Commit 0dffdb3b authored by Alexander Lobakin's avatar Alexander Lobakin Committed by Jakub Kicinski
Browse files

skbuff: allow 2-4-argument skb_frag_dma_map() 



skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag), DMA_TO_DEVICE)
is repeated across dozens of drivers and really wants a shorthand.
Add a macro which will count args and handle all possible number
from 2 to 5. Semantics:

skb_frag_dma_map(dev, frag) ->
__skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag), DMA_TO_DEVICE)

skb_frag_dma_map(dev, frag, offset) ->
__skb_frag_dma_map(dev, frag, offset, skb_frag_size(frag) - offset,
		   DMA_TO_DEVICE)

skb_frag_dma_map(dev, frag, offset, size) ->
__skb_frag_dma_map(dev, frag, offset, size, DMA_TO_DEVICE)

skb_frag_dma_map(dev, frag, offset, size, dir) ->
__skb_frag_dma_map(dev, frag, offset, size, dir)

No object code size changes for the existing callers. Users passing
less arguments also won't have bigger size comparing to the full
equivalent call.

Signed-off-by: default avatarAlexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20241211172649.761483-11-aleksander.lobakin@intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 207ff83c

include/linux/skbuff.h

+26 −5
Original line number Diff line number Diff line
@@ -3674,7 +3674,7 @@ static inline void skb_frag_page_copy(skb_frag_t *fragto, 
bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);



/**

 * skb_frag_dma_map - maps a paged fragment via the DMA API

 * __skb_frag_dma_map - maps a paged fragment via the DMA API

 * @dev: the device to map the fragment to

 * @frag: the paged fragment to map

 * @offset: the offset within the fragment (starting at the
@@ -3684,7 +3684,7 @@ bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio); 
 *

 * Maps the page associated with @frag to @device.

 */

static inline dma_addr_t skb_frag_dma_map(struct device *dev,

static inline dma_addr_t __skb_frag_dma_map(struct device *dev,

					    const skb_frag_t *frag,

					    size_t offset, size_t size,

					    enum dma_data_direction dir)
@@ -3693,6 +3693,27 @@ static inline dma_addr_t skb_frag_dma_map(struct device *dev, 
			    skb_frag_off(frag) + offset, size, dir);

}



#define skb_frag_dma_map(dev, frag, ...)				\

	CONCATENATE(_skb_frag_dma_map,					\

		    COUNT_ARGS(__VA_ARGS__))(dev, frag, ##__VA_ARGS__)



#define __skb_frag_dma_map1(dev, frag, offset, uf, uo) ({		\

	const skb_frag_t *uf = (frag);					\

	size_t uo = (offset);						\

									\

	__skb_frag_dma_map(dev, uf, uo, skb_frag_size(uf) - uo,		\

			   DMA_TO_DEVICE);				\

})

#define _skb_frag_dma_map1(dev, frag, offset)				\

	__skb_frag_dma_map1(dev, frag, offset, __UNIQUE_ID(frag_),	\

			    __UNIQUE_ID(offset_))

#define _skb_frag_dma_map0(dev, frag)					\

	_skb_frag_dma_map1(dev, frag, 0)

#define _skb_frag_dma_map2(dev, frag, offset, size)			\

	__skb_frag_dma_map(dev, frag, offset, size, DMA_TO_DEVICE)

#define _skb_frag_dma_map3(dev, frag, offset, size, dir)		\

	__skb_frag_dma_map(dev, frag, offset, size, dir)



static inline struct sk_buff *pskb_copy(struct sk_buff *skb,

					gfp_t gfp_mask)

{