kernel/cpu: add cpu_frequency()

implement on x86 with APERFMPERF.

Change-Id: Ia484854c76dee76c5447983de15800a25d791d39
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3213
Reviewed-by: Jérôme Duval <[email protected]>

headers/private/kernel/arch/system_info.h

@@ -19,6 +19,8 @@ extern "C" {
 
 status_t arch_system_info_init(struct kernel_args *args);
 void arch_fill_topology_node(cpu_topology_node_info* node, int32 cpu);
+status_t arch_get_frequency(uint64 *frequency, int32 cpu);
+
 
 #ifdef __cplusplus
 }

headers/private/kernel/cpu.h

@@ -102,6 +102,7 @@ status_t cpu_init_percpu(struct kernel_args *ka, int curr_cpu);
 status_t cpu_init_post_vm(struct kernel_args *args);
 status_t cpu_init_post_modules(struct kernel_args *args);
 bigtime_t cpu_get_active_time(int32 cpu);
+uint64 cpu_frequency(int32 cpu);
 
 cpu_ent *get_cpu_struct(void);
 extern inline cpu_ent *get_cpu_struct(void) { return &gCPU[smp_get_current_cpu()]; }

src/system/kernel/arch/arm/arch_system_info.cpp

@@ -54,3 +54,12 @@ arch_system_info_init(struct kernel_args *args)
 {
 	return B_OK;
 }
+
+
+status_t
+arch_get_frequency(uint64 *frequency, int32 cpu)
+{
+	*frequency = 0;
+	return B_OK;
+}
+

src/system/kernel/arch/arm64/arch_system_info.cpp

@@ -27,3 +27,11 @@ arch_system_info_init(struct kernel_args *args)
 {
 	return B_OK;
 }
+
+
+status_t
+arch_get_frequency(uint64 *frequency, int32 cpu)
+{
+	*frequency = 0;
+	return B_OK;
+}

src/system/kernel/arch/m68k/arch_system_info.cpp

@@ -57,3 +57,11 @@ arch_system_info_init(struct kernel_args *args)
 	
 	return B_OK;
 }
+
+
+status_t
+arch_get_frequency(uint64 *frequency, int32 cpu)
+{
+	*frequency = sCPUClockFrequency;
+	return B_OK;
+}

src/system/kernel/arch/ppc/arch_system_info.cpp

@@ -110,3 +110,11 @@ arch_system_info_init(struct kernel_args *args)
 
 	return B_OK;
 }
+
+
+status_t
+arch_get_frequency(uint64 *frequency, int32 cpu)
+{
+	*frequency = sCPUClockFrequency;
+	return B_OK;
+}

src/system/kernel/arch/riscv64/arch_system_info.cpp

@@ -33,3 +33,10 @@ arch_system_info_init(struct kernel_args *args)
 	return B_OK;
 }
 
+
+status_t
+arch_get_frequency(uint64 *frequency, int32 cpu)
+{
+	*frequency = sCPUClockFrequency;
+	return B_OK;
+}

src/system/kernel/arch/sparc/arch_system_info.cpp

@@ -33,3 +33,10 @@ arch_system_info_init(struct kernel_args *args)
 	return B_OK;
 }
 
+
+status_t
+arch_get_frequency(uint64 *frequency, int32 cpu)
+{
+	*frequency = sCPUClockFrequency;
+	return B_OK;
+}

src/system/kernel/arch/x86/arch_system_info.cpp

@@ -131,6 +131,38 @@ arch_fill_topology_node(cpu_topology_node_info* node, int32 cpu)
 }
 
 
+static void
+get_frequency_for(void *_frequency, int /*cpu*/)
+{
+	uint64 *frequency = (uint64*)_frequency;
+	uint64 mperf = x86_read_msr(IA32_MSR_MPERF);
+	uint64 aperf = x86_read_msr(IA32_MSR_APERF);
+
+	for (int i = 0; i < 1000; i++)
+		arch_cpu_pause();
+
+	uint64 mperf2 = x86_read_msr(IA32_MSR_MPERF);
+	uint64 aperf2 = x86_read_msr(IA32_MSR_APERF);
+
+	if (mperf2 == mperf)
+		*frequency = 0;
+	else
+		*frequency = (aperf2 - aperf) * sCPUClockSpeed / (mperf2 - mperf);
+}
+
+
+status_t
+arch_get_frequency(uint64 *frequency, int32 cpu)
+{
+	if (x86_check_feature(IA32_FEATURE_APERFMPERF, FEATURE_6_ECX))
+		call_single_cpu_sync(cpu, get_frequency_for, frequency);
+	else
+		*frequency = sCPUClockSpeed;
+
+	return B_OK;
+}
+
+
 //	#pragma mark -
 
 

src/system/kernel/cpu.cpp

@@ -12,6 +12,7 @@
 
 #include <cpu.h>
 #include <arch/cpu.h>
+#include <arch/system_info.h>
 
 #include <string.h>
 
@@ -171,6 +172,17 @@ cpu_get_active_time(int32 cpu)
 }
 
 
+uint64
+cpu_frequency(int32 cpu)
+{
+	if (cpu < 0 || cpu >= smp_get_num_cpus())
+		return 0;
+	uint64 frequency = 0;
+	arch_get_frequency(&frequency, cpu);
+	return frequency;
+}
+
+
 void
 clear_caches(void *address, size_t length, uint32 flags)
 {