diff mbox series

[v6] media: mtk-vpu: Ensure alignment of 8 for DTCM buffer

Message ID 20230526063149.1801196-1-treapking@chromium.org (mailing list archive)
State New, archived
Headers show
Series [v6] media: mtk-vpu: Ensure alignment of 8 for DTCM buffer | expand

Commit Message

Pin-yen Lin May 26, 2023, 6:31 a.m. UTC 
From: Alexandre Courbot <acourbot@chromium.org>

When running memcpy_toio:
memcpy_toio(send_obj->share_buf, buf, len);
it was found that errors appear if len is not a multiple of 8:

[58.350841] mtk-mdp 14001000.rdma: processing failed: -22

This is because in ARM64, memcpy_toio does byte-size access
when the length is not a multiple of 8 while access to the
vpu iomem must be 4 aligned.

This patch ensures the copy of a multiple of 8 size by calling
round_up(len, 8) when copying.

Fixes: e6599adfad30 ("media: mtk-vpu: avoid unaligned access to DTCM buffer.")
Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Houlong Wei <houlong.wei@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

---
This is a re-send of v5 because it was marked obsolete, but this patch
is required for MT8173 platforms.

Changes in v6:
- Collect review tag

 drivers/media/platform/mediatek/vpu/mtk_vpu.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

Comments

AngeloGioacchino Del Regno May 29, 2023, 8:31 a.m. UTC | #1 
Il 26/05/23 08:31, Pin-yen Lin ha scritto:
> From: Alexandre Courbot <acourbot@chromium.org>
> 
> When running memcpy_toio:
> memcpy_toio(send_obj->share_buf, buf, len);
> it was found that errors appear if len is not a multiple of 8:
> 
> [58.350841] mtk-mdp 14001000.rdma: processing failed: -22
> 
> This is because in ARM64, memcpy_toio does byte-size access
> when the length is not a multiple of 8 while access to the
> vpu iomem must be 4 aligned.
> 
> This patch ensures the copy of a multiple of 8 size by calling
> round_up(len, 8) when copying.
> 
> Fixes: e6599adfad30 ("media: mtk-vpu: avoid unaligned access to DTCM buffer.")
> Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> Signed-off-by: Pin-yen Lin <treapking@chromium.org>
> Reviewed-by: Houlong Wei <houlong.wei@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> 
> ---
> This is a re-send of v5 because it was marked obsolete, but this patch
> is required for MT8173 platforms.
> 

Hello,
I have solved this issue in a different way and the commit was already picked.

Please check:
ab14c99c035d ("media: platform: mtk-mdp: Fix mdp_ipi_comm structure alignment")

Regards,
Angelo
Pin-yen Lin May 30, 2023, 8:16 a.m. UTC | #2 
Hi Angelo,

Thanks for letting me know. Then, this patch is not needed.

Regards,
Pin-yen

On Mon, May 29, 2023 at 4:31 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com> wrote:
>
> Il 26/05/23 08:31, Pin-yen Lin ha scritto:
> > From: Alexandre Courbot <acourbot@chromium.org>
> >
> > When running memcpy_toio:
> > memcpy_toio(send_obj->share_buf, buf, len);
> > it was found that errors appear if len is not a multiple of 8:
> >
> > [58.350841] mtk-mdp 14001000.rdma: processing failed: -22
> >
> > This is because in ARM64, memcpy_toio does byte-size access
> > when the length is not a multiple of 8 while access to the
> > vpu iomem must be 4 aligned.
> >
> > This patch ensures the copy of a multiple of 8 size by calling
> > round_up(len, 8) when copying.
> >
> > Fixes: e6599adfad30 ("media: mtk-vpu: avoid unaligned access to DTCM buffer.")
> > Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
> > Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> > Signed-off-by: Pin-yen Lin <treapking@chromium.org>
> > Reviewed-by: Houlong Wei <houlong.wei@mediatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> >
> > ---
> > This is a re-send of v5 because it was marked obsolete, but this patch
> > is required for MT8173 platforms.
> >
>
> Hello,
> I have solved this issue in a different way and the commit was already picked.
>
> Please check:
> ab14c99c035d ("media: platform: mtk-mdp: Fix mdp_ipi_comm structure alignment")
>
> Regards,
> Angelo
>
diff mbox series

Patch

diff --git a/drivers/media/platform/mediatek/vpu/mtk_vpu.c b/drivers/media/platform/mediatek/vpu/mtk_vpu.c
index 5e2bc286f168..19ff4afea456 100644
--- a/drivers/media/platform/mediatek/vpu/mtk_vpu.c
+++ b/drivers/media/platform/mediatek/vpu/mtk_vpu.c
@@ -349,7 +349,22 @@  int vpu_ipi_send(struct platform_device *pdev,
 		}
 	} while (vpu_cfg_readl(vpu, HOST_TO_VPU));
 
-	memcpy_toio(send_obj->share_buf, buf, len);
+	/*
+	 * On Arm64, the memcpy_toio does byte-size access as long as address or length are
+	 * not 8 aligned. Access to the vpu iomem must be 4 aligned. Byte-size access is
+	 * not allowed and cause processing to fail. Therefore make sure the length
+	 * sent to memcpy_toio is a multiply of 8.
+	 */
+	if (len % 8 != 0) {
+		unsigned char data[sizeof(send_obj->share_buf)];
+
+		memset(data + len, 0, sizeof(data) - len);
+		memcpy(data, buf, len);
+		memcpy_toio(send_obj->share_buf, data, round_up(len, 8));
+	} else {
+		memcpy_toio(send_obj->share_buf, buf, len);
+	}
+
 	writel(len, &send_obj->len);
 	writel(id, &send_obj->id);