On 27/01/24 02:19, Linus Walleij wrote: > Use sg_miter iterator instead of sg_virt() and custom code > to loop over the scatterlist. The memory iterator will do > bounce buffering if the page happens to be located in high memory, > which the driver may or may not be using. > > Suggested-by: Christoph Hellwig <hch@xxxxxx> > Link: https://lore.kernel.org/linux-mmc/20240122073423.GA25859@xxxxxx/ > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > --- > drivers/mmc/host/sdhci-esdhc-mcf.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/host/sdhci-esdhc-mcf.c b/drivers/mmc/host/sdhci-esdhc-mcf.c > index a07f8333cd6b..1909a11fd065 100644 > --- a/drivers/mmc/host/sdhci-esdhc-mcf.c > +++ b/drivers/mmc/host/sdhci-esdhc-mcf.c > @@ -299,9 +299,8 @@ static void esdhc_mcf_pltfm_set_bus_width(struct sdhci_host *host, int width) > static void esdhc_mcf_request_done(struct sdhci_host *host, > struct mmc_request *mrq) > { > - struct scatterlist *sg; > + struct sg_mapping_iter sgm; > u32 *buffer; > - int i; > > if (!mrq->data || !mrq->data->bytes_xfered) > goto exit_done; > @@ -313,10 +312,13 @@ static void esdhc_mcf_request_done(struct sdhci_host *host, > * On mcf5441x there is no hw sdma option/flag to select the dma > * transfer endiannes. A swap after the transfer is needed. > */ > - for_each_sg(mrq->data->sg, sg, mrq->data->sg_len, i) { > - buffer = (u32 *)sg_virt(sg); > - esdhc_mcf_buffer_swap32(buffer, sg->length); > + sg_miter_start(&sgm, mrq->data->sg, mrq->data->sg_len, > + SG_MITER_TO_SG | SG_MITER_FROM_SG); Could be called from atomic context, so probably needs SG_MITER_ATOMIC > + while (sg_miter_next(&sgm)) { > + buffer = sgm.addr; > + esdhc_mcf_buffer_swap32(buffer, sgm.length); > } > + sg_miter_stop(&sgm); > > exit_done: > mmc_request_done(host->mmc, mrq); >
