[PATCH] drm/core: Do not preserve framebuffer on rmfb.
Maarten Lankhorst
maarten.lankhorst at linux.intel.com
Tue Mar 22 10:53:53 UTC 2016
Op 22-03-16 om 11:50 schreef Daniel Vetter:
> On Tue, Mar 22, 2016 at 10:32:32AM +0100, Maarten Lankhorst wrote:
>> Op 21-03-16 om 18:37 schreef Daniel Vetter:
>>> On Mon, Mar 21, 2016 at 03:11:17PM +0100, Maarten Lankhorst wrote:
>>>> It turns out that preserving framebuffers after the rmfb call breaks
>>>> vmwgfx userspace. This was originally introduced because it was thought
>>>> nobody relied on the behavior, but unfortunately it seems there are
>>>> exceptions.
>>>>
>>>> drm_framebuffer_remove may fail with -EINTR now, so a straight revert
>>>> is impossible. There is no way to remove the framebuffer from the lists
>>>> and active planes without introducing a race because of the different
>>>> locking requirements. Instead call drm_framebuffer_remove from a
>>>> workqueue, which is unaffected by signals.
>>>>
>>>> Cc: stable at vger.kernel.org #v4.4+
>>>> Fixes: 13803132818c ("drm/core: Preserve the framebuffer after removing it.")
>>>> Testcase: kms_flip.flip-vs-rmfb-interruptible
>>>> References: https://lists.freedesktop.org/archives/dri-devel/2016-March/102876.html
>>>> Cc: Thomas Hellstrom <thellstrom at vmware.com>
>>>> Cc: David Herrmann <dh.herrmann at gmail.com>
>>>> ---
>>>> drivers/gpu/drm/drm_crtc.c | 20 +++++++++++++++++++-
>>>> 1 file changed, 19 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
>>>> index e08f962288d9..b7d0b959f088 100644
>>>> --- a/drivers/gpu/drm/drm_crtc.c
>>>> +++ b/drivers/gpu/drm/drm_crtc.c
>>>> @@ -3434,6 +3434,18 @@ int drm_mode_addfb2(struct drm_device *dev,
>>>> return 0;
>>>> }
>>>>
>>>> +struct drm_mode_rmfb_work {
>>>> + struct work_struct work;
>>>> + struct drm_framebuffer *fb;
>>>> +};
>>>> +
>>>> +static void drm_mode_rmfb_work_fn(struct work_struct *w)
>>>> +{
>>>> + struct drm_mode_rmfb_work *arg = container_of(w, typeof(*arg), work);
>>>> +
>>>> + drm_framebuffer_remove(arg->fb);
>>> drm_framebuffer_remove still has the problem of not working correctly with
>>> atomic since atomic commit will complain if we try to do more than 1
>>> commit per ww_acquire_ctx. I think we still need an atomic version of
>>> this. Also probably a more nasty igt testcase which uses the same fb on
>>> more than one plane to be able to hit this case.
>> That's true, but a separate bug. :)
> Atm we only use drm_framebuffer_remove in atomic drivers to nuke the fbdev
> one at unload. With your patch userspace can't get there easily, and hence
> it must be fixed. Maybe separate prep patch (also cc: stable) upfront?
>
Something like this?
Unfortunately I need to collect acks first.
commit ed242f92c2e7571a6a5f649c2a67031debc73e44
Author: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Date: Thu Mar 17 13:42:08 2016 +0100
drm/atomic: Add remove_fb function pointer.
Use this in drm_framebuffer_remove, this is to remove the fb in an atomic way.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c
index 56b829f97699..50ba6adb74e8 100644
--- a/drivers/gpu/drm/arm/hdlcd_drv.c
+++ b/drivers/gpu/drm/arm/hdlcd_drv.c
@@ -324,6 +324,7 @@ static struct drm_driver hdlcd_driver = {
.dumb_create = drm_gem_cma_dumb_create,
.dumb_map_offset = drm_gem_cma_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
.gem_prime_export = drm_gem_prime_export,
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 3d8d16402d07..5d357f729114 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -711,6 +711,7 @@ static struct drm_driver atmel_hlcdc_dc_driver = {
.dumb_create = drm_gem_cma_dumb_create,
.dumb_map_offset = drm_gem_cma_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.fops = &fops,
.name = "atmel-hlcdc",
.desc = "Atmel HLCD Controller DRM",
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 4befe25c81c7..eb3b413560df 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1960,6 +1960,72 @@ commit:
return 0;
}
+int drm_atomic_helper_remove_fb(struct drm_framebuffer *fb)
+{
+ struct drm_modeset_acquire_ctx ctx;
+ struct drm_device *dev = fb->dev;
+ struct drm_atomic_state *state;
+ struct drm_plane *plane;
+ int ret = 0;
+ unsigned plane_mask;
+
+ state = drm_atomic_state_alloc(dev);
+ if (!state)
+ return -ENOMEM;
+
+ drm_modeset_acquire_init(&ctx, 0);
+
+retry:
+ plane_mask = 0;
+ ret = drm_modeset_lock_all_ctx(dev, &ctx);
+ if (ret)
+ goto unlock;
+
+ drm_for_each_plane(plane, dev) {
+ struct drm_plane_state *plane_state;
+
+ if (plane->state->fb != fb)
+ continue;
+
