x86/cpufeatures: Remove get_scattered_cpuid_leaf()

Sean Christopherson · suryasaimadhu · commit 43500e6f294d · 2018-11-05T20:54:20.000+01:00
get_scattered_cpuid_leaf() was added[1] to help KVM rebuild hardware- defined leafs that are rearranged by Linux to avoid bloating the x86_capability array. Eventually, the last consumer of the function was removed[2], but the function itself was kept, perhaps even intentionally as a form of documentation. Remove get_scattered_cpuid_leaf() as it is currently not used by KVM. Furthermore, simply rebuilding the "real" leaf does not resolve all of KVM's woes when it comes to exposing a scattered CPUID feature, i.e. keeping the function as documentation may be counter-productive in some scenarios, e.g. when KVM needs to do more than simply expose the leaf. [1] 47bdf33 ("x86/cpuid: Provide get_scattered_cpuid_leaf()") [2] b7b27aa ("KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Ingo Molnar <mingo@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/20181105185725.18679-1-sean.j.christopherson@intel.com
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
@@ -49,9 +49,6 @@ extern void get_cpu_cap(struct cpuinfo_x86 *c);
 extern void get_cpu_address_sizes(struct cpuinfo_x86 *c);
 extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
 extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
-extern u32 get_scattered_cpuid_leaf(unsigned int level,
-				    unsigned int sub_leaf,
-				    enum cpuid_regs_idx reg);
 extern void init_intel_cacheinfo(struct cpuinfo_x86 *c);
 extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
 extern void init_hygon_cacheinfo(struct cpuinfo_x86 *c);
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
@@ -56,27 +56,3 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
 			set_cpu_cap(c, cb->feature);
 	}
 }
-
-u32 get_scattered_cpuid_leaf(unsigned int level, unsigned int sub_leaf,
-			     enum cpuid_regs_idx reg)
-{
-	const struct cpuid_bit *cb;
-	u32 cpuid_val = 0;
-
-	for (cb = cpuid_bits; cb->feature; cb++) {
-
-		if (level > cb->level)
-			continue;
-
-		if (level < cb->level)
-			break;
-
-		if (reg == cb->reg && sub_leaf == cb->sub_leaf) {
-			if (cpu_has(&boot_cpu_data, cb->feature))
-				cpuid_val |= BIT(cb->bit);
-		}
-	}
-
-	return cpuid_val;
-}
-EXPORT_SYMBOL_GPL(get_scattered_cpuid_leaf);
