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powernow-k8: Misc fixes

PATCH In review Andreas Herrmann 2 participants 5 messages Jan 6, 2012 CPU frequency scaling framework

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#0 lore raw

cover powernow-k8: Misc fixes

Hi Dave,

Following two fixes are required on systems where intermediate Pstates are disabled.

Please apply.

Thanks,

Andreas

#1 lore raw

PATCH 1/3 powernow-k8: Avoid Pstate MSR accesses on systems supporting CPB

Due to CPB we can't directly map SW Pstates to Pstate MSRs. Get rid of the paranoia check. (assuming that the ACPI Pstate information is correct.)

---
 drivers/cpufreq/powernow-k8.c |   19 ++++++++++---------
 1 files changed, 10 insertions(+), 9 deletions(-)
drivers/cpufreq/powernow-k8.c +10 -9
index bce576d..e0329f9 100644
@@ -926,23 +926,24 @@ static int fill_powernow_table_pstate(struct powernow_k8_data *data,
 			invalidate_entry(powernow_table, i);
 			continue;
 		}
-		rdmsr(MSR_PSTATE_DEF_BASE + index, lo, hi);
-		if (!(hi & HW_PSTATE_VALID_MASK)) {
-			pr_debug("invalid pstate %d, ignoring\n", index);
-			invalidate_entry(powernow_table, i);
-			continue;
-		}
-
-		powernow_table[i].index = index;
-
 		/* Frequency may be rounded for these */
 		if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
 				 || boot_cpu_data.x86 == 0x11) {
+
+			rdmsr(MSR_PSTATE_DEF_BASE + index, lo, hi);
+			if (!(hi & HW_PSTATE_VALID_MASK)) {
+				pr_debug("invalid pstate %d, ignoring\n", index);
+				invalidate_entry(powernow_table, i);
+				continue;
+			}
+
 			powernow_table[i].frequency =
 				freq_from_fid_did(lo & 0x3f, (lo >> 6) & 7);
 		} else
 			powernow_table[i].frequency =
 				data->acpi_data.states[i].core_frequency * 1000;
+
+		powernow_table[i].index = index;
 	}
 	return 0;
 }
Signature · 1 line
1.7.8.1
#2 lore raw

PATCH 2/3 powernow-k8: Fix indexing issue

In reply to Andreas Herrmann

The driver uses the pstate number from the status register as index in its table of ACPI pstates (powernow_table). This is wrong as this is not a 1-to-1 mapping.

For example we can have _PSS information to just utilize Pstate 0 and Pstate 4, ie.

powernow-k8: Core Performance Boosting: on.
powernow-k8: 0 : pstate 0 (2200 MHz)
powernow-k8: 1 : pstate 4 (1400 MHz)

In this example the driver's powernow_table has just 2 entries. Using the pstate number (4) as index into this table is just plain wrong.

---
 drivers/cpufreq/powernow-k8.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)
drivers/cpufreq/powernow-k8.c +11 -4
index e0329f9..ad683ec 100644
@@ -54,6 +54,9 @@ static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
 
 static int cpu_family = CPU_OPTERON;
 
+/* array to map SW pstate number to acpi state */
+static u32 ps_to_as[8];
+
 /* core performance boost */
 static bool cpb_capable, cpb_enabled;
 static struct msr __percpu *msrs;
@@ -80,9 +83,9 @@ static u32 find_khz_freq_from_fid(u32 fid)
 }
 
 static u32 find_khz_freq_from_pstate(struct cpufreq_frequency_table *data,
-		u32 pstate)
+				     u32 pstate)
 {
-	return data[pstate].frequency;
+	return data[ps_to_as[pstate]].frequency;
 }
 
 /* Return the vco fid for an input fid
@@ -926,6 +929,9 @@ static int fill_powernow_table_pstate(struct powernow_k8_data *data,
 			invalidate_entry(powernow_table, i);
 			continue;
 		}
+
+		ps_to_as[index] = i;
+
 		/* Frequency may be rounded for these */
 		if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
 				 || boot_cpu_data.x86 == 0x11) {
@@ -1190,7 +1196,8 @@ static int powernowk8_target(struct cpufreq_policy *pol,
 	powernow_k8_acpi_pst_values(data, newstate);
 
 	if (cpu_family == CPU_HW_PSTATE)
-		ret = transition_frequency_pstate(data, newstate);
+		ret = transition_frequency_pstate(data,
+			data->powernow_table[newstate].index);
 	else
 		ret = transition_frequency_fidvid(data, newstate);
 	if (ret) {
@@ -1203,7 +1210,7 @@ static int powernowk8_target(struct cpufreq_policy *pol,
 
 	if (cpu_family == CPU_HW_PSTATE)
 		pol->cur = find_khz_freq_from_pstate(data->powernow_table,
-				newstate);
+				data->powernow_table[newstate].index);
 	else
 		pol->cur = find_khz_freq_from_fid(data->currfid);
 	ret = 0;
Signature · 1 line
1.7.8.1
#3 lore raw

