On 10/28/2023 9:59 AM, Stanislaw Gruszka wrote:
From: Karol Wachowski <karol.wachowski@xxxxxxxxxxxxxxx> Previously using dma_alloc_wc() API we created cache coherent (mapped as write-back) mappings. Because we disable MMU600 snooping it was required to do costly page walk and cache flushes after each page table modification. With write-combined buffers it's possible to do a single write memory barrier to flush write-combined buffer to memory which simplifies the driver and significantly reduce time of map/unmap operations. Mapping time of 255 MB is reduced from 2.5 ms to 500 us. Signed-off-by: Karol Wachowski <karol.wachowski@xxxxxxxxxxxxxxx> Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@xxxxxxxxxxxxxxx> Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@xxxxxxxxxxxxxxx>
Reviewed-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
