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

[Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>]

On 08/01/2024 13:37, Tomi Valkeinen wrote:
> 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?

Oh, and the patch title is not quite right anymore. I think this is more 
about supporting i.MX8MP's 34-bit DMA.

 Tomi

> For the change itself:
>
> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
>
>   Tomi
>
> > Signed-off-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> > Tested-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> > Tested-by: Adam Ford <aford173@xxxxxxxxx>
> > ---
> > 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@xxxxxxxxxxxxxxxx>
>
>   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);