tools/power/cpupower: Read energy_perf_bias from sysfs

... instead of poking at the MSR. For that, move the accessor functions
to misc.c and add a sysfs-writing function too.

There should be no functional changes resulting from this.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: Thomas Renninger <trenn@suse.com>
Link: https://lkml.kernel.org/r/20201029190259.3476-2-bp@alien8.de

diff --git a/tools/power/cpupower/lib/cpupower.c b/tools/power/cpupower/lib/cpupower.c
index 3656e69..3f7d0c0 100644 (file)
--- a/tools/power/cpupower/lib/cpupower.c
+++ b/tools/power/cpupower/lib/cpupower.c
@@ -16,8 +16,8 @@
 
 unsigned int cpupower_read_sysfs(const char *path, char *buf, size_t buflen)
 {
-       int fd;
        ssize_t numread;
+       int fd;
 
        fd = open(path, O_RDONLY);
        if (fd == -1)
@@ -35,6 +35,27 @@ unsigned int cpupower_read_sysfs(const char *path, char *buf, size_t buflen)
        return (unsigned int) numread;
 }
 
+unsigned int cpupower_write_sysfs(const char *path, char *buf, size_t buflen)
+{
+       ssize_t numwritten;
+       int fd;
+
+       fd = open(path, O_WRONLY);
+       if (fd == -1)
+               return 0;
+
+       numwritten = write(fd, buf, buflen - 1);
+       if (numwritten < 1) {
+               perror(path);
+               close(fd);
+               return -1;
+       }
+
+       close(fd);
+
+       return (unsigned int) numwritten;
+}
+
 /*
  * Detect whether a CPU is online
  *

diff --git a/tools/power/cpupower/lib/cpupower_intern.h b/tools/power/cpupower/lib/cpupower_intern.h
index 4887c76..ac1112b 100644 (file)
--- a/tools/power/cpupower/lib/cpupower_intern.h
+++ b/tools/power/cpupower/lib/cpupower_intern.h
@@ -1,6 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #define PATH_TO_CPU "/sys/devices/system/cpu/"
+
+#ifndef MAX_LINE_LEN
 #define MAX_LINE_LEN 4096
+#endif
+
 #define SYSFS_PATH_MAX 255
 
 unsigned int cpupower_read_sysfs(const char *path, char *buf, size_t buflen);
+unsigned int cpupower_write_sysfs(const char *path, char *buf, size_t buflen);

diff --git a/tools/power/cpupower/utils/cpupower-info.c b/tools/power/cpupower/utils/cpupower-info.c
index 0ba61a2..06345b5 100644 (file)
--- a/tools/power/cpupower/utils/cpupower-info.c
+++ b/tools/power/cpupower/utils/cpupower-info.c
@@ -101,7 +101,7 @@ int cmd_info(int argc, char **argv)
                }
 
                if (params.perf_bias) {
-                       ret = msr_intel_get_perf_bias(cpu);
+                       ret = cpupower_intel_get_perf_bias(cpu);
                        if (ret < 0) {
                                fprintf(stderr,
                        _("Could not read perf-bias value[%d]\n"), ret);

diff --git a/tools/power/cpupower/utils/cpupower-set.c b/tools/power/cpupower/utils/cpupower-set.c
index 052044d..180d5ba 100644 (file)
--- a/tools/power/cpupower/utils/cpupower-set.c
+++ b/tools/power/cpupower/utils/cpupower-set.c
@@ -95,7 +95,7 @@ int cmd_set(int argc, char **argv)
                }
 
                if (params.perf_bias) {
-                       ret = msr_intel_set_perf_bias(cpu, perf_bias);
+                       ret = cpupower_intel_set_perf_bias(cpu, perf_bias);
                        if (ret) {
                                fprintf(stderr, _("Error setting perf-bias "
                                                  "value on CPU %d\n"), cpu);

diff --git a/tools/power/cpupower/utils/helpers/helpers.h b/tools/power/cpupower/utils/helpers/helpers.h
index c258eec..37dac16 100644 (file)
--- a/tools/power/cpupower/utils/helpers/helpers.h
+++ b/tools/power/cpupower/utils/helpers/helpers.h
@@ -105,8 +105,8 @@ extern struct cpupower_cpu_info cpupower_cpu_info;
 extern int read_msr(int cpu, unsigned int idx, unsigned long long *val);
 extern int write_msr(int cpu, unsigned int idx, unsigned long long val);
 
