From b85c997d2cfefe7d1f706b85ae46e35a50e3131c Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Tue, 28 Aug 2018 17:48:14 +0800 Subject: [PATCH] mmc: sdhci-of-dwcmshc: solve 128MB DMA boundary limitation When using DMA, if the DMA addr spans 128MB boundary, we have to split the DMA transfer into two so that each one doesn't exceed the boundary. Signed-off-by: Jisheng Zhang Acked-by: Adrian Hunter Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-of-dwcmshc.c | 39 +++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c index 1b7cd14..a513784 100644 --- a/drivers/mmc/host/sdhci-of-dwcmshc.c +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c @@ -8,21 +8,51 @@ */ #include +#include +#include #include #include +#include #include "sdhci-pltfm.h" +#define BOUNDARY_OK(addr, len) \ + ((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1))) + struct dwcmshc_priv { struct clk *bus_clk; }; +/* + * If DMA addr spans 128MB boundary, we split the DMA transfer into two + * so that each DMA transfer doesn't exceed the boundary. + */ +static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc, + dma_addr_t addr, int len, unsigned int cmd) +{ + int tmplen, offset; + + if (likely(!len || BOUNDARY_OK(addr, len))) { + sdhci_adma_write_desc(host, desc, addr, len, cmd); + return; + } + + offset = addr & (SZ_128M - 1); + tmplen = SZ_128M - offset; + sdhci_adma_write_desc(host, desc, addr, tmplen, cmd); + + addr += tmplen; + len -= tmplen; + sdhci_adma_write_desc(host, desc, addr, len, cmd); +} + static const struct sdhci_ops sdhci_dwcmshc_ops = { .set_clock = sdhci_set_clock, .set_bus_width = sdhci_set_bus_width, .set_uhs_signaling = sdhci_set_uhs_signaling, .get_max_clock = sdhci_pltfm_clk_get_max_clock, .reset = sdhci_reset, + .adma_write_desc = dwcmshc_adma_write_desc, }; static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = { @@ -36,12 +66,21 @@ static int dwcmshc_probe(struct platform_device *pdev) struct sdhci_host *host; struct dwcmshc_priv *priv; int err; + u32 extra; host = sdhci_pltfm_init(pdev, &sdhci_dwcmshc_pdata, sizeof(struct dwcmshc_priv)); if (IS_ERR(host)) return PTR_ERR(host); + /* + * extra adma table cnt for cross 128M boundary handling. + */ + extra = DIV_ROUND_UP_ULL(dma_get_required_mask(&pdev->dev), SZ_128M); + if (extra > SDHCI_MAX_SEGS) + extra = SDHCI_MAX_SEGS; + host->adma_table_cnt += extra; + pltfm_host = sdhci_priv(host); priv = sdhci_pltfm_priv(pltfm_host); -- 2.7.4