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Message-ID: <Y2UFuvg5sq9tLf83@matsya>
Date: Fri, 4 Nov 2022 17:59:46 +0530
From: Vinod Koul <vkoul@...nel.org>
To: Sireesh Kodali <sireeshkodali1@...il.com>
Cc: andersson@...nel.org, agross@...nel.org,
~postmarketos/upstreaming@...ts.sr.ht,
linux-kernel@...r.kernel.org, dmaengine@...r.kernel.org,
Vladimir Lypak <vladimir.lypak@...il.com>,
Konrad Dybcio <konrad.dybcio@...ainline.org>,
"open list:ARM/QUALCOMM SUPPORT" <linux-arm-msm@...r.kernel.org>
Subject: Re: [PATCH v2 1/1] dmaengine: qcom: bam_dma: Add support for metadata
On 27-10-22, 10:50, Sireesh Kodali wrote:
> From: Vladimir Lypak <vladimir.lypak@...il.com>
>
> Add client metadata support for receiving information about transfers.
> Only type of metadata implemented is amount of transferred bytes. This
> can be used to know how much data is actually received if information
> transferred doesn't contain header with size or is aggregated.
>
> Signed-off-by: Vladimir Lypak <vladimir.lypak@...il.com>
> Signed-off-by: Sireesh Kodali <sireeshkodali1@...il.com>
> ---
> drivers/dma/qcom/bam_dma.c | 57 ++++++++++++++++++++++++++++++++
> include/linux/dma/qcom_bam_dma.h | 8 +++++
> 2 files changed, 65 insertions(+)
>
> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
> index 3135a3e4a167..264a9a2e199f 100644
> --- a/drivers/dma/qcom/bam_dma.c
> +++ b/drivers/dma/qcom/bam_dma.c
> @@ -30,6 +30,7 @@
> #include <linux/module.h>
> #include <linux/interrupt.h>
> #include <linux/dma-mapping.h>
> +#include <linux/dma/qcom_bam_dma.h>
> #include <linux/scatterlist.h>
> #include <linux/device.h>
> #include <linux/platform_device.h>
> @@ -70,6 +71,7 @@ struct bam_async_desc {
> u16 flags;
>
> struct bam_desc_hw *curr_desc;
> + struct bam_dma_metadata *metadata;
>
> /* list node for the desc in the bam_chan list of descriptors */
> struct list_head desc_node;
> @@ -418,6 +420,52 @@ static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
> r.ee_mult * bdev->ee;
> }
>
> +/**
> + * bam_update_metadata - update metadata buffer
> + * @bchan: BAM channel to read metadata from
> + * @async_desc: BAM async descriptior
> + *
> + * Updates metadata buffer (transfer size) based on values
> + * read from FIFO descriptors at bchan->head
> + */
> +
> +static inline void bam_update_metadata(struct bam_chan *bchan,
> + struct bam_async_desc *async_desc)
> +{
> + unsigned int i, e, len = 0;
> + struct bam_desc_hw *fifo;
> +
> + if (!async_desc->metadata)
> + return;
> +
> + fifo = PTR_ALIGN(bchan->fifo_virt, sizeof(struct bam_desc_hw));
> + for (i = bchan->head, e = i + async_desc->xfer_len; i < e; i++)
> + len += fifo[i % MAX_DESCRIPTORS].size;
> +
> + async_desc->metadata->xfer_len_bytes += len;
> +}
> +
> +/**
> + * bam_attach_metadata - attach metadata buffer to the async descriptor
> + * @desc: async descriptor
> + * @data: buffer pointer
> + * @len: length of passed buffer
> + */
> +static int bam_attach_metadata(struct dma_async_tx_descriptor *desc, void *data,
> + size_t len)
> +{
> + struct bam_async_desc *async_desc;
> +
> + if (!data || len != sizeof(struct bam_dma_metadata))
> + return -EINVAL;
> +
> + async_desc = container_of(desc, struct bam_async_desc, vd.tx);
> + async_desc->metadata = data;
> + async_desc->metadata->xfer_len_bytes = 0;
> +
> + return 0;
> +}
> +
> /**
> * bam_reset() - reset and initialize BAM registers
> * @bdev: bam device
> @@ -456,6 +504,10 @@ static void bam_reset(struct bam_device *bdev)
> writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
> }
>
> +static struct dma_descriptor_metadata_ops metadata_ops = {
> + .attach = bam_attach_metadata,
> +};
> +
> /**
> * bam_reset_channel - Reset individual BAM DMA channel
> * @bchan: bam channel
> @@ -714,6 +766,8 @@ static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
> } while (remainder > 0);
> }
>
> + async_desc->vd.tx.metadata_ops = &metadata_ops;
> +
> return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
> }
>
> @@ -867,6 +921,8 @@ static u32 process_channel_irqs(struct bam_device *bdev)
> if (avail < async_desc->xfer_len)
> break;
>
> + bam_update_metadata(bchan, async_desc);
> +
> /* manage FIFO */
> bchan->head += async_desc->xfer_len;
> bchan->head %= MAX_DESCRIPTORS;
> @@ -1347,6 +1403,7 @@ static int bam_dma_probe(struct platform_device *pdev)
> bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
> bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
> bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + bdev->common.desc_metadata_modes = DESC_METADATA_CLIENT;
> bdev->common.device_alloc_chan_resources = bam_alloc_chan;
> bdev->common.device_free_chan_resources = bam_free_chan;
> bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
> diff --git a/include/linux/dma/qcom_bam_dma.h b/include/linux/dma/qcom_bam_dma.h
> index 68fc0e643b1b..8168b0573f45 100644
> --- a/include/linux/dma/qcom_bam_dma.h
> +++ b/include/linux/dma/qcom_bam_dma.h
> @@ -8,6 +8,14 @@
>
> #include <asm/byteorder.h>
>
> +/*
> + * This data type is used as client metadata buffer in bam driver.
> + */
> +struct bam_dma_metadata {
> + /* Actual number of bytes transferred by hardware */
> + size_t xfer_len_bytes;
Pls implement dmaengine_result() and report that with proper residue
set...
Thanks
--
~Vinod
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