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RDMSR: fix last P-state calculation with AMD CPUs

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Xorg 2017-03-04 16:40:46 +01:00
parent 6ae7e344be
commit e5193b0163
1 changed files with 27 additions and 14 deletions
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39
libcpuid/rdmsr.c
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@ -699,10 +699,30 @@ static int get_amd_multipliers(struct msr_info_t *info, uint32_t pstate, uint64_
return err;
}
static uint32_t get_amd_last_pstate_addr(struct msr_info_t *info)
{
static uint32_t last_addr = 0x0;
uint64_t reg = 0x0;
/* The result is cached, need to be computed once */
if(last_addr != 0x0)
return last_addr;
/* Refer links above
MSRC001_00[6B:64][63] is PstateEn
PstateEn indicates if the rest of the P-state information in the register is valid after a reset */
last_addr = MSR_PSTATE_7 + 1;
while((reg == 0x0) && (last_addr > MSR_PSTATE_0)) {
last_addr--;
cpu_rdmsr_range(info->handle, last_addr, 63, 63, &reg);
}
return last_addr;
}
static double get_info_min_multiplier(struct msr_info_t *info)
{
int err;
uint32_t addr = MSR_PSTATE_7 + 1;
uint32_t addr;
uint64_t reg;
if(info->id->vendor == VENDOR_INTEL) {
@ -722,12 +742,8 @@ static double get_info_min_multiplier(struct msr_info_t *info)
}
else if(info->id->vendor == VENDOR_AMD) {
/* N.B.: Find the last P-state
MSRC001_00[6B:64][8:0] is { CpuDid, CpuFid }
If all bits are 0 in a given P-state, we can consider the P-state is unused */
do {
addr--;
cpu_rdmsr_range(info->handle, addr, 8, 0, &reg);
} while((reg == 0x0) && (addr > MSR_PSTATE_0));
get_amd_last_pstate_addr() returns the last P-state, MSR_PSTATE_0 <= addr <= MSR_PSTATE_7 */
addr = get_amd_last_pstate_addr(info);
err = get_amd_multipliers(info, addr, &reg);
if (!err) return (double) reg;
}
@ -858,7 +874,7 @@ static double get_info_voltage(struct msr_info_t *info)
static double get_info_bus_clock(struct msr_info_t *info)
{
int err;
uint32_t addr = MSR_PSTATE_7 + 1;
uint32_t addr;
uint64_t reg;
if(info->id->vendor == VENDOR_INTEL) {
@ -878,12 +894,9 @@ static double get_info_bus_clock(struct msr_info_t *info)
/* Refer links above
MSRC001_0061[6:4] is PstateMaxVal
PstateMaxVal is the the lowest-performance non-boosted P-state */
do {
addr--;
cpu_rdmsr_range(info->handle, addr, 8, 0, &reg);
} while((reg == 0x0) && (addr > MSR_PSTATE_0));
addr = get_amd_last_pstate_addr(info);
err = cpu_rdmsr_range(info->handle, MSR_PSTATE_L, 6, 4, &reg);
err += get_amd_multipliers(info, MSR_PSTATE_0 + (addr - MSR_PSTATE_0 - (uint32_t) reg), &reg);
err += get_amd_multipliers(info, addr - reg, &reg);
if (!err) return (double) info->cpu_clock / reg;
}