tree 8f1c1a245a342946660d717db55560f68a31e207
parent 97e7e82088a9e2316baaece7833aec255cc6aa7c
author Masahiro Yamada <yamada.masahiro@socionext.com> 1581666027 +0900
committer Peng Fan <peng.fan@nxp.com> 1582182597 +0800

mmc: sdhci: fix missing cache invalidation after reading by DMA

This driver currently performs cache operation before the DMA start,
but does nothing after the DMA completion.

When reading data by DMA, the cache invalidation is needed also after
finishing the DMA transfer. Otherwise, the CPU might read data from
the cache instead of from the main memory when speculative memory read
or memory prefetch occurs.

Instead of calling the cache operation directly, this commit adds
dma_unmap_single(), which performs cache invalidation internally,
but drivers do not need which operation is being run.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>