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authorAaron Durbin <adurbin@chromium.org>2018-01-24 17:42:51 -0700
committerAaron Durbin <adurbin@chromium.org>2018-01-25 23:30:14 +0000
commit51e4c1a76cafa0ddd429ffa78d0e6fdee179f731 (patch)
tree1c540ebc0ba5a94ed9119b02be2e985597e5c2f9
parentf49ddb67de5b6ff86ad080585bd835779521d647 (diff)
downloadcoreboot-51e4c1a76cafa0ddd429ffa78d0e6fdee179f731.tar.xz
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 <adurbin@chromium.org> Reviewed-on: https://review.coreboot.org/23424 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Furquan Shaikh <furquan@google.com>
-rw-r--r--src/soc/amd/stoneyridge/Kconfig4
-rw-r--r--src/soc/amd/stoneyridge/bootblock/bootblock.c4
-rw-r--r--src/soc/amd/stoneyridge/monotonic_timer.c8
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 <soc/northbridge.h>
#include <soc/southbridge.h>
#include <amdblocks/psp.h>
+#include <timestamp.h>
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
@@ -15,12 +15,18 @@
#include <cpu/x86/msr.h>
#include <timer.h>
+#include <timestamp.h>
#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;
}