linux/drivers/gpu/drm/drm_plane_helper.c
Gabriel Krisman Bertazi cd2523569a drm: Always prepare null framebuffer in transitional helper
Despite the documentation claim that cleanup_fb will match prior calls
to prepare_fb, in case of NULL framebuffers in the transitional helpers,
the code will skip the call to prepare_fb but not the corresponding
cleanup_fb call.  This asymmetry in semantics is unnecessarily surprising
for developers transitioning drivers to atomic model, specially because
the final atomic handlers don't have the issue - the prepare_fb is
always called, despite the new state framebuffer being null.

The only current user of the transitional helper that doesn't take care
of null framebuffers explicitly inside the prepare_fb hook is
atmel_hlcdc, so we take special care to make sure we don't break
anything there.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170216164442.28704-1-krisman@collabora.co.uk
2017-02-26 21:57:24 +01:00

619 lines
19 KiB
C

/*
* Copyright (C) 2014 Intel Corporation
*
* DRM universal plane helper functions
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/list.h>
#include <drm/drmP.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_rect.h>
#include <drm/drm_atomic.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_encoder.h>
#include <drm/drm_atomic_helper.h>
#define SUBPIXEL_MASK 0xffff
/**
* DOC: overview
*
* This helper library has two parts. The first part has support to implement
* primary plane support on top of the normal CRTC configuration interface.
* Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
* plane together with the CRTC state this does not allow userspace to disable
* the primary plane itself. To avoid too much duplicated code use
* drm_plane_helper_check_update() which can be used to enforce the same
* restrictions as primary planes had thus. The default primary plane only
* expose XRBG8888 and ARGB8888 as valid pixel formats for the attached
* framebuffer.
*
* Drivers are highly recommended to implement proper support for primary
* planes, and newly merged drivers must not rely upon these transitional
* helpers.
*
* The second part also implements transitional helpers which allow drivers to
* gradually switch to the atomic helper infrastructure for plane updates. Once
* that switch is complete drivers shouldn't use these any longer, instead using
* the proper legacy implementations for update and disable plane hooks provided
* by the atomic helpers.
*
* Again drivers are strongly urged to switch to the new interfaces.
*
* The plane helpers share the function table structures with other helpers,
* specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
* the details.
*/
/*
* Returns the connectors currently associated with a CRTC. This function
* should be called twice: once with a NULL connector list to retrieve
* the list size, and once with the properly allocated list to be filled in.
*/
static int get_connectors_for_crtc(struct drm_crtc *crtc,
struct drm_connector **connector_list,
int num_connectors)
{
struct drm_device *dev = crtc->dev;
struct drm_connector *connector;
struct drm_connector_list_iter conn_iter;
int count = 0;
/*
* Note: Once we change the plane hooks to more fine-grained locking we
* need to grab the connection_mutex here to be able to make these
* checks.
*/
WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
drm_connector_list_iter_get(dev, &conn_iter);
drm_for_each_connector_iter(connector, &conn_iter) {
if (connector->encoder && connector->encoder->crtc == crtc) {
if (connector_list != NULL && count < num_connectors)
*(connector_list++) = connector;
count++;
}
}
drm_connector_list_iter_put(&conn_iter);
return count;
}
/**
* drm_plane_helper_check_state() - Check plane state for validity
* @state: plane state to check
* @clip: integer clipping coordinates
* @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
* @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
* @can_position: is it legal to position the plane such that it
* doesn't cover the entire crtc? This will generally
* only be false for primary planes.
* @can_update_disabled: can the plane be updated while the crtc
* is disabled?
*
* Checks that a desired plane update is valid, and updates various
* bits of derived state (clipped coordinates etc.). Drivers that provide
* their own plane handling rather than helper-provided implementations may
* still wish to call this function to avoid duplication of error checking
* code.
