On Sat, Aug 3, 2019 at 11:30 AM Park, Aiden <[email protected]> wrote: > > 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 >
I'm not convinced with this approach (no tag from me), but I'm not going to block it. So, if Bin takes it. I'm fine. > Signed-off-by: Aiden Park <[email protected]> > Reviewed-by: Bin Meng <[email protected]> > --- > Changes in v6: > * Use EFI_GUID > * Add more comments while setting tsc_base and clock_rate > * Apply code-review comments > > Changes in v3: > * Use HOB function from the common HOB library > > arch/x86/cpu/slimbootloader/slimbootloader.c | 37 +++++++++++++++++++ > .../asm/arch-slimbootloader/slimbootloader.h | 28 ++++++++++++++ > 2 files changed, 65 insertions(+) > > diff --git a/arch/x86/cpu/slimbootloader/slimbootloader.c > b/arch/x86/cpu/slimbootloader/slimbootloader.c > index 9f3a61ec61..e6b174ca88 100644 > --- a/arch/x86/cpu/slimbootloader/slimbootloader.c > +++ b/arch/x86/cpu/slimbootloader/slimbootloader.c > @@ -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(); > } > > diff --git a/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h > b/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h > index 174a341d32..05dd1b2b44 100644 > --- a/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h > +++ b/arch/x86/include/asm/arch-slimbootloader/slimbootloader.h > @@ -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__ */ > -- > 2.20.1 > -- With Best Regards, Andy Shevchenko _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
