x86/tsc_msr: Update comments, expand definitions
Syntax only, no functional change. Signed-off-by: Len Brown <len.brown@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/8653a2dba21fef122fc7b29eafb750e2004d3976.1466138954.git.len.brown@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Родитель
14bb4e3486
Коммит
9e0cae9f62
|
@ -1,14 +1,5 @@
|
|||
/*
|
||||
* tsc_msr.c - MSR based TSC calibration on Intel Atom SoC platforms.
|
||||
*
|
||||
* TSC in Intel Atom SoC runs at a constant rate which can be figured
|
||||
* by this formula:
|
||||
* <maximum core-clock to bus-clock ratio> * <maximum resolved frequency>
|
||||
* See Intel 64 and IA-32 System Programming Guid section 16.12 and 30.11.5
|
||||
* for details.
|
||||
* Especially some Intel Atom SoCs don't have PIT(i8254) or HPET, so MSR
|
||||
* based calibration is the only option.
|
||||
*
|
||||
* tsc_msr.c - TSC frequency enumeration via MSR
|
||||
*
|
||||
* Copyright (C) 2013 Intel Corporation
|
||||
* Author: Bin Gao <bin.gao@intel.com>
|
||||
|
@ -22,17 +13,10 @@
|
|||
#include <asm/apic.h>
|
||||
#include <asm/param.h>
|
||||
|
||||
/* CPU reference clock frequency: in KHz */
|
||||
#define FREQ_83 83200
|
||||
#define FREQ_100 99840
|
||||
#define FREQ_133 133200
|
||||
#define FREQ_166 166400
|
||||
|
||||
#define MAX_NUM_FREQS 8
|
||||
|
||||
/*
|
||||
* According to Intel 64 and IA-32 System Programming Guide,
|
||||
* if MSR_PERF_STAT[31] is set, the maximum resolved bus ratio can be
|
||||
* If MSR_PERF_STAT[31] is set, the maximum resolved bus ratio can be
|
||||
* read in MSR_PLATFORM_ID[12:8], otherwise in MSR_PERF_STAT[44:40].
|
||||
* Unfortunately some Intel Atom SoCs aren't quite compliant to this,
|
||||
* so we need manually differentiate SoC families. This is what the
|
||||
|
@ -47,15 +31,15 @@ struct freq_desc {
|
|||
|
||||
static struct freq_desc freq_desc_tables[] = {
|
||||
/* PNW */
|
||||
{ 6, 0x27, 0, { 0, 0, 0, 0, 0, FREQ_100, 0, FREQ_83 } },
|
||||
{ 6, 0x27, 0, { 0, 0, 0, 0, 0, 99840, 0, 83200 } },
|
||||
/* CLV+ */
|
||||
{ 6, 0x35, 0, { 0, FREQ_133, 0, 0, 0, FREQ_100, 0, FREQ_83 } },
|
||||
/* TNG */
|
||||
{ 6, 0x4a, 1, { 0, FREQ_100, FREQ_133, 0, 0, 0, 0, 0 } },
|
||||
/* VLV2 */
|
||||
{ 6, 0x37, 1, { FREQ_83, FREQ_100, FREQ_133, FREQ_166, 0, 0, 0, 0 } },
|
||||
/* ANN */
|
||||
{ 6, 0x5a, 1, { FREQ_83, FREQ_100, FREQ_133, FREQ_100, 0, 0, 0, 0 } },
|
||||
{ 6, 0x35, 0, { 0, 133200, 0, 0, 0, 99840, 0, 83200 } },
|
||||
/* TNG - Intel Atom processor Z3400 series */
|
||||
{ 6, 0x4a, 1, { 0, 99840, 133200, 0, 0, 0, 0, 0 } },
|
||||
/* VLV2 - Intel Atom processor E3000, Z3600, Z3700 series */
|
||||
{ 6, 0x37, 1, { 83200, 99840, 133200, 166400, 0, 0, 0, 0 } },
|
||||
/* ANN - Intel Atom processor Z3500 series */
|
||||
{ 6, 0x5a, 1, { 83200, 99840, 133200, 99840, 0, 0, 0, 0 } },
|
||||
};
|
||||
|
||||
static int match_cpu(u8 family, u8 model)
|
||||
|
|
Загрузка…
Ссылка в новой задаче