[PATCH 0/5] powernow-k8: Core Performance Boost and effective frequency support

[PATCH 0/5] powernow-k8: Core Performance Boost and effective frequency support

[Borislav Petkov]

From: Borislav Petkov <borislav.petkov@amd.com>

Hi all,

here's the reworked version after incorporating most of your comments.

In particular, this version adds a /proc/cpuinfo flag and removes the
scaling_cur_freq interface overload in favor of cpufreq-aperf userspace
tool.

Please review,
thanks.

Changelog:

v0: initial submission


-- 
Regards/Gruss,
Boris.

[PATCH 1/5] x86, cpu: Add AMD core boosting feature flag to /proc/cpuinfo

[Borislav Petkov]

From: Borislav Petkov <borislav.petkov@amd.com>

By semi-popular demand, this adds the Core Performance Boost feature
flag to /proc/cpuinfo. Possible use case for this is userspace tools
like cpufreq-aperf, for example, so that they don't have to jump through
hoops of accessing "/dev/cpu/%d/cpuid" in order to check for CPB hw
support.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 arch/x86/include/asm/cpufeature.h          |    1 +
 arch/x86/kernel/cpu/addon_cpuid_features.c |    5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 0cd82d0..630e623 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -161,6 +161,7 @@
  */
 #define X86_FEATURE_IDA		(7*32+ 0) /* Intel Dynamic Acceleration */
 #define X86_FEATURE_ARAT	(7*32+ 1) /* Always Running APIC Timer */
+#define X86_FEATURE_CPB		(7*32+ 2) /* AMD Core Performance Boost */
 
 /* Virtualization flags: Linux defined */
 #define X86_FEATURE_TPR_SHADOW  (8*32+ 0) /* Intel TPR Shadow */
diff --git a/arch/x86/kernel/cpu/addon_cpuid_features.c b/arch/x86/kernel/cpu/addon_cpuid_features.c
index 97ad79c..ead2a1c 100644
--- a/arch/x86/kernel/cpu/addon_cpuid_features.c
+++ b/arch/x86/kernel/cpu/addon_cpuid_features.c
@@ -30,8 +30,9 @@ void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c)
 	const struct cpuid_bit *cb;
 
 	static const struct cpuid_bit __cpuinitconst cpuid_bits[] = {
-		{ X86_FEATURE_IDA, CR_EAX, 1, 0x00000006 },
-		{ X86_FEATURE_ARAT, CR_EAX, 2, 0x00000006 },
+		{ X86_FEATURE_IDA,   CR_EAX, 1, 0x00000006 },
+		{ X86_FEATURE_ARAT,  CR_EAX, 2, 0x00000006 },
+		{ X86_FEATURE_CPB,   CR_EDX, 9, 0x80000007 },
 		{ X86_FEATURE_NPT,   CR_EDX, 0, 0x8000000a },
 		{ X86_FEATURE_LBRV,  CR_EDX, 1, 0x8000000a },
 		{ X86_FEATURE_SVML,  CR_EDX, 2, 0x8000000a },
-- 
1.7.0

[PATCH 2/5] powernow-k8: Add core performance boost support

[Borislav Petkov]

From: Borislav Petkov <borislav.petkov@amd.com>

Starting with F10h, revE, AMD processors add support for a dynamic
core boosting feature called Core Performance Boost. When a specific
condition is present, a subset of the cores on a system are boosted
beyond their P0 operating frequency to speed up the performance of
single-threaded applications.

In the normal case, the system comes out of reset with core boosting
enabled. This patch adds a sysfs knob with which core boosting can be
switched on or off for benchmarking purposes.

While at it, cleanup the driver init codepath and update copyrights.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 arch/x86/kernel/cpu/cpufreq/powernow-k8.c |  110 ++++++++++++++++++++++++++---
 arch/x86/kernel/cpu/cpufreq/powernow-k8.h |    2 -
 2 files changed, 100 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index d360b56..b86daa6 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -1,6 +1,5 @@
-
 /*
- *   (c) 2003-2006 Advanced Micro Devices, Inc.
+ *   (c) 2003-2010 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
@@ -54,6 +53,10 @@ static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
 
 static int cpu_family = CPU_OPTERON;
 
+/* core performance boost */
+static bool cpb_capable, cpb_enabled;
+static struct msr __percpu *msrs;
+
 #ifndef CONFIG_SMP
 static inline const struct cpumask *cpu_core_mask(int cpu)
 {
@@ -1393,8 +1396,73 @@ out:
 	return khz;
 }
 
+static void _cpb_toggle_msrs(bool t)
+{
+	int cpu;
+
+	rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
+
+	for_each_cpu(cpu, cpu_online_mask) {
+		struct msr *reg = per_cpu_ptr(msrs, cpu);
+		if (t)
+			reg->l &= ~BIT(25);
+		else
+			reg->l |= BIT(25);
+	}
+	wrmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
+}
+
+/*
+ * Switch on/off core performance boosting.
+ *
+ * 0=disable
+ * 1=enable.
+ */
+static void cpb_toggle(bool t)
+{
+	if (!cpb_capable)
+		return;
+
+	if (t && !cpb_enabled) {
+		cpb_enabled = true;
+		_cpb_toggle_msrs(t);
+		printk(KERN_INFO PFX "Core Boosting enabled.\n");
+	} else if (!t && cpb_enabled) {
+		cpb_enabled = false;
+		_cpb_toggle_msrs(t);
+		printk(KERN_INFO PFX "Core Boosting disabled.\n");
+	}
+}
+
+static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
+				 size_t count)
+{
+	int ret = -EINVAL;
+	unsigned long val = 0;
+
+	ret = strict_strtoul(buf, 10, &val);
+	if (!ret && (val == 0 || val == 1) && cpb_capable)
+		cpb_toggle(val);
+	else
+		return -EINVAL;
+
+	return count;
+}
+
+static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
+{
+	return sprintf(buf, "%u\n", cpb_enabled);
+}
+
+#define define_one_rw(_name) \
+static struct freq_attr _name = \
+__ATTR(_name, 0644, show_##_name, store_##_name)
+
+define_one_rw(cpb);
+
 static struct freq_attr *powernow_k8_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
+	&cpb,
 	NULL,
 };
 
@@ -1413,7 +1481,7 @@ static struct cpufreq_driver cpufreq_amd64_driver = {
 /* driver entry point for init */
 static int __cpuinit powernowk8_init(void)
 {
-	unsigned int i, supported_cpus = 0;
+	unsigned int i, supported_cpus = 0, cpu;
 
 	for_each_online_cpu(i) {
 		int rc;
@@ -1422,15 +1490,34 @@ static int __cpuinit powernowk8_init(void)
 			supported_cpus++;
 	}
 
