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x86/cpu: Use parsed CPUID(0x1)

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On early boot CPU detection, use parsed CPUID(0x1) instead of a direct CPUID
query.

Beside the parser's centralization benefits, use the auto generated CPUID data
types, and their C99 bitfields, instead of doing ugly bitwise operations.

  [ bp: - Use a common code pattern for l1 of fetching and checking it
          right after that
	- flip the check to save an indentation level
	- align assignments vertically.
  ]

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260528153923.403473-12-darwi@linutronix.de
This commit is contained in:
Ahmed S. Darwish 2026-05-28 17:37:33 +02:00 committed by Borislav Petkov (AMD)
parent 21834b541d
commit 173dfdce3b
1 changed files with 11 additions and 11 deletions
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22
arch/x86/kernel/cpu/common.c
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@ -943,6 +943,7 @@ void get_cpu_vendor(struct cpuinfo_x86 *c)
void cpu_detect(struct cpuinfo_x86 *c)
{
const struct leaf_0x0_0 *l0 = cpuid_leaf(c, 0x0);
const struct leaf_0x1_0 *l1;
c->cpuid_level = l0->max_std_leaf;
*(u32 *)&c->x86_vendor_id[0] = l0->cpu_vendorid_0;
@ -950,19 +951,18 @@ void cpu_detect(struct cpuinfo_x86 *c)
*(u32 *)&c->x86_vendor_id[8] = l0->cpu_vendorid_2;
c->x86 = 4;
/* Intel-defined flags: level 0x00000001 */
if (c->cpuid_level >= 0x00000001) {
u32 junk, tfms, cap0, misc;
cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
c->x86 = x86_family(tfms);
c->x86_model = x86_model(tfms);
c->x86_stepping = x86_stepping(tfms);
l1 = cpuid_leaf(c, 0x1);
if (!l1)
return;
if (cap0 & (1<<19)) {
c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
c->x86_cache_alignment = c->x86_clflush_size;
}
c->x86 = cpuid_family(l1);
c->x86_model = cpuid_model(l1);
c->x86_stepping = l1->stepping;
if (l1->clflush) {
c->x86_clflush_size = l1->clflush_size * 8;
c->x86_cache_alignment = c->x86_clflush_size;
}
}