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[PATCH v4 06/22] x86/mce/amd: Remove return value for mce_threshold_{create,remove}_device()

Yazen Ghannam posted 22 patches 3 months, 2 weeks ago
There is a newer version of this series
[PATCH v4 06/22] x86/mce/amd: Remove return value for mce_threshold_{create,remove}_device()
Posted by Yazen Ghannam 3 months, 2 weeks ago 
The return values are not checked, so set return type to 'void'.

Also, move function declarations to internal.h, since these functions are
only used within the MCE subsystem.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---

Notes:
    Link:
    https://lore.kernel.org/r/20250415-wip-mca-updates-v3-2-8ffd9eb4aa56@amd.com
    
    v3->v4:
    * No change.
    
    v2->v3:
    * Include mce_threshold_remove_device().
    
    v1->v2:
    * New in v2.

 arch/x86/include/asm/mce.h         |  6 ------
 arch/x86/kernel/cpu/mce/amd.c      | 22 ++++++++++------------
 arch/x86/kernel/cpu/mce/internal.h |  4 ++++
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 6c77c03139f7..752802bf966b 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -371,15 +371,9 @@ enum smca_bank_types {
 
 extern bool amd_mce_is_memory_error(struct mce *m);
 
-extern int mce_threshold_create_device(unsigned int cpu);
-extern int mce_threshold_remove_device(unsigned int cpu);
-
 void mce_amd_feature_init(struct cpuinfo_x86 *c);
 enum smca_bank_types smca_get_bank_type(unsigned int cpu, unsigned int bank);
 #else
-
-static inline int mce_threshold_create_device(unsigned int cpu)		{ return 0; };
-static inline int mce_threshold_remove_device(unsigned int cpu)		{ return 0; };
 static inline bool amd_mce_is_memory_error(struct mce *m)		{ return false; };
 static inline void mce_amd_feature_init(struct cpuinfo_x86 *c)		{ }
 #endif
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 9b980aecb6b3..f429451cafc8 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -1296,12 +1296,12 @@ static void __threshold_remove_device(struct threshold_bank **bp)
 	kfree(bp);
 }
 
-int mce_threshold_remove_device(unsigned int cpu)
+void mce_threshold_remove_device(unsigned int cpu)
 {
 	struct threshold_bank **bp = this_cpu_read(threshold_banks);
 
 	if (!bp)
-		return 0;
+		return;
 
 	/*
 	 * Clear the pointer before cleaning up, so that the interrupt won't
@@ -1310,7 +1310,7 @@ int mce_threshold_remove_device(unsigned int cpu)
 	this_cpu_write(threshold_banks, NULL);
 
 	__threshold_remove_device(bp);
-	return 0;
+	return;
 }
 
 /**
@@ -1324,36 +1324,34 @@ int mce_threshold_remove_device(unsigned int cpu)
  * thread running on @cpu.  The callback is invoked on all CPUs which are
  * online when the callback is installed or during a real hotplug event.
  */
-int mce_threshold_create_device(unsigned int cpu)
+void mce_threshold_create_device(unsigned int cpu)
 {
 	unsigned int numbanks, bank;
 	struct threshold_bank **bp;
-	int err;
 
 	if (!mce_flags.amd_threshold)
-		return 0;
+		return;
 
 	bp = this_cpu_read(threshold_banks);
 	if (bp)
-		return 0;
+		return;
 
 	numbanks = this_cpu_read(mce_num_banks);
 	bp = kcalloc(numbanks, sizeof(*bp), GFP_KERNEL);
 	if (!bp)
-		return -ENOMEM;
+		return;
 
 	for (bank = 0; bank < numbanks; ++bank) {
 		if (!(this_cpu_read(bank_map) & BIT_ULL(bank)))
 			continue;
-		err = threshold_create_bank(bp, cpu, bank);
-		if (err) {
+		if (threshold_create_bank(bp, cpu, bank)) {
 			__threshold_remove_device(bp);
-			return err;
+			return;
 		}
 	}
 	this_cpu_write(threshold_banks, bp);
 
 	if (thresholding_irq_en)
 		mce_threshold_vector = amd_threshold_interrupt;
-	return 0;
+	return;
 }
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index b5ba598e54cb..64ac25b95360 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -265,6 +265,8 @@ void mce_prep_record_common(struct mce *m);
 void mce_prep_record_per_cpu(unsigned int cpu, struct mce *m);
 
 #ifdef CONFIG_X86_MCE_AMD
+void mce_threshold_create_device(unsigned int cpu);
+void mce_threshold_remove_device(unsigned int cpu);
 extern bool amd_filter_mce(struct mce *m);
 bool amd_mce_usable_address(struct mce *m);
 
@@ -293,6 +295,8 @@ static __always_inline void smca_extract_err_addr(struct mce *m)
 }
 
 #else
+static inline void mce_threshold_create_device(unsigned int cpu)	{ }
+static inline void mce_threshold_remove_device(unsigned int cpu)	{ }
 static inline bool amd_filter_mce(struct mce *m) { return false; }
 static inline bool amd_mce_usable_address(struct mce *m) { return false; }
 static inline void smca_extract_err_addr(struct mce *m) { }

-- 
2.49.0
Re: [PATCH v4 06/22] x86/mce/amd: Remove return value for mce_threshold_{create,remove}_device()
Posted by Nikolay Borisov 3 months, 2 weeks ago 

On 6/24/25 17:16, Yazen Ghannam wrote:
> The return values are not checked, so set return type to 'void'.
> 
> Also, move function declarations to internal.h, since these functions are
> only used within the MCE subsystem.
> 
> Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>


Realistically the only case when this code can fail is if the machine is 
tight on memory and a cpu is brought on. So the wider question is should 
such a situation fail the hotplug event? Likely something else in the 
chain would have failed up earlier, so I guess the answer is no.