-	if (supported_cpus == num_online_cpus()) {
-		printk(KERN_INFO PFX "Found %d %s "
-			"processors (%d cpu cores) (" VERSION ")\n",
-			num_online_nodes(),
-			boot_cpu_data.x86_model_id, supported_cpus);
-		return cpufreq_register_driver(&cpufreq_amd64_driver);
+	if (supported_cpus != num_online_cpus())
+		return -ENODEV;
+
+	printk(KERN_INFO PFX "Found %d %s (%d cpu cores) (" VERSION ")\n",
+		num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
+
+	if (boot_cpu_has(X86_FEATURE_CPB)) {
+
+		cpb_capable = true;
+
+		msrs = msrs_alloc();
+		if (!msrs) {
+			printk(KERN_ERR "%s: Error allocating msrs!\n", __func__);
+			return -ENOMEM;
+		}
+
+		rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
+
+		for_each_cpu(cpu, cpu_online_mask) {
+			struct msr *reg = per_cpu_ptr(msrs, cpu);
+			cpb_enabled |= !(!!(reg->l & BIT(25)));
+		}
+
+		printk(KERN_INFO PFX "Core Performance Boosting: %s.\n",
+			(cpb_enabled ? "on" : "off"));
 	}
 
-	return -ENODEV;
+	return cpufreq_register_driver(&cpufreq_amd64_driver);
 }
 
 /* driver entry point for term */
@@ -1438,6 +1525,9 @@ static void __exit powernowk8_exit(void)
 {
 	dprintk("exit\n");
 
+	msrs_free(msrs);
+	msrs = NULL;
+
 	cpufreq_unregister_driver(&cpufreq_amd64_driver);
 }
 
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
index 02ce824..df3529b 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
@@ -5,7 +5,6 @@
  *  http://www.gnu.org/licenses/gpl.html
  */
 
-
 enum pstate {
 	HW_PSTATE_INVALID = 0xff,
 	HW_PSTATE_0 = 0,
@@ -55,7 +54,6 @@ struct powernow_k8_data {
 	struct cpumask *available_cores;
 };
 
-
 /* processor's cpuid instruction support */
 #define CPUID_PROCESSOR_SIGNATURE	1	/* function 1 */
 #define CPUID_XFAM			0x0ff00000	/* extended family */
-- 
1.7.0

[PATCH 3/5] cpufreq: Add APERF/MPERF support for AMD processors

[Borislav Petkov]

From: Mark Langsdorf <mark.langsdorf@amd.com>

Starting with model 10 of Family 0x10, AMD processors may have
support for APERF/MPERF.  Add support for identifying it and using
it within cpufreq.  Move the APERF/MPERF functions out of the
acpi-cpufreq code and into their own file so they can easily be
shared.

Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 arch/x86/kernel/cpu/amd.c                  |    6 +++
 arch/x86/kernel/cpu/cpufreq/Makefile       |    4 +-
 arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c |   44 +-----------------------
 arch/x86/kernel/cpu/cpufreq/mperf.c        |   50 ++++++++++++++++++++++++++++
 arch/x86/kernel/cpu/cpufreq/mperf.h        |    9 +++++
 arch/x86/kernel/cpu/cpufreq/powernow-k8.c  |    8 ++++
 6 files changed, 77 insertions(+), 44 deletions(-)
 create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.c
 create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.h

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index e485825..796f662 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -537,6 +537,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
 	}
 
+	if (c->cpuid_level >= 6) {
+		unsigned ecx = cpuid_ecx(6);
+		if (ecx & 0x01)
+			set_cpu_cap(c, X86_FEATURE_APERFMPERF);
+	}
+
 #ifdef CONFIG_X86_64
 	if (c->x86 == 0x10) {
 		/* do this for boot cpu */
diff --git a/arch/x86/kernel/cpu/cpufreq/Makefile b/arch/x86/kernel/cpu/cpufreq/Makefile
index 1840c0a..bd54bf6 100644
--- a/arch/x86/kernel/cpu/cpufreq/Makefile
+++ b/arch/x86/kernel/cpu/cpufreq/Makefile
@@ -2,8 +2,8 @@
 # K8 systems. ACPI is preferred to all other hardware-specific drivers.
 # speedstep-* is preferred over p4-clockmod.
 
-obj-$(CONFIG_X86_POWERNOW_K8)		+= powernow-k8.o
-obj-$(CONFIG_X86_ACPI_CPUFREQ)		+= acpi-cpufreq.o
+obj-$(CONFIG_X86_POWERNOW_K8)		+= powernow-k8.o mperf.o
+obj-$(CONFIG_X86_ACPI_CPUFREQ)		+= acpi-cpufreq.o mperf.o
 obj-$(CONFIG_X86_PCC_CPUFREQ)		+= pcc-cpufreq.o
 obj-$(CONFIG_X86_POWERNOW_K6)		+= powernow-k6.o
 obj-$(CONFIG_X86_POWERNOW_K7)		+= powernow-k7.o
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 1b1920f..dc68e5c 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -45,6 +45,7 @@
 #include <asm/msr.h>
 #include <asm/processor.h>
 #include <asm/cpufeature.h>
+#include "mperf.h"
 
 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
 		"acpi-cpufreq", msg)
@@ -70,8 +71,6 @@ struct acpi_cpufreq_data {
 
 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
 
-static DEFINE_PER_CPU(struct aperfmperf, acfreq_old_perf);
-
 /* acpi_perf_data is a pointer to percpu data. */
 static struct acpi_processor_performance *acpi_perf_data;
 
@@ -239,45 +238,6 @@ static u32 get_cur_val(const struct cpumask *mask)
 	return cmd.val;
 }
 
-/* Called via smp_call_function_single(), on the target CPU */
-static void read_measured_perf_ctrs(void *_cur)
-{
-	struct aperfmperf *am = _cur;
-
-	get_aperfmperf(am);
-}
-
-/*
- * Return the measured active (C0) frequency on this CPU since last call
- * to this function.
- * Input: cpu number
- * Return: Average CPU frequency in terms of max frequency (zero on error)
- *
- * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
- * over a period of time, while CPU is in C0 state.
- * IA32_MPERF counts at the rate of max advertised frequency
- * IA32_APERF counts at the rate of actual CPU frequency
- * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
- * no meaning should be associated with absolute values of these MSRs.
- */
-static unsigned int get_measured_perf(struct cpufreq_policy *policy,
-				      unsigned int cpu)
-{
-	struct aperfmperf perf;
-	unsigned long ratio;
-	unsigned int retval;
-
-	if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))
-		return 0;
-
-	ratio = calc_aperfmperf_ratio(&per_cpu(acfreq_old_perf, cpu), &perf);
-	per_cpu(acfreq_old_perf, cpu) = perf;
-
-	retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;
-
-	return retval;
-}
-
 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 {
 	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
@@ -701,7 +661,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 
 	/* Check for APERF/MPERF support in hardware */
 	if (cpu_has(c, X86_FEATURE_APERFMPERF))
-		acpi_cpufreq_driver.getavg = get_measured_perf;
+		acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf;
 
