Re: [PATCH 11/16] dma-debug: add checking for [alloc|free]_coherent

From: FUJITA Tomonori
Date: Sun Jan 11 2009 - 01:26:34 EST


On Fri, 9 Jan 2009 17:19:25 +0100
Joerg Roedel <joerg.roedel@xxxxxxx> wrote:

> Impact: add debug callbacks for dma_[alloc|free]_coherent
>
> Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
> ---
> include/linux/dma-debug.h | 16 ++++++++++++++++
> lib/dma-debug.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 61 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h
> index b2131f4..a28a701 100644
> --- a/include/linux/dma-debug.h
> +++ b/include/linux/dma-debug.h
> @@ -40,6 +40,12 @@ extern void debug_map_sg(struct device *dev, struct scatterlist *sg,
> extern void debug_unmap_sg(struct device *dev, struct scatterlist *sglist,
> int nelems, int dir);
>
> +extern void debug_alloc_coherent(struct device *dev, size_t size,
> + dma_addr_t dma_addr, void *virt);
> +
> +extern void debug_free_coherent(struct device *dev, size_t size,
> + void *virt, dma_addr_t addr);
> +
> #else /* CONFIG_DMA_API_DEBUG */
>
> static inline void dma_debug_init(u32 num_entries)
> @@ -68,6 +74,16 @@ static inline void debug_unmap_sg(struct device *dev,
> {
> }
>
> +static inline void debug_alloc_coherent(struct device *dev, size_t size,
> + dma_addr_t dma_addr, void *virt)
> +{
> +}
> +
> +static inline void debug_free_coherent(struct device *dev, size_t size,
> + void *virt, dma_addr_t addr)
> +{
> +}
> +
> #endif /* CONFIG_DMA_API_DEBUG */
>
> #endif /* __DMA_DEBUG_H */
> diff --git a/lib/dma-debug.c b/lib/dma-debug.c
> index e6d45f9..a4a5b0f 100644
> --- a/lib/dma-debug.c
> +++ b/lib/dma-debug.c
> @@ -604,3 +604,48 @@ void debug_unmap_sg(struct device *dev, struct scatterlist *sglist,
> }
> EXPORT_SYMBOL(debug_unmap_sg);
>
> +void debug_alloc_coherent(struct device *dev, size_t size,
> + dma_addr_t dma_addr, void *virt)
> +{
> + struct dma_debug_entry *entry;
> +
> + if (global_disable)
> + return;
> +
> + if (dma_addr == bad_dma_address)
> + return;

Only X86 has 'bad_dma_address' (IA64 also has with some configurations
though). You need to use dma_mapping_error, as I pointed out in the
previous submission.

I recommend you to try this on one non-x86 box (at least). Even if you
don't have non x86, you can use cross compiler.
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