arch/x86/kernel/cpu/scattered.c

Source file repositories/reference/linux-study-clean/arch/x86/kernel/cpu/scattered.c

File Facts

System
Linux kernel
Corpus path
arch/x86/kernel/cpu/scattered.c
Extension
.c
Size
3688 bytes
Lines
96
Domain
Architecture Layer
Bucket
arch/x86
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct cpuid_bit {
	u16 feature;
	u8 reg;
	u8 bit;
	u32 level;
	u32 sub_leaf;
};

/*
 * Please keep the leaf sorted by cpuid_bit.level for faster search.
 * X86_FEATURE_MBA is supported by both Intel and AMD. But the CPUID
 * levels are different and there is a separate entry for each.
 */
static const struct cpuid_bit cpuid_bits[] = {
	{ X86_FEATURE_APERFMPERF,		CPUID_ECX,  0, 0x00000006, 0 },
	{ X86_FEATURE_EPB,			CPUID_ECX,  3, 0x00000006, 0 },
	{ X86_FEATURE_INTEL_PPIN,		CPUID_EBX,  0, 0x00000007, 1 },
	{ X86_FEATURE_MSR_IMM,			CPUID_ECX,  5, 0x00000007, 1 },
	{ X86_FEATURE_APX,			CPUID_EDX, 21, 0x00000007, 1 },
	{ X86_FEATURE_RRSBA_CTRL,		CPUID_EDX,  2, 0x00000007, 2 },
	{ X86_FEATURE_BHI_CTRL,			CPUID_EDX,  4, 0x00000007, 2 },
	{ X86_FEATURE_CQM_LLC,			CPUID_EDX,  1, 0x0000000f, 0 },
	{ X86_FEATURE_CQM_OCCUP_LLC,		CPUID_EDX,  0, 0x0000000f, 1 },
	{ X86_FEATURE_CQM_MBM_TOTAL,		CPUID_EDX,  1, 0x0000000f, 1 },
	{ X86_FEATURE_CQM_MBM_LOCAL,		CPUID_EDX,  2, 0x0000000f, 1 },
	{ X86_FEATURE_CAT_L3,			CPUID_EBX,  1, 0x00000010, 0 },
	{ X86_FEATURE_CAT_L2,			CPUID_EBX,  2, 0x00000010, 0 },
	{ X86_FEATURE_CDP_L3,			CPUID_ECX,  2, 0x00000010, 1 },
	{ X86_FEATURE_CDP_L2,			CPUID_ECX,  2, 0x00000010, 2 },
	{ X86_FEATURE_MBA,			CPUID_EBX,  3, 0x00000010, 0 },
	{ X86_FEATURE_PER_THREAD_MBA,		CPUID_ECX,  0, 0x00000010, 3 },
	{ X86_FEATURE_SGX1,			CPUID_EAX,  0, 0x00000012, 0 },
	{ X86_FEATURE_SGX2,			CPUID_EAX,  1, 0x00000012, 0 },
	{ X86_FEATURE_SGX_EUPDATESVN,		CPUID_EAX, 10, 0x00000012, 0 },
	{ X86_FEATURE_SGX_EDECCSSA,		CPUID_EAX, 11, 0x00000012, 0 },
	{ X86_FEATURE_OVERFLOW_RECOV,		CPUID_EBX,  0, 0x80000007, 0 },
	{ X86_FEATURE_SUCCOR,			CPUID_EBX,  1, 0x80000007, 0 },
	{ X86_FEATURE_SMCA,			CPUID_EBX,  3, 0x80000007, 0 },
	{ X86_FEATURE_HW_PSTATE,		CPUID_EDX,  7, 0x80000007, 0 },
	{ X86_FEATURE_CPB,			CPUID_EDX,  9, 0x80000007, 0 },
	{ X86_FEATURE_PROC_FEEDBACK,		CPUID_EDX, 11, 0x80000007, 0 },
	{ X86_FEATURE_AMD_FAST_CPPC,		CPUID_EDX, 15, 0x80000007, 0 },
	{ X86_FEATURE_CPPC_PERF_PRIO,		CPUID_EDX, 16, 0x80000007, 0 },
	{ X86_FEATURE_MBA,			CPUID_EBX,  6, 0x80000008, 0 },
	{ X86_FEATURE_X2AVIC_EXT,		CPUID_ECX,  6, 0x8000000a, 0 },
	{ X86_FEATURE_COHERENCY_SFW_NO,		CPUID_EBX, 31, 0x8000001f, 0 },
	{ X86_FEATURE_SMBA,			CPUID_EBX,  2, 0x80000020, 0 },
	{ X86_FEATURE_BMEC,			CPUID_EBX,  3, 0x80000020, 0 },
	{ X86_FEATURE_ABMC,			CPUID_EBX,  5, 0x80000020, 0 },
	{ X86_FEATURE_SDCIAE,			CPUID_EBX,  6, 0x80000020, 0 },
	{ X86_FEATURE_TSA_SQ_NO,		CPUID_ECX,  1, 0x80000021, 0 },
	{ X86_FEATURE_TSA_L1_NO,		CPUID_ECX,  2, 0x80000021, 0 },
	{ X86_FEATURE_AMD_WORKLOAD_CLASS,	CPUID_EAX, 22, 0x80000021, 0 },
	{ X86_FEATURE_PERFMON_V2,		CPUID_EAX,  0, 0x80000022, 0 },
	{ X86_FEATURE_AMD_LBR_V2,		CPUID_EAX,  1, 0x80000022, 0 },
	{ X86_FEATURE_AMD_LBR_PMC_FREEZE,	CPUID_EAX,  2, 0x80000022, 0 },
	{ X86_FEATURE_AMD_HTR_CORES,		CPUID_EAX, 30, 0x80000026, 0 },
	{ 0, 0, 0, 0, 0 }
};

void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{
	u32 max_level;
	u32 regs[4];
	const struct cpuid_bit *cb;

	for (cb = cpuid_bits; cb->feature; cb++) {

		/* Verify that the level is valid */
		max_level = cpuid_eax(cb->level & 0xffff0000);
		if (max_level < cb->level ||
		    max_level > (cb->level | 0xffff))
			continue;

		cpuid_count(cb->level, cb->sub_leaf, &regs[CPUID_EAX],
			    &regs[CPUID_EBX], &regs[CPUID_ECX],
			    &regs[CPUID_EDX]);

		if (regs[cb->reg] & (1 << cb->bit))
			set_cpu_cap(c, cb->feature);
	}
}

Annotation

Implementation Notes