 	dprintk("CPU%u - ACPI performance management activated.\n", cpu);
 	for (i = 0; i < perf->state_count; i++)
diff --git a/arch/x86/kernel/cpu/cpufreq/mperf.c b/arch/x86/kernel/cpu/cpufreq/mperf.c
new file mode 100644
index 0000000..bc5a5df
--- /dev/null
+++ b/arch/x86/kernel/cpu/cpufreq/mperf.c
@@ -0,0 +1,50 @@
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/slab.h>
+
+#include "mperf.h"
+
+static DEFINE_PER_CPU(struct aperfmperf, acfreq_old_perf);
+
+/* Called via smp_call_function_single(), on the target CPU */
+static void read_measured_perf_ctrs(void *_cur)
+{
+	struct aperfmperf *am = _cur;
+
+	get_aperfmperf(am);
+}
+
+/*
+ * Return the measured active (C0) frequency on this CPU since last call
+ * to this function.
+ * Input: cpu number
+ * Return: Average CPU frequency in terms of max frequency (zero on error)
+ *
+ * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
+ * over a period of time, while CPU is in C0 state.
+ * IA32_MPERF counts at the rate of max advertised frequency
+ * IA32_APERF counts at the rate of actual CPU frequency
+ * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
+ * no meaning should be associated with absolute values of these MSRs.
+ */
+unsigned int cpufreq_get_measured_perf(struct cpufreq_policy *policy,
+					unsigned int cpu)
+{
+	struct aperfmperf perf;
+	unsigned long ratio;
+	unsigned int retval;
+
+	if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))
+		return 0;
+
+	ratio = calc_aperfmperf_ratio(&per_cpu(acfreq_old_perf, cpu), &perf);
+	per_cpu(acfreq_old_perf, cpu) = perf;
+
+	retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;
+
+	return retval;
+}
+EXPORT_SYMBOL_GPL(cpufreq_get_measured_perf);
diff --git a/arch/x86/kernel/cpu/cpufreq/mperf.h b/arch/x86/kernel/cpu/cpufreq/mperf.h
new file mode 100644
index 0000000..5dbf295
--- /dev/null
+++ b/arch/x86/kernel/cpu/cpufreq/mperf.h
@@ -0,0 +1,9 @@
+/*
+ *  (c) 2010 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
+ */
+
+unsigned int cpufreq_get_measured_perf(struct cpufreq_policy *policy,
+					unsigned int cpu);
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index b86daa6..1dd292c 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -45,6 +45,7 @@
 #define PFX "powernow-k8: "
 #define VERSION "version 2.20.00"
 #include "powernow-k8.h"
+#include "mperf.h"
 
 /* serialize freq changes  */
 static DEFINE_MUTEX(fidvid_mutex);
@@ -57,6 +58,8 @@ static int cpu_family = CPU_OPTERON;
 static bool cpb_capable, cpb_enabled;
 static struct msr __percpu *msrs;
 
+static struct cpufreq_driver cpufreq_amd64_driver;
+
 #ifndef CONFIG_SMP
 static inline const struct cpumask *cpu_core_mask(int cpu)
 {
@@ -1251,6 +1254,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
 	struct powernow_k8_data *data;
 	struct init_on_cpu init_on_cpu;
 	int rc;
+	struct cpuinfo_x86 *c = &cpu_data(pol->cpu);
 
 	if (!cpu_online(pol->cpu))
 		return -ENODEV;
@@ -1325,6 +1329,10 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
 		return -EINVAL;
 	}
 
+	/* Check for APERF/MPERF support in hardware */
+	if (cpu_has(c, X86_FEATURE_APERFMPERF))
+		cpufreq_amd64_driver.getavg = cpufreq_get_measured_perf;
+
 	cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);
 
 	if (cpu_family == CPU_HW_PSTATE)
-- 
1.7.0

[PATCH 4/5] powernow-k8: Fix frequency reporting

[Borislav Petkov]

From: Mark Langsdorf <mark.langsdorf@amd.com>

With F10, model 10, all valid frequencies are in the ACPI _PST table.

Cc: <stable@kernel.org> # 33.x 32.x
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 arch/x86/kernel/cpu/cpufreq/powernow-k8.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index 1dd292c..317db7b 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -935,7 +935,8 @@ static int fill_powernow_table_pstate(struct powernow_k8_data *data,
 		powernow_table[i].index = index;
 
 		/* Frequency may be rounded for these */
-		if (boot_cpu_data.x86 == 0x10 || boot_cpu_data.x86 == 0x11) {
+		if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
+				 || boot_cpu_data.x86 == 0x11) {
 			powernow_table[i].frequency =
 				freq_from_fid_did(lo & 0x3f, (lo >> 6) & 7);
 		} else
-- 
1.7.0

[PATCH 5/5] cpufreq: Unify sysfs attribute definition macros

[Borislav Petkov]

From: Borislav Petkov <borislav.petkov@amd.com>

Multiple modules used to define those which are with identical
functionality and were needlessly replicated among the different cpufreq
drivers. Push them into the header and remove duplication.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 drivers/cpufreq/cpufreq.c              |   40 +++++++++-----------------
 drivers/cpufreq/cpufreq_conservative.c |   48 ++++++++++---------------------
 drivers/cpufreq/cpufreq_ondemand.c     |   40 ++++++++------------------
 include/linux/cpufreq.h                |   30 ++++++++++++++++++++
 4 files changed, 72 insertions(+), 86 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 2d5d575..e02e417 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -662,32 +662,20 @@ static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
 	return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
 }
 
