From 51e4c1a76cafa0ddd429ffa78d0e6fdee179f731 Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Wed, 24 Jan 2018 17:42:51 -0700 Subject: soc/amd/stoneyridge: remove dependence on TSC The TSC rate is empirically swinging during early boot. That leaves timestamps and udelay()s to not be correct. To rectify this stop using TSC for all of these time sources. Instead use the performance TSC which is at a fixed 100MHz clock. That provides stable time sources and legit timestamps. BUG=b:72378235,b:72170796 Change-Id: Ia2693c415c557aac687bcb48ee69358ea1c53d67 Signed-off-by: Aaron Durbin Reviewed-on: https://review.coreboot.org/23424 Tested-by: build bot (Jenkins) Reviewed-by: Furquan Shaikh --- src/soc/amd/stoneyridge/Kconfig | 4 ++-- src/soc/amd/stoneyridge/bootblock/bootblock.c | 4 +++- src/soc/amd/stoneyridge/monotonic_timer.c | 8 +++++++- 3 files changed, 12 insertions(+), 4 deletions(-) diff --git a/src/soc/amd/stoneyridge/Kconfig b/src/soc/amd/stoneyridge/Kconfig index fbeabb71cd..148ca3ff04 100644 --- a/src/soc/amd/stoneyridge/Kconfig +++ b/src/soc/amd/stoneyridge/Kconfig @@ -32,14 +32,14 @@ config CPU_SPECIFIC_OPTIONS select ARCH_ROMSTAGE_X86_32 select ARCH_RAMSTAGE_X86_32 select ACPI_AMD_HARDWARE_SLEEP_VALUES + select COLLECT_TIMESTAMPS_NO_TSC select DRIVERS_I2C_DESIGNWARE select GENERIC_GPIO_LIB + select GENERIC_UDELAY select IOAPIC select HAVE_USBDEBUG_OPTIONS select HAVE_HARD_RESET - select UDELAY_TSC select HAVE_MONOTONIC_TIMER - select TSC_CONSTANT_RATE select SPI_FLASH if HAVE_ACPI_RESUME select TSC_SYNC_LFENCE select COLLECT_TIMESTAMPS diff --git a/src/soc/amd/stoneyridge/bootblock/bootblock.c b/src/soc/amd/stoneyridge/bootblock/bootblock.c index 4b58287ba5..f9ae365c0d 100644 --- a/src/soc/amd/stoneyridge/bootblock/bootblock.c +++ b/src/soc/amd/stoneyridge/bootblock/bootblock.c @@ -28,6 +28,7 @@ #include #include #include +#include asmlinkage void bootblock_c_entry(uint64_t base_timestamp) { @@ -40,7 +41,8 @@ asmlinkage void bootblock_c_entry(uint64_t base_timestamp) if (!boot_cpu()) bootblock_soc_early_init(); /* APs will not return */ - bootblock_main_with_timestamp(base_timestamp); + /* TSC cannot be relied upon. Override the TSC value passed in. */ + bootblock_main_with_timestamp(timestamp_get()); } /* Set the MMIO Configuration Base Address and Bus Range. */ diff --git a/src/soc/amd/stoneyridge/monotonic_timer.c b/src/soc/amd/stoneyridge/monotonic_timer.c index 170a640233..7ea571f635 100644 --- a/src/soc/amd/stoneyridge/monotonic_timer.c +++ b/src/soc/amd/stoneyridge/monotonic_timer.c @@ -15,11 +15,17 @@ #include #include +#include #define CU_PTSC_MSR 0xc0010280 #define PTSC_FREQ_MHZ 100 void timer_monotonic_get(struct mono_time *mt) +{ + mono_time_set_usecs(mt, timestamp_get()); +} + +uint64_t timestamp_get(void) { unsigned long long val; msr_t msr; @@ -28,5 +34,5 @@ void timer_monotonic_get(struct mono_time *mt) val = ((unsigned long long)msr.hi << 32) | msr.lo; - mono_time_set_usecs(mt, val / PTSC_FREQ_MHZ); + return val / PTSC_FREQ_MHZ; } -- cgit v1.2.3