[PATCH] [v2] x86: Fix amd_check_microcode() declaration

[PATCH] [v2] x86: Fix amd_check_microcode() declaration

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

The newly added amd_check_microcode() function has two conflicting definitions
if CONFIG_CPU_SUP_AMD is enabled and CONFIG_MICROCODE_AMD is disabled. Since
the header with the stub definition is not included in cpu/amd.c, this only
causes a -Wmissing-prototype warning with W=1

arch/x86/kernel/cpu/amd.c:1289:6: error: no previous prototype for 'amd_check_microcode' [-Werror=missing-prototypes]

Adding the missing #include shows the other problem:

arch/x86/kernel/cpu/amd.c:1290:6: error: redefinition of 'amd_check_microcode'
arch/x86/include/asm/microcode_amd.h:58:20: note: previous definition of 'amd_check_microcode' with type 'void(void)'

Move the declaration into a more appropriate header that is already included,
with the #ifdef check changed to match the definition's.

Fixes: 522b1d69219d8 ("x86/cpu/amd: Add a Zenbleed fix")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/x86/include/asm/microcode_amd.h | 3 +--
 arch/x86/include/asm/processor.h     | 2 ++
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
index 9675c621c1ca4..2ed09a1da4a27 100644
--- a/arch/x86/include/asm/microcode_amd.h
+++ b/arch/x86/include/asm/microcode_amd.h
@@ -48,13 +48,12 @@ extern void __init load_ucode_amd_bsp(unsigned int family);
 extern void load_ucode_amd_ap(unsigned int family);
 extern int __init save_microcode_in_initrd_amd(unsigned int family);
 void reload_ucode_amd(unsigned int cpu);
-extern void amd_check_microcode(void);
 #else
 static inline void __init load_ucode_amd_bsp(unsigned int family) {}
 static inline void load_ucode_amd_ap(unsigned int family) {}
 static inline int __init
 save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; }
 static inline void reload_ucode_amd(unsigned int cpu) {}
-static inline void amd_check_microcode(void) {}
 #endif
+
 #endif /* _ASM_X86_MICROCODE_AMD_H */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index d46300e94f853..36d52075fdade 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -682,9 +682,11 @@ extern u16 get_llc_id(unsigned int cpu);
 #ifdef CONFIG_CPU_SUP_AMD
 extern u32 amd_get_nodes_per_socket(void);
 extern u32 amd_get_highest_perf(void);
+extern void amd_check_microcode(void);
 #else
 static inline u32 amd_get_nodes_per_socket(void)	{ return 0; }
 static inline u32 amd_get_highest_perf(void)		{ return 0; }
+static inline void amd_check_microcode(void)		{ }
 #endif
 
 extern unsigned long arch_align_stack(unsigned long sp);
-- 
2.39.2

[tip: x86/cleanups] x86/cpu: Fix amd_check_microcode() declaration

[tip-bot2 for Arnd Bergmann]

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

Commit-ID:     566ffa3ae9649f7aa1debcf559ee7e26ed4a110f
Gitweb:        https://git.kernel.org/tip/566ffa3ae9649f7aa1debcf559ee7e26ed4a110f
Author:        Arnd Bergmann <arnd@arndb.de>
AuthorDate:    Tue, 25 Jul 2023 14:17:39 +02:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Mon, 31 Jul 2023 11:03:16 +02:00

x86/cpu: Fix amd_check_microcode() declaration

The newly added amd_check_microcode() function has two conflicting definitions
if CONFIG_CPU_SUP_AMD is enabled and CONFIG_MICROCODE_AMD is disabled. Since
the header with the stub definition is not included in cpu/amd.c, this only
causes a -Wmissing-prototype warning with W=1:

  arch/x86/kernel/cpu/amd.c:1289:6: error: no previous prototype for 'amd_check_microcode' [-Werror=missing-prototypes]

Adding the missing #include shows the other problem:

  arch/x86/kernel/cpu/amd.c:1290:6: error: redefinition of 'amd_check_microcode'
  arch/x86/include/asm/microcode_amd.h:58:20: note: previous definition of 'amd_check_microcode' with type 'void(void)'

Move the declaration into a more appropriate header that is already
included, with the #ifdef check changed to match the definition's.

Fixes: 522b1d69219d8 ("x86/cpu/amd: Add a Zenbleed fix")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230725121751.2007665-1-arnd@kernel.org
---
 arch/x86/include/asm/microcode_amd.h | 3 +--
 arch/x86/include/asm/processor.h     | 2 ++
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
index 9675c62..2ed09a1 100644
--- a/arch/x86/include/asm/microcode_amd.h
+++ b/arch/x86/include/asm/microcode_amd.h
@@ -48,13 +48,12 @@ extern void __init load_ucode_amd_bsp(unsigned int family);
 extern void load_ucode_amd_ap(unsigned int family);
 extern int __init save_microcode_in_initrd_amd(unsigned int family);
 void reload_ucode_amd(unsigned int cpu);
-extern void amd_check_microcode(void);
 #else
 static inline void __init load_ucode_amd_bsp(unsigned int family) {}
 static inline void load_ucode_amd_ap(unsigned int family) {}
 static inline int __init
 save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; }
 static inline void reload_ucode_amd(unsigned int cpu) {}
-static inline void amd_check_microcode(void) {}
 #endif
+
 #endif /* _ASM_X86_MICROCODE_AMD_H */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index d46300e..36d5207 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -682,9 +682,11 @@ extern u16 get_llc_id(unsigned int cpu);
 #ifdef CONFIG_CPU_SUP_AMD
 extern u32 amd_get_nodes_per_socket(void);
 extern u32 amd_get_highest_perf(void);
+extern void amd_check_microcode(void);
 #else
 static inline u32 amd_get_nodes_per_socket(void)	{ return 0; }
 static inline u32 amd_get_highest_perf(void)		{ return 0; }
+static inline void amd_check_microcode(void)		{ }
 #endif
 
 extern unsigned long arch_align_stack(unsigned long sp);