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

Tomi Valkeinen
2024-01-08T11:39:06Z

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@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);
>