media: s5p-mfc: Use 'bitmap_zalloc()' when applicable

'mfc_dev->mem_bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify
code and improve the semantic.

Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
consistency.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/s5p-mfc/s5p_mfc.c

@@ -1185,7 +1185,6 @@ static int s5p_mfc_configure_common_memory(struct s5p_mfc_dev *mfc_dev)
 {
 	struct device *dev = &mfc_dev->plat_dev->dev;
 	unsigned long mem_size = SZ_4M;
-	unsigned int bitmap_size;
 
 	if (IS_ENABLED(CONFIG_DMA_CMA) || exynos_is_iommu_available(dev))
 		mem_size = SZ_8M;
@@ -1193,16 +1192,14 @@ static int s5p_mfc_configure_common_memory(struct s5p_mfc_dev *mfc_dev)
 	if (mfc_mem_size)
 		mem_size = memparse(mfc_mem_size, NULL);
 
-	bitmap_size = BITS_TO_LONGS(mem_size >> PAGE_SHIFT) * sizeof(long);
-
-	mfc_dev->mem_bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+	mfc_dev->mem_bitmap = bitmap_zalloc(mem_size >> PAGE_SHIFT, GFP_KERNEL);
 	if (!mfc_dev->mem_bitmap)
 		return -ENOMEM;
 
 	mfc_dev->mem_virt = dma_alloc_coherent(dev, mem_size,
 					       &mfc_dev->mem_base, GFP_KERNEL);
 	if (!mfc_dev->mem_virt) {
-		kfree(mfc_dev->mem_bitmap);
+		bitmap_free(mfc_dev->mem_bitmap);
 		dev_err(dev, "failed to preallocate %ld MiB for the firmware and context buffers\n",
 			(mem_size / SZ_1M));
 		return -ENOMEM;
@@ -1241,7 +1238,7 @@ static void s5p_mfc_unconfigure_common_memory(struct s5p_mfc_dev *mfc_dev)
 
 	dma_free_coherent(dev, mfc_dev->mem_size, mfc_dev->mem_virt,
 			  mfc_dev->mem_base);
-	kfree(mfc_dev->mem_bitmap);
+	bitmap_free(mfc_dev->mem_bitmap);
 	vb2_dma_contig_clear_max_seg_size(dev);
 }