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kern/i386/pc/init: Flush cache only on VIA C3 and earlier

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The code flushes the cache on VIA processors unconditionally which
is excessive. Check for cpuid family and execute wbinvd only on C3
and earlier.

Fixes: https://savannah.gnu.org/bugs/?45149
Fixes: 25492a0f0 (Add wbinvd around bios call.)

Signed-off-by: ValdikSS <iam@valdikss.org.ru>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
ValdikSS 2023-10-06 20:13:51 +03:00 committed by Daniel Kiper
parent 3c7e842571
commit cab04dcda3
1 changed files with 10 additions and 1 deletions
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11
grub-core/kern/i386/pc/init.c
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@ -191,7 +191,7 @@ extern grub_uint16_t grub_bios_via_workaround1, grub_bios_via_workaround2;
static void
grub_via_workaround_init (void)
{
grub_uint32_t manufacturer[3], max_cpuid;
grub_uint32_t manufacturer[3], max_cpuid, proc_info;
if (! grub_cpu_is_cpuid_supported ())
return;
@ -200,6 +200,15 @@ grub_via_workaround_init (void)
if (grub_memcmp (manufacturer, "CentaurHauls", 12) != 0)
return;
if (max_cpuid > 0)
{
grub_cpuid (1, proc_info, /* Don't care. */ manufacturer[0],
manufacturer[2], manufacturer[1]);
/* Check model, apply only to VIA C3 and lower. */
if (((proc_info & 0xf0) >> 4 | (proc_info & 0xf0000) >> 12) > 10)
return;
}
grub_bios_via_workaround1 = 0x090f;
grub_bios_via_workaround2 = 0x090f;
asm volatile ("wbinvd");