PATCH 3/3 powernow-k8: Update copyright, maintainer and documentation information

In reply to Andreas Herrmann
---
 drivers/cpufreq/powernow-k8.c |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)
drivers/cpufreq/powernow-k8.c +10 -7
index ad683ec..8f9b2ce 100644
@@ -1,10 +1,11 @@
 /*
- *   (c) 2003-2010 Advanced Micro Devices, Inc.
+ *   (c) 2003-2012 Advanced Micro Devices, Inc.
  *  Your use of this code is subject to the terms and conditions of the
  *  GNU general public license version 2. See "COPYING" or
  *  http://www.gnu.org/licenses/gpl.html
  *
- *  Support : [email protected]
+ *  Maintainer:
+ *  Andreas Herrmann <[email protected]>
  *
  *  Based on the powernow-k7.c module written by Dave Jones.
  *  (C) 2003 Dave Jones on behalf of SuSE Labs
@@ -16,12 +17,14 @@
  *  Valuable input gratefully received from Dave Jones, Pavel Machek,
  *  Dominik Brodowski, Jacob Shin, and others.
  *  Originally developed by Paul Devriendt.
- *  Processor information obtained from Chapter 9 (Power and Thermal Management)
- *  of the "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD
- *  Opteron Processors" available for download from www.amd.com
  *
- *  Tables for specific CPUs can be inferred from
- *     http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf
+ *  Processor information obtained from Chapter 9 (Power and Thermal
+ *  Management) of the "BIOS and Kernel Developer's Guide (BKDG) for
+ *  the AMD Athlon 64 and AMD Opteron Processors" and section "2.x
+ *  Power Management" in BKDGs for newer AMD CPU families.
+ *
+ *  Tables for specific CPUs can be inferred from AMD's processor
+ *  power and thermal data sheets, (e.g. 30417.pdf, 30430.pdf, 43375.pdf)
  */
 
 #include <linux/kernel.h>
Signature · 1 line
1.7.8.1
Acked-by on v1 3/3
#4 lore raw

Re: [PATCH 3/3] powernow-k8: Update copyright, maintainer and documentation information

Quoted 34 lines · Andreas Herrmann
---
 drivers/cpufreq/powernow-k8.c |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)
drivers/cpufreq/powernow-k8.c +3 -7
index ad683ec..8f9b2ce 100644
@@ -1,10 +1,11 @@
 /*
- *   (c) 2003-2010 Advanced Micro Devices, Inc.
+ *   (c) 2003-2012 Advanced Micro Devices, Inc.
  *  Your use of this code is subject to the terms and conditions of the
  *  GNU general public license version 2. See "COPYING" or
  *  http://www.gnu.org/licenses/gpl.html
  *
- *  Support : [email protected]
+ *  Maintainer:
+ *  Andreas Herrmann <[email protected]>
  *
  *  Based on the powernow-k7.c module written by Dave Jones.
  *  (C) 2003 Dave Jones on behalf of SuSE Labs
@@ -16,12 +17,14 @@
  *  Valuable input gratefully received from Dave Jones, Pavel Machek,
  *  Dominik Brodowski, Jacob Shin, and others.
  *  Originally developed by Paul Devriendt.
- *  Processor information obtained from Chapter 9 (Power and Thermal Management)
- *  of the "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD
- *  Opteron Processors" available for download from www.amd.com
  *
- *  Tables for specific CPUs can be inferred from
- *     http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf

drivers/cpufreq/powernow-k8.c line 30

Quoted 10 lines
drivers/cpufreq/powernow-k8.c +7 -0
+ *  Processor information obtained from Chapter 9 (Power and Thermal
+ *  Management) of the "BIOS and Kernel Developer's Guide (BKDG) for
+ *  the AMD Athlon 64 and AMD Opteron Processors" and section "2.x
+ *  Power Management" in BKDGs for newer AMD CPU families.
+ *
+ *  Tables for specific CPUs can be inferred from AMD's processor
+ *  power and thermal data sheets, (e.g. 30417.pdf, 30430.pdf, 43375.pdf)
  */
 
 #include <linux/kernel.h>

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