[tip: x86/microcode] x86/microcode/amd: Use cached microcode for AP load

tip-bot2 for Thomas Gleixner
2023-10-11T09:01:14Z

Commit-ID: 1c9faa6577b3230ba62a51dc504d841b5ef630de
Gitweb: https://git.kernel.org/tip/1c9faa6577b3230ba62a51dc504d841b5ef630de
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 10 Oct 2023 17:08:45 +02:00
Committer: Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Tue, 10 Oct 2023 21:16:47 +02:00

x86/microcode/amd: Use cached microcode for AP load

Now that the microcode cache is initialized before the APs are brought up,
there is no point in scanning builtin/initrd microcode during AP
loading.

Convert the AP loader to utilize the cache, which in turn makes the CPU
hotplug callback which applies the microcode after initrd/builtin is
gone, obsolete as the early loading during late hotplug operations
including the resume path depends now only on the cache.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231010150702.606691031@linutronix.de
---
arch/x86/kernel/cpu/microcode/amd.c | 20 +++++++++++---------
arch/x86/kernel/cpu/microcode/core.c | 15 ++-------------
arch/x86/kernel/cpu/microcode/internal.h | 2 --
3 files changed, 13 insertions(+), 24 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 6a1495a..8baa8ce 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -496,7 +496,7 @@ static bool get_builtin_microcode(struct cpio_data *cp, unsigned int family)
return false;
}

-static void find_blobs_in_containers(unsigned int cpuid_1_eax, struct cpio_data *ret)
+static void __init find_blobs_in_containers(unsigned int cpuid_1_eax, struct cpio_data *ret)
{
struct cpio_data cp;

@@ -506,12 +506,12 @@ static void find_blobs_in_containers(unsigned int cpuid_1_eax, struct cpio_data
*ret = cp;
}

-static void apply_ucode_from_containers(unsigned int cpuid_1_eax)
+void __init load_ucode_amd_bsp(unsigned int cpuid_1_eax)
{
struct cpio_data cp = { };

/* Needed in load_microcode_amd() */
- ucode_cpu_info[smp_processor_id()].cpu_sig.sig = cpuid_1_eax;
+ ucode_cpu_info[0].cpu_sig.sig = cpuid_1_eax;

find_blobs_in_containers(cpuid_1_eax, &cp);
if (!(cp.data && cp.size))
@@ -520,11 +520,6 @@ static void apply_ucode_from_containers(unsigned int cpuid_1_eax)
early_apply_microcode(cpuid_1_eax, cp.data, cp.size);
}

-void load_ucode_amd_early(unsigned int cpuid_1_eax)
-{
- return apply_ucode_from_containers(cpuid_1_eax);
-}
-
static enum ucode_state load_microcode_amd(u8 family, const u8 *data, size_t size);

static int __init save_microcode_in_initrd(void)
@@ -608,7 +603,6 @@ static struct ucode_patch *find_patch(unsigned int cpu)
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
u16 equiv_id;

-
equiv_id = find_equiv_id(&equiv_table, uci->cpu_sig.sig);
if (!equiv_id)
return NULL;
@@ -710,6 +704,14 @@ out:
return ret;
}

+void load_ucode_amd_ap(unsigned int cpuid_1_eax)
+{
+ unsigned int cpu = smp_processor_id();
+
+ ucode_cpu_info[cpu].cpu_sig.sig = cpuid_1_eax;
+ apply_microcode_amd(cpu);
+}
+
static size_t install_equiv_cpu_table(const u8 *buf, size_t buf_size)
{
u32 equiv_tbl_len;
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index b71bac0..57dde24 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -159,7 +159,7 @@ void __init load_ucode_bsp(void)
if (intel)
load_ucode_intel_bsp();
else
- load_ucode_amd_early(cpuid_1_eax);
+ load_ucode_amd_bsp(cpuid_1_eax);
}

void load_ucode_ap(void)
@@ -178,7 +178,7 @@ void load_ucode_ap(void)
break;
case X86_VENDOR_AMD:
if (x86_family(cpuid_1_eax) >= 0x10)
- load_ucode_amd_early(cpuid_1_eax);
+ load_ucode_amd_ap(cpuid_1_eax);
break;
default:
break;
@@ -789,15 +789,6 @@ static struct syscore_ops mc_syscore_ops = {
.resume = microcode_bsp_resume,
};

-static int mc_cpu_starting(unsigned int cpu)
-{
- enum ucode_state err = microcode_ops->apply_microcode(cpu);
-
- pr_debug("%s: CPU%d, err: %d\n", __func__, cpu, err);
-
- return err == UCODE_ERROR;
-}
-
static int mc_cpu_online(unsigned int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
@@ -870,8 +861,6 @@ static int __init microcode_init(void)
}

register_syscore_ops(&mc_syscore_ops);
- cpuhp_setup_state_nocalls(CPUHP_AP_MICROCODE_LOADER, "x86/microcode:starting",
- mc_cpu_starting, NULL);
cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
mc_cpu_online, mc_cpu_down_prep);

diff --git a/arch/x86/kernel/cpu/microcode/internal.h b/arch/x86/kernel/cpu/microcode/internal.h
index de37255..9930788 100644
--- a/arch/x86/kernel/cpu/microcode/internal.h
+++ b/arch/x86/kernel/cpu/microcode/internal.h
@@ -95,7 +95,6 @@ extern bool initrd_gone;
#ifdef CONFIG_CPU_SUP_AMD
void load_ucode_amd_bsp(unsigned int family);
void load_ucode_amd_ap(unsigned int family);
-void load_ucode_amd_early(unsigned int cpuid_1_eax);
int save_microcode_in_initrd_amd(unsigned int family);
void reload_ucode_amd(unsigned int cpu);
struct microcode_ops *init_amd_microcode(void);
@@ -103,7 +102,6 @@ void exit_amd_microcode(void);
#else /* CONFIG_CPU_SUP_AMD */
static inline void load_ucode_amd_bsp(unsigned int family) { }
static inline void load_ucode_amd_ap(unsigned int family) { }
-static inline void load_ucode_amd_early(unsigned int family) { }
static inline int save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; }
static inline void reload_ucode_amd(unsigned int cpu) { }
static inline struct microcode_ops *init_amd_microcode(void) { return NULL; }