dma: dma-axi-dmac: support bigger than 32bits addresses

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In some supported platforms as ARCH_ZYNQMP, part of the memory is mapped
above 32bit addresses and since the DMA mask, by default, is set to 32bits,
we would need to rely on swiotlb (which incurs a performance penalty)
for the DMA mappings. Thus, we can write either the SRC or DEST high
addresses with 1's and read them back. The last bit set on the return
value will reflect the IP address bus width and so we can update the
device DMA mask accordingly.

While at it, support bigger that 32 bits transfers in IP without HW
scatter gather support.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
base-commit: 3980351785
change-id: 20251104-axi-dmac-fixes-and-improvs-e3ad512a329c
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Link: https://patch.msgid.link/20251104-axi-dmac-fixes-and-improvs-v1-3-3e6fd9328f72@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

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Nuno Sá 2025-11-04 16:22:27 +00:00 • committed by Vinod Koul

parent bbcbafb99d

commit b2440442cc

1 changed files with 24 additions and 0 deletions

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drivers/dma/dma-axi-dmac.c

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