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Add wbinvd around bios call.

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Via C3 has problems with cache coherency when transitioning between the modes,
so flush it around bios calls.
This commit is contained in:
Vladimir Serbinenko 2016-01-10 13:48:26 +01:00 committed by root
parent 080a20861c
commit 25492a0f04
2 changed files with 35 additions and 0 deletions
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11
grub-core/kern/i386/int.S
View file

@ -44,6 +44,13 @@ FUNCTION(grub_bios_interrupt)
movl 24(%edx), %esi
movl 28(%edx), %edx
/*
Via C3 CPUs have cache coherence problems, so we need to call
wbinvd at these 2 points. As wbinvd slows down boot, don't do
it on non-VIA. 9090 is nop nop. */
VARIABLE(grub_bios_via_workaround1)
.byte 0x90, 0x90
PROT_TO_REAL
.code16
pushf
@ -92,6 +99,10 @@ intno:
movw %ax, LOCAL(bios_register_es)
popf
VARIABLE(grub_bios_via_workaround2)
.byte 0x90, 0x90
REAL_TO_PROT
.code32

24
grub-core/kern/i386/pc/init.c
View file

@ -32,6 +32,7 @@
#include <grub/env.h>
#include <grub/cache.h>
#include <grub/time.h>
#include <grub/cpu/cpuid.h>
#include <grub/cpu/tsc.h>
#include <grub/machine/time.h>
@ -184,6 +185,26 @@ mmap_iterate_hook (grub_uint64_t addr, grub_uint64_t size,
return 0;
}
extern grub_uint16_t grub_bios_via_workaround1, grub_bios_via_workaround2;
/* Via needs additional wbinvd. */
static void
grub_via_workaround_init (void)
{
grub_uint32_t manufacturer[3], max_cpuid;
if (! grub_cpu_is_cpuid_supported ())
return;
grub_cpuid (0, max_cpuid, manufacturer[0], manufacturer[2], manufacturer[1]);
if (grub_memcmp (manufacturer, "CentaurHauls", 12) != 0)
return;
grub_bios_via_workaround1 = 0x090f;
grub_bios_via_workaround2 = 0x090f;
asm volatile ("wbinvd");
}
void
grub_machine_init (void)
{
@ -193,6 +214,9 @@ grub_machine_init (void)
#endif
grub_addr_t modend;
/* This has to happen before any BIOS calls. */
grub_via_workaround_init ();
grub_modbase = GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR + (_edata - _start);
/* Initialize the console as early as possible. */