*
* RETURNS:
* Zero if update appears valid, error code on failure
*/
int drm_plane_helper_check_state(struct drm_plane_state *state,
const struct drm_rect *clip,
int min_scale,
int max_scale,
bool can_position,
bool can_update_disabled)
{
struct drm_crtc *crtc = state->crtc;
struct drm_framebuffer *fb = state->fb;
struct drm_rect *src = &state->src;
struct drm_rect *dst = &state->dst;
unsigned int rotation = state->rotation;
int hscale, vscale;
*src = drm_plane_state_src(state);
*dst = drm_plane_state_dest(state);
if (!fb) {
state->visible = false;
return 0;
}
/* crtc should only be NULL when disabling (i.e., !fb) */
if (WARN_ON(!crtc)) {
state->visible = false;
return 0;
}
if (!crtc->enabled && !can_update_disabled) {
DRM_DEBUG_KMS("Cannot update plane of a disabled CRTC.\n");
return -EINVAL;
}
drm_rect_rotate(src, fb->width << 16, fb->height << 16, rotation);
/* Check scaling */
hscale = drm_rect_calc_hscale(src, dst, min_scale, max_scale);
vscale = drm_rect_calc_vscale(src, dst, min_scale, max_scale);
if (hscale < 0 || vscale < 0) {
DRM_DEBUG_KMS("Invalid scaling of plane\n");
drm_rect_debug_print("src: ", &state->src, true);
drm_rect_debug_print("dst: ", &state->dst, false);
return -ERANGE;
}
state->visible = drm_rect_clip_scaled(src, dst, clip, hscale, vscale);
drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16, rotation);
if (!state->visible)
/*
* Plane isn't visible; some drivers can handle this
* so we just return success here. Drivers that can't
* (including those that use the primary plane helper's
* update function) will return an error from their
* update_plane handler.
*/
return 0;
if (!can_position && !drm_rect_equals(dst, clip)) {
DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
drm_rect_debug_print("dst: ", dst, false);
drm_rect_debug_print("clip: ", clip, false);
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL(drm_plane_helper_check_state);
/**
* drm_plane_helper_check_update() - Check plane update for validity
* @plane: plane object to update
* @crtc: owning CRTC of owning plane
* @fb: framebuffer to flip onto plane
* @src: source coordinates in 16.16 fixed point
* @dst: integer destination coordinates
* @clip: integer clipping coordinates
* @rotation: plane rotation
* @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
* @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
* @can_position: is it legal to position the plane such that it
* doesn't cover the entire crtc? This will generally
* only be false for primary planes.
* @can_update_disabled: can the plane be updated while the crtc
* is disabled?
* @visible: output parameter indicating whether plane is still visible after
* clipping
*
* Checks that a desired plane update is valid. Drivers that provide
* their own plane handling rather than helper-provided implementations may
* still wish to call this function to avoid duplication of error checking
* code.
*
* RETURNS:
* Zero if update appears valid, error code on failure
*/
int drm_plane_helper_check_update(struct drm_plane *plane,
struct drm_crtc *crtc,
struct drm_framebuffer *fb,
struct drm_rect *src,
struct drm_rect *dst,
const struct drm_rect *clip,
unsigned int rotation,
int min_scale,
int max_scale,
bool can_position,
bool can_update_disabled,
bool *visible)
{
struct drm_plane_state state = {
.plane = plane,
.crtc = crtc,
.fb = fb,
.src_x = src->x1,
.src_y = src->y1,
.src_w = drm_rect_width(src),
.src_h = drm_rect_height(src),
.crtc_x = dst->x1,
.crtc_y = dst->y1,
.crtc_w = drm_rect_width(dst),
.crtc_h = drm_rect_height(dst),
.rotation = rotation,
.visible = *visible,
};
int ret;
ret = drm_plane_helper_check_state(&state, clip,
min_scale, max_scale,
can_position,
can_update_disabled);
if (ret)
return ret;
*src = state.src;
*dst = state.dst;
*visible = state.visible;
return 0;
}
EXPORT_SYMBOL(drm_plane_helper_check_update);
/**
* drm_primary_helper_update() - Helper for primary plane update
* @plane: plane object to update
* @crtc: owning CRTC of owning plane
* @fb: framebuffer to flip onto plane
* @crtc_x: x offset of primary plane on crtc
* @crtc_y: y offset of primary plane on crtc
* @crtc_w: width of primary plane rectangle on crtc
* @crtc_h: height of primary plane rectangle on crtc
* @src_x: x offset of @fb for panning
* @src_y: y offset of @fb for panning
* @src_w: width of source rectangle in @fb
* @src_h: height of source rectangle in @fb
*
* Provides a default plane update handler for primary planes. This is handler
* is called in response to a userspace SetPlane operation on the plane with a
* non-NULL framebuffer. We call the driver's modeset handler to update the
* framebuffer.
