Re: [PATCH] include/asm-ppc/dma-mapping.h macro patch

From: Jason McMullan
Date: Wed Dec 08 2004 - 11:43:48 EST


On Tue, 2004-12-07 at 15:03 +0000, Christoph Hellwig wrote:
> +#define dma_cache_inv(_start,_size) do { (void)(_start);
> (void)(_size); } while (0)
>
> this looks really horrible. What about turning these into inlines?
>

Sure thing:

Signed-off-by: Jason McMullan <jason.mcmullan@xxxxxxxxxxx>
Summary: [ppc] dma-mapping.h - Fix macro semantics
Release: Dec 8, 2004
Description:
This patch makes the macros for dma_* semantically
equivalent to the functions they mask. For example,
dma_cache_inv(func_with_side_effects(), sizeof(foo))
will execure 'func_with_side_effects()' in the function
case, but would not execute it in the macro case.
This patch fixes this discrepancy using 'static inline'
functions.

--- linux-orig/include/asm-ppc/dma-mapping.h
+++ linux/include/asm-ppc/dma-mapping.h
@@ -24,34 +24,43 @@
extern void __dma_sync(void *vaddr, size_t size, int direction);
extern void __dma_sync_page(struct page *page, unsigned long offset,
size_t size, int direction);
-#define dma_cache_inv(_start,_size) \
- invalidate_dcache_range(_start, (_start + _size))
-#define dma_cache_wback(_start,_size) \
- clean_dcache_range(_start, (_start + _size))
-#define dma_cache_wback_inv(_start,_size) \
- flush_dcache_range(_start, (_start + _size))
+
+static inline void dma_cache_inv(unsigned long _start,size_t _size)
+{
+ invalidate_dcache_range(_start, (_start + _size));
+}
+
+static inline void dma_cache_wback(unsigned long _start,size_t _size)
+{
+ clean_dcache_range(_start, (_start + _size));
+}
+
+static inline void dma_cache_wback_inv(unsigned long _start,size_t _size)
+{
+ flush_dcache_range(_start, (_start + _size));
+}

#else /* ! CONFIG_NOT_COHERENT_CACHE */
/*
* Cache coherent cores.
*/

-#define dma_cache_inv(_start,_size) do { } while (0)
-#define dma_cache_wback(_start,_size) do { } while (0)
-#define dma_cache_wback_inv(_start,_size) do { } while (0)
+static inline void dma_cache_inv(unsigned long _start,size_t _size) {}
+static inline void dma_cache_wback(unsigned long _start,size_t _size) {}
+static inline void dma_cache_wback_inv(unsigned long _start,size_t _size) {}

-#define __dma_alloc_coherent(gfp, size, handle) NULL
-#define __dma_free_coherent(size, addr) do { } while (0)
-#define __dma_sync(addr, size, rw) do { } while (0)
-#define __dma_sync_page(pg, off, sz, rw) do { } while (0)
+static inline void *__dma_alloc_coherent(size_t size, dma_addr_t handle, int gfp) { return NULL; }
+static inline void __dma_free_coherent(size_t size, void *vaddr) {}
+static inline void __dma_sync(void *vaddr, size_t size, int rw) {}
+static inline void __dma_sync_page(struct page *pg, unsigned long off, size_t sz, int rw) {}

#endif /* ! CONFIG_NOT_COHERENT_CACHE */

-#define dma_supported(dev, mask) (1)
+static inline int dma_supported(struct device *dev, u64 dma_mask) { return 1; }

static inline int dma_set_mask(struct device *dev, u64 dma_mask)
{
- if (!dev->dma_mask || !dma_supported(dev, mask))
+ if (!dev->dma_mask || !dma_supported(dev, dma_mask))
return -EIO;

*dev->dma_mask = dma_mask;
@@ -106,7 +115,11 @@
}

/* We do nothing. */
-#define dma_unmap_single(dev, addr, size, dir) do { } while (0)
+static inline void
+dma_unmap_single(struct device *dev, unsigned long addr, size_t size,
+ enum dma_data_direction direction)
+{
+}

static inline dma_addr_t
dma_map_page(struct device *dev, struct page *page,
@@ -121,7 +134,9 @@
}

/* We do nothing. */
-#define dma_unmap_page(dev, handle, size, dir) do { } while (0)
+static inline void
+dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
+ size_t size, enum dma_data_direction direction) {}

static inline int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
@@ -141,7 +156,9 @@
}

/* We don't do anything here. */
-#define dma_unmap_sg(dev, sg, nents, dir) do { } while (0)
+static inline void
+dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction dir) {}

static inline void
dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
@@ -190,9 +207,9 @@
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
#ifdef CONFIG_NOT_COHERENT_CACHE
-#define dma_is_consistent(d) (0)
+static inline int dma_is_consistent(dma_addr_t dma_handle) { return 0; }
#else
-#define dma_is_consistent(d) (1)
+static inline int dma_is_consistent(dma_addr_t dma_handle) { return 1; }
#endif

static inline int dma_get_cache_alignment(void)

--
Jason McMullan <jason.mcmullan@xxxxxxxxxxx>
TimeSys Corporation
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