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From:   Arnd Bergmann <arnd@kernel.org>
To:     Borislav Petkov <bp@alien8.de>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        linux-kernel@vger.kernel.org, x86@kernel.org,
        Arnd Bergmann <arnd@arndb.de>
Subject: [PATCH v3 1/7] x86: Fix amd_check_microcode() declaration
Date:   Thu,  3 Aug 2023 10:26:13 +0200
Message-Id: <20230803082619.1369127-2-arnd@kernel.org>
In-Reply-To: <20230803082619.1369127-1-arnd@kernel.org>
References: <20230803082619.1369127-1-arnd@kernel.org>
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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 a9b3f9635727e..81d3294b2b5e2 100644
--- a/arch/x86/include/asm/microcode_amd.h
+++ b/arch/x86/include/asm/microcode_amd.h
@@ -47,12 +47,11 @@ struct microcode_amd {
 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);
-extern void amd_check_microcode(void);
 #else
 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) {}
-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