buffer: add data_ptr access flags

This allows callers to specify the operations they'll perform on
the returned data pointer. The motivations for this are:

- The upcoming Linux MAP_NOSIGBUS flag may only be usable on
  read-only mappings.
- gbm_bo_map with GBM_BO_TRANSFER_READ hurts performance.
This commit is contained in:
Simon Ser 2021-06-29 17:08:32 +02:00 committed by Simon Zeni
parent 105fdecd0c
commit 4e7a8707cc
7 changed files with 46 additions and 22 deletions

View File

@ -69,17 +69,31 @@ struct wlr_dmabuf_buffer *dmabuf_buffer_create(
*/
bool dmabuf_buffer_drop(struct wlr_dmabuf_buffer *buffer);
/**
* Buffer data pointer access flags.
*/
enum wlr_buffer_data_ptr_access_flag {
/**
* The buffer contents can be read back.
*/
WLR_BUFFER_DATA_PTR_ACCESS_READ = 1 << 0,
/**
* The buffer contents can be written to.
*/
WLR_BUFFER_DATA_PTR_ACCESS_WRITE = 1 << 1,
};
/**
* Get a pointer to a region of memory referring to the buffer's underlying
* storage. The format and stride can be used to interpret the memory region
* contents.
*
* The returned pointer should be pointing to a valid memory region for read
* and write operations. The returned pointer is only valid up to the next
* buffer_end_data_ptr_access call.
* The returned pointer should be pointing to a valid memory region for the
* operations specified in the flags. The returned pointer is only valid up to
* the next buffer_end_data_ptr_access call.
*/
bool buffer_begin_data_ptr_access(struct wlr_buffer *buffer, void **data,
uint32_t *format, size_t *stride);
bool buffer_begin_data_ptr_access(struct wlr_buffer *buffer, uint32_t flags,
void **data, uint32_t *format, size_t *stride);
void buffer_end_data_ptr_access(struct wlr_buffer *buffer);
#endif

View File

@ -30,8 +30,8 @@ struct wlr_buffer_impl {
struct wlr_dmabuf_attributes *attribs);
bool (*get_shm)(struct wlr_buffer *buffer,
struct wlr_shm_attributes *attribs);
bool (*begin_data_ptr_access)(struct wlr_buffer *buffer, void **data,
uint32_t *format, size_t *stride);
bool (*begin_data_ptr_access)(struct wlr_buffer *buffer, uint32_t flags,
void **data, uint32_t *format, size_t *stride);
void (*end_data_ptr_access)(struct wlr_buffer *buffer);
};

View File

@ -128,7 +128,7 @@ create_err:
}
static bool drm_dumb_buffer_begin_data_ptr_access(struct wlr_buffer *wlr_buffer,
void **data, uint32_t *format, size_t *stride) {
uint32_t flags, void **data, uint32_t *format, size_t *stride) {
struct wlr_drm_dumb_buffer *buf = drm_dumb_buffer_from_buffer(wlr_buffer);
*data = buf->data;
*stride = buf->stride;

View File

@ -31,7 +31,7 @@ static bool buffer_get_shm(struct wlr_buffer *wlr_buffer,
}
static bool shm_buffer_begin_data_ptr_access(struct wlr_buffer *wlr_buffer,
void **data, uint32_t *format, size_t *stride) {
uint32_t flags, void **data, uint32_t *format, size_t *stride) {
struct wlr_shm_buffer *buffer = shm_buffer_from_buffer(wlr_buffer);
*data = buffer->data;
*format = buffer->shm.format;

View File

@ -346,7 +346,8 @@ struct wlr_texture *gles2_texture_from_buffer(struct wlr_renderer *wlr_renderer,
struct wlr_dmabuf_attributes dmabuf;
if (wlr_buffer_get_dmabuf(buffer, &dmabuf)) {
return gles2_texture_from_dmabuf_buffer(renderer, buffer, &dmabuf);
} else if (buffer_begin_data_ptr_access(buffer, &data, &format, &stride)) {
} else if (buffer_begin_data_ptr_access(buffer,
WLR_BUFFER_DATA_PTR_ACCESS_READ, &data, &format, &stride)) {
struct wlr_texture *tex = gles2_texture_from_pixels(wlr_renderer,
format, stride, buffer->width, buffer->height, data);
buffer_end_data_ptr_access(buffer);

