acpi-cpufreq: Add support for modern AMD CPUs

The programming model for P-states on modern AMD CPUs is very similar to
that of Intel and VIA. It makes sense to consolidate this support into one
driver rather than duplicating functionality between two of them. This
patch adds support for AMDs with hardware P-state control to acpi-cpufreq.

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>

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 957ec87385afe0c5c53fbac8afac109e75c374d5..1e1f3eb58638272090174f3d8617e781d99c019f 100644 (file)
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -248,6 +248,8 @@
 
 #define MSR_IA32_PERF_STATUS           0x00000198
 #define MSR_IA32_PERF_CTL              0x00000199
+#define MSR_AMD_PERF_STATUS            0xc0010063
+#define MSR_AMD_PERF_CTL               0xc0010062
 
 #define MSR_IA32_MPERF                 0x000000e7
 #define MSR_IA32_APERF                 0x000000e8

diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index 78ff7ee48951b6d6d488f0da4d40e47929608f24..8d12e378a7efad6d1a05b73b1b3c4d8ddd334711 100644 (file)
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -23,7 +23,8 @@ config X86_ACPI_CPUFREQ
        help
          This driver adds a CPUFreq driver which utilizes the ACPI
          Processor Performance States.
-         This driver also supports Intel Enhanced Speedstep.
+         This driver also supports Intel Enhanced Speedstep and newer
+         AMD CPUs.
 
          To compile this driver as a module, choose M here: the
          module will be called acpi-cpufreq.

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 56c6c6b4eb4d61043bfdd9b61a95e71ee34f424a..067a61f06bb5dd075300b6d159104cac03506f9a 100644 (file)
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -54,10 +54,12 @@ MODULE_LICENSE("GPL");
 enum {
        UNDEFINED_CAPABLE = 0,
        SYSTEM_INTEL_MSR_CAPABLE,
+       SYSTEM_AMD_MSR_CAPABLE,
        SYSTEM_IO_CAPABLE,
 };
 
 #define INTEL_MSR_RANGE                (0xffff)
+#define AMD_MSR_RANGE          (0x7)
 
 struct acpi_cpufreq_data {
        struct acpi_processor_performance *acpi_data;
@@ -82,6 +84,13 @@ static int check_est_cpu(unsigned int cpuid)
        return cpu_has(cpu, X86_FEATURE_EST);
 }
 
+static int check_amd_hwpstate_cpu(unsigned int cpuid)
+{
+       struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
+
+       return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
+}
+
 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
 {
        struct acpi_processor_performance *perf;
@@ -101,7 +110,11 @@ static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
        int i;
        struct acpi_processor_performance *perf;
 
-       msr &= INTEL_MSR_RANGE;
+       if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+               msr &= AMD_MSR_RANGE;
+       else
+               msr &= INTEL_MSR_RANGE;
+
        perf = data->acpi_data;
 
        for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
@@ -115,6 +128,7 @@ static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
 {
        switch (data->cpu_feature) {
        case SYSTEM_INTEL_MSR_CAPABLE:
+       case SYSTEM_AMD_MSR_CAPABLE:
                return extract_msr(val, data);
        case SYSTEM_IO_CAPABLE:
                return extract_io(val, data);
@@ -150,6 +164,7 @@ static void do_drv_read(void *_cmd)
 
        switch (cmd->type) {
        case SYSTEM_INTEL_MSR_CAPABLE:
+       case SYSTEM_AMD_MSR_CAPABLE:
                rdmsr(cmd->addr.msr.reg, cmd->val, h);
                break;
        case SYSTEM_IO_CAPABLE:
@@ -174,6 +189,9 @@ static void do_drv_write(void *_cmd)
                lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
                wrmsr(cmd->addr.msr.reg, lo, hi);
                break;
+       case SYSTEM_AMD_MSR_CAPABLE:
+               wrmsr(cmd->addr.msr.reg, cmd->val, 0);
+               break;
        case SYSTEM_IO_CAPABLE:
                acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
                                cmd->val,
@@ -217,6 +235,10 @@ static u32 get_cur_val(const struct cpumask *mask)
                cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
                cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
                break;
+       case SYSTEM_AMD_MSR_CAPABLE:
+               cmd.type = SYSTEM_AMD_MSR_CAPABLE;
+               cmd.addr.msr.reg = MSR_AMD_PERF_STATUS;
+               break;
        case SYSTEM_IO_CAPABLE:
                cmd.type = SYSTEM_IO_CAPABLE;
                perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
@@ -326,6 +348,11 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
                cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
                cmd.val = (u32) perf->states[next_perf_state].control;
                break;
+       case SYSTEM_AMD_MSR_CAPABLE:
+               cmd.type = SYSTEM_AMD_MSR_CAPABLE;
+               cmd.addr.msr.reg = MSR_AMD_PERF_CTL;
+               cmd.val = (u32) perf->states[next_perf_state].control;
+               break;
        case SYSTEM_IO_CAPABLE:
                cmd.type = SYSTEM_IO_CAPABLE;
                cmd.addr.io.port = perf->control_register.address;
@@ -580,12 +607,16 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
                break;
        case ACPI_ADR_SPACE_FIXED_HARDWARE:
                pr_debug("HARDWARE addr space\n");
-               if (!check_est_cpu(cpu)) {
-                       result = -ENODEV;
-                       goto err_unreg;
+               if (check_est_cpu(cpu)) {
+                       data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
+                       break;
                }
-               data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
-               break;
+               if (check_amd_hwpstate_cpu(cpu)) {
+                       data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
+                       break;
+               }
+               result = -ENODEV;
+               goto err_unreg;
        default:
                pr_debug("Unknown addr space %d\n",
                        (u32) (perf->control_register.space_id));