[U-Boot] [PATCH 07/19] x86: Add TSC timer

[Simon Glass]

Hi Graeme,

On Wed, Apr 17, 2013 at 8:03 PM, Graeme Russ <graeme.russ at gmail.com> wrote:
> Hi Simon,
>
>
>
> On Thu, Apr 18, 2013 at 12:13 PM, Simon Glass <sjg at chromium.org> wrote:
>>
>> This timer runs at a rate that can be calculated, well over 100MHz. It is
>> ideal for accurate timing and does not need interrupt servicing.
>>
>> Tidy up some old broken and unneeded implementations at the same time.
>>
>> To provide a consistent view of boot time, we use the same time
>> base as coreboot. Use the base timestamp supplied by coreboot
>> as U-Boot's base time.
>>
>> Signed-off-by: Simon Glass <sjg at chromium.org>base
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>>  arch/x86/cpu/coreboot/timestamp.c |   4 +-
>>  arch/x86/cpu/timer.c              |   3 ++
>>  arch/x86/include/asm/u-boot-x86.h |   2 +
>>  arch/x86/lib/Makefile             |   1 +
>>  arch/x86/lib/tsc_timer.c          | 103
>> ++++++++++++++++++++++++++++++++++++++
>>  include/configs/coreboot.h        |   4 +-
>>  6 files changed, 113 insertions(+), 4 deletions(-)
>>  create mode 100644 arch/x86/lib/tsc_timer.c
>>
>> diff --git a/arch/x86/cpu/coreboot/timestamp.c
>> b/arch/x86/cpu/coreboot/timestamp.c
>> index 2ca7a57..d26718e 100644
>> --- a/arch/x86/cpu/coreboot/timestamp.c
>> +++ b/arch/x86/cpu/coreboot/timestamp.c
>> @@ -39,7 +39,9 @@ static struct timestamp_table *ts_table
>> __attribute__((section(".data")));
>>  void timestamp_init(void)
>>  {
>>         ts_table = lib_sysinfo.tstamp_table;
>> -       timer_set_tsc_base(ts_table->base_time);
>> +#ifdef CONFIG_SYS_X86_TSC_TIMER
>> +       timer_set_base(ts_table->base_time);
>> +#endif
>>         timestamp_add_now(TS_U_BOOT_INITTED);
>>  }
>>
>> diff --git a/arch/x86/cpu/timer.c b/arch/x86/cpu/timer.c
>> index 149109d..f95fce5 100644
>> --- a/arch/x86/cpu/timer.c
>> +++ b/arch/x86/cpu/timer.c
>> @@ -10,8 +10,11 @@
>>
>>  #include <common.h>
>>
>> +/* Temporary patch to maintain bisectability, removed in next commit */
>> +#ifndef CONFIG_SYS_X86_TSC_TIMER
>>  unsigned long timer_get_us(void)
>>  {
>>         printf("timer_get_us used but not implemented.\n");
>>         return 0;
>>  }
>> +#endif
>
> Why bother? Why not just one commit 'Replace timer implementation with TSC
> Timer'?

OK will do.