+ plane_state = drm_atomic_get_plane_state(state, plane);
+ if (IS_ERR(plane_state)) {
+ ret = PTR_ERR(plane_state);
+ goto unlock;
+ }
+
+ drm_atomic_set_fb_for_plane(plane_state, NULL);
+ ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+ if (ret)
+ goto unlock;
+
+ plane_mask |= BIT(drm_plane_index(plane));
+
+ plane->old_fb = plane->fb;
+ plane->fb = NULL;
+ }
+
+ if (plane_mask)
+ ret = drm_atomic_commit(state);
+
+unlock:
+ if (plane_mask)
+ drm_atomic_clean_old_fb(dev, plane_mask, ret);
+
+ if (ret == -EDEADLK) {
+ drm_modeset_backoff(&ctx);
+ goto retry;
+ }
+
+ if (ret || !plane_mask)
+ drm_atomic_state_free(state);
+
+ drm_modeset_drop_locks(&ctx);
+ drm_modeset_acquire_fini(&ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_remove_fb);
+
/**
* drm_atomic_helper_disable_all - disable all currently active outputs
* @dev: DRM device
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index aaf6ab42f2c1..51c5a00ffdff 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -577,6 +577,42 @@ void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
}
EXPORT_SYMBOL(drm_framebuffer_cleanup);
+static int
+legacy_remove_fb(struct drm_framebuffer *fb)
+{
+ struct drm_device *dev = fb->dev;
+ struct drm_crtc *crtc;
+ struct drm_plane *plane;
+ struct drm_mode_set set;
+ int ret = 0;
+
+ /* atomic drivers must use drm_atomic_helper_remove_fb */
+ WARN_ON(drm_core_check_feature(dev, DRIVER_ATOMIC));
+
+ drm_modeset_lock_all(dev);
+ /* remove from any CRTC */
+ drm_for_each_crtc(crtc, dev) {
+ if (crtc->primary->fb == fb) {
+ /* should turn off the crtc */
+ memset(&set, 0, sizeof(struct drm_mode_set));
+ set.crtc = crtc;
+ set.fb = NULL;
+ ret = drm_mode_set_config_internal(&set);
+ if (ret)
+ goto out;
+ }
+ }
+
+ drm_for_each_plane(plane, dev) {
+ if (plane->fb == fb)
+ drm_plane_force_disable(plane);
+ }
+
+out:
+ drm_modeset_unlock_all(dev);
+ return ret;
+}
+
/**
* drm_framebuffer_remove - remove and unreference a framebuffer object
* @fb: framebuffer to remove
@@ -592,9 +628,6 @@ EXPORT_SYMBOL(drm_framebuffer_cleanup);
void drm_framebuffer_remove(struct drm_framebuffer *fb)
{
struct drm_device *dev;
- struct drm_crtc *crtc;
- struct drm_plane *plane;
- struct drm_mode_set set;
int ret;
if (!fb)
@@ -620,25 +653,13 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
* in this manner.
*/
if (atomic_read(&fb->refcount.refcount) > 1) {
- drm_modeset_lock_all(dev);
- /* remove from any CRTC */
- drm_for_each_crtc(crtc, dev) {
- if (crtc->primary->fb == fb) {
- /* should turn off the crtc */
- memset(&set, 0, sizeof(struct drm_mode_set));
- set.crtc = crtc;
- set.fb = NULL;
- ret = drm_mode_set_config_internal(&set);
- if (ret)
- DRM_ERROR("failed to reset crtc %p when fb was deleted\n", crtc);
- }
- }
+ if (dev->driver->remove_fb)
+ ret = dev->driver->remove_fb(fb);
+ else
+ ret = legacy_remove_fb(fb);
- drm_for_each_plane(plane, dev) {
- if (plane->fb == fb)
- drm_plane_force_disable(plane);
- }
- drm_modeset_unlock_all(dev);
+ if (ret)
+ DRM_ERROR("failed to remove fb %i/%p with %i\n", fb->base.id, fb, ret);
}
drm_framebuffer_unreference(fb);
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index 5344940c8a07..2705a315f1ec 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -423,6 +423,7 @@ static struct drm_driver exynos_drm_driver = {
.dumb_create = exynos_drm_gem_dumb_create,
.dumb_map_offset = exynos_drm_gem_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
.gem_prime_export = drm_gem_prime_export,
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
index e8d9337a66d8..f7562b178819 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
@@ -24,6 +24,7 @@
#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_atomic_helper.h>
#include "fsl_dcu_drm_crtc.h"
#include "fsl_dcu_drm_drv.h"
@@ -194,6 +195,7 @@ static struct drm_driver fsl_dcu_drm_driver = {
.dumb_create = drm_gem_cma_dumb_create,
.dumb_map_offset = drm_gem_cma_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.fops = &fsl_dcu_drm_fops,
.name = "fsl-dcu-drm",
.desc = "Freescale DCU DRM",
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 2a076b005af9..9cbf88adf280 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -42,6 +42,7 @@
#include <linux/vgaarb.h>
#include <linux/vga_switcheroo.h>
#include <drm/drm_crtc_helper.h>
+#include <drm/drm_atomic_helper.h>
static struct drm_driver driver;
@@ -1712,6 +1713,7 @@ static struct drm_driver driver = {
.dumb_create = i915_gem_dumb_create,
.dumb_map_offset = i915_gem_mmap_gtt,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.ioctls = i915_ioctls,
