drm/panthor: Force an immediate reset on unrecoverable faults

If the FW reports an unrecoverable fault, we need to reset the GPU
before we can start re-using it again.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240502183813.1612017-2-boris.brezillon@collabora.com

drm/panthor: Cleanup unused variable 'cookie'

Commit 962f88b9c916 ("drm/panthor: Drop the dev_enter/exit() sections in
_irq_suspend/resume()") removed the code that used the 'cookie' variable
but left the declaration in place. Remove it.

Fixes: 962f88b9c916 ("drm/panthor: Drop the dev_enter/exit() sections in _irq_suspend/resume()")
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Steven Price <steven.price@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402215423.360341-1-liviu.dudau@arm.com

drm/panthor: Drop the dev_enter/exit() sections in _irq_suspend/resume()

There's no reason for _irq_suspend/resume() to be called after the
device has been unplugged, and keeping this dev_enter/exit()
section in _irq_suspend() is turns _irq_suspend() into a NOP
when called from the _unplug() functions, which we don't want.

v3:
- New patch

Fixes: 5fe909cae118 ("drm/panthor: Add the device logical block")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240326111205.510019-3-boris.brezillon@collabora.com

drm/panthor: Fix ordering in _irq_suspend()

Make sure we set suspended=true last to avoid generating an irq storm
in the unlikely case where an IRQ happens between the suspended=true
assignment and the _INT_MASK update.

We also move the mask=0 assignment before writing to the _INT_MASK
register to prevent the thread handler from unmasking the interrupt
behind our back. This means we might lose events if there were some
pending when we get to suspend the IRQ, but that's fine.
The synchronize_irq() we have in the _irq_suspend() path was not
there to make sure all IRQs are processed, just to make sure we don't
have registers accesses coming from the irq handlers after
_irq_suspend() has been called. If there's a need to have all pending
IRQs processed, it should happen before _irq_suspend() is called.

v3:
- Add Steve's R-b

v2:
- New patch

Fixes: 5fe909cae118 ("drm/panthor: Add the device logical block")
Reported-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240326111205.510019-2-boris.brezillon@collabora.com

drm/panthor: Fix IO-page mmap() for 32-bit userspace on 64-bit kernel

When mapping an IO region, the pseudo-file offset is dependent on the
userspace architecture. panthor_device_mmio_offset() abstracts that
away for us by turning a userspace MMIO offset into its kernel
equivalent, but we were not updating vm_area_struct::vm_pgoff
accordingly, leading us to attach the MMIO region to the wrong file
offset.

This has implications when we start mixing 64 bit and 32 bit apps, but
that's only really a problem when we start having more that 2^43 bytes of
memory allocated, which is very unlikely to happen.

What's more problematic is the fact this turns our
unmap_mapping_range(DRM_PANTHOR_USER_MMIO_OFFSET) calls, which are
supposed to kill the MMIO mapping when entering suspend, into NOPs.
Which means we either keep the dummy flush_id mapping active at all
times, or we risk a BUS_FAULT if the MMIO region was mapped, and the
GPU is suspended after that.

Solve that by patching vm_pgoff early in panthor_mmap(). With
this in place, we no longer need the panthor_device_mmio_offset()
helper.

v3:
- No changes

v2:
- Kill panthor_device_mmio_offset()

Fixes: 5fe909cae118 ("drm/panthor: Add the device logical block")
Reported-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reported-by: Lukas F. Hartmann <lukas@mntmn.com>
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/10835
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240326111205.510019-1-boris.brezillon@collabora.com

drm/panthor: Don't use virt_to_pfn()

virt_to_pfn() isn't available on x86 (except to xen) so breaks
COMPILE_TEST builds. Avoid its use completely by instead storing the
struct page pointer allocated in panthor_device_init() and using
page_to_pfn() instead.

Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240318145119.368582-1-steven.price@arm.com

drm/panthor: Add the device logical block

The panthor driver is designed in a modular way, where each logical
block is dealing with a specific HW-block or software feature. In order
for those blocks to communicate with each other, we need a central
panthor_device collecting all the blocks, and exposing some common
features, like interrupt handling, power management, reset, ...

This what this panthor_device logical block is about.

v6:
- Add Maxime's and Heiko's