diff --git a/src/soc/intel/xeon_sp/cpx/cpu.c b/src/soc/intel/xeon_sp/cpx/cpu.c index 386401f7e3..1df5c1350c 100644 --- a/src/soc/intel/xeon_sp/cpx/cpu.c +++ b/src/soc/intel/xeon_sp/cpx/cpu.c @@ -188,3 +188,34 @@ void cpx_init_cpus(struct device *dev) /* update numa domain for all cpu devices */ xeonsp_init_cpu_config(); } + +msr_t read_msr_ppin(void) +{ + msr_t ppin = {0}; + msr_t msr; + + /* If MSR_PLATFORM_INFO PPIN_CAP is 0, PPIN capability is not supported */ + msr = rdmsr(MSR_PLATFORM_INFO); + if ((msr.lo & MSR_PPIN_CAP) == 0) { + printk(BIOS_ERR, "MSR_PPIN_CAP is 0, PPIN is not supported\n"); + return ppin; + } + + /* Access to MSR_PPIN is permitted only if MSR_PPIN_CTL LOCK is 0 and ENABLE is 1 */ + msr = rdmsr(MSR_PPIN_CTL); + if (msr.lo & MSR_PPIN_CTL_LOCK) { + printk(BIOS_ERR, "MSR_PPIN_CTL_LOCK is 1, PPIN access is not allowed\n"); + return ppin; + } + + if ((msr.lo & MSR_PPIN_CTL_ENABLE) == 0) { + /* Set MSR_PPIN_CTL ENABLE to 1 */ + msr.lo |= MSR_PPIN_CTL_ENABLE; + wrmsr(MSR_PPIN_CTL, msr); + } + ppin = rdmsr(MSR_PPIN); + /* Set enable to 0 after reading MSR_PPIN */ + msr.lo &= ~MSR_PPIN_CTL_ENABLE; + wrmsr(MSR_PPIN_CTL, msr); + return ppin; +} diff --git a/src/soc/intel/xeon_sp/cpx/include/soc/cpu.h b/src/soc/intel/xeon_sp/cpx/include/soc/cpu.h index 2d1269949c..14580004d0 100644 --- a/src/soc/intel/xeon_sp/cpx/include/soc/cpu.h +++ b/src/soc/intel/xeon_sp/cpx/include/soc/cpu.h @@ -4,6 +4,7 @@ #define _SOC_CPU_H #include +#include #define CPUID_COOPERLAKE_SP_A0 0x05065a @@ -11,5 +12,6 @@ #define CPU_BCLK 100 void cpx_init_cpus(struct device *dev); +msr_t read_msr_ppin(void); #endif diff --git a/src/soc/intel/xeon_sp/skx/cpu.c b/src/soc/intel/xeon_sp/skx/cpu.c index f97c37da08..c59edab0bb 100644 --- a/src/soc/intel/xeon_sp/skx/cpu.c +++ b/src/soc/intel/xeon_sp/skx/cpu.c @@ -244,3 +244,34 @@ void xeon_sp_init_cpus(struct device *dev) FUNC_EXIT(); } + +msr_t read_msr_ppin(void) +{ + msr_t ppin = {0}; + msr_t msr; + + /* If MSR_PLATFORM_INFO PPIN_CAP is 0, PPIN capability is not supported */ + msr = rdmsr(MSR_PLATFORM_INFO); + if ((msr.lo & MSR_PPIN_CAP) == 0) { + printk(BIOS_ERR, "MSR_PPIN_CAP is 0, PPIN is not supported\n"); + return ppin; + } + + /* Access to MSR_PPIN is permitted only if MSR_PPIN_CTL LOCK is 0 and ENABLE is 1 */ + msr = rdmsr(MSR_PPIN_CTL); + if (msr.lo & MSR_PPIN_CTL_LOCK) { + printk(BIOS_ERR, "MSR_PPIN_CTL_LOCK is 1, PPIN access is not allowed\n"); + return ppin; + } + + if ((msr.lo & MSR_PPIN_CTL_ENABLE) == 0) { + /* Set MSR_PPIN_CTL ENABLE to 1 */ + msr.lo |= MSR_PPIN_CTL_ENABLE; + wrmsr(MSR_PPIN_CTL, msr); + } + ppin = rdmsr(MSR_PPIN); + /* Set enable to 0 after reading MSR_PPIN */ + msr.lo &= ~MSR_PPIN_CTL_ENABLE; + wrmsr(MSR_PPIN_CTL, msr); + return ppin; +} diff --git a/src/soc/intel/xeon_sp/skx/include/soc/cpu.h b/src/soc/intel/xeon_sp/skx/include/soc/cpu.h index 0221c7d057..c2af265b91 100644 --- a/src/soc/intel/xeon_sp/skx/include/soc/cpu.h +++ b/src/soc/intel/xeon_sp/skx/include/soc/cpu.h @@ -4,6 +4,7 @@ #define _SOC_CPU_H_ #include +#include /* SKXSP CPUID */ #define CPUID_SKYLAKE_SP_A0_A1 0x506f0 @@ -15,5 +16,6 @@ int get_cpu_count(void); void xeon_sp_init_cpus(struct device *dev); +msr_t read_msr_ppin(void); #endif