Re: [PATCH v5 08/10] media: rkisp1: Shift DMA buffer addresses on i.MX8MP

Tomi Valkeinen
2024-01-08T11:38:05Z

On 06/01/2024 18:02, Paul Elder wrote:
> On the ISP that is integrated in the i.MX8MP, DMA addresses have been
> extended to 34 bits, with the 32 MSBs stored in the DMA address
> registers and the 2 LSBs set to 0. Shift the buffer addresses right by 2
> on that platform.
>
> While at it, fix an issue where if the system allocated CMA memory
> happens to be located higher than 32-bits, the driver will fail to
> allocate CMA memory and falls back to kmalloc(), which will fail for
> larger allocations (over MAX_ORDER, which often mean 4MB).
>
> Fix this by setting the dma mask to 34 bits when allowed, and fixing the
> use dma_addr_t when storing dma addresses instead of u32.

I think the desc could be rewritten a bit for clarity. "While at it"
sounds like doing some secondary changes too, but it's all required. And
it's not really "fixing", as this is adding a new feature.

To support i.MX8MP's 34-bit addresses, we need to:

- shift the addresses when writing to registers
- set the dma mask
- use dma_addr_t instead of u32 when storing the addresses

Can you rewrite the desc to describe the above?

For the change itself:

Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

Tomi

> Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> Tested-by: Adam Ford <aford173@gmail.com>
> ---
> Changes since v4:
>
> - Squash in fix from Tomi:
> - https://gitlab.com/ideasonboard/nxp/linux/-/commit/d6477fe673b1c0d05d12ae21d8db9a03b07e7fea
>
> Changes since v2:
>
> - Document the RKISP1_FEATURE_DMA_34BIT bit
> - Use the rkisp1_has_feature() macro
> ---
> .../platform/rockchip/rkisp1/rkisp1-capture.c | 20 ++++++++++---------
> .../platform/rockchip/rkisp1/rkisp1-common.h | 4 +++-
> .../platform/rockchip/rkisp1/rkisp1-dev.c | 11 +++++++++-
> 3 files changed, 24 insertions(+), 11 deletions(-)

Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

Tomi

> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
> index ca95f62822fa..1ee7639c42b7 100644
> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-capture.c
> @@ -648,11 +648,13 @@ static void rkisp1_dummy_buf_destroy(struct rkisp1_capture *cap)
>
> static void rkisp1_set_next_buf(struct rkisp1_capture *cap)
> {
> + u8 shift = rkisp1_has_feature(cap->rkisp1, DMA_34BIT) ? 2 : 0;
> +
> cap->buf.curr = cap->buf.next;
> cap->buf.next = NULL;
>
> if (!list_empty(&cap->buf.queue)) {
> - u32 *buff_addr;
> + dma_addr_t *buff_addr;
>
> cap->buf.next = list_first_entry(&cap->buf.queue, struct rkisp1_buffer, queue);
> list_del(&cap->buf.next->queue);
> @@ -660,7 +662,7 @@ static void rkisp1_set_next_buf(struct rkisp1_capture *cap)
> buff_addr = cap->buf.next->buff_addr;
>
> rkisp1_write(cap->rkisp1, cap->config->mi.y_base_ad_init,
> - buff_addr[RKISP1_PLANE_Y]);
> + buff_addr[RKISP1_PLANE_Y] >> shift);
> /*
> * In order to support grey format we capture
> * YUV422 planar format from the camera and
> @@ -669,17 +671,17 @@ static void rkisp1_set_next_buf(struct rkisp1_capture *cap)
> if (cap->pix.cfg->fourcc == V4L2_PIX_FMT_GREY) {
> rkisp1_write(cap->rkisp1,
> cap->config->mi.cb_base_ad_init,
> - cap->buf.dummy.dma_addr);
> + cap->buf.dummy.dma_addr >> shift);
> rkisp1_write(cap->rkisp1,
> cap->config->mi.cr_base_ad_init,
> - cap->buf.dummy.dma_addr);
> + cap->buf.dummy.dma_addr >> shift);
> } else {
> rkisp1_write(cap->rkisp1,
> cap->config->mi.cb_base_ad_init,
> - buff_addr[RKISP1_PLANE_CB]);
> + buff_addr[RKISP1_PLANE_CB] >> shift);
> rkisp1_write(cap->rkisp1,
> cap->config->mi.cr_base_ad_init,
> - buff_addr[RKISP1_PLANE_CR]);
> + buff_addr[RKISP1_PLANE_CR] >> shift);
> }
> } else {
> /*
> @@ -687,11 +689,11 @@ static void rkisp1_set_next_buf(struct rkisp1_capture *cap)
> * throw data if there is no available buffer.
> */
> rkisp1_write(cap->rkisp1, cap->config->mi.y_base_ad_init,
> - cap->buf.dummy.dma_addr);
> + cap->buf.dummy.dma_addr >> shift);
> rkisp1_write(cap->rkisp1, cap->config->mi.cb_base_ad_init,
> - cap->buf.dummy.dma_addr);
> + cap->buf.dummy.dma_addr >> shift);
> rkisp1_write(cap->rkisp1, cap->config->mi.cr_base_ad_init,
> - cap->buf.dummy.dma_addr);
> + cap->buf.dummy.dma_addr >> shift);
> }
>
> /* Set plane offsets */
> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> index 69940014d597..26573f6ae575 100644
> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> @@ -114,6 +114,7 @@ enum rkisp1_isp_pad {
> * @RKISP1_FEATURE_MAIN_STRIDE: The ISP supports configurable stride on the main path
> * @RKISP1_FEATURE_SELF_PATH: The ISP has a self path
> * @RKISP1_FEATURE_DUAL_CROP: The ISP has the dual crop block at the resizer input
> + * @RKISP1_FEATURE_DMA_34BIT: The ISP uses 34-bit DMA addresses
> *
> * The ISP features are stored in a bitmask in &rkisp1_info.features and allow
> * the driver to implement support for features present in some ISP versions
> @@ -124,6 +125,7 @@ enum rkisp1_feature {
> RKISP1_FEATURE_MAIN_STRIDE = BIT(1),
> RKISP1_FEATURE_SELF_PATH = BIT(2),
> RKISP1_FEATURE_DUAL_CROP = BIT(3),
> + RKISP1_FEATURE_DMA_34BIT = BIT(4),
> };
>
> #define rkisp1_has_feature(rkisp1, feature) \
> @@ -239,7 +241,7 @@ struct rkisp1_vdev_node {
> struct rkisp1_buffer {
> struct vb2_v4l2_buffer vb;
> struct list_head queue;
> - u32 buff_addr[VIDEO_MAX_PLANES];
> + dma_addr_t buff_addr[VIDEO_MAX_PLANES];
> };
>
> /*
> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
> index 01f811b9f9a5..fd99355d5fe0 100644
> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-dev.c
> @@ -549,7 +549,8 @@ static const struct rkisp1_info imx8mp_isp_info = {
> .isrs = imx8mp_isp_isrs,
> .isr_size = ARRAY_SIZE(imx8mp_isp_isrs),
> .isp_ver = IMX8MP_V10,
> - .features = RKISP1_FEATURE_MAIN_STRIDE,
> + .features = RKISP1_FEATURE_MAIN_STRIDE
> + | RKISP1_FEATURE_DMA_34BIT,
> };
>
> static const struct of_device_id rkisp1_of_match[] = {
> @@ -575,6 +576,7 @@ static int rkisp1_probe(struct platform_device *pdev)
> struct device *dev = &pdev->dev;
> struct rkisp1_device *rkisp1;
> struct v4l2_device *v4l2_dev;
> + unsigned long long dma_mask;
> unsigned int i;
> int ret, irq;
> u32 cif_id;
> @@ -589,6 +591,13 @@ static int rkisp1_probe(struct platform_device *pdev)
> dev_set_drvdata(dev, rkisp1);
> rkisp1->dev = dev;
>
> + dma_mask = rkisp1_has_feature(rkisp1, DMA_34BIT) ? DMA_BIT_MASK(34) :
> + DMA_BIT_MASK(32);
> +
> + ret = dma_set_mask_and_coherent(dev, dma_mask);
> + if (ret)
> + return ret;
> +
> mutex_init(&rkisp1->stream_lock);
>
> rkisp1->base_addr = devm_platform_ioremap_resource(pdev, 0);