return true;
+ }
+ return false;
+}
+
+enum {
+ PSS,
+ PCC,
+};
+
struct hw_vendor_info {
u16 valid;
char oem_id[ACPI_OEM_ID_SIZE];
char oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
+ int oem_pwr_table;
};

/* Hardware vendor-specific info that has its own power management modes */
static struct hw_vendor_info vendor_info[] = {
- {1, "HP ", "ProLiant"},
+ {1, "HP ", "ProLiant", PSS},
+ {1, "ORACLE", "X4-2 ", PCC},
+ {1, "ORACLE", "X4-2L ", PCC},
+ {1, "ORACLE", "X4-2B ", PCC},
+ {1, "ORACLE", "X3-2 ", PCC},
+ {1, "ORACLE", "X3-2L ", PCC},
+ {1, "ORACLE", "X3-2B ", PCC},
+ {1, "ORACLE", "X4470M2 ", PCC},
+ {1, "ORACLE", "X4270M3 ", PCC},
+ {1, "ORACLE", "X4270M2 ", PCC},
+ {1, "ORACLE", "X4170M2 ", PCC},
{0, "", ""},
};

@@ -966,15 +997,21 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)

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;
+ !strncmp(hdr.oem_table_id, v_info->oem_table_id,
+ ACPI_OEM_TABLE_ID_SIZE))
+ switch (v_info->oem_pwr_table) {
+ case PSS:
+ return intel_pstate_no_acpi_pss();
+ case PCC:
+ return intel_pstate_has_acpi_ppc();
+ }
}

return false;
}
#else /* CONFIG_ACPI not enabled */
static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
+static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
#endif /* CONFIG_ACPI */

static int __init intel_pstate_init(void)
--
1.8.3.1

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