.fops = &i915_driver_fops,
.name = DRIVER_NAME,
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index d52910e2c26c..fab3d7f036ae 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -973,6 +973,7 @@ static struct drm_driver msm_driver = {
.dumb_create = msm_gem_dumb_create,
.dumb_map_offset = msm_gem_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
.gem_prime_export = drm_gem_prime_export,
diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
index 80398a684cae..9f3bacbad118 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -817,6 +817,7 @@ static struct drm_driver omap_drm_driver = {
.dumb_create = omap_gem_dumb_create,
.dumb_map_offset = omap_gem_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.ioctls = ioctls,
.num_ioctls = DRM_OMAP_NUM_IOCTLS,
.fops = &omapdriver_fops,
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index ed6006bf6bd8..3b7388d87815 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -25,6 +25,7 @@
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_atomic_helper.h>
#include "rcar_du_crtc.h"
#include "rcar_du_drv.h"
@@ -231,6 +232,7 @@ static struct drm_driver rcar_du_driver = {
.dumb_create = rcar_du_dumb_create,
.dumb_map_offset = drm_gem_cma_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.fops = &rcar_du_fops,
.name = "rcar-du",
.desc = "Renesas R-Car Display Unit",
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index 896da09e49ee..bf2162e4b131 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
@@ -19,6 +19,7 @@
#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>
+#include <drm/drm_atomic_helper.h>
#include <linux/dma-mapping.h>
#include <linux/pm_runtime.h>
#include <linux/module.h>
@@ -290,6 +291,7 @@ static struct drm_driver rockchip_drm_driver = {
.dumb_create = rockchip_gem_dumb_create,
.dumb_map_offset = rockchip_gem_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
.gem_prime_import = drm_gem_prime_import,
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 8e6b18caa706..c60f86c8f73d 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -944,6 +944,8 @@ static struct drm_driver tegra_drm_driver = {
.dumb_map_offset = tegra_bo_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
+
.ioctls = tegra_drm_ioctls,
.num_ioctls = ARRAY_SIZE(tegra_drm_ioctls),
.fops = &tegra_drm_fops,
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
index b7d2ff0e6e1f..4dde5d924d51 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -15,6 +15,7 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include "drm_fb_cma_helper.h"
+#include "drm/drm_atomic_helper.h"
#include "uapi/drm/vc4_drm.h"
#include "vc4_drv.h"
@@ -115,6 +116,8 @@ static struct drm_driver vc4_drm_driver = {
.dumb_map_offset = drm_gem_cma_dumb_map_offset,
.dumb_destroy = drm_gem_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
+
.ioctls = vc4_drm_ioctls,
.num_ioctls = ARRAY_SIZE(vc4_drm_ioctls),
.fops = &vc4_drm_fops,
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index 7f898cfdc746..56912941eaf8 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -31,6 +31,7 @@
#include <linux/pci.h>
#include "drmP.h"
#include "drm/drm.h"
+#include "drm/drm_atomic_helper.h"
#include "virtgpu_drv.h"
static struct drm_driver driver;
@@ -129,6 +130,8 @@ static struct drm_driver driver = {
.dumb_map_offset = virtio_gpu_mode_dumb_mmap,
.dumb_destroy = virtio_gpu_mode_dumb_destroy,
+ .remove_fb = drm_atomic_helper_remove_fb,
+
#if defined(CONFIG_DEBUG_FS)
.debugfs_init = virtio_gpu_debugfs_init,
.debugfs_cleanup = virtio_gpu_debugfs_takedown,
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 3c8422c69572..31483c2fef51 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -638,6 +638,9 @@ struct drm_driver {
struct drm_device *dev,
uint32_t handle);
+ /* rmfb and drm_framebuffer_remove hook */
+ int (*remove_fb)(struct drm_framebuffer *fb);
+
/* Driver private ops for this object */
const struct vm_operations_struct *gem_vm_ops;
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 9054598c9a7a..2d5ff5c80c76 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -87,6 +87,8 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set);
int __drm_atomic_helper_set_config(struct drm_mode_set *set,
struct drm_atomic_state *state);
+int drm_atomic_helper_remove_fb(struct drm_framebuffer *fb);
+
int drm_atomic_helper_disable_all(struct drm_device *dev,
struct drm_modeset_acquire_ctx *ctx);
struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev);
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