From fdaf9c4b22247a6cc6cda9459be3e52764c14d95 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Wed, 25 Apr 2012 20:50:52 +0200 Subject: [PATCH] dmaengine: Use dma_sg_len(sg) instead of sg->length sg->length may or may not contain the length of the dma region to transfer, depending on the architecture - dma_sg_len(sg) always will though. For the architectures which use the drivers modified by this patch it probably is the case that sg->length contains the dma transfer length. But to be consistent and future proof change them to use dma_sg_len. To quote Russel King: sg->length is meaningless to something performing DMA. In cases where sg_dma_len(sg) and sg->length are the same storage, then there's no problem. But scatterlists _can_ (and one some architectures) do split them - especially when you have an IOMMU which can allow you to combine a scatterlist into fewer entries. So, anything using sg->length for the size of a scatterlist's DMA transfer _after_ a call to dma_map_sg() is almost certainly buggy. The patch has been generated using the following coccinelle patch: @@ struct scatterlist *sg; expression X; @@ -sg[X].length +sg_dma_len(&sg[X]) @@ struct scatterlist *sg; @@ -sg->length +sg_dma_len(sg) Signed-off-by: Lars-Peter Clausen Acked-by: Linus Walleij Signed-off-by: Vinod Koul --- drivers/dma/amba-pl08x.c | 2 +- drivers/dma/coh901318.c | 2 +- drivers/dma/imx-dma.c | 12 ++++++------ drivers/dma/imx-sdma.c | 2 +- drivers/dma/intel_mid_dma.c | 6 +++--- drivers/dma/mxs-dma.c | 6 +++--- drivers/dma/ste_dma40.c | 2 +- 7 files changed, 16 insertions(+), 16 deletions(-) diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c index 003220a60bcb..49ecbbb8932d 100644 --- a/drivers/dma/amba-pl08x.c +++ b/drivers/dma/amba-pl08x.c @@ -1328,7 +1328,7 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg( int ret, tmp; dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n", - __func__, sgl->length, plchan->name); + __func__, sg_dma_len(sgl), plchan->name); txd = pl08x_get_txd(plchan, flags); if (!txd) { diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c index dc89455f5550..c0b650c70bbd 100644 --- a/drivers/dma/coh901318.c +++ b/drivers/dma/coh901318.c @@ -1040,7 +1040,7 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, if (!sgl) goto out; - if (sgl->length == 0) + if (sg_dma_len(sgl) == 0) goto out; spin_lock_irqsave(&cohc->lock, flg); diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c index bb787d8e1529..fcfeb3cd8d31 100644 --- a/drivers/dma/imx-dma.c +++ b/drivers/dma/imx-dma.c @@ -227,7 +227,7 @@ static inline int imxdma_sg_next(struct imxdma_desc *d) struct scatterlist *sg = d->sg; unsigned long now; - now = min(d->len, sg->length); + now = min(d->len, sg_dma_len(sg)); if (d->len != IMX_DMA_LENGTH_LOOP) d->len -= now; @@ -763,16 +763,16 @@ static struct dma_async_tx_descriptor *imxdma_prep_slave_sg( desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node); for_each_sg(sgl, sg, sg_len, i) { - dma_length += sg->length; + dma_length += sg_dma_len(sg); } switch (imxdmac->word_size) { case DMA_SLAVE_BUSWIDTH_4_BYTES: - if (sgl->length & 3 || sgl->dma_address & 3) + if (sg_dma_len(sgl) & 3 || sgl->dma_address & 3) return NULL; break; case DMA_SLAVE_BUSWIDTH_2_BYTES: - if (sgl->length & 1 || sgl->dma_address & 1) + if (sg_dma_len(sgl) & 1 || sgl->dma_address & 1) return NULL; break; case DMA_SLAVE_BUSWIDTH_1_BYTE: @@ -831,13 +831,13 @@ static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic( imxdmac->sg_list[i].page_link = 0; imxdmac->sg_list[i].offset = 0; imxdmac->sg_list[i].dma_address = dma_addr; - imxdmac->sg_list[i].length = period_len; + sg_dma_len(&imxdmac->sg_list[i]) = period_len; dma_addr += period_len; } /* close the loop */ imxdmac->sg_list[periods].offset = 0; - imxdmac->sg_list[periods].length = 0; + sg_dma_len(&imxdmac->sg_list[periods]) = 0; imxdmac->sg_list[periods].page_link = ((unsigned long)imxdmac->sg_list | 0x01) & ~0x02; diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 5a457777f5c0..cd0619a897ff 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -941,7 +941,7 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg( bd->buffer_addr = sg->dma_address; - count = sg->length; + count = sg_dma_len(sg); if (count > 0xffff) { dev_err(sdma->dev, "SDMA channel %d: maximum bytes for sg entry exceeded: %d > %d\n", diff --git a/drivers/dma/intel_mid_dma.c b/drivers/dma/intel_mid_dma.c index d0ef5937fbf6..222e907bfaaa 100644 --- a/drivers/dma/intel_mid_dma.c +++ b/drivers/dma/intel_mid_dma.c @@ -394,7 +394,7 @@ static int midc_lli_fill_sg(struct intel_mid_dma_chan *midc, } } /*Populate CTL_HI values*/ - ctl_hi.ctlx.block_ts = get_block_ts(sg->length, + ctl_hi.ctlx.block_ts = get_block_ts(sg_dma_len(sg), desc->width, midc->dma->block_size); /*Populate SAR and DAR values*/ @@ -747,7 +747,7 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg( txd = intel_mid_dma_prep_memcpy(chan, mids->dma_slave.dst_addr, mids->dma_slave.src_addr, - sgl->length, + sg_dma_len(sgl), flags); return txd; } else { @@ -759,7 +759,7 @@ static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg( pr_debug("MDMA: SG Length = %d, direction = %d, Flags = %#lx\n", sg_len, direction, flags); - txd = intel_mid_dma_prep_memcpy(chan, 0, 0, sgl->length, flags); + txd = intel_mid_dma_prep_memcpy(chan, 0, 0, sg_dma_len(sgl), flags); if (NULL == txd) { pr_err("MDMA: Prep memcpy failed\n"); return NULL; diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c index 655d4ce6ed0d..3db3a48d3f01 100644 --- a/drivers/dma/mxs-dma.c +++ b/drivers/dma/mxs-dma.c @@ -415,9 +415,9 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg( ccw->bits |= BF_CCW(MXS_DMA_CMD_NO_XFER, COMMAND); } else { for_each_sg(sgl, sg, sg_len, i) { - if (sg->length > MAX_XFER_BYTES) { + if (sg_dma_len(sg) > MAX_XFER_BYTES) { dev_err(mxs_dma->dma_device.dev, "maximum bytes for sg entry exceeded: %d > %d\n", - sg->length, MAX_XFER_BYTES); + sg_dma_len(sg), MAX_XFER_BYTES); goto err_out; } @@ -425,7 +425,7 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg( ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx; ccw->bufaddr = sg->dma_address; - ccw->xfer_bytes = sg->length; + ccw->xfer_bytes = sg_dma_len(sg); ccw->bits = 0; ccw->bits |= CCW_CHAIN; diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c index 2ed1ac3513f3..000d309602b2 100644 --- a/drivers/dma/ste_dma40.c +++ b/drivers/dma/ste_dma40.c @@ -2362,7 +2362,7 @@ dma40_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t dma_addr, } sg[periods].offset = 0; - sg[periods].length = 0; + sg_dma_len(&sg[periods]) = 0; sg[periods].page_link = ((unsigned long)sg | 0x01) & ~0x02;