From: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
Signed-off-by: Pin-yen Lin <treapking@xxxxxxxxxxxx>
Reviewed-by: Houlong Wei <houlong.wei@xxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
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(-)
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);
--
2.41.0.rc0.172.g3f132b7071-goog
