diff mbox series

[net-next,v5,02/19] skbuff: allow 2-4-argument skb_frag_dma_map()

Message ID 20241113152442.4000468-3-aleksander.lobakin@intel.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series xdp: a fistful of generic changes (+libeth_xdp) | expand

Checks

Context Check Description
netdev/series_format fail Series longer than 15 patches
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 42 this patch: 42
netdev/build_tools success Errors and warnings before: 0 (+0) this patch: 0 (+0)
netdev/cc_maintainers warning 1 maintainers not CCed: horms@kernel.org
netdev/build_clang success Errors and warnings before: 78 this patch: 78
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5000 this patch: 5000
netdev/checkpatch warning CHECK: Macro argument 'uf' may be better as '(uf)' to avoid precedence issues
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 58 this patch: 58
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-11-14--03-00 (tests: 782)

Commit Message

Alexander Lobakin Nov. 13, 2024, 3:24 p.m. UTC
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: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 include/linux/skbuff.h | 31 ++++++++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 58009fa66102..c212c1dad461 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -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
@@ -3684,15 +3684,36 @@  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,
-					  const skb_frag_t *frag,
-					  size_t offset, size_t size,
-					  enum dma_data_direction dir)
+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)
 {
 	return dma_map_page(dev, skb_frag_page(frag),
 			    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)
 {