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Commit 7ce2f039 authored by Borislav Petkov's avatar Borislav Petkov Committed by Thomas Gleixner
Browse files

x86/CPU/AMD: Move TOPOEXT reenablement before reading smp_num_siblings 



The TOPOEXT reenablement is a workaround for broken BIOSen which didn't
enable the CPUID bit. amd_get_topology_early(), however, relies on
that bit being set so that it can read out the CPUID leaf and set
smp_num_siblings properly.

Move the reenablement up to early_init_amd(). While at it, simplify
amd_get_topology_early().

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 11e34e64

arch/x86/kernel/cpu/amd.c

+17 −20
Original line number Diff line number Diff line
@@ -318,12 +318,8 @@ static void legacy_fixup_core_id(struct cpuinfo_x86 *c) 


static void amd_get_topology_early(struct cpuinfo_x86 *c)

{

	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {

		u32 eax, ebx, ecx, edx;



		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);

		smp_num_siblings = ((ebx >> 8) & 0xff) + 1;

	}

	if (cpu_has(c, X86_FEATURE_TOPOEXT))

		smp_num_siblings = ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1;

}



/*
@@ -345,7 +341,6 @@ static void amd_get_topology(struct cpuinfo_x86 *c) 
		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);



		node_id  = ecx & 0xff;

		smp_num_siblings = ((ebx >> 8) & 0xff) + 1;



		if (c->x86 == 0x15)

			c->cu_id = ebx & 0xff;
@@ -622,6 +617,7 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c) 


static void early_init_amd(struct cpuinfo_x86 *c)

{

	u64 value;

	u32 dummy;



	early_init_amd_mc(c);
@@ -693,6 +689,20 @@ static void early_init_amd(struct cpuinfo_x86 *c) 


	early_detect_mem_encrypt(c);



	/* Re-enable TopologyExtensions if switched off by BIOS */

	if (c->x86 == 0x15 &&

	    (c->x86_model >= 0x10 && c->x86_model <= 0x6f) &&

	    !cpu_has(c, X86_FEATURE_TOPOEXT)) {



		if (msr_set_bit(0xc0011005, 54) > 0) {

			rdmsrl(0xc0011005, value);

			if (value & BIT_64(54)) {

				set_cpu_cap(c, X86_FEATURE_TOPOEXT);

				pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");

			}

		}

	}



	amd_get_topology_early(c);

}
@@ -785,19 +795,6 @@ static void init_amd_bd(struct cpuinfo_x86 *c) 
{

	u64 value;



	/* re-enable TopologyExtensions if switched off by BIOS */

	if ((c->x86_model >= 0x10) && (c->x86_model <= 0x6f) &&

	    !cpu_has(c, X86_FEATURE_TOPOEXT)) {



		if (msr_set_bit(0xc0011005, 54) > 0) {

			rdmsrl(0xc0011005, value);

			if (value & BIT_64(54)) {

				set_cpu_cap(c, X86_FEATURE_TOPOEXT);

				pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");

			}

		}

	}



	/*

	 * The way access filter has a performance penalty on some workloads.

	 * Disable it on the affected CPUs.