diff options
Diffstat (limited to 'src/cpu')
| -rw-r--r-- | src/cpu/x86/Kconfig | 6 | ||||
| -rw-r--r-- | src/cpu/x86/tsc/delay_tsc.c | 58 |
2 files changed, 0 insertions, 64 deletions
diff --git a/src/cpu/x86/Kconfig b/src/cpu/x86/Kconfig index d8f338d5d0..6cd65cc490 100644 --- a/src/cpu/x86/Kconfig +++ b/src/cpu/x86/Kconfig @@ -49,12 +49,6 @@ config TSC_MONOTONIC_TIMER Expose monotonic time using the TSC. # This option is used in code but never selected. -config TSC_CALIBRATE_WITH_IO - bool - depends on UDELAY_TSC - default n - -# This option is used in code but never selected. config UDELAY_TIMER2 bool default n diff --git a/src/cpu/x86/tsc/delay_tsc.c b/src/cpu/x86/tsc/delay_tsc.c index 0ad5d3bbdf..9441622ce3 100644 --- a/src/cpu/x86/tsc/delay_tsc.c +++ b/src/cpu/x86/tsc/delay_tsc.c @@ -16,7 +16,6 @@ static unsigned long calibrate_tsc(void) return tsc_freq_mhz(); } #else /* CONFIG_TSC_CONSTANT_RATE */ -#if !CONFIG_TSC_CALIBRATE_WITH_IO #define CLOCK_TICK_RATE 1193180U /* Underlying HZ */ /* ------ Calibrate the TSC ------- @@ -91,63 +90,6 @@ bad_ctc: return 0; } -#else /* CONFIG_TSC_CALIBRATE_WITH_IO */ - -/* - * this is the "no timer2" version. - * to calibrate tsc, we get a TSC reading, then do 1,000,000 outbs to port 0x80 - * then we read TSC again, and divide the difference by 1,000,000 - * we have found on a wide range of machines that this gives us a a - * good microsecond value - * to +- 10%. On a dual AMD 1.6 Ghz box, it gives us .97 microseconds, and on a - * 267 Mhz. p5, it gives us 1.1 microseconds. - * also, since gcc now supports long long, we use that. - * also no unsigned long long / operator, so we play games. - * about the only thing you can do with long longs, it seems, - *is return them and assign them. - * (and do asm on them, yuck) - * so avoid all ops on long longs. - */ -static unsigned long long calibrate_tsc(void) -{ - unsigned long long start, end, delta; - unsigned long result, count; - - printk(BIOS_SPEW, "Calibrating delay loop...\n"); - start = rdtscll(); - // no udivdi3 because we don't like libgcc. (only in x86emu) - // so we count to 1<< 20 and then right shift 20 - for(count = 0; count < (1<<20); count ++) - inb(0x80); - end = rdtscll(); - -#if 0 - // make delta be (endhigh - starthigh) + (endlow - startlow) - // but >> 20 - // do it this way to avoid gcc warnings. - start = tsc_start.hi; - start <<= 32; - start |= start.lo; - end = tsc_end.hi; - end <<= 32; - end |= tsc_end.lo; -#endif - delta = end - start; - // at this point we have a delta for 1,000,000 outbs. Now rescale for one microsecond. - delta >>= 20; - // save this for microsecond timing. - result = delta; - printk(BIOS_SPEW, "end %llx, start %llx\n", end, start); - printk(BIOS_SPEW, "32-bit delta %ld\n", (unsigned long) delta); - - printk(BIOS_SPEW, "%s 32-bit result is %ld\n", - __func__, - result); - return delta; -} - - -#endif /* CONFIG_TSC_CALIBRATE_WITH_IO */ #endif /* CONFIG_TSC_CONSTANT_RATE */ void init_timer(void) |