[tip: x86/microcode] x86/microcode/AMD: Rip out static buffers

From: tip-bot2 for Borislav Petkov (AMD)
Date: Thu Jul 27 2023 - 05:14:41 EST


The following commit has been merged into the x86/microcode branch of tip:

Commit-ID: 05e91e72113833385fb8c9a33bda9dbd93e27609
Gitweb: https://git.kernel.org/tip/05e91e72113833385fb8c9a33bda9dbd93e27609
Author: Borislav Petkov (AMD) <bp@xxxxxxxxx>
AuthorDate: Wed, 07 Jun 2023 21:01:06 +02:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Thu, 27 Jul 2023 10:04:54 +02:00

x86/microcode/AMD: Rip out static buffers

Load straight from the containers (initrd or builtin, for example).
There's no need to cache the patch per node.

This even simplifies the code a bit with the opportunity for more
cleanups later.

Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Tested-by: John Allen <john.allen@xxxxxxx>
Link: https://lore.kernel.org/r/20230720202813.3269888-1-john.allen@xxxxxxx
---
arch/x86/include/asm/microcode_amd.h | 6 +--
arch/x86/kernel/cpu/microcode/amd.c | 91 ++++++++-------------------
arch/x86/kernel/cpu/microcode/core.c | 4 +-
3 files changed, 31 insertions(+), 70 deletions(-)

diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
index e6662ad..a995b76 100644
--- a/arch/x86/include/asm/microcode_amd.h
+++ b/arch/x86/include/asm/microcode_amd.h
@@ -44,13 +44,11 @@ struct microcode_amd {
#define PATCH_MAX_SIZE (3 * PAGE_SIZE)

#ifdef CONFIG_MICROCODE_AMD
-extern void __init load_ucode_amd_bsp(unsigned int family);
-extern void load_ucode_amd_ap(unsigned int family);
+extern void load_ucode_amd_early(unsigned int cpuid_1_eax);
extern int __init save_microcode_in_initrd_amd(unsigned int family);
void reload_ucode_amd(unsigned int cpu);
#else
-static inline void __init 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 cpuid_1_eax) {}
static inline int __init
save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; }
static inline void reload_ucode_amd(unsigned int cpu) {}
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 87208e4..a28b103 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -56,9 +56,6 @@ struct cont_desc {

static u32 ucode_new_rev;

-/* One blob per node. */
-static u8 amd_ucode_patch[MAX_NUMNODES][PATCH_MAX_SIZE];
-
/*
* Microcode patch container file is prepended to the initrd in cpio
* format. See Documentation/arch/x86/microcode.rst
@@ -415,20 +412,17 @@ static int __apply_microcode_amd(struct microcode_amd *mc)
*
* Returns true if container found (sets @desc), false otherwise.
*/
-static bool early_apply_microcode(u32 cpuid_1_eax, void *ucode, size_t size, bool save_patch)
+static bool early_apply_microcode(u32 cpuid_1_eax, void *ucode, size_t size)
{
struct cont_desc desc = { 0 };
- u8 (*patch)[PATCH_MAX_SIZE];
struct microcode_amd *mc;
u32 rev, dummy, *new_rev;
bool ret = false;

#ifdef CONFIG_X86_32
new_rev = (u32 *)__pa_nodebug(&ucode_new_rev);
- patch = (u8 (*)[PATCH_MAX_SIZE])__pa_nodebug(&amd_ucode_patch);
#else
new_rev = &ucode_new_rev;
- patch = &amd_ucode_patch[0];
#endif

desc.cpuid_1_eax = cpuid_1_eax;
@@ -452,9 +446,6 @@ static bool early_apply_microcode(u32 cpuid_1_eax, void *ucode, size_t size, boo
if (!__apply_microcode_amd(mc)) {
*new_rev = mc->hdr.patch_id;
ret = true;
-
- if (save_patch)
- memcpy(patch, mc, min_t(u32, desc.psize, PATCH_MAX_SIZE));
}

return ret;
@@ -507,7 +498,7 @@ static void find_blobs_in_containers(unsigned int cpuid_1_eax, struct cpio_data
*ret = cp;
}

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

@@ -515,42 +506,12 @@ void __init load_ucode_amd_bsp(unsigned int cpuid_1_eax)
if (!(cp.data && cp.size))
return;

