4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Gleixner <t...@linutronix.de>
commit 1e1d7e25fd759eddf96d8ab39d0a90a1979b2d8c upstream
To support force disabling of SMT it's required to know the number of
thread siblings early. amd_get_topology() cannot be called before the APIC
driver is selected, so split out the part which initializes
smp_num_siblings and invoke it from amd_early_init().
[dwmw2: Backport to 4.9]
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Acked-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/x86/kernel/cpu/amd.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -296,13 +296,24 @@ static int nearby_node(int apicid)
}
#endif
+#ifdef CONFIG_SMP
+
+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;
+ }
+}
+
/*
* Fixup core topology information for
* (1) AMD multi-node processors
* Assumption: Number of cores in each internal node is the same.
* (2) AMD processors supporting compute units
*/
-#ifdef CONFIG_SMP
static void amd_get_topology(struct cpuinfo_x86 *c)
{
u8 node_id;
@@ -633,6 +644,8 @@ static void early_init_amd(struct cpuinf
*/
if (cpu_has_amd_erratum(c, amd_erratum_400))
set_cpu_bug(c, X86_BUG_AMD_E400);
+
+ amd_get_topology_early(c);
}
static void init_amd_k8(struct cpuinfo_x86 *c)