>
>> diff --git a/arch/x86/include/asm/u-boot-x86.h
>> b/arch/x86/include/asm/u-boot-x86.h
>> index 5a59db6..bec583f 100644
>> --- a/arch/x86/include/asm/u-boot-x86.h
>> +++ b/arch/x86/include/asm/u-boot-x86.h
>> @@ -39,6 +39,8 @@ void panic_puts(const char *str);
>>  void timer_isr(void *);
>>  typedef void (timer_fnc_t) (void);
>>  int register_timer_isr (timer_fnc_t *isr_func);
>> +unsigned long get_tbclk_mhz(void);
>> +void timer_set_base(uint64_t base);
>>
>>  /* Architecture specific - can be in arch/x86/cpu/, arch/x86/lib/, or
>> $(BOARD)/ */
>>  int dram_init_f(void);
>> diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
>> index 962593d..0bc8c2f 100644
>> --- a/arch/x86/lib/Makefile
>> +++ b/arch/x86/lib/Makefile
>> @@ -37,6 +37,7 @@ COBJS-y       += relocate.o
>>  COBJS-y += physmem.o
>>  COBJS-y        += string.o
>>  COBJS-$(CONFIG_SYS_X86_ISR_TIMER)      += timer.o
>> +COBJS-$(CONFIG_SYS_X86_TSC_TIMER)      += tsc_timer.o
>>  COBJS-$(CONFIG_VIDEO_VGA)      += video.o
>>  COBJS-$(CONFIG_CMD_ZBOOT)      += zimage.o
>>
>> diff --git a/arch/x86/lib/tsc_timer.c b/arch/x86/lib/tsc_timer.c
>> new file mode 100644
>> index 0000000..d931e5f
>> --- /dev/null
>> +++ b/arch/x86/lib/tsc_timer.c
>> @@ -0,0 +1,103 @@
>> +/*
>> + * Copyright (c) 2012 The Chromium OS Authors.
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License as
>> + * published by the Free Software Foundation; either version 2 of
>> + * the License, or (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, write to the Free Software
>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
>> + * MA 02111-1307 USA
>> + */
>> +
>> +#include <common.h>
>> +#include <malloc.h>
>> +#include <asm/io.h>
>> +#include <asm/i8254.h>
>> +#include <asm/ibmpc.h>
>> +#include <asm/msr.h>
>> +#include <asm/u-boot-x86.h>
>> +
>> +DECLARE_GLOBAL_DATA_PTR;
>> +
>> +void timer_set_base(u64 base)
>> +{
>> +       gd->arch.tsc_base = base;
>> +}
>> +
>> +/*
>> + * Get the number of CPU time counter ticks since it was read first time
>> after
>> + * restart. This yields a free running counter guaranteed to take almost
>> 6
>> + * years to wrap around even at 100GHz clock rate.
>> + */
>> +u64 get_ticks(void)
>> +{
>> +       u64 now_tick = rdtsc();
>> +
>> +       /* We assume that 0 means the base hasn't been set yet */
>> +       if (!gd->arch.tsc_base)
>> +               panic("No tick base available");
>> +       return now_tick - gd->arch.tsc_base;
>> +}
>> +
>> +#define PLATFORM_INFO_MSR 0xce
>> +
>> +/* Get the speed of the TSC timer in MHz */
>> +unsigned long get_tbclk_mhz(void)
>> +{
>> +       u32 ratio;
>> +       u64 platform_info = native_read_msr(PLATFORM_INFO_MSR);
>> +
>> +       /* 100MHz times Max Non Turbo ratio */
>> +       ratio = (platform_info >> 8) & 0xff;
>> +       return 100 * ratio;
>> +}
>> +
>> +unsigned long get_tbclk(void)
>> +{
>> +       return get_tbclk_mhz() * 1000 * 1000;
>> +}
>> +
>> +static ulong get_ms_timer(void)
>> +{
>> +       return (get_ticks() * 1000) / get_tbclk();
>> +}
>> +
>> +ulong get_timer(ulong base)
>> +{
>> +       return get_ms_timer() - base;
>> +}
>> +
>> +ulong timer_get_us(void)
>> +{
>> +       return get_ticks() / get_tbclk_mhz();
>> +}
>> +
>> +ulong timer_get_boot_us(void)
>> +{
>> +       return timer_get_us();
>> +}
>> +
>> +void __udelay(unsigned long usec)
>> +{
>> +       u64 now = get_ticks();
>> +       u64 stop;
>> +
>> +       stop = now + usec * get_tbclk_mhz();
>> +
>> +       while ((int64_t)(stop - get_ticks()) > 0)
>> +               ;
>> +}
>> +
>> +int timer_init(void)
>> +{
>> +       /* Nothing to do here - the timer needs no init */
>> +       return 0;
>> +}
>> diff --git a/include/configs/coreboot.h b/include/configs/coreboot.h
>> index 5bacc77..99408dc 100644
>> --- a/include/configs/coreboot.h
>> +++ b/include/configs/coreboot.h
>> @@ -38,7 +38,6 @@
>>  #define CONFIG_SHOW_BOOT_PROGRESS
>>  #define CONFIG_LAST_STAGE_INIT
>>  #define CONFIG_SYS_VSNPRINTF
>> -#define CONFIG_INTEL_CORE_ARCH /* Sandy bridge and ivy bridge chipsets.
>> */
>
> Why this?

We don't need the code that is enabled by this CONFIG, and we don't
need the CONFIG. I will squash this in also.

Regards,
Simon