Philipp Deppenwiese has submitted this change. ( https://review.coreboot.org/c/coreboot/+/42901 )
Change subject: soc/intel/xeon_sp: Add read CPU PPIN MSR function ......................................................................
soc/intel/xeon_sp: Add read CPU PPIN MSR function
These changes are in accordance with the documentation: [*] page 208-209 Intel(R) 64 and IA-32 Architectures, Software Developer’s Manual, Volume 4: Model-Specific Registers. May 2019. Order Number: 335592-070US
Tested on OCP Tioga Pass and Delta Lake.
Change-Id: I8c2eac055a065c06859a3cb7b48ed59f15ae2fc4 Signed-off-by: Johnny Lin johnny_lin@wiwynn.com Reviewed-on: https://review.coreboot.org/c/coreboot/+/42901 Reviewed-by: Patrick Rudolph siro@das-labor.org Reviewed-by: Jonathan Zhang jonzhang@fb.com Tested-by: build bot (Jenkins) no-reply@coreboot.org --- M src/soc/intel/xeon_sp/cpx/cpu.c M src/soc/intel/xeon_sp/cpx/include/soc/cpu.h M src/soc/intel/xeon_sp/skx/cpu.c M src/soc/intel/xeon_sp/skx/include/soc/cpu.h 4 files changed, 66 insertions(+), 0 deletions(-)
Approvals: build bot (Jenkins): Verified Patrick Rudolph: Looks good to me, approved Jonathan Zhang: Looks good to me, but someone else must approve
diff --git a/src/soc/intel/xeon_sp/cpx/cpu.c b/src/soc/intel/xeon_sp/cpx/cpu.c index 386401f..1df5c13 100644 --- a/src/soc/intel/xeon_sp/cpx/cpu.c +++ b/src/soc/intel/xeon_sp/cpx/cpu.c @@ -188,3 +188,34 @@ /* 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 2d12699..1458000 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 <device/device.h> +#include <cpu/x86/msr.h>
#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 f97c37d..c59edab 100644 --- a/src/soc/intel/xeon_sp/skx/cpu.c +++ b/src/soc/intel/xeon_sp/skx/cpu.c @@ -244,3 +244,34 @@
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 0221c7d..c2af265 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 <device/device.h> +#include <cpu/x86/msr.h>
/* 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