-#define define_one_ro(_name) \
-static struct freq_attr _name = \
-__ATTR(_name, 0444, show_##_name, NULL)
-
-#define define_one_ro0400(_name) \
-static struct freq_attr _name = \
-__ATTR(_name, 0400, show_##_name, NULL)
-
-#define define_one_rw(_name) \
-static struct freq_attr _name = \
-__ATTR(_name, 0644, show_##_name, store_##_name)
-
-define_one_ro0400(cpuinfo_cur_freq);
-define_one_ro(cpuinfo_min_freq);
-define_one_ro(cpuinfo_max_freq);
-define_one_ro(cpuinfo_transition_latency);
-define_one_ro(scaling_available_governors);
-define_one_ro(scaling_driver);
-define_one_ro(scaling_cur_freq);
-define_one_ro(bios_limit);
-define_one_ro(related_cpus);
-define_one_ro(affected_cpus);
-define_one_rw(scaling_min_freq);
-define_one_rw(scaling_max_freq);
-define_one_rw(scaling_governor);
-define_one_rw(scaling_setspeed);
+cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
+cpufreq_freq_attr_ro(cpuinfo_min_freq);
+cpufreq_freq_attr_ro(cpuinfo_max_freq);
+cpufreq_freq_attr_ro(cpuinfo_transition_latency);
+cpufreq_freq_attr_ro(scaling_available_governors);
+cpufreq_freq_attr_ro(scaling_driver);
+cpufreq_freq_attr_ro(scaling_cur_freq);
+cpufreq_freq_attr_ro(bios_limit);
+cpufreq_freq_attr_ro(related_cpus);
+cpufreq_freq_attr_ro(affected_cpus);
+cpufreq_freq_attr_rw(scaling_min_freq);
+cpufreq_freq_attr_rw(scaling_max_freq);
+cpufreq_freq_attr_rw(scaling_governor);
+cpufreq_freq_attr_rw(scaling_setspeed);
 
 static struct attribute *default_attrs[] = {
 	&cpuinfo_min_freq.attr,
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 599a40b..ce5248e 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -178,12 +178,8 @@ static ssize_t show_sampling_rate_min(struct kobject *kobj,
 	return sprintf(buf, "%u\n", min_sampling_rate);
 }
 
-#define define_one_ro(_name)		\
-static struct global_attr _name =	\
-__ATTR(_name, 0444, show_##_name, NULL)
-
-define_one_ro(sampling_rate_max);
-define_one_ro(sampling_rate_min);
+define_one_global_ro(sampling_rate_max);
+define_one_global_ro(sampling_rate_min);
 
 /* cpufreq_conservative Governor Tunables */
 #define show_one(file_name, object)					\
@@ -221,12 +217,8 @@ show_one_old(freq_step);
 show_one_old(sampling_rate_min);
 show_one_old(sampling_rate_max);
 
-#define define_one_ro_old(object, _name)	\
-static struct freq_attr object =		\
-__ATTR(_name, 0444, show_##_name##_old, NULL)
-
-define_one_ro_old(sampling_rate_min_old, sampling_rate_min);
-define_one_ro_old(sampling_rate_max_old, sampling_rate_max);
+cpufreq_freq_attr_ro_old(sampling_rate_min);
+cpufreq_freq_attr_ro_old(sampling_rate_max);
 
 /*** delete after deprecation time ***/
 
@@ -364,16 +356,12 @@ static ssize_t store_freq_step(struct kobject *a, struct attribute *b,
 	return count;
 }
 
-#define define_one_rw(_name) \
-static struct global_attr _name = \
-__ATTR(_name, 0644, show_##_name, store_##_name)
-
-define_one_rw(sampling_rate);
-define_one_rw(sampling_down_factor);
-define_one_rw(up_threshold);
-define_one_rw(down_threshold);
-define_one_rw(ignore_nice_load);
-define_one_rw(freq_step);
+define_one_global_rw(sampling_rate);
+define_one_global_rw(sampling_down_factor);
+define_one_global_rw(up_threshold);
+define_one_global_rw(down_threshold);
+define_one_global_rw(ignore_nice_load);
+define_one_global_rw(freq_step);
 
 static struct attribute *dbs_attributes[] = {
 	&sampling_rate_max.attr,
@@ -409,16 +397,12 @@ write_one_old(down_threshold);
 write_one_old(ignore_nice_load);
 write_one_old(freq_step);
 
-#define define_one_rw_old(object, _name)	\
-static struct freq_attr object =		\
-__ATTR(_name, 0644, show_##_name##_old, store_##_name##_old)
-
-define_one_rw_old(sampling_rate_old, sampling_rate);
-define_one_rw_old(sampling_down_factor_old, sampling_down_factor);
-define_one_rw_old(up_threshold_old, up_threshold);
-define_one_rw_old(down_threshold_old, down_threshold);
-define_one_rw_old(ignore_nice_load_old, ignore_nice_load);
-define_one_rw_old(freq_step_old, freq_step);
+cpufreq_freq_attr_rw_old(sampling_rate);
+cpufreq_freq_attr_rw_old(sampling_down_factor);
+cpufreq_freq_attr_rw_old(up_threshold);
+cpufreq_freq_attr_rw_old(down_threshold);
+cpufreq_freq_attr_rw_old(ignore_nice_load);
+cpufreq_freq_attr_rw_old(freq_step);
 
 static struct attribute *dbs_attributes_old[] = {
 	&sampling_rate_max_old.attr,
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index bd444dc..c00b25f 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -234,12 +234,8 @@ static ssize_t show_sampling_rate_min(struct kobject *kobj,
 	return sprintf(buf, "%u\n", min_sampling_rate);
 }
 
-#define define_one_ro(_name)		\
-static struct global_attr _name =	\
-__ATTR(_name, 0444, show_##_name, NULL)
-
-define_one_ro(sampling_rate_max);
-define_one_ro(sampling_rate_min);
+define_one_global_ro(sampling_rate_max);
+define_one_global_ro(sampling_rate_min);
 
 /* cpufreq_ondemand Governor Tunables */
 #define show_one(file_name, object)					\
@@ -274,12 +270,8 @@ show_one_old(powersave_bias);
 show_one_old(sampling_rate_min);
 show_one_old(sampling_rate_max);
 
-#define define_one_ro_old(object, _name)       \
-static struct freq_attr object =               \
-__ATTR(_name, 0444, show_##_name##_old, NULL)
-
-define_one_ro_old(sampling_rate_min_old, sampling_rate_min);
-define_one_ro_old(sampling_rate_max_old, sampling_rate_max);
+cpufreq_freq_attr_ro_old(sampling_rate_min);
+cpufreq_freq_attr_ro_old(sampling_rate_max);
 
 /*** delete after deprecation time ***/
 
@@ -376,14 +368,10 @@ static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b,
 	return count;
 }
 
-#define define_one_rw(_name) \
-static struct global_attr _name = \
-__ATTR(_name, 0644, show_##_name, store_##_name)
-
-define_one_rw(sampling_rate);
-define_one_rw(up_threshold);
-define_one_rw(ignore_nice_load);
-define_one_rw(powersave_bias);
+define_one_global_rw(sampling_rate);
+define_one_global_rw(up_threshold);
+define_one_global_rw(ignore_nice_load);
+define_one_global_rw(powersave_bias);
 
 static struct attribute *dbs_attributes[] = {
 	&sampling_rate_max.attr,
@@ -415,14 +403,10 @@ write_one_old(up_threshold);
 write_one_old(ignore_nice_load);
 write_one_old(powersave_bias);
 
