[PATCH] dma-debug: make dma_debug_add_bus take a const pointer

[PATCH] dma-debug: make dma_debug_add_bus take a const pointer

[Greg Kroah-Hartman]

The driver core now can handle a const struct bus_type pointer, and the
dma_debug_add_bus() call just passes on the pointer give to it to the
driver core, so make this pointer const as well to allow everyone to use
read-only struct bus_type pointers going forward.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: iommu@lists.linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/dma-map-ops.h | 4 ++--
 kernel/dma/debug.c          | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
index f2fc203fb8a1..e401f824a007 100644
--- a/include/linux/dma-map-ops.h
+++ b/include/linux/dma-map-ops.h
@@ -443,10 +443,10 @@ static inline void arch_teardown_dma_ops(struct device *dev)
 #endif /* CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS */
 
 #ifdef CONFIG_DMA_API_DEBUG
-void dma_debug_add_bus(struct bus_type *bus);
+void dma_debug_add_bus(const struct bus_type *bus);
 void debug_dma_dump_mappings(struct device *dev);
 #else
-static inline void dma_debug_add_bus(struct bus_type *bus)
+static inline void dma_debug_add_bus(const struct bus_type *bus)
 {
 }
 static inline void debug_dma_dump_mappings(struct device *dev)
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 3de494375b7b..1a5c86dd87d5 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -876,7 +876,7 @@ static int dma_debug_device_change(struct notifier_block *nb, unsigned long acti
 	return 0;
 }
 
-void dma_debug_add_bus(struct bus_type *bus)
+void dma_debug_add_bus(const struct bus_type *bus)
 {
 	struct notifier_block *nb;
 
-- 
2.43.0

Re: [PATCH] dma-debug: make dma_debug_add_bus take a const pointer

[Christoph Hellwig]

On Tue, Dec 19, 2023 at 02:41:42PM +0100, Greg Kroah-Hartman wrote:
> The driver core now can handle a const struct bus_type pointer, and the
> dma_debug_add_bus() call just passes on the pointer give to it to the
> driver core, so make this pointer const as well to allow everyone to use
> read-only struct bus_type pointers going forward.

This looks good to me.  Do you want me to queue it up or take it with
the other constification patches?

Re: [PATCH] dma-debug: make dma_debug_add_bus take a const pointer

[Robin Murphy]

On 2023-12-19 1:41 pm, Greg Kroah-Hartman wrote:
> The driver core now can handle a const struct bus_type pointer, and the
> dma_debug_add_bus() call just passes on the pointer give to it to the
> driver core, so make this pointer const as well to allow everyone to use
> read-only struct bus_type pointers going forward.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Marek Szyprowski <m.szyprowski@samsung.com>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: iommu@lists.linux.dev
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>   include/linux/dma-map-ops.h | 4 ++--
>   kernel/dma/debug.c          | 2 +-
>   2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
> index f2fc203fb8a1..e401f824a007 100644
> --- a/include/linux/dma-map-ops.h
> +++ b/include/linux/dma-map-ops.h
> @@ -443,10 +443,10 @@ static inline void arch_teardown_dma_ops(struct device *dev)
>   #endif /* CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS */
>   
>   #ifdef CONFIG_DMA_API_DEBUG
> -void dma_debug_add_bus(struct bus_type *bus);
> +void dma_debug_add_bus(const struct bus_type *bus);
>   void debug_dma_dump_mappings(struct device *dev);
>   #else
> -static inline void dma_debug_add_bus(struct bus_type *bus)
> +static inline void dma_debug_add_bus(const struct bus_type *bus)
>   {
>   }
>   static inline void debug_dma_dump_mappings(struct device *dev)
> diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
> index 3de494375b7b..1a5c86dd87d5 100644
> --- a/kernel/dma/debug.c
> +++ b/kernel/dma/debug.c
> @@ -876,7 +876,7 @@ static int dma_debug_device_change(struct notifier_block *nb, unsigned long acti
>   	return 0;
>   }
>   
> -void dma_debug_add_bus(struct bus_type *bus)
> +void dma_debug_add_bus(const struct bus_type *bus)
>   {
>   	struct notifier_block *nb;
>