View File

@ -96,7 +96,9 @@ static struct wlr_pixman_buffer *create_buffer(
void *data = NULL;
uint32_t drm_format;
size_t stride;
if (!buffer_begin_data_ptr_access(wlr_buffer, &data, &drm_format, &stride)) {
if (!buffer_begin_data_ptr_access(wlr_buffer,
WLR_BUFFER_DATA_PTR_ACCESS_READ | WLR_BUFFER_DATA_PTR_ACCESS_WRITE,
&data, &drm_format, &stride)) {
wlr_log(WLR_ERROR, "Failed to get buffer data");
goto error_buffer;
}
@ -143,7 +145,9 @@ static void pixman_begin(struct wlr_renderer *wlr_renderer, uint32_t width,
void *data = NULL;
uint32_t drm_format;
size_t stride;
buffer_begin_data_ptr_access(buffer->buffer, &data, &drm_format, &stride);
buffer_begin_data_ptr_access(buffer->buffer,
WLR_BUFFER_DATA_PTR_ACCESS_READ | WLR_BUFFER_DATA_PTR_ACCESS_WRITE,
&data, &drm_format, &stride);
// If the data pointer has changed, re-create the Pixman image. This can
// happen if it's a client buffer and the wl_shm_pool has been resized.
@ -229,8 +233,8 @@ static bool pixman_render_subtexture_with_matrix(
void *data;
uint32_t drm_format;
size_t stride;
if (!buffer_begin_data_ptr_access(texture->buffer, &data, &drm_format,
&stride)) {
if (!buffer_begin_data_ptr_access(texture->buffer,
WLR_BUFFER_DATA_PTR_ACCESS_READ, &data, &drm_format, &stride)) {
return false;
}
@ -376,7 +380,8 @@ static struct wlr_texture *pixman_texture_from_buffer(
void *data = NULL;
uint32_t drm_format;
size_t stride;
if (!buffer_begin_data_ptr_access(buffer, &data, &drm_format, &stride)) {
if (!buffer_begin_data_ptr_access(buffer, WLR_BUFFER_DATA_PTR_ACCESS_READ,
&data, &drm_format, &stride)) {
return NULL;
}
buffer_end_data_ptr_access(buffer);

View File

@ -75,13 +75,13 @@ bool wlr_buffer_get_dmabuf(struct wlr_buffer *buffer,
return buffer->impl->get_dmabuf(buffer, attribs);
}
bool buffer_begin_data_ptr_access(struct wlr_buffer *buffer, void **data,
uint32_t *format, size_t *stride) {
bool buffer_begin_data_ptr_access(struct wlr_buffer *buffer, uint32_t flags,
void **data, uint32_t *format, size_t *stride) {
assert(!buffer->accessing_data_ptr);
if (!buffer->impl->begin_data_ptr_access) {
return false;
}
if (!buffer->impl->begin_data_ptr_access(buffer, data, format, stride)) {
if (!buffer->impl->begin_data_ptr_access(buffer, flags, data, format, stride)) {
return false;
}
buffer->accessing_data_ptr = true;
@ -292,7 +292,8 @@ bool wlr_client_buffer_apply_damage(struct wlr_client_buffer *client_buffer,
void *data;
uint32_t format;
size_t stride;
if (!buffer_begin_data_ptr_access(next, &data, &format, &stride)) {
if (!buffer_begin_data_ptr_access(next, WLR_BUFFER_DATA_PTR_ACCESS_READ,
&data, &format, &stride)) {
return false;
}
@ -343,7 +344,7 @@ static void shm_client_buffer_destroy(struct wlr_buffer *wlr_buffer) {
}
static bool shm_client_buffer_begin_data_ptr_access(struct wlr_buffer *wlr_buffer,
void **data, uint32_t *format, size_t *stride) {
uint32_t flags, void **data, uint32_t *format, size_t *stride) {
struct wlr_shm_client_buffer *buffer =
shm_client_buffer_from_buffer(wlr_buffer);
*format = buffer->format;
@ -454,12 +455,15 @@ static void readonly_data_buffer_destroy(struct wlr_buffer *wlr_buffer) {
}
static bool readonly_data_buffer_begin_data_ptr_access(struct wlr_buffer *wlr_buffer,
void **data, uint32_t *format, size_t *stride) {
uint32_t flags, void **data, uint32_t *format, size_t *stride) {
struct wlr_readonly_data_buffer *buffer =
readonly_data_buffer_from_buffer(wlr_buffer);
if (buffer->data == NULL) {
return false;
}
if (flags & WLR_BUFFER_DATA_PTR_ACCESS_WRITE) {
return false;
}
*data = (void *)buffer->data;
*format = buffer->format;
*stride = buffer->stride;