diff options
| author | Aaron Durbin <adurbin@chromium.org> | 2016-02-10 11:01:49 -0600 |
|---|---|---|
| committer | Martin Roth <martinroth@google.com> | 2016-02-19 19:50:25 +0100 |
| commit | 152e5a03a130cea3009685cbf7eb0ea354d9fd1c (patch) | |
| tree | d84669468988416d9d37f15c54d5db3343363cd5 /payloads/libpayload/arch | |
| parent | e0969aec2573872b9f528e33edd2cf3fb84c5948 (diff) | |
libpayload: honor TSC information under CONFIG_LP_TIMER_RDTSC
When CONFIG_LP_TIMER_RDTSC is enabled honor the TSC information
exported in the coreboot tables as the cpu_khz frequency. That
allows get_cpu_speed() not to be called which currently relies
on the 8254 PIT. As certain x86 platforms allow that device
to be optional or turned off for power saving reasons, allow
a path where get_cpu_speed() is no longer called. Additionally,
this approach also allows the libpayload to not duplicate logic
that already exists in coreboot.
BUG=chrome-os-partner:50214
BRANCH=glados
TEST=Confirmed in payload TSC frequency is honored instead of
using get_cpu_speed().
Change-Id: Ib8993afdfb49065d43de705d6dbbdb9174b6f2c4
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/13671
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Andrey Petrov <andrey.petrov@intel.com>
Diffstat (limited to 'payloads/libpayload/arch')
| -rw-r--r-- | payloads/libpayload/arch/x86/sysinfo.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/payloads/libpayload/arch/x86/sysinfo.c b/payloads/libpayload/arch/x86/sysinfo.c index c3336b81e4..ddd6550e08 100644 --- a/payloads/libpayload/arch/x86/sysinfo.c +++ b/payloads/libpayload/arch/x86/sysinfo.c @@ -32,12 +32,14 @@ #include <coreboot_tables.h> #include <multiboot_tables.h> +#define CPU_KHZ_DEFAULT 200 + /** * This is a global structure that is used through the library - we set it * up initially with some dummy values - hopefully they will be overridden. */ struct sysinfo_t lib_sysinfo = { - .cpu_khz = 200, + .cpu_khz = CPU_KHZ_DEFAULT, #if IS_ENABLED(CONFIG_LP_SERIAL_CONSOLE) .ser_ioport = CONFIG_LP_SERIAL_IOBASE, #else @@ -49,9 +51,6 @@ int lib_get_sysinfo(void) { int ret; - /* Get the CPU speed (for delays). */ - lib_sysinfo.cpu_khz = get_cpu_speed(); - #if IS_ENABLED(CONFIG_LP_MULTIBOOT) /* Get the information from the multiboot tables, * if they exist */ @@ -63,6 +62,10 @@ int lib_get_sysinfo(void) ret = get_coreboot_info(&lib_sysinfo); + /* Get the CPU speed (for delays) if not set from the default value. */ + if (lib_sysinfo.cpu_khz == CPU_KHZ_DEFAULT) + lib_sysinfo.cpu_khz = get_cpu_speed(); + if (!lib_sysinfo.n_memranges) { /* If we can't get a good memory range, use the default. */ lib_sysinfo.n_memranges = 2; |