diff options
Diffstat (limited to 'src/cpu/intel/haswell/haswell_init.c')
| -rw-r--r-- | src/cpu/intel/haswell/haswell_init.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/src/cpu/intel/haswell/haswell_init.c b/src/cpu/intel/haswell/haswell_init.c index 5b53afedf5..0b7a8985cf 100644 --- a/src/cpu/intel/haswell/haswell_init.c +++ b/src/cpu/intel/haswell/haswell_init.c @@ -34,6 +34,7 @@ #include <cpu/intel/turbo.h> #include <cpu/x86/cache.h> #include <cpu/x86/name.h> +#include <delay.h> #include <pc80/mc146818rtc.h> #include <northbridge/intel/haswell/haswell.h> #include <southbridge/intel/lynxpoint/pch.h> @@ -217,6 +218,62 @@ static int is_ult(void) return ult; } +/* The core 100MHz BLCK is disabled in deeper c-states. One needs to calibrate + * the 100MHz BCLCK against the 24MHz BLCK to restore the clocks properly + * when a core is woken up. */ +static int pcode_ready(void) +{ + int wait_count; + const int delay_step = 10; + + wait_count = 0; + do { + if (!(MCHBAR32(BIOS_MAILBOX_INTERFACE) & MAILBOX_RUN_BUSY)) + return 0; + wait_count += delay_step; + udelay(delay_step); + } while (wait_count < 1000); + + return -1; +} + +static void calibrate_24mhz_bclk(void) +{ + int err_code; + + if (pcode_ready() < 0) { + printk(BIOS_ERR, "PCODE: mailbox timeout on wait ready.\n"); + return; + } + + /* A non-zero value initiates the PCODE calibration. */ + MCHBAR32(BIOS_MAILBOX_DATA) = ~0; + MCHBAR32(BIOS_MAILBOX_INTERFACE) = + MAILBOX_RUN_BUSY | MAILBOX_BIOS_CMD_FSM_MEASURE_INTVL; + + if (pcode_ready() < 0) { + printk(BIOS_ERR, "PCODE: mailbox timeout on completion.\n"); + return; + } + + err_code = MCHBAR32(BIOS_MAILBOX_INTERFACE) & 0xff; + + printk(BIOS_DEBUG, "PCODE: 24MHz BLCK calibration response: %d\n", + err_code); + + /* Read the calibrated value. */ + MCHBAR32(BIOS_MAILBOX_INTERFACE) = + MAILBOX_RUN_BUSY | MAILBOX_BIOS_CMD_READ_CALIBRATION; + + if (pcode_ready() < 0) { + printk(BIOS_ERR, "PCODE: mailbox timeout on read.\n"); + return; + } + + printk(BIOS_DEBUG, "PCODE: 24MHz BLCK calibration value: 0x%08x\n", + MCHBAR32(BIOS_MAILBOX_DATA)); +} + int cpu_config_tdp_levels(void) { msr_t platform_info; @@ -517,6 +574,9 @@ static void bsp_init_before_ap_bringup(struct bus *cpu_bus) x86_setup_var_mtrrs(cpuid_eax(0x80000008) & 0xff, 2); x86_mtrr_check(); + if (is_ult()) + calibrate_24mhz_bclk(); + /* Call through the cpu driver's initialization. */ cpu_initialize(0); } |