-extern int msr_intel_set_perf_bias(unsigned int cpu, unsigned int val);
-extern int msr_intel_get_perf_bias(unsigned int cpu);
+extern int cpupower_intel_set_perf_bias(unsigned int cpu, unsigned int val);
+extern int cpupower_intel_get_perf_bias(unsigned int cpu);
 extern unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu);
 
 /* Read/Write msr ****************************/
@@ -150,9 +150,9 @@ static inline int read_msr(int cpu, unsigned int idx, unsigned long long *val)
 { return -1; };
 static inline int write_msr(int cpu, unsigned int idx, unsigned long long val)
 { return -1; };
-static inline int msr_intel_set_perf_bias(unsigned int cpu, unsigned int val)
+static inline int cpupower_intel_set_perf_bias(unsigned int cpu, unsigned int val)
 { return -1; };
-static inline int msr_intel_get_perf_bias(unsigned int cpu)
+static inline int cpupower_intel_get_perf_bias(unsigned int cpu)
 { return -1; };
 static inline unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu)
 { return 0; };

diff --git a/tools/power/cpupower/utils/helpers/misc.c b/tools/power/cpupower/utils/helpers/misc.c
index f406adc..e8f8f64 100644 (file)
--- a/tools/power/cpupower/utils/helpers/misc.c
+++ b/tools/power/cpupower/utils/helpers/misc.c
@@ -1,7 +1,15 @@
 // SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+
 #if defined(__i386__) || defined(__x86_64__)
 
 #include "helpers/helpers.h"
+#include "helpers/sysfs.h"
+
+#include "cpupower_intern.h"
 
 #define MSR_AMD_HWCR   0xc0010015
 
@@ -40,4 +48,44 @@ int cpufreq_has_boost_support(unsigned int cpu, int *support, int *active,
                *support = *active = 1;
        return 0;
 }
+
+int cpupower_intel_get_perf_bias(unsigned int cpu)
+{
+       char linebuf[MAX_LINE_LEN];
+       char path[SYSFS_PATH_MAX];
+       unsigned long val;
+       char *endp;
+
+       if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS))
+               return -1;
+
+       snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/power/energy_perf_bias", cpu);
+
+       if (cpupower_read_sysfs(path, linebuf, MAX_LINE_LEN) == 0)
+               return -1;
+
+       val = strtol(linebuf, &endp, 0);
+       if (endp == linebuf || errno == ERANGE)
+               return -1;
+
+       return val;
+}
+
+int cpupower_intel_set_perf_bias(unsigned int cpu, unsigned int val)
+{
+       char path[SYSFS_PATH_MAX];
+       char linebuf[3] = {};
+
+       if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS))
+               return -1;
+
+       snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/power/energy_perf_bias", cpu);
+       snprintf(linebuf, sizeof(linebuf), "%d", val);
+
+       if (cpupower_write_sysfs(path, linebuf, 3) <= 0)
+               return -1;
+
+       return 0;
+}
+
 #endif /* #if defined(__i386__) || defined(__x86_64__) */

diff --git a/tools/power/cpupower/utils/helpers/msr.c b/tools/power/cpupower/utils/helpers/msr.c
index ab99507..8b0b6be 100644 (file)
--- a/tools/power/cpupower/utils/helpers/msr.c
+++ b/tools/power/cpupower/utils/helpers/msr.c
@@ -11,7 +11,6 @@
 /* Intel specific MSRs */
 #define MSR_IA32_PERF_STATUS           0x198
 #define MSR_IA32_MISC_ENABLES          0x1a0
-#define MSR_IA32_ENERGY_PERF_BIAS      0x1b0
 #define MSR_NEHALEM_TURBO_RATIO_LIMIT  0x1ad
 
 /*
@@ -73,33 +72,6 @@ int write_msr(int cpu, unsigned int idx, unsigned long long val)
        return -1;
 }
 
-int msr_intel_get_perf_bias(unsigned int cpu)
-{
-       unsigned long long val;
-       int ret;
-
-       if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS))
-               return -1;
-
-       ret = read_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &val);
-       if (ret)
-               return ret;
-       return val;
-}
-
-int msr_intel_set_perf_bias(unsigned int cpu, unsigned int val)
-{
-       int ret;
-
-       if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_PERF_BIAS))
-               return -1;
-
-       ret = write_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, val);
-       if (ret)
-               return ret;
-       return 0;
-}
-
 unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu)
 {
        unsigned long long val;