- early_apply_microcode(cpuid_1_eax, cp.data, cp.size, true);
+ early_apply_microcode(cpuid_1_eax, cp.data, cp.size);
}

-void load_ucode_amd_ap(unsigned int cpuid_1_eax)
+void load_ucode_amd_early(unsigned int cpuid_1_eax)
{
- struct microcode_amd *mc;
- struct cpio_data cp;
- u32 *new_rev, rev, dummy;
-
- if (IS_ENABLED(CONFIG_X86_32)) {
- mc = (struct microcode_amd *)__pa_nodebug(amd_ucode_patch);
- new_rev = (u32 *)__pa_nodebug(&ucode_new_rev);
- } else {
- mc = (struct microcode_amd *)amd_ucode_patch;
- new_rev = &ucode_new_rev;
- }
-
- native_rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
-
- /*
- * Check whether a new patch has been saved already. Also, allow application of
- * the same revision in order to pick up SMT-thread-specific configuration even
- * if the sibling SMT thread already has an up-to-date revision.
- */
- if (*new_rev && rev <= mc->hdr.patch_id) {
- if (!__apply_microcode_amd(mc)) {
- *new_rev = mc->hdr.patch_id;
- return;
- }
- }
-
- find_blobs_in_containers(cpuid_1_eax, &cp);
- if (!(cp.data && cp.size))
- return;
-
- early_apply_microcode(cpuid_1_eax, cp.data, cp.size, false);
+ return apply_ucode_from_containers(cpuid_1_eax);
}

static enum ucode_state load_microcode_amd(u8 family, const u8 *data, size_t size);
@@ -578,23 +539,6 @@ int __init save_microcode_in_initrd_amd(unsigned int cpuid_1_eax)
return 0;
}

-void reload_ucode_amd(unsigned int cpu)
-{
- u32 rev, dummy __always_unused;
- struct microcode_amd *mc;
-
- mc = (struct microcode_amd *)amd_ucode_patch[cpu_to_node(cpu)];
-
- rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
-
- if (rev < mc->hdr.patch_id) {
- if (!__apply_microcode_amd(mc)) {
- ucode_new_rev = mc->hdr.patch_id;
- pr_info("reload patch_level=0x%08x\n", ucode_new_rev);
- }
- }
-}
-
/*
* a small, trivial cache of per-family ucode patches
*/
@@ -655,6 +599,28 @@ static struct ucode_patch *find_patch(unsigned int cpu)
return cache_find_patch(equiv_id);
}

+void reload_ucode_amd(unsigned int cpu)
+{
+ u32 rev, dummy __always_unused;
+ struct microcode_amd *mc;
+ struct ucode_patch *p;
+
+ p = find_patch(cpu);
+ if (!p)
+ return;
+
+ mc = p->data;
+
+ rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
+
+ if (rev < mc->hdr.patch_id) {
+ if (!__apply_microcode_amd(mc)) {
+ ucode_new_rev = mc->hdr.patch_id;
+ pr_info("reload patch_level=0x%08x\n", ucode_new_rev);
+ }
+ }
+}
+
static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
{
struct cpuinfo_x86 *c = &cpu_data(cpu);
@@ -875,9 +841,6 @@ static enum ucode_state load_microcode_amd(u8 family, const u8 *data, size_t siz
continue;

ret = UCODE_NEW;
-
- memset(&amd_ucode_patch[nid], 0, PATCH_MAX_SIZE);
- memcpy(&amd_ucode_patch[nid], p->data, min_t(u32, p->size, PATCH_MAX_SIZE));
}

return ret;
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 3afcf3d..192adf5 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -172,7 +172,7 @@ void __init load_ucode_bsp(void)
if (intel)
load_ucode_intel_bsp();
else
- load_ucode_amd_bsp(cpuid_1_eax);
+ load_ucode_amd_early(cpuid_1_eax);
}

static bool check_loader_disabled_ap(void)
@@ -200,7 +200,7 @@ void load_ucode_ap(void)
break;
case X86_VENDOR_AMD:
if (x86_family(cpuid_1_eax) >= 0x10)
- load_ucode_amd_ap(cpuid_1_eax);
+ load_ucode_amd_early(cpuid_1_eax);
break;
default:
break;