[02/13] x86/CPU/AMD: Carve out the erratum 1386 fix
Commit Message
From: "Borislav Petkov (AMD)" <bp@alien8.de>
Call it on the affected CPU generations.
No functional changes.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
---
arch/x86/kernel/cpu/amd.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
@@ -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)
@@ -1040,10 +1044,12 @@ static void init_amd_zn(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)