[PATCH] x86/cpu/amd: Move TOPOEXT enablement into the topology parser

From: Thomas Gleixner
Date: Thu Apr 11 2024 - 14:06:56 EST


The topology rework missed that early_init_amd() tries to re-enable the
Topology Extensions when the BIOS disabled them.

The new parser is invoked before early_init_amd() so the re-enable attempt
happens too late.

Move it into the AMD specific topology parser code where it belongs.

Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/amd.c | 15 ---------------
arch/x86/kernel/cpu/topology_amd.c | 21 +++++++++++++++++++++
2 files changed, 21 insertions(+), 15 deletions(-)

--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -535,7 +535,6 @@ static void early_detect_mem_encrypt(str

static void early_init_amd(struct cpuinfo_x86 *c)
{
- u64 value;
u32 dummy;

if (c->x86 >= 0xf)
@@ -603,20 +602,6 @@ static void early_init_amd(struct cpuinf

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");
- }
- }
- }
-
if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && !cpu_has(c, X86_FEATURE_IBPB_BRTYPE)) {
if (c->x86 == 0x17 && boot_cpu_has(X86_FEATURE_AMD_IBPB))
setup_force_cpu_cap(X86_FEATURE_IBPB_BRTYPE);
--- a/arch/x86/kernel/cpu/topology_amd.c
+++ b/arch/x86/kernel/cpu/topology_amd.c
@@ -147,6 +147,26 @@ static void legacy_set_llc(struct topo_s
tscan->c->topo.llc_id = apicid >> tscan->dom_shifts[TOPO_CORE_DOMAIN];
}

+static void topoext_fixup(struct topo_scan *tscan)
+{
+ struct cpuinfo_x86 *c = tscan->c;
+ u64 msrval;
+
+ /* Try to re-enable TopologyExtensions if switched off by BIOS */
+ if (cpu_has(c, X86_FEATURE_TOPOEXT) || c->x86_vendor != X86_VENDOR_AMD ||
+ c->x86 != 0x15 || c->x86_model < 0x10 || c->x86_model > 0x6f)
+ return;
+
+ if (msr_set_bit(0xc0011005, 54) <= 0)
+ return;
+
+ rdmsrl(0xc0011005, msrval);
+ if (msrval & BIT_64(54)) {
+ set_cpu_cap(c, X86_FEATURE_TOPOEXT);
+ pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
+ }
+}
+
static void parse_topology_amd(struct topo_scan *tscan)
{
bool has_0xb = false;
@@ -176,6 +196,7 @@ static void parse_topology_amd(struct to
void cpu_parse_topology_amd(struct topo_scan *tscan)
{
tscan->amd_nodes_per_pkg = 1;
+ topoext_fixup(tscan);
parse_topology_amd(tscan);

if (tscan->amd_nodes_per_pkg > 1)