*
* SetPlane() on a primary plane of a disabled CRTC is not supported, and will
* return an error.
*
* Note that we make some assumptions about hardware limitations that may not be
* true for all hardware --
*
* 1. Primary plane cannot be repositioned.
* 2. Primary plane cannot be scaled.
* 3. Primary plane must cover the entire CRTC.
* 4. Subpixel positioning is not supported.
*
* Drivers for hardware that don't have these restrictions can provide their
* own implementation rather than using this helper.
*
* RETURNS:
* Zero on success, error code on failure
*/
int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
struct drm_framebuffer *fb,
int crtc_x, int crtc_y,
unsigned int crtc_w, unsigned int crtc_h,
uint32_t src_x, uint32_t src_y,
uint32_t src_w, uint32_t src_h)
{
struct drm_mode_set set = {
.crtc = crtc,
.fb = fb,
.mode = &crtc->mode,
.x = src_x >> 16,
.y = src_y >> 16,
};
struct drm_rect src = {
.x1 = src_x,
.y1 = src_y,
.x2 = src_x + src_w,
.y2 = src_y + src_h,
};
struct drm_rect dest = {
.x1 = crtc_x,
.y1 = crtc_y,
.x2 = crtc_x + crtc_w,
.y2 = crtc_y + crtc_h,
};
const struct drm_rect clip = {
.x2 = crtc->mode.hdisplay,
.y2 = crtc->mode.vdisplay,
};
struct drm_connector **connector_list;
int num_connectors, ret;
bool visible;
ret = drm_plane_helper_check_update(plane, crtc, fb,
&src, &dest, &clip,
DRM_ROTATE_0,
DRM_PLANE_HELPER_NO_SCALING,
DRM_PLANE_HELPER_NO_SCALING,
false, false, &visible);
if (ret)
return ret;
if (!visible)
/*
* Primary plane isn't visible. Note that unless a driver
* provides their own disable function, this will just
* wind up returning -EINVAL to userspace.
*/
return plane->funcs->disable_plane(plane);
/* Find current connectors for CRTC */
num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
BUG_ON(num_connectors == 0);
connector_list = kzalloc(num_connectors * sizeof(*connector_list),
GFP_KERNEL);
if (!connector_list)
return -ENOMEM;
get_connectors_for_crtc(crtc, connector_list, num_connectors);
set.connectors = connector_list;
set.num_connectors = num_connectors;
/*
* We call set_config() directly here rather than using
* drm_mode_set_config_internal. We're reprogramming the same
* connectors that were already in use, so we shouldn't need the extra
* cross-CRTC fb refcounting to accomodate stealing connectors.
* drm_mode_setplane() already handles the basic refcounting for the
* framebuffers involved in this operation.
*/
ret = crtc->funcs->set_config(&set);
kfree(connector_list);
return ret;
}
EXPORT_SYMBOL(drm_primary_helper_update);
/**
* drm_primary_helper_disable() - Helper for primary plane disable
* @plane: plane to disable
*
* Provides a default plane disable handler for primary planes. This is handler
* is called in response to a userspace SetPlane operation on the plane with a
* NULL framebuffer parameter. It unconditionally fails the disable call with
* -EINVAL the only way to disable the primary plane without driver support is
* to disable the entire CRTC. Which does not match the plane
* &drm_plane_funcs.disable_plane hook.
