[PATCH v2 3/4] drm/mediatek: Add casting before assign

[Jason-JH . Lin]

1. Add casting before assign to avoid the unintentional integer
   overflow or unintended sign extension.
2. Add a int varriable for multiplier calculation instead of calculating
   different types multiplier with dma_addr_t varriable directly.

Signed-off-by: Jason-JH.Lin <jason-jh....@mediatek.com>
Fixes: 1a64a7aff8da ("drm/mediatek: Fix cursor plane no update")
---
 drivers/gpu/drm/mediatek/mtk_drm_gem.c   |  2 +-
 drivers/gpu/drm/mediatek/mtk_drm_plane.c | 22 +++++++++++++---------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c 
b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index a25b28d3ee90..0c7878bc0b37 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -121,7 +121,7 @@ int mtk_drm_gem_dumb_create(struct drm_file *file_priv, 
struct drm_device *dev,
        int ret;
 
        args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
-       args->size = args->pitch * args->height;
+       args->size = (__u64)args->pitch * args->height;
 
        mtk_gem = mtk_drm_gem_create(dev, args->size, false);
        if (IS_ERR(mtk_gem))
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c 
b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
index 31f9420aff6f..1cd41454d545 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
@@ -145,6 +145,7 @@ static void mtk_plane_update_new_state(struct 
drm_plane_state *new_state,
        dma_addr_t addr;
        dma_addr_t hdr_addr = 0;
        unsigned int hdr_pitch = 0;
+       int offset;
 
        gem = fb->obj[0];
        mtk_gem = to_mtk_gem_obj(gem);
@@ -154,8 +155,10 @@ static void mtk_plane_update_new_state(struct 
drm_plane_state *new_state,
        modifier = fb->modifier;
 
        if (modifier == DRM_FORMAT_MOD_LINEAR) {
-               addr += (new_state->src.x1 >> 16) * fb->format->cpp[0];
-               addr += (new_state->src.y1 >> 16) * pitch;
+               offset = (new_state->src.x1 >> 16) * fb->format->cpp[0];
+               addr += offset;
+               offset = (new_state->src.y1 >> 16) * pitch;
+               addr += offset;
        } else {
                int width_in_blocks = ALIGN(fb->width, AFBC_DATA_BLOCK_WIDTH)
                                      / AFBC_DATA_BLOCK_WIDTH;
@@ -163,21 +166,22 @@ static void mtk_plane_update_new_state(struct 
drm_plane_state *new_state,
                                       / AFBC_DATA_BLOCK_HEIGHT;
                int x_offset_in_blocks = (new_state->src.x1 >> 16) / 
AFBC_DATA_BLOCK_WIDTH;
                int y_offset_in_blocks = (new_state->src.y1 >> 16) / 
AFBC_DATA_BLOCK_HEIGHT;
-               int hdr_size;
+               int hdr_size, hdr_offset;
 
                hdr_pitch = width_in_blocks * AFBC_HEADER_BLOCK_SIZE;
                pitch = width_in_blocks * AFBC_DATA_BLOCK_WIDTH *
                        AFBC_DATA_BLOCK_HEIGHT * fb->format->cpp[0];
 
                hdr_size = ALIGN(hdr_pitch * height_in_blocks, 
AFBC_HEADER_ALIGNMENT);
+               hdr_offset = hdr_pitch * y_offset_in_blocks +
+                       AFBC_HEADER_BLOCK_SIZE * x_offset_in_blocks;
+               hdr_addr = addr + hdr_offset;
 
-               hdr_addr = addr + hdr_pitch * y_offset_in_blocks +
-                          AFBC_HEADER_BLOCK_SIZE * x_offset_in_blocks;
                /* The data plane is offset by 1 additional block. */
-               addr = addr + hdr_size +
-                      pitch * y_offset_in_blocks +
-                      AFBC_DATA_BLOCK_WIDTH * AFBC_DATA_BLOCK_HEIGHT *
-                      fb->format->cpp[0] * (x_offset_in_blocks + 1);
+               offset = pitch * y_offset_in_blocks +
+                        AFBC_DATA_BLOCK_WIDTH * AFBC_DATA_BLOCK_HEIGHT *
+                        fb->format->cpp[0] * (x_offset_in_blocks + 1);
+               addr = addr + hdr_size + offset;
        }
 
        mtk_plane_state->pending.enable = true;
-- 
2.18.0