In any case LGTM:

Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
[tip: ras/core] x86/mce/amd: Remove return value for mce_threshold_{create,remove}_device()
Posted by tip-bot2 for Yazen Ghannam 1 month ago 
The following commit has been merged into the ras/core branch of tip:

Commit-ID:     4d2161b9e8ba64076f520ec2f00eefb00722c15e
Gitweb:        https://git.kernel.org/tip/4d2161b9e8ba64076f520ec2f00eefb00722c15e
Author:        Yazen Ghannam <yazen.ghannam@amd.com>
AuthorDate:    Tue, 24 Jun 2025 14:16:01 
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Fri, 05 Sep 2025 12:40:44 +02:00

x86/mce/amd: Remove return value for mce_threshold_{create,remove}_device()

The return values are not checked, so set return type to 'void'.

Also, move function declarations to internal.h, since these functions are
only used within the MCE subsystem.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Link: https://lore.kernel.org/20250624-wip-mca-updates-v4-6-236dd74f645f@amd.com
---
 arch/x86/include/asm/mce.h         |  6 ------
 arch/x86/kernel/cpu/mce/amd.c      | 22 ++++++++++------------
 arch/x86/kernel/cpu/mce/internal.h |  4 ++++
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 6c77c03..752802b 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -371,15 +371,9 @@ enum smca_bank_types {
 
 extern bool amd_mce_is_memory_error(struct mce *m);
 
-extern int mce_threshold_create_device(unsigned int cpu);
-extern int mce_threshold_remove_device(unsigned int cpu);
-
 void mce_amd_feature_init(struct cpuinfo_x86 *c);
 enum smca_bank_types smca_get_bank_type(unsigned int cpu, unsigned int bank);
 #else
-
-static inline int mce_threshold_create_device(unsigned int cpu)		{ return 0; };
-static inline int mce_threshold_remove_device(unsigned int cpu)		{ return 0; };
 static inline bool amd_mce_is_memory_error(struct mce *m)		{ return false; };
 static inline void mce_amd_feature_init(struct cpuinfo_x86 *c)		{ }
 #endif
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 9b980ae..f429451 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -1296,12 +1296,12 @@ static void __threshold_remove_device(struct threshold_bank **bp)
 	kfree(bp);
 }
 
-int mce_threshold_remove_device(unsigned int cpu)
+void mce_threshold_remove_device(unsigned int cpu)
 {
 	struct threshold_bank **bp = this_cpu_read(threshold_banks);
 
 	if (!bp)
-		return 0;
+		return;
 
 	/*
 	 * Clear the pointer before cleaning up, so that the interrupt won't
@@ -1310,7 +1310,7 @@ int mce_threshold_remove_device(unsigned int cpu)
 	this_cpu_write(threshold_banks, NULL);
 
 	__threshold_remove_device(bp);
-	return 0;
+	return;
 }
 
 /**
@@ -1324,36 +1324,34 @@ int mce_threshold_remove_device(unsigned int cpu)
  * thread running on @cpu.  The callback is invoked on all CPUs which are
  * online when the callback is installed or during a real hotplug event.
  */
-int mce_threshold_create_device(unsigned int cpu)
+void mce_threshold_create_device(unsigned int cpu)
 {
 	unsigned int numbanks, bank;
 	struct threshold_bank **bp;
-	int err;
 
 	if (!mce_flags.amd_threshold)
-		return 0;
+		return;
 
 	bp = this_cpu_read(threshold_banks);
 	if (bp)
-		return 0;
+		return;
 
 	numbanks = this_cpu_read(mce_num_banks);
 	bp = kcalloc(numbanks, sizeof(*bp), GFP_KERNEL);
 	if (!bp)
-		return -ENOMEM;
+		return;
 
 	for (bank = 0; bank < numbanks; ++bank) {
 		if (!(this_cpu_read(bank_map) & BIT_ULL(bank)))
 			continue;
-		err = threshold_create_bank(bp, cpu, bank);
-		if (err) {
+		if (threshold_create_bank(bp, cpu, bank)) {
 			__threshold_remove_device(bp);
-			return err;
+			return;
 		}
 	}
 	this_cpu_write(threshold_banks, bp);
 
 	if (thresholding_irq_en)
 		mce_threshold_vector = amd_threshold_interrupt;
-	return 0;
+	return;
 }
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index b5ba598..64ac25b 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -265,6 +265,8 @@ void mce_prep_record_common(struct mce *m);
 void mce_prep_record_per_cpu(unsigned int cpu, struct mce *m);
 
 #ifdef CONFIG_X86_MCE_AMD
+void mce_threshold_create_device(unsigned int cpu);
+void mce_threshold_remove_device(unsigned int cpu);
 extern bool amd_filter_mce(struct mce *m);
 bool amd_mce_usable_address(struct mce *m);
 
@@ -293,6 +295,8 @@ static __always_inline void smca_extract_err_addr(struct mce *m)
 }
 
 #else
+static inline void mce_threshold_create_device(unsigned int cpu)	{ }
+static inline void mce_threshold_remove_device(unsigned int cpu)	{ }
 static inline bool amd_filter_mce(struct mce *m) { return false; }
 static inline bool amd_mce_usable_address(struct mce *m) { return false; }
 static inline void smca_extract_err_addr(struct mce *m) { }

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