-#define define_one_rw_old(object, _name)       \
-static struct freq_attr object =               \
-__ATTR(_name, 0644, show_##_name##_old, store_##_name##_old)
-
-define_one_rw_old(sampling_rate_old, sampling_rate);
-define_one_rw_old(up_threshold_old, up_threshold);
-define_one_rw_old(ignore_nice_load_old, ignore_nice_load);
-define_one_rw_old(powersave_bias_old, powersave_bias);
+cpufreq_freq_attr_rw_old(sampling_rate);
+cpufreq_freq_attr_rw_old(up_threshold);
+cpufreq_freq_attr_rw_old(ignore_nice_load);
+cpufreq_freq_attr_rw_old(powersave_bias);
 
 static struct attribute *dbs_attributes_old[] = {
        &sampling_rate_max_old.attr,
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 4de02b1..9f15150 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -278,6 +278,27 @@ struct freq_attr {
 	ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 };
 
+#define cpufreq_freq_attr_ro(_name)		\
+static struct freq_attr _name =			\
+__ATTR(_name, 0444, show_##_name, NULL)
+
+#define cpufreq_freq_attr_ro_perm(_name, _perm)	\
+static struct freq_attr _name =			\
+__ATTR(_name, _perm, show_##_name, NULL)
+
+#define cpufreq_freq_attr_ro_old(_name)		\
+static struct freq_attr _name##_old =		\
+__ATTR(_name, 0444, show_##_name##_old, NULL)
+
+#define cpufreq_freq_attr_rw(_name)		\
+static struct freq_attr _name =			\
+__ATTR(_name, 0644, show_##_name, store_##_name)
+
+#define cpufreq_freq_attr_rw_old(_name)		\
+static struct freq_attr _name##_old =		\
+__ATTR(_name, 0644, show_##_name##_old, store_##_name##_old)
+
+
 struct global_attr {
 	struct attribute attr;
 	ssize_t (*show)(struct kobject *kobj,
@@ -286,6 +307,15 @@ struct global_attr {
 			 const char *c, size_t count);
 };
 
+#define define_one_global_ro(_name)		\
+static struct global_attr _name =		\
+__ATTR(_name, 0444, show_##_name, NULL)
+
+#define define_one_global_rw(_name)		\
+static struct global_attr _name =		\
+__ATTR(_name, 0644, show_##_name, store_##_name)
+
+
 /*********************************************************************
  *                        CPUFREQ 2.6. INTERFACE                     *
  *********************************************************************/
-- 
1.7.0

Re: [PATCH 3/5] cpufreq: Add APERF/MPERF support for AMD processors

[Thomas Renninger]

On Wednesday 24 March 2010 18:46:21 Borislav Petkov wrote:
> From: Mark Langsdorf <mark.langsdorf@amd.com>
> 
> Starting with model 10 of Family 0x10, AMD processors may have
> support for APERF/MPERF.  Add support for identifying it and using
> it within cpufreq.  Move the APERF/MPERF functions out of the
> acpi-cpufreq code and into their own file so they can easily be
> shared.
> 
> Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
> ---
>  arch/x86/kernel/cpu/amd.c                  |    6 +++
>  arch/x86/kernel/cpu/cpufreq/Makefile       |    4 +-
>  arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c |   44 +-----------------------
>  arch/x86/kernel/cpu/cpufreq/mperf.c        |   50 ++++++++++++++++++++++++++++
>  arch/x86/kernel/cpu/cpufreq/mperf.h        |    9 +++++
>  arch/x86/kernel/cpu/cpufreq/powernow-k8.c  |    8 ++++
>  6 files changed, 77 insertions(+), 44 deletions(-)
>  create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.c
>  create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.h
> 
> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> index e485825..796f662 100644
> --- a/arch/x86/kernel/cpu/amd.c
> +++ b/arch/x86/kernel/cpu/amd.c
> @@ -537,6 +537,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
>  		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
>  	}
>  
> +	if (c->cpuid_level >= 6) {
> +		unsigned ecx = cpuid_ecx(6);
> +		if (ecx & 0x01)
> +			set_cpu_cap(c, X86_FEATURE_APERFMPERF);
> +	}
> +
Can you put this into:
arch/x86/kernel/cpu/common.c (or wherever it fits in general x86 cpu init code)
and remove this (arch/x86/kernel/cpu/intel.c):
        if (c->cpuid_level > 6) {
                unsigned ecx = cpuid_ecx(6);
                if (ecx & 0x01)
                        set_cpu_cap(c, X86_FEATURE_APERFMPERF);
        }

an x86 maintainer might want to double check, but I expect this should work
for all x86 machines?

    Thomas

Re: [PATCH 0/5] powernow-k8: Core Performance Boost and effective frequency support

[Thomas Renninger]

On Wednesday 24 March 2010 18:46:18 Borislav Petkov wrote:
> From: Borislav Petkov <borislav.petkov@amd.com>
> 
> Hi all,
> 
> here's the reworked version after incorporating most of your comments.
> 
> In particular, this version adds a /proc/cpuinfo flag and removes the
> scaling_cur_freq interface overload in favor of cpufreq-aperf userspace
> tool.
> 
> Please review,
Beside the one (Intel/AMD) duplicate APERF/MPERF cpuid check which
I expect can get unified, looks fine to me.

Thanks,

    Thomas

Re: [PATCH 3/5] cpufreq: Add APERF/MPERF support for AMD processors

[Borislav Petkov]

From: Thomas Renninger <trenn@suse.de>
Date: Thu, Mar 25, 2010 at 10:43:04AM +0100

Hi Thomas,

> On Wednesday 24 March 2010 18:46:21 Borislav Petkov wrote:
> > From: Mark Langsdorf <mark.langsdorf@amd.com>
> > 
> > Starting with model 10 of Family 0x10, AMD processors may have
> > support for APERF/MPERF.  Add support for identifying it and using
> > it within cpufreq.  Move the APERF/MPERF functions out of the
> > acpi-cpufreq code and into their own file so they can easily be
> > shared.
> > 
> > Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
> > Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
> > ---
> >  arch/x86/kernel/cpu/amd.c                  |    6 +++
> >  arch/x86/kernel/cpu/cpufreq/Makefile       |    4 +-
> >  arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c |   44 +-----------------------
> >  arch/x86/kernel/cpu/cpufreq/mperf.c        |   50 ++++++++++++++++++++++++++++
> >  arch/x86/kernel/cpu/cpufreq/mperf.h        |    9 +++++
> >  arch/x86/kernel/cpu/cpufreq/powernow-k8.c  |    8 ++++
> >  6 files changed, 77 insertions(+), 44 deletions(-)
> >  create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.c
> >  create mode 100644 arch/x86/kernel/cpu/cpufreq/mperf.h
> > 
> > diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> > index e485825..796f662 100644
> > --- a/arch/x86/kernel/cpu/amd.c
> > +++ b/arch/x86/kernel/cpu/amd.c
> > @@ -537,6 +537,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
> >  		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
> >  	}
> >  
> > +	if (c->cpuid_level >= 6) {
> > +		unsigned ecx = cpuid_ecx(6);
> > +		if (ecx & 0x01)
> > +			set_cpu_cap(c, X86_FEATURE_APERFMPERF);
> > +	}
> > +
> Can you put this into:
> arch/x86/kernel/cpu/common.c (or wherever it fits in general x86 cpu init code)
> and remove this (arch/x86/kernel/cpu/intel.c):
>         if (c->cpuid_level > 6) {
>                 unsigned ecx = cpuid_ecx(6);
>                 if (ecx & 0x01)
>                         set_cpu_cap(c, X86_FEATURE_APERFMPERF);
>         }
> 
> an x86 maintainer might want to double check, but I expect this should work
> for all x86 machines?

