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x86: Centaur Isaiah processor to use sysenter in 64-bit compatibility…
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… mode rather than syscall

Upcoming 64 bit processors from Centaur can use sysenter.

Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Jesse Ahrens <jahrens@centtech.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Dave Jones authored and Ingo Molnar committed Apr 17, 2008
1 parent aa040b2 commit 0e03eb8
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Showing 2 changed files with 41 additions and 2 deletions.
35 changes: 35 additions & 0 deletions arch/x86/kernel/setup_64.c
Original file line number Diff line number Diff line change
Expand Up @@ -885,6 +885,32 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c)
srat_detect_node();
}

static void __cpuinit early_init_centaur(struct cpuinfo_x86 *c)
{
if (c->x86 == 0x6 && c->x86_model >= 0xf)
set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability);
}

static void __cpuinit init_centaur(struct cpuinfo_x86 *c)
{
/* Cache sizes */
unsigned n;

n = c->extended_cpuid_level;
if (n >= 0x80000008) {
unsigned eax = cpuid_eax(0x80000008);
c->x86_virt_bits = (eax >> 8) & 0xff;
c->x86_phys_bits = eax & 0xff;
}

if (c->x86 == 0x6 && c->x86_model >= 0xf) {
c->x86_cache_alignment = c->x86_clflush_size * 2;
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
set_cpu_cap(c, X86_FEATURE_REP_GOOD);
}
set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
}

static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
{
char *v = c->x86_vendor_id;
Expand All @@ -893,6 +919,8 @@ static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
c->x86_vendor = X86_VENDOR_AMD;
else if (!strcmp(v, "GenuineIntel"))
c->x86_vendor = X86_VENDOR_INTEL;
else if (!strcmp(v, "CentaurHauls"))
c->x86_vendor = X86_VENDOR_CENTAUR;
else
c->x86_vendor = X86_VENDOR_UNKNOWN;
}
Expand Down Expand Up @@ -989,6 +1017,9 @@ static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15))
set_cpu_cap(c, X86_FEATURE_PAT);
break;
case X86_VENDOR_CENTAUR:
early_init_centaur(c);
break;
}

}
Expand Down Expand Up @@ -1025,6 +1056,10 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
init_intel(c);
break;

case X86_VENDOR_CENTAUR:
init_centaur(c);
break;

case X86_VENDOR_UNKNOWN:
default:
display_cacheinfo(c);
Expand Down
8 changes: 6 additions & 2 deletions arch/x86/vdso/vdso32-setup.c
Original file line number Diff line number Diff line change
Expand Up @@ -210,8 +210,12 @@ static int use_sysenter __read_mostly = -1;
/* May not be __init: called during resume */
void syscall32_cpu_init(void)
{
if (use_sysenter < 0)
use_sysenter = (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL);
if (use_sysenter < 0) {
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
use_sysenter = 1;
if (boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR)
use_sysenter = 1;
}

/* Load these always in case some future AMD CPU supports
SYSENTER from compat mode too. */
Expand Down

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