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x86: slimbootloader: Set TSC information for tsc_timer

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Slim Bootloader already calibrated TSC and provides it to U-Boot.
Therefore, U-Boot does not have to re-calibrate TSC.
Configuring tsc_base and clock_rate makes x86 tsc_timer driver bypass
TSC calibration and use the provided TSC frequency.
- Get TSC frequency from performance info hob
- Set tsc_base and clock_rate for tsc_timer driver

Signed-off-by: Aiden Park <aiden.park@intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Park, Aiden 2019-08-03 08:30:52 +00:00 committed by Bin Meng
parent 2869c3b3de
commit 14360bf059
2 changed files with 65 additions and 0 deletions
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37
arch/x86/cpu/slimbootloader/slimbootloader.c
View file

@ -4,9 +4,46 @@
*/
#include <common.h>
#include <asm/arch/slimbootloader.h>
DECLARE_GLOBAL_DATA_PTR;
/**
* This sets tsc_base and clock_rate for early_timer and tsc_timer.
* The performance info guid hob has all performance timestamp data, but
* the only tsc frequency info is used for the timer driver for now.
*
* Slim Bootloader already calibrated TSC and provides it to U-Boot.
* Therefore, U-Boot does not have to re-calibrate TSC.
* Configuring tsc_base and clock_rate here makes x86 tsc_timer driver
* bypass TSC calibration and use the provided TSC frequency.
*/
static void tsc_init(void)
{
struct sbl_performance_info *data;
const efi_guid_t guid = SBL_PERFORMANCE_INFO_GUID;
if (!gd->arch.hob_list)
panic("hob list not found!");
gd->arch.tsc_base = rdtsc();
debug("tsc_base=0x%llx\n", gd->arch.tsc_base);
data = hob_get_guid_hob_data(gd->arch.hob_list, NULL, &guid);
if (!data) {
debug("performance info hob not found\n");
return;
}
/* frequency is in KHz, so to Hz */
gd->arch.clock_rate = data->frequency * 1000;
debug("freq=0x%lx\n", gd->arch.clock_rate);
}
int arch_cpu_init(void)
{
tsc_init();
return x86_cpu_init_f();
}

28
arch/x86/include/asm/arch-slimbootloader/slimbootloader.h
View file

@ -23,6 +23,13 @@
EFI_GUID(0x6c6872fe, 0x56a9, 0x4403, \
0xbb, 0x98, 0x95, 0x8d, 0x62, 0xde, 0x87, 0xf1)
/**
* A GUID to get boot performance info hob which is provided by Slim Bootloader
*/
#define SBL_PERFORMANCE_INFO_GUID \
EFI_GUID(0x868204be, 0x23d0, 0x4ff9, \
0xac, 0x34, 0xb9, 0x95, 0xac, 0x04, 0xb1, 0xb9)
/**
* A single entry of memory map information
*
@ -84,4 +91,25 @@ struct sbl_serial_port_info {
u32 rsvd1;
};
/**
* This includes timestamp data which has been collected in Slim Bootloader
* stages from the reset vector. In addition, this has TSC frequency in KHz to
* calculate each timestamp.
*
* @rev : revision of performance_info structure. currently 1.
* @rsvd : padding for alignment
* @count : the number of collected timestamp data
* @flags : only used in Slim Bootloader
* @frequency: tsc frequency in KHz
* @timestamp: the array of timestamp data which has 64-bit tsc value
*/
struct sbl_performance_info {
u8 rev;
u8 rsvd[3];
u16 count;
u16 flags;
u32 frequency;
u64 timestamp[0];
};
#endif /* __SLIMBOOTLOADER_ARCH_H__ */