Yes, it should. However, there's the remote, far-fetched possibility
that other x86 vendors besides AMD and Intel, might have/plan to have
CPUID, base function 6, ECX[1] defined as a completely different feature
flag. And then it becomes ugly.

Besides, this is, strictly speaking, not x86 generic code but AMD- and
Intel-generic (huh, is there something like that? :)) code.

So, IMO, this is a judgement call based on the current settings of the
duplication and bloating levels of the x86 maintainers' filters :)

Let's have some more opinions, please...

Thanks.

-- 
Regards/Gruss,
Boris.

--
Advanced Micro Devices, Inc.
Operating Systems Research Center

Re: [PATCH 3/5] cpufreq: Add APERF/MPERF support for AMD processors

[Valdis.Kletnieks]

[-- Attachment #1: Type: text/plain, Size: 222 bytes --]

On Thu, 25 Mar 2010 10:43:04 BST, Thomas Renninger said:

> > +	if (c->cpuid_level >= 6) {

> and remove this (arch/x86/kernel/cpu/intel.c):
>         if (c->cpuid_level > 6) {

So is > or >= the correct comparator here?


[-- Attachment #2: Type: application/pgp-signature, Size: 227 bytes --]

Re: [PATCH 3/5] cpufreq: Add APERF/MPERF support for AMD processors

[Thomas Renninger]

On Thursday 25 March 2010 08:55:19 pm Valdis.Kletnieks@vt.edu wrote:
> On Thu, 25 Mar 2010 10:43:04 BST, Thomas Renninger said:
> > > +	if (c->cpuid_level >= 6) {
> >
> > and remove this (arch/x86/kernel/cpu/intel.c):
> >         if (c->cpuid_level > 6) {
>
> So is > or >= the correct comparator here?

This one: >= is correct (for both).
I double checked, there is one Intel CPU type
having a cpuid_level of 6, but this would not support aperf/mperf, thus
above is still fine.

The remaining question is what Borislav said:
are there other x86 CPU vendors who could use this differently.
I very much expect there are not.

IMO you should resubmit this one or the whole series with this change
and Dave should just push this in his tree and queue it up, there was enough
time to object.

Thanks,

      Thomas

Re: [PATCH 3/5] cpufreq: Add APERF/MPERF support for AMD processors

[Borislav Petkov]

From: Thomas Renninger <trenn@suse.de>
Date: Thu, Mar 25, 2010 at 09:59:31PM +0100

> On Thursday 25 March 2010 08:55:19 pm Valdis.Kletnieks@vt.edu wrote:
> > On Thu, 25 Mar 2010 10:43:04 BST, Thomas Renninger said:
> > > > +	if (c->cpuid_level >= 6) {
> > >
> > > and remove this (arch/x86/kernel/cpu/intel.c):
> > >         if (c->cpuid_level > 6) {
> >
> > So is > or >= the correct comparator here?
> 
> This one: >= is correct (for both).
> I double checked, there is one Intel CPU type
> having a cpuid_level of 6, but this would not support aperf/mperf, thus
> above is still fine.

Agreed. ">" won't work on machines which have base cpuidlevel == 6 (like
AMD, f.e.)

> The remaining question is what Borislav said:
> are there other x86 CPU vendors who could use this differently.
> I very much expect there are not.
> 
> IMO you should resubmit this one or the whole series with this change

Ok, will do tomorrow.

> and Dave should just push this in his tree and queue it up, there was enough
> time to object.

The problem here is that the patches touch both cpufreq and x86 code.
Hmmm...

-- 
Regards/Gruss,
Boris.

--
Advanced Micro Devices, Inc.
Operating Systems Research Center

Re: [PATCH 2/5] powernow-k8: Add core performance boost support

[Borislav Petkov]

From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Tue, Mar 23, 2010 at 03:47:57PM +0100

> > > If it's a percpu var, isn't it local anyway?
> > 
> > I meant driver-local. So that I don't have to deref even the per_cpu var
> > and thus save some cycles.
> 
> Well, it doesn't seem to be used in any hot path (and if it were, using a
> per-cpu var was better anyway, because of no contention etc.). If it really
> saves some cycles, I'm more than fine with keeping it; still, informing the
> user in /proc/cpuinfo seems like a sensible thing to do.

No, the idea was to do the local caching _in addition_ to advertising it
over /proc/cpuinfo. Let's see what the x86 maintainers think though...

-- 
Regards/Gruss,
Boris.

--
Advanced Micro Devices, Inc.
Operating Systems Research Center

Re: [PATCH 2/5] powernow-k8: Add core performance boost support

[Dominik Brodowski]

Hey Borislav,

On Tue, Mar 23, 2010 at 03:19:34PM +0100, Borislav Petkov wrote:
> From: Dominik Brodowski <linux@dominikbrodowski.net>
> Date: Tue, Mar 23, 2010 at 02:27:37PM +0100
> 
> Hi Dominik,
> 
> > On Tue, Mar 23, 2010 at 12:58:58PM +0100, Borislav Petkov wrote:
> > > > It could already be set in arch/x86/kernel/cpu/amd.c and
> > > > powernow-k8 could use cpu_has(cpu, X86_FEATURE_CPB);
> > > 
> > > I'd still like to cache the cpb_capable value locally instead of getting
> > > x86_cpuinfo percpu var and querying it. Especially if this happens often
> > > and not only at driver init.
> > 
> > If it's a percpu var, isn't it local anyway?
> 
> I meant driver-local. So that I don't have to deref even the per_cpu var
> and thus save some cycles.

Well, it doesn't seem to be used in any hot path (and if it were, using a
per-cpu var was better anyway, because of no contention etc.). If it really
saves some cycles, I'm more than fine with keeping it; still, informing the
user in /proc/cpuinfo seems like a sensible thing to do.

