Revert "drm/msm: Fix failure paths in msm_drm_init()"

This reverts commit 8636500300a01740d92b345c680b036b94555b1b.

A recent commit tried to address a drm device leak in the early
msm_drm_uninit() error paths but ended up making things worse.

Specifically, it moved the drm device reference put in msm_drm_uninit()
to msm_drm_init() which means that the drm would now be leaked on normal
unbind.

For reasons that were never spelled out, it also added kms NULL pointer
checks to a couple of helper functions that had nothing to do with the
paths modified by the patch.

Instead of trying to salvage this incrementally, let's revert the bad
commit so that clean and backportable fixes can be added in its place.

Fixes: 8636500300a0 ("drm/msm: Fix failure paths in msm_drm_init()")
Cc: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/525092/
Link: https://lore.kernel.org/r/20230306100722.28485-3-johan+linaro@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drm/msm: Fix failure paths in msm_drm_init()

Ensure that we do drm_dev_put() when there is an early return in
msm_drm_init().

Signed-off-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/515606/
Link: https://lore.kernel.org/r/20221221203925.v2.2.I49dfc3654040be61702e491f1aa63d3a5f308852@changeid
Signed-off-by: Rob Clark <robdclark@chromium.org>

Revert "devcoredump: remove the useless gfp_t parameter in dev_coredumpv and dev_coredumpm"

This reverts commit 77515ebaf01920e2db49e04672ef669a7c2907f2 as it
causes build problems in linux-next. It needs to be reintroduced in a
way that can allow the api to evolve and not require a "flag day" to
catch all users.

Link: https://lore.kernel.org/r/20220623160723.7a44b573@canb.auug.org.au
Cc: Duoming Zhou <duoming@zju.edu.cn>
Cc: Brian Norris <briannorris@chromium.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

devcoredump: remove the useless gfp_t parameter in dev_coredumpv and dev_coredumpm

The dev_coredumpv() and dev_coredumpm() could not be used in atomic
context, because they call kvasprintf_const() and kstrdup() with
GFP_KERNEL parameter. The process is shown below:

dev_coredumpv(.., gfp_t gfp)
dev_coredumpm(.., gfp_t gfp)
dev_set_name
kobject_set_name_vargs
kvasprintf_const(GFP_KERNEL, ...); //may sleep
kstrdup(s, GFP_KERNEL); //may sleep

This patch removes gfp_t parameter of dev_coredumpv() and dev_coredumpm()
and changes the gfp_t parameter of kzalloc() in dev_coredumpm() to
GFP_KERNEL in order to show they could not be used in atomic context.

Fixes: 833c95456a70 ("device coredump: add new device coredump class")
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Link: https://lore.kernel.org/r/df72af3b1862bac7d8e793d1f3931857d3779dfd.1654569290.git.duoming@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drm/msm/disp: Export helper for capturing snapshot

We'll re-use this for debugfs.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20211215174524.1742389-3-robdclark@gmail.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drm/msm: make msm_disp_state transient data struct

Instead of allocating snapshotting structure at the driver probe time
and later handling concurrent access, actual state, etc, make
msm_disp_state transient struct. Allocate one when snapshotting happens
and free it after coredump data is read by userspace.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Link: https://lore.kernel.org/r/20210427001828.2375555-3-dmitry.baryshkov@linaro.org
Signed-off-by: Rob Clark <robdclark@chromium.org>

drm/msm: add support to take dpu snapshot

Add the msm_disp_snapshot module which adds supports to dump dpu
registers and capture the drm atomic state which can be used in
case of error conditions.

changes in v5:
- start storing disp_state in msm_kms instead of dpu_kms
- get rid of MSM_DISP_SNAPSHOT_IN_* enum by simplifying the functions
- move snprintf inside the snapshot core by using varargs
- get rid of some stale code comments
- allow snapshot module for non-DPU targets

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/1618606645-19695-3-git-send-email-abhinavk@codeaurora.org
Signed-off-by: Rob Clark <robdclark@chromium.org>