125 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			125 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Declare dependencies between CPUIDs */
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <asm/cpufeature.h>
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struct cpuid_dep {
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	unsigned int	feature;
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	unsigned int	depends;
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};
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/*
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 * Table of CPUID features that depend on others.
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 *
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 * This only includes dependencies that can be usefully disabled, not
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 * features part of the base set (like FPU).
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 *
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 * Note this all is not __init / __initdata because it can be
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 * called from cpu hotplug. It shouldn't do anything in this case,
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 * but it's difficult to tell that to the init reference checker.
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 */
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static const struct cpuid_dep cpuid_deps[] = {
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	{ X86_FEATURE_XSAVEOPT,		X86_FEATURE_XSAVE     },
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	{ X86_FEATURE_XSAVEC,		X86_FEATURE_XSAVE     },
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	{ X86_FEATURE_XSAVES,		X86_FEATURE_XSAVE     },
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	{ X86_FEATURE_AVX,		X86_FEATURE_XSAVE     },
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	{ X86_FEATURE_PKU,		X86_FEATURE_XSAVE     },
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	{ X86_FEATURE_MPX,		X86_FEATURE_XSAVE     },
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	{ X86_FEATURE_XGETBV1,		X86_FEATURE_XSAVE     },
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	{ X86_FEATURE_FXSR_OPT,		X86_FEATURE_FXSR      },
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	{ X86_FEATURE_XMM,		X86_FEATURE_FXSR      },
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	{ X86_FEATURE_XMM2,		X86_FEATURE_XMM       },
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	{ X86_FEATURE_XMM3,		X86_FEATURE_XMM2      },
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	{ X86_FEATURE_XMM4_1,		X86_FEATURE_XMM2      },
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	{ X86_FEATURE_XMM4_2,		X86_FEATURE_XMM2      },
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	{ X86_FEATURE_XMM3,		X86_FEATURE_XMM2      },
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	{ X86_FEATURE_PCLMULQDQ,	X86_FEATURE_XMM2      },
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	{ X86_FEATURE_SSSE3,		X86_FEATURE_XMM2,     },
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	{ X86_FEATURE_F16C,		X86_FEATURE_XMM2,     },
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	{ X86_FEATURE_AES,		X86_FEATURE_XMM2      },
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	{ X86_FEATURE_SHA_NI,		X86_FEATURE_XMM2      },
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	{ X86_FEATURE_FMA,		X86_FEATURE_AVX       },
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	{ X86_FEATURE_AVX2,		X86_FEATURE_AVX,      },
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	{ X86_FEATURE_AVX512F,		X86_FEATURE_AVX,      },
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	{ X86_FEATURE_AVX512IFMA,	X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512PF,		X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512ER,		X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512CD,		X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512DQ,		X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512BW,		X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512VL,		X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512VBMI,	X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512_VBMI2,	X86_FEATURE_AVX512VL  },
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	{ X86_FEATURE_GFNI,		X86_FEATURE_AVX512VL  },
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	{ X86_FEATURE_VAES,		X86_FEATURE_AVX512VL  },
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	{ X86_FEATURE_VPCLMULQDQ,	X86_FEATURE_AVX512VL  },
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	{ X86_FEATURE_AVX512_VNNI,	X86_FEATURE_AVX512VL  },
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	{ X86_FEATURE_AVX512_BITALG,	X86_FEATURE_AVX512VL  },
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	{ X86_FEATURE_AVX512_4VNNIW,	X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512_4FMAPS,	X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_AVX512_VPOPCNTDQ, X86_FEATURE_AVX512F   },
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	{ X86_FEATURE_CQM_OCCUP_LLC,	X86_FEATURE_CQM_LLC   },
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	{ X86_FEATURE_CQM_MBM_TOTAL,	X86_FEATURE_CQM_LLC   },
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	{ X86_FEATURE_CQM_MBM_LOCAL,	X86_FEATURE_CQM_LLC   },
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	{}
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};
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static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)
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{
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	/*
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	 * Note: This could use the non atomic __*_bit() variants, but the
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	 * rest of the cpufeature code uses atomics as well, so keep it for
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	 * consistency. Cleanup all of it separately.
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	 */
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	if (!c) {
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		clear_cpu_cap(&boot_cpu_data, feature);
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		set_bit(feature, (unsigned long *)cpu_caps_cleared);
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	} else {
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		clear_bit(feature, (unsigned long *)c->x86_capability);
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	}
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}
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/* Take the capabilities and the BUG bits into account */
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#define MAX_FEATURE_BITS ((NCAPINTS + NBUGINTS) * sizeof(u32) * 8)
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static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
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{
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	DECLARE_BITMAP(disable, MAX_FEATURE_BITS);
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	const struct cpuid_dep *d;
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	bool changed;
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	if (WARN_ON(feature >= MAX_FEATURE_BITS))
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		return;
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	clear_feature(c, feature);
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	/* Collect all features to disable, handling dependencies */
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	memset(disable, 0, sizeof(disable));
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	__set_bit(feature, disable);
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	/* Loop until we get a stable state. */
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	do {
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		changed = false;
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		for (d = cpuid_deps; d->feature; d++) {
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			if (!test_bit(d->depends, disable))
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				continue;
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			if (__test_and_set_bit(d->feature, disable))
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				continue;
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			changed = true;
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			clear_feature(c, d->feature);
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		}
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	} while (changed);
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}
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void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
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{
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	do_clear_cpu_cap(c, feature);
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}
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void setup_clear_cpu_cap(unsigned int feature)
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{
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	do_clear_cpu_cap(NULL, feature);
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}
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