ALSA: memalloc: Make SG-buffer helper usable for continuous buffer, too (2a1f3368) · Commits · 戴 / test

We have a few helper functions for making the access to the buffer address easier on SG-buffer. Those are specific to the buffer that is allocated with SG-buffer type, and it makes hard to use both SG and non-SG buffers in the same code. This patch adds a few simple checks and lets the helpers to deal with both SG- and continuous buffers gracefully. It's a preliminary step for the upcoming patch that mimics the buffer type on the fly. Link: https://lore.kernel.org/r/20200615160045.2703-4-tiwai@suse.de Signed-off-by:

Takashi Iwai <tiwai@suse.de>

include/sound/memalloc.h

+8 −1

Original line number	Diff line number	Diff line
		@@ -94,7 +94,11 @@ static inline dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab,
		size_t offset)
		{
		struct snd_sg_buf *sgbuf = dmab->private_data;
		dma_addr_t addr = sgbuf->table[offset >> PAGE_SHIFT].addr;
		dma_addr_t addr;

		if (!sgbuf)
		return dmab->addr + offset;
		addr = sgbuf->table[offset >> PAGE_SHIFT].addr;
		addr &= ~((dma_addr_t)PAGE_SIZE - 1);
		return addr + offset % PAGE_SIZE;
		}
		@@ -106,6 +110,9 @@ static inline void snd_sgbuf_get_ptr(struct snd_dma_buffer dmab,
		size_t offset)
		{
		struct snd_sg_buf *sgbuf = dmab->private_data;

		if (!sgbuf)
		return dmab->area + offset;
		return sgbuf->table[offset >> PAGE_SHIFT].buf + offset % PAGE_SIZE;
		}

sound/core/sgbuf.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -142,6 +142,9 @@ unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
		struct snd_sg_buf *sg = dmab->private_data;
		unsigned int start, end, pg;

		if (!sg)
		return size;

		start = ofs >> PAGE_SHIFT;
		end = (ofs + size - 1) >> PAGE_SHIFT;
		/* check page continuity */

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