diff options
| author | Alok Kataria <akataria@vmware.com> | 2008-07-01 14:43:24 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-09 01:43:25 -0400 |
| commit | bfc0f5947afa5e3a13e55867f4478c8a92c11dca (patch) | |
| tree | bb642adee69c7804eaafbb7fad66af61b4f9f56f /arch/x86/kernel/tsc_64.c | |
| parent | 0ef95533326a7b37d16025af9edc0c18e644b346 (diff) | |
x86: merge tsc calibration
Merge the tsc calibration code for the 32bit and 64bit kernel.
The paravirtualized calculate_cpu_khz for 64bit now points to the correct
tsc_calibrate code as in 32bit.
Original native_calculate_cpu_khz for 64 bit is now called as calibrate_cpu.
Also moved the recalibrate_cpu_khz function in the common file.
Note that this function is called only from powernow K7 cpu freq driver.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Cc: Dan Hecht <dhecht@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/tsc_64.c')
| -rw-r--r-- | arch/x86/kernel/tsc_64.c | 94 |
1 files changed, 1 insertions, 93 deletions
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c index 69cbe4c9f050..c852ff9bd5d4 100644 --- a/arch/x86/kernel/tsc_64.c +++ b/arch/x86/kernel/tsc_64.c | |||
| @@ -40,7 +40,7 @@ extern int tsc_disabled; | |||
| 40 | 40 | ||
| 41 | DEFINE_PER_CPU(unsigned long, cyc2ns); | 41 | DEFINE_PER_CPU(unsigned long, cyc2ns); |
| 42 | 42 | ||
| 43 | static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu) | 43 | void set_cyc2ns_scale(unsigned long cpu_khz, int cpu) |
| 44 | { | 44 | { |
| 45 | unsigned long long tsc_now, ns_now; | 45 | unsigned long long tsc_now, ns_now; |
| 46 | unsigned long flags, *scale; | 46 | unsigned long flags, *scale; |
| @@ -130,98 +130,6 @@ core_initcall(cpufreq_tsc); | |||
| 130 | 130 | ||
| 131 | #endif | 131 | #endif |
| 132 | 132 | ||
| 133 | #define MAX_RETRIES 5 | ||
| 134 | #define SMI_TRESHOLD 50000 | ||
| 135 | |||
| 136 | /* | ||
| 137 | * Read TSC and the reference counters. Take care of SMI disturbance | ||
| 138 | */ | ||
| 139 | static unsigned long __init tsc_read_refs(unsigned long *pm, | ||
| 140 | unsigned long *hpet) | ||
| 141 | { | ||
| 142 | unsigned long t1, t2; | ||
| 143 | int i; | ||
| 144 | |||
| 145 | for (i = 0; i < MAX_RETRIES; i++) { | ||
| 146 | t1 = get_cycles(); | ||
| 147 | if (hpet) | ||
| 148 | *hpet = hpet_readl(HPET_COUNTER) & 0xFFFFFFFF; | ||
| 149 | else | ||
| 150 | *pm = acpi_pm_read_early(); | ||
| 151 | t2 = get_cycles(); | ||
| 152 | if ((t2 - t1) < SMI_TRESHOLD) | ||
| 153 | return t2; | ||
| 154 | } | ||
| 155 | return ULONG_MAX; | ||
| 156 | } | ||
| 157 | |||
| 158 | /** | ||
| 159 | * tsc_calibrate - calibrate the tsc on boot | ||
| 160 | */ | ||
| 161 | void __init tsc_calibrate(void) | ||
| 162 | { | ||
| 163 | unsigned long flags, tsc1, tsc2, tr1, tr2, pm1, pm2, hpet1, hpet2; | ||
| 164 | int hpet = is_hpet_enabled(), cpu; | ||
| 165 | |||
| 166 | local_irq_save(flags); | ||
| 167 | |||
| 168 | tsc1 = tsc_read_refs(&pm1, hpet ? &hpet1 : NULL); | ||
| 169 | |||
| 170 | outb((inb(0x61) & ~0x02) | 0x01, 0x61); | ||
| 171 | |||
| 172 | outb(0xb0, 0x43); | ||
| 173 | outb((CLOCK_TICK_RATE / (1000 / 50)) & 0xff, 0x42); | ||
| 174 | outb((CLOCK_TICK_RATE / (1000 / 50)) >> 8, 0x42); | ||
| 175 | tr1 = get_cycles(); | ||
| 176 | while ((inb(0x61) & 0x20) == 0); | ||
| 177 | tr2 = get_cycles(); | ||
| 178 | |||
| 179 | tsc2 = tsc_read_refs(&pm2, hpet ? &hpet2 : NULL); | ||
| 180 | |||
| 181 | local_irq_restore(flags); | ||
| 182 | |||
| 183 | /* | ||
| 184 | * Preset the result with the raw and inaccurate PIT | ||
| 185 | * calibration value | ||
| 186 | */ | ||
| 187 | tsc_khz = (tr2 - tr1) / 50; | ||
| 188 | |||
| 189 | /* hpet or pmtimer available ? */ | ||
| 190 | if (!hpet && !pm1 && !pm2) { | ||
| 191 | printk(KERN_INFO "TSC calibrated against PIT\n"); | ||
| 192 | goto out; | ||
| 193 | } | ||
| 194 | |||
| 195 | /* Check, whether the sampling was disturbed by an SMI */ | ||
| 196 | if (tsc1 == ULONG_MAX || tsc2 == ULONG_MAX) { | ||
| 197 | printk(KERN_WARNING "TSC calibration disturbed by SMI, " | ||
| 198 | "using PIT calibration result\n"); | ||
| 199 | goto out; | ||
| 200 | } | ||
| 201 | |||
| 202 | tsc2 = (tsc2 - tsc1) * 1000000L; | ||
| 203 | |||
| 204 | if (hpet) { | ||
| 205 | printk(KERN_INFO "TSC calibrated against HPET\n"); | ||
| 206 | if (hpet2 < hpet1) | ||
| 207 | hpet2 += 0x100000000UL; | ||
| 208 | hpet2 -= hpet1; | ||
| 209 | tsc1 = (hpet2 * hpet_readl(HPET_PERIOD)) / 1000000; | ||
| 210 | } else { | ||
| 211 | printk(KERN_INFO "TSC calibrated against PM_TIMER\n"); | ||
| 212 | if (pm2 < pm1) | ||
| 213 | pm2 += ACPI_PM_OVRRUN; | ||
| 214 | pm2 -= pm1; | ||
| 215 | tsc1 = (pm2 * 1000000000) / PMTMR_TICKS_PER_SEC; | ||
| 216 | } | ||
| 217 | |||
| 218 | tsc_khz = tsc2 / tsc1; | ||
| 219 | |||
| 220 | out: | ||
| 221 | for_each_possible_cpu(cpu) | ||
| 222 | set_cyc2ns_scale(tsc_khz, cpu); | ||
| 223 | } | ||
| 224 | |||
| 225 | /* | 133 | /* |
| 226 | * Make an educated guess if the TSC is trustworthy and synchronized | 134 | * Make an educated guess if the TSC is trustworthy and synchronized |
| 227 | * over all CPUs. | 135 | * over all CPUs. |