*
* Note that some hardware may be able to disable the primary plane without
* disabling the whole CRTC. Drivers for such hardware should provide their
* own disable handler that disables just the primary plane (and they'll likely
* need to provide their own update handler as well to properly re-enable a
* disabled primary plane).
*
* RETURNS:
* Unconditionally returns -EINVAL.
*/
int drm_primary_helper_disable(struct drm_plane *plane)
{
return -EINVAL;
}
EXPORT_SYMBOL(drm_primary_helper_disable);
/**
* drm_primary_helper_destroy() - Helper for primary plane destruction
* @plane: plane to destroy
*
* Provides a default plane destroy handler for primary planes. This handler
* is called during CRTC destruction. We disable the primary plane, remove
* it from the DRM plane list, and deallocate the plane structure.
*/
void drm_primary_helper_destroy(struct drm_plane *plane)
{
drm_plane_cleanup(plane);
kfree(plane);
}
EXPORT_SYMBOL(drm_primary_helper_destroy);
const struct drm_plane_funcs drm_primary_helper_funcs = {
.update_plane = drm_primary_helper_update,
.disable_plane = drm_primary_helper_disable,
.destroy = drm_primary_helper_destroy,
};
EXPORT_SYMBOL(drm_primary_helper_funcs);
int drm_plane_helper_commit(struct drm_plane *plane,
struct drm_plane_state *plane_state,
struct drm_framebuffer *old_fb)
{
const struct drm_plane_helper_funcs *plane_funcs;
struct drm_crtc *crtc[2];
const struct drm_crtc_helper_funcs *crtc_funcs[2];
int i, ret = 0;
plane_funcs = plane->helper_private;
/* Since this is a transitional helper we can't assume that plane->state
* is always valid. Hence we need to use plane->crtc instead of
* plane->state->crtc as the old crtc. */
crtc[0] = plane->crtc;
crtc[1] = crtc[0] != plane_state->crtc ? plane_state->crtc : NULL;
for (i = 0; i < 2; i++)
crtc_funcs[i] = crtc[i] ? crtc[i]->helper_private : NULL;
if (plane_funcs->atomic_check) {
ret = plane_funcs->atomic_check(plane, plane_state);
if (ret)
goto out;
}
if (plane_funcs->prepare_fb && plane_state->fb != old_fb) {
ret = plane_funcs->prepare_fb(plane,
plane_state);
if (ret)
goto out;
}
/* Point of no return, commit sw state. */
swap(plane->state, plane_state);
for (i = 0; i < 2; i++) {
if (crtc_funcs[i] && crtc_funcs[i]->atomic_begin)
crtc_funcs[i]->atomic_begin(crtc[i], crtc[i]->state);
}
/*
* Drivers may optionally implement the ->atomic_disable callback, so
* special-case that here.
*/
if (drm_atomic_plane_disabling(plane, plane_state) &&
plane_funcs->atomic_disable)
plane_funcs->atomic_disable(plane, plane_state);
else
plane_funcs->atomic_update(plane, plane_state);
for (i = 0; i < 2; i++) {
if (crtc_funcs[i] && crtc_funcs[i]->atomic_flush)
crtc_funcs[i]->atomic_flush(crtc[i], crtc[i]->state);
}
/*
* If we only moved the plane and didn't change fb's, there's no need to
* wait for vblank.