Best,
	Dominik

Re: [PATCH 2/5] powernow-k8: Add core performance boost support

[Borislav Petkov]

From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Tue, Mar 23, 2010 at 02:27:37PM +0100

Hi Dominik,

> On Tue, Mar 23, 2010 at 12:58:58PM +0100, Borislav Petkov wrote:
> > > It could already be set in arch/x86/kernel/cpu/amd.c and
> > > powernow-k8 could use cpu_has(cpu, X86_FEATURE_CPB);
> > 
> > I'd still like to cache the cpb_capable value locally instead of getting
> > x86_cpuinfo percpu var and querying it. Especially if this happens often
> > and not only at driver init.
> 
> If it's a percpu var, isn't it local anyway?

I meant driver-local. So that I don't have to deref even the per_cpu var
and thus save some cycles.

-- 
Regards/Gruss,
Boris.

--
Advanced Micro Devices, Inc.
Operating Systems Research Center

Re: [PATCH 2/5] powernow-k8: Add core performance boost support

[Dominik Brodowski]

Hey,

On Tue, Mar 23, 2010 at 12:58:58PM +0100, Borislav Petkov wrote:
> > It could already be set in arch/x86/kernel/cpu/amd.c and
> > powernow-k8 could use cpu_has(cpu, X86_FEATURE_CPB);
> 
> I'd still like to cache the cpb_capable value locally instead of getting
> x86_cpuinfo percpu var and querying it. Especially if this happens often
> and not only at driver init.

If it's a percpu var, isn't it local anyway?

Best,
	Dominik

Re: [PATCH 2/5] powernow-k8: Add core performance boost support

[Borislav Petkov]

(Adding hpa to Cc)

From: Thomas Renninger <trenn@suse.de>
Date: Tue, Mar 23, 2010 at 12:17:16PM +0100

> > +/* core performance boost */
> > +static bool cpb_capable, cpb_disabled;
> Whatabout using a cpufeature (arch/x86/include/asm/cpufeature.h)
> instead of cpb_capable. Then people could see this feature in 
> /proc/cpuinfo and other code parts could check for it easily if
> needed later.

I don't have a problem with that per se. It's just that /proc/cpuinfo
is a widely used interface and, AFAIR, changing it is not taken that
lightly.

Peter, what do you think?

> It could already be set in arch/x86/kernel/cpu/amd.c and
> powernow-k8 could use cpu_has(cpu, X86_FEATURE_CPB);

I'd still like to cache the cpb_capable value locally instead of getting
x86_cpuinfo percpu var and querying it. Especially if this happens often
and not only at driver init.

> Instead of cpb_disabled, I'd use cpb_enabled. Checking for
> !cpb_disabled whether it's enabled, is ugly to read.

Fair enough, cpb_disabled reflects the bit semantics in the MSR but why
not, don't matter which to me.

[..]

> > +		_cpb_toggle_msrs(t);
> > +		printk(KERN_INFO PFX "Core Boosting enabled.\n");
> Always printk on every toggle?
> That should not happen often and a user might want to get noticed if
> an app does this behind his back -> should be fine w/ or w/o, just not 
> sure whether it's intended.

Well, actually, this should be on by default and the user or an app
shouldn't be fidgeting with it all the time. It's there only for
benchmarking purposes so that you can disable it when you really have
to. But I guess it actually is going to get used if its there so maybe
we should have to rethink our approach. Hmm...

-- 
Regards/Gruss,
Boris.

--
Advanced Micro Devices, Inc.
Operating Systems Research Center

Re: [PATCH 2/5] powernow-k8: Add core performance boost support

[Thomas Renninger]

On Monday 22 March 2010 19:38:38 Borislav Petkov wrote:
> From: Borislav Petkov <borislav.petkov@amd.com>
> 
> Starting with F10h, revE, AMD processors add support for a dynamic
> core boosting feature called Core Performance Boost. When a specific
> condition is present, a subset of the cores on a system are boosted
> beyond their P0 operating frequency to speed up the performance of
> single-threaded applications.
> 
> In the normal case, the system comes out of reset with core boosting
> enabled. This patch adds a sysfs knob with which core boosting can be
> switched on or off for benchmarking purposes.
> 
> While at it, cleanup the driver init codepath and update copyrights.
> 
> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
> ---
>  arch/x86/kernel/cpu/cpufreq/powernow-k8.c |  115 ++++++++++++++++++++++++++---
>  arch/x86/kernel/cpu/cpufreq/powernow-k8.h |    3 +-
>  2 files changed, 106 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
> index d360b56..90fda2c 100644
> --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
> +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
> @@ -1,6 +1,5 @@
> -
>  /*
> - *   (c) 2003-2006 Advanced Micro Devices, Inc.
> + *   (c) 2003-2010 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
> @@ -54,6 +53,10 @@ static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
>  
>  static int cpu_family = CPU_OPTERON;
>  
> +/* core performance boost */
> +static bool cpb_capable, cpb_disabled;
Whatabout using a cpufeature (arch/x86/include/asm/cpufeature.h)
instead of cpb_capable. Then people could see this feature in 
/proc/cpuinfo and other code parts could check for it easily if
needed later.
It could already be set in arch/x86/kernel/cpu/amd.c and
powernow-k8 could use cpu_has(cpu, X86_FEATURE_CPB);

Instead of cpb_disabled, I'd use cpb_enabled. Checking for
!cpb_disabled whether it's enabled, is ugly to read.

> +static struct msr __percpu *msrs;
> +
>  #ifndef CONFIG_SMP
>  static inline const struct cpumask *cpu_core_mask(int cpu)
>  {
> @@ -1393,8 +1396,69 @@ out:
>  	return khz;
>  }
>  
> +static void _cpb_toggle_msrs(bool t)
> +{
> +	int cpu;
> +
> +	rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
> +
> +	for_each_cpu(cpu, cpu_online_mask) {
> +		struct msr *reg = per_cpu_ptr(msrs, cpu);
> +		if (t)
> +			reg->l &= ~BIT(25);
> +		else
> +			reg->l |= BIT(25);
> +	}
> +	wrmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
> +}
> +
> +/*
> + * Switch on/off core performance boosting.
> + *
> + * 0=disable
> + * 1=enable.
> + */
> +static void cpb_toggle(bool t)
> +{
> +	if (!cpb_capable)
> +		return;
> +
> +	if (t && cpb_disabled) {
> +		cpb_disabled = false;
cpb_enabled = true
is better.
> +		_cpb_toggle_msrs(t);
> +		printk(KERN_INFO PFX "Core Boosting enabled.\n");
Always printk on every toggle?
That should not happen often and a user might want to get noticed if
an app does this behind his back -> should be fine w/ or w/o, just not 
sure whether it's intended.

