Commit a7c32a1a authored by Borislav Petkov (AMD)'s avatar Borislav Petkov (AMD)
Browse files

x86/CPU/AMD: Carve out the erratum 1386 fix 



Call it on the affected CPU generations.

No functional changes.

Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarNikolay Borisov <nik.borisov@suse.com>
Link: http://lore.kernel.org/r/20231120104152.13740-3-bp@alien8.de
parent 30fa9283

arch/x86/kernel/cpu/amd.c

+15 −9
Original line number Diff line number Diff line
@@ -984,6 +984,19 @@ static void init_amd_bd(struct cpuinfo_x86 *c) 
	clear_rdrand_cpuid_bit(c);

}



static void fix_erratum_1386(struct cpuinfo_x86 *c)

{

	/*

	 * Work around Erratum 1386.  The XSAVES instruction malfunctions in

	 * certain circumstances on Zen1/2 uarch, and not all parts have had

	 * updated microcode at the time of writing (March 2023).

	 *

	 * Affected parts all have no supervisor XSAVE states, meaning that

	 * the XSAVEC instruction (which works fine) is equivalent.

	 */

	clear_cpu_cap(c, X86_FEATURE_XSAVES);

}



void init_spectral_chicken(struct cpuinfo_x86 *c)

{

#ifdef CONFIG_CPU_UNRET_ENTRY
@@ -1004,15 +1017,6 @@ void init_spectral_chicken(struct cpuinfo_x86 *c) 
		}

	}

#endif

	/*

	 * Work around Erratum 1386.  The XSAVES instruction malfunctions in

	 * certain circumstances on Zen1/2 uarch, and not all parts have had

	 * updated microcode at the time of writing (March 2023).

	 *

	 * Affected parts all have no supervisor XSAVE states, meaning that

	 * the XSAVEC instruction (which works fine) is equivalent.

	 */

	clear_cpu_cap(c, X86_FEATURE_XSAVES);

}



static void init_amd_zn(struct cpuinfo_x86 *c)
@@ -1080,10 +1084,12 @@ static void zenbleed_check(struct cpuinfo_x86 *c) 


static void init_amd_zen(struct cpuinfo_x86 *c)

{

	fix_erratum_1386(c);

}



static void init_amd_zen2(struct cpuinfo_x86 *c)

{

	fix_erratum_1386(c);

}



static void init_amd_zen3(struct cpuinfo_x86 *c)