*/
if (plane->state->fb == old_fb)
goto out;
for (i = 0; i < 2; i++) {
if (!crtc[i])
continue;
if (crtc[i]->cursor == plane)
continue;
/* There's no other way to figure out whether the crtc is running. */
ret = drm_crtc_vblank_get(crtc[i]);
if (ret == 0) {
drm_crtc_wait_one_vblank(crtc[i]);
drm_crtc_vblank_put(crtc[i]);
}
ret = 0;
}
if (plane_funcs->cleanup_fb)
plane_funcs->cleanup_fb(plane, plane_state);
out:
if (plane_state) {
if (plane->funcs->atomic_destroy_state)
plane->funcs->atomic_destroy_state(plane, plane_state);
else
drm_atomic_helper_plane_destroy_state(plane, plane_state);
}
return ret;
}
/**
* drm_plane_helper_update() - Transitional helper for plane update
* @plane: plane object to update
* @crtc: owning CRTC of owning plane
* @fb: framebuffer to flip onto plane
* @crtc_x: x offset of primary plane on crtc
* @crtc_y: y offset of primary plane on crtc
* @crtc_w: width of primary plane rectangle on crtc
* @crtc_h: height of primary plane rectangle on crtc
* @src_x: x offset of @fb for panning
* @src_y: y offset of @fb for panning
* @src_w: width of source rectangle in @fb
* @src_h: height of source rectangle in @fb
*
* Provides a default plane update handler using the atomic plane update
* functions. It is fully left to the driver to check plane constraints and
* handle corner-cases like a fully occluded or otherwise invisible plane.
*
* This is useful for piecewise transitioning of a driver to the atomic helpers.
*
* RETURNS:
* Zero on success, error code on failure
*/
int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
struct drm_framebuffer *fb,
int crtc_x, int crtc_y,
unsigned int crtc_w, unsigned int crtc_h,
uint32_t src_x, uint32_t src_y,
uint32_t src_w, uint32_t src_h)
{
struct drm_plane_state *plane_state;
if (plane->funcs->atomic_duplicate_state)
plane_state = plane->funcs->atomic_duplicate_state(plane);
else {
if (!plane->state)
drm_atomic_helper_plane_reset(plane);
plane_state = drm_atomic_helper_plane_duplicate_state(plane);
}
if (!plane_state)
return -ENOMEM;
plane_state->plane = plane;
plane_state->crtc = crtc;
drm_atomic_set_fb_for_plane(plane_state, fb);
plane_state->crtc_x = crtc_x;
plane_state->crtc_y = crtc_y;
plane_state->crtc_h = crtc_h;
plane_state->crtc_w = crtc_w;
plane_state->src_x = src_x;
plane_state->src_y = src_y;
plane_state->src_h = src_h;
plane_state->src_w = src_w;
return drm_plane_helper_commit(plane, plane_state, plane->fb);
}
EXPORT_SYMBOL(drm_plane_helper_update);
/**
* drm_plane_helper_disable() - Transitional helper for plane disable
* @plane: plane to disable
*
* Provides a default plane disable handler using the atomic plane update
* functions. It is fully left to the driver to check plane constraints and
* handle corner-cases like a fully occluded or otherwise invisible plane.
*
* This is useful for piecewise transitioning of a driver to the atomic helpers.
*
* RETURNS:
* Zero on success, error code on failure
*/
int drm_plane_helper_disable(struct drm_plane *plane)
{
struct drm_plane_state *plane_state;
/* crtc helpers love to call disable functions for already disabled hw
* functions. So cope with that. */
if (!plane->crtc)
return 0;
if (plane->funcs->atomic_duplicate_state)
plane_state = plane->funcs->atomic_duplicate_state(plane);
else {
if (!plane->state)
drm_atomic_helper_plane_reset(plane);
plane_state = drm_atomic_helper_plane_duplicate_state(plane);
}
if (!plane_state)
return -ENOMEM;
plane_state->plane = plane;
plane_state->crtc = NULL;
drm_atomic_set_fb_for_plane(plane_state, NULL);
return drm_plane_helper_commit(plane, plane_state, plane->fb);
}
EXPORT_SYMBOL(drm_plane_helper_disable);