...

     Thomas

[PATCH 2/5] powernow-k8: Add core performance boost support

[Borislav Petkov]

From: Borislav Petkov <borislav.petkov@amd.com>

Starting with F10h, revE, AMD processors add support for a dynamic
core boosting feature called Core Performance Boost. When a specific
condition is present, a subset of the cores on a system are boosted
beyond their P0 operating frequency to speed up the performance of
single-threaded applications.

In the normal case, the system comes out of reset with core boosting
enabled. This patch adds a sysfs knob with which core boosting can be
switched on or off for benchmarking purposes.

While at it, cleanup the driver init codepath and update copyrights.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 arch/x86/kernel/cpu/cpufreq/powernow-k8.c |  115 ++++++++++++++++++++++++++---
 arch/x86/kernel/cpu/cpufreq/powernow-k8.h |    3 +-
 2 files changed, 106 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index d360b56..90fda2c 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -1,6 +1,5 @@
-
 /*
- *   (c) 2003-2006 Advanced Micro Devices, Inc.
+ *   (c) 2003-2010 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
@@ -54,6 +53,10 @@ static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
 
 static int cpu_family = CPU_OPTERON;
 
+/* core performance boost */
+static bool cpb_capable, cpb_disabled;
+static struct msr __percpu *msrs;
+
 #ifndef CONFIG_SMP
 static inline const struct cpumask *cpu_core_mask(int cpu)
 {
@@ -1393,8 +1396,69 @@ out:
 	return khz;
 }
 
+static void _cpb_toggle_msrs(bool t)
+{
+	int cpu;
+
+	rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
+
+	for_each_cpu(cpu, cpu_online_mask) {
+		struct msr *reg = per_cpu_ptr(msrs, cpu);
+		if (t)
+			reg->l &= ~BIT(25);
+		else
+			reg->l |= BIT(25);
+	}
+	wrmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
+}
+
+/*
+ * Switch on/off core performance boosting.
+ *
+ * 0=disable
+ * 1=enable.
+ */
+static void cpb_toggle(bool t)
+{
+	if (!cpb_capable)
+		return;
+
+	if (t && cpb_disabled) {
+		cpb_disabled = false;
+		_cpb_toggle_msrs(t);
+		printk(KERN_INFO PFX "Core Boosting enabled.\n");
+	} else if (!(t || cpb_disabled)) {
+		cpb_disabled = true;
+		_cpb_toggle_msrs(t);
+		printk(KERN_INFO PFX "Core Boosting disabled.\n");
+	}
+}
+
+static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
+				 size_t count)
+{
+	int ret = -EINVAL;
+	unsigned long val = 0;
+
+	ret = strict_strtoul(buf, 10, &val);
+	if (!ret && (val == 0 || val == 1) && cpb_capable)
+		cpb_toggle(val);
+	else
+		return -EINVAL;
+
+	return count;
+}
+
+static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
+{
+	return sprintf(buf, "%u\n", !cpb_disabled);
+}
+
+define_one_freq_rw(cpb);
+
 static struct freq_attr *powernow_k8_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
+	&cpb,
 	NULL,
 };
 
@@ -1410,10 +1474,17 @@ static struct cpufreq_driver cpufreq_amd64_driver = {
 	.attr		= powernow_k8_attr,
 };
 
+static bool __cpuinit check_cpb_capable(void)
+{
+	u32 tmp = cpuid_edx(CPUID_FREQ_VOLT_CAPABILITIES);
+
+	return (tmp & CPB_CAPABLE);
+}
+
 /* driver entry point for init */
 static int __cpuinit powernowk8_init(void)
 {
-	unsigned int i, supported_cpus = 0;
+	unsigned int i, supported_cpus = 0, cpu;
 
 	for_each_online_cpu(i) {
 		int rc;
@@ -1422,15 +1493,36 @@ static int __cpuinit powernowk8_init(void)
 			supported_cpus++;
 	}
 
-	if (supported_cpus == num_online_cpus()) {
-		printk(KERN_INFO PFX "Found %d %s "
-			"processors (%d cpu cores) (" VERSION ")\n",
-			num_online_nodes(),
-			boot_cpu_data.x86_model_id, supported_cpus);
-		return cpufreq_register_driver(&cpufreq_amd64_driver);
+	if (supported_cpus != num_online_cpus())
+		return -ENODEV;
+
+	printk(KERN_INFO PFX "Found %d %s (%d cpu cores) (" VERSION ")\n",
+		num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
+
+	cpb_capable = check_cpb_capable();
+	if (cpb_capable) {
+
+		msrs = msrs_alloc();
+		if (!msrs) {
+			printk(KERN_ERR "%s: Error allocating msrs!\n", __func__);
+			return -ENOMEM;
+		}
+
+		rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
+
+		for_each_cpu(cpu, cpu_online_mask) {
+			struct msr *reg = per_cpu_ptr(msrs, cpu);
+			cpb_disabled |= !!(reg->l & BIT(25));
+		}
+
+		printk(KERN_INFO PFX "Core Performance Boosting: ");
+		if (cpb_disabled)
+			printk(KERN_CONT "off.\n");
+		else
+			printk(KERN_CONT "on.\n");
 	}
 
-	return -ENODEV;
+	return cpufreq_register_driver(&cpufreq_amd64_driver);
 }
 
 /* driver entry point for term */
@@ -1438,6 +1530,9 @@ static void __exit powernowk8_exit(void)
 {
 	dprintk("exit\n");
 
+	msrs_free(msrs);
+	msrs = NULL;
+
 	cpufreq_unregister_driver(&cpufreq_amd64_driver);
 }
 
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
index 02ce824..3be308e 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.h
@@ -5,7 +5,6 @@
  *  http://www.gnu.org/licenses/gpl.html
  */
 
-
 enum pstate {
 	HW_PSTATE_INVALID = 0xff,
 	HW_PSTATE_0 = 0,
@@ -55,7 +54,6 @@ struct powernow_k8_data {
 	struct cpumask *available_cores;
 };
 
-
 /* processor's cpuid instruction support */
 #define CPUID_PROCESSOR_SIGNATURE	1	/* function 1 */
 #define CPUID_XFAM			0x0ff00000	/* extended family */
@@ -67,6 +65,7 @@ struct powernow_k8_data {
 #define CPUID_GET_MAX_CAPABILITIES	0x80000000
 #define CPUID_FREQ_VOLT_CAPABILITIES	0x80000007
 #define P_STATE_TRANSITION_CAPABLE	6
+#define CPB_CAPABLE			0x00000200
 
 /* Model Specific Registers for p-state transitions. MSRs are 64-bit. For     */
 /* writes (wrmsr - opcode 0f 30), the register number is placed in ecx, and   */
-- 
1.7.0