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95ca0ee863
This is a pure feature bits leaf. There are two AVX512 feature bits in it already which were handled as scattered bits, and three more from this leaf are going to be added for speculation control features. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: gnomes@lxorguk.ukuu.org.uk Cc: ak@linux.intel.com Cc: ashok.raj@intel.com Cc: dave.hansen@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1516896855-7642-2-git-send-email-dwmw@amazon.co.uk
80 lines
2 KiB
C
80 lines
2 KiB
C
/*
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* Routines to identify additional cpu features that are scattered in
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* cpuid space.
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*/
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#include <linux/cpu.h>
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#include <asm/pat.h>
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#include <asm/processor.h>
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#include <asm/apic.h>
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struct cpuid_bit {
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u16 feature;
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u8 reg;
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u8 bit;
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u32 level;
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u32 sub_leaf;
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};
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/* Please keep the leaf sorted by cpuid_bit.level for faster search. */
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static const struct cpuid_bit cpuid_bits[] = {
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{ X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
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{ X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
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{ X86_FEATURE_CAT_L3, CPUID_EBX, 1, 0x00000010, 0 },
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{ X86_FEATURE_CAT_L2, CPUID_EBX, 2, 0x00000010, 0 },
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{ X86_FEATURE_CDP_L3, CPUID_ECX, 2, 0x00000010, 1 },
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{ X86_FEATURE_MBA, CPUID_EBX, 3, 0x00000010, 0 },
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{ X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
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{ X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
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{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
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{ X86_FEATURE_SME, CPUID_EAX, 0, 0x8000001f, 0 },
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{ 0, 0, 0, 0, 0 }
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};
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void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
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{
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u32 max_level;
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u32 regs[4];
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const struct cpuid_bit *cb;
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for (cb = cpuid_bits; cb->feature; cb++) {
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/* Verify that the level is valid */
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max_level = cpuid_eax(cb->level & 0xffff0000);
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if (max_level < cb->level ||
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max_level > (cb->level | 0xffff))
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continue;
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cpuid_count(cb->level, cb->sub_leaf, ®s[CPUID_EAX],
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®s[CPUID_EBX], ®s[CPUID_ECX],
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®s[CPUID_EDX]);
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if (regs[cb->reg] & (1 << cb->bit))
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set_cpu_cap(c, cb->feature);
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}
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}
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u32 get_scattered_cpuid_leaf(unsigned int level, unsigned int sub_leaf,
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enum cpuid_regs_idx reg)
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{
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const struct cpuid_bit *cb;
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u32 cpuid_val = 0;
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for (cb = cpuid_bits; cb->feature; cb++) {
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if (level > cb->level)
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continue;
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if (level < cb->level)
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break;
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if (reg == cb->reg && sub_leaf == cb->sub_leaf) {
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if (cpu_has(&boot_cpu_data, cb->feature))
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cpuid_val |= BIT(cb->bit);
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}
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}
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return cpuid_val;
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}
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EXPORT_SYMBOL_GPL(get_scattered_cpuid_leaf);
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