render/vulkan: vkMapMemory stage spans up front

We always need these mapped for CPU access, so map it up front instead
of duplicating lazy mapping at each site of use.

render/vulkan/pass.c

@@ -822,13 +822,6 @@ static bool create_3d_lut_image(struct wlr_vk_renderer *renderer,
 		goto fail_imageview;
 	}
 
-	if (!span.buffer->cpu_mapping) {
-		res = vkMapMemory(dev, span.buffer->memory, 0, VK_WHOLE_SIZE, 0, &span.buffer->cpu_mapping);
-		if (res != VK_SUCCESS) {
-			wlr_vk_error("vkMapMemory", res);
-			goto fail_imageview;
-		}
-	}
 	char *map = (char*)span.buffer->cpu_mapping + span.alloc.start;
 	float *dst = (float*)map;
 	size_t dim_len = lut_3d->dim_len;

render/vulkan/renderer.c

@@ -309,6 +309,12 @@ struct wlr_vk_buffer_span vulkan_get_stage_span(struct wlr_vk_renderer *r,
 		goto error;
 	}
 
+	res = vkMapMemory(r->dev->dev, buf->memory, 0, VK_WHOLE_SIZE, 0, &buf->cpu_mapping);
+	if (res != VK_SUCCESS) {
+		wlr_vk_error("vkMapMemory", res);
+		goto error;
+	}
+
 	struct wlr_vk_allocation *a = wl_array_add(&buf->allocs, sizeof(*a));
 	if (a == NULL) {
 		wlr_log_errno(WLR_ERROR, "Allocation failed");

render/vulkan/texture.c

@@ -41,9 +41,7 @@ static bool write_pixels(struct wlr_vk_texture *texture,
 		uint32_t stride, const pixman_region32_t *region, const void *vdata,
 		VkImageLayout old_layout, VkPipelineStageFlags src_stage,
 		VkAccessFlags src_access) {
-	VkResult res;
 	struct wlr_vk_renderer *renderer = texture->renderer;
-	VkDevice dev = texture->renderer->dev->dev;
 
 	const struct wlr_pixel_format_info *format_info = drm_get_pixel_format_info(texture->format->drm);
 	assert(format_info);
@@ -79,15 +77,6 @@ static bool write_pixels(struct wlr_vk_texture *texture,
 		free(copies);
 		return false;
 	}
-
-	if (!span.buffer->cpu_mapping) {
-		res = vkMapMemory(dev, span.buffer->memory, 0, VK_WHOLE_SIZE, 0, &span.buffer->cpu_mapping);
-		if (res != VK_SUCCESS) {
-			wlr_vk_error("vkMapMemory", res);
-			free(copies);
-			return false;
-		}
-	}
 	char *map = (char*)span.buffer->cpu_mapping + span.alloc.start;
 
 	// upload data