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haswell: check for clean reset

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When an INIT# is delivered to the CPU the CPU starts
executing from the reset vector. However, the internal state
is maintained. Therefore, check for such a condition and
reset the system.

BUG=chrome-os-partner:19355
BRANCH=None
TEST=Issues 'apreset warm' on the EC console. INIT# is sent and
     CPU notices it's not a clean reset and forces one. No hangs.

Change-Id: I71229e0e5015ba8c60f5989c533268604ecc1ecc
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/57111
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
This commit is contained in:
Aaron Durbin 2013-05-30 10:40:54 -05:00 • committed by ChromeBot
commit 40e55948b2
1 changed files with 18 additions and 0 deletions
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18
src/cpu/intel/haswell/bootblock.c
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@ -112,10 +112,28 @@ static void set_flex_ratio_to_tdp_nominal(void)
}
}
static void check_for_clean_reset(void)
{
msr_t msr;
msr = rdmsr(MTRRdefType_MSR);
/* Use the MTRR default type MSR as a proxy for detecting INIT#.
* Reset the system if any known bits are set in that MSR. That is
* an indication of the CPU not being properly reset. */
if (msr.lo & (MTRRdefTypeEn | MTRRdefTypeFixEn)) {
outb(0x0, 0xcf9);
outb(0x6, 0xcf9);
while (1) {
asm("hlt");
}
}
}
static void bootblock_cpu_init(void)
{
/* Set flex ratio and reset if needed */
set_flex_ratio_to_tdp_nominal();
check_for_clean_reset();
enable_rom_caching();
intel_update_microcode_from_cbfs();
}