[PATCH 07/14] x86/microcode: Use the firmware_loader built-in API

From: Luis R. Rodriguez
Date: Fri Sep 17 2021 - 14:24:21 EST


From: Borislav Petkov <bp@xxxxxxx>

The microcode loader has been looping through __start_builtin_fw down to
__end_builtin_fw to look for possibly built-in firmware for microcode
updates.

Now that the firmware loader code has exported an API for looping
through the kernel's built-in firmware section, use it and drop the x86
implementation in favor.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
arch/x86/include/asm/microcode.h | 3 ---
arch/x86/kernel/cpu/microcode/amd.c | 14 ++++++++++----
arch/x86/kernel/cpu/microcode/core.c | 17 -----------------
arch/x86/kernel/cpu/microcode/intel.c | 9 ++++++++-
4 files changed, 18 insertions(+), 25 deletions(-)

diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h
index ab45a220fac4..d6bfdfb0f0af 100644
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -130,14 +130,11 @@ static inline unsigned int x86_cpuid_family(void)
extern void __init load_ucode_bsp(void);
extern void load_ucode_ap(void);
void reload_early_microcode(void);
-extern bool get_builtin_firmware(struct cpio_data *cd, const char *name);
extern bool initrd_gone;
#else
static inline void __init load_ucode_bsp(void) { }
static inline void load_ucode_ap(void) { }
static inline void reload_early_microcode(void) { }
-static inline bool
-get_builtin_firmware(struct cpio_data *cd, const char *name) { return false; }
#endif

#endif /* _ASM_X86_MICROCODE_H */
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 3d4a48336084..8b2fcdfa6d31 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -456,17 +456,23 @@ apply_microcode_early_amd(u32 cpuid_1_eax, void *ucode, size_t size, bool save_p

static bool get_builtin_microcode(struct cpio_data *cp, unsigned int family)
{
-#ifdef CONFIG_X86_64
char fw_name[36] = "amd-ucode/microcode_amd.bin";
+ struct firmware fw;
+
+ if (IS_ENABLED(CONFIG_X86_32))
+ return false;

if (family >= 0x15)
snprintf(fw_name, sizeof(fw_name),
"amd-ucode/microcode_amd_fam%.2xh.bin", family);

- return get_builtin_firmware(cp, fw_name);
-#else
+ if (firmware_request_builtin(&fw, fw_name)) {
+ cp->size = fw.size;
+ cp->data = (void *)fw.data;
+ return true;
+ }
+
return false;
-#endif
}

static void __load_ucode_amd(unsigned int cpuid_1_eax, struct cpio_data *ret)
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index efb69be41ab1..f955d25076ba 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -140,23 +140,6 @@ static bool __init check_loader_disabled_bsp(void)
return *res;
}

-extern struct builtin_fw __start_builtin_fw[];
-extern struct builtin_fw __end_builtin_fw[];
-
-bool get_builtin_firmware(struct cpio_data *cd, const char *name)
-{
- struct builtin_fw *b_fw;
-
- for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
- if (!strcmp(name, b_fw->name)) {
- cd->size = b_fw->size;
- cd->data = b_fw->data;
- return true;
- }
- }
- return false;
-}
-
void __init load_ucode_bsp(void)
{
unsigned int cpuid_1_eax;
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 7e8e07bddd5f..d28a9f8f3fec 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -456,6 +456,7 @@ static void save_mc_for_early(struct ucode_cpu_info *uci, u8 *mc, unsigned int s
static bool load_builtin_intel_microcode(struct cpio_data *cp)
{
unsigned int eax = 1, ebx, ecx = 0, edx;
+ struct firmware fw;
char name[30];

if (IS_ENABLED(CONFIG_X86_32))
@@ -466,7 +467,13 @@ static bool load_builtin_intel_microcode(struct cpio_data *cp)
sprintf(name, "intel-ucode/%02x-%02x-%02x",
x86_family(eax), x86_model(eax), x86_stepping(eax));

- return get_builtin_firmware(cp, name);
+ if (firmware_request_builtin(&fw, name)) {
+ cp->size = fw.size;
+ cp->data = (void *)fw.data;
+ return true;
+ }
+
+ return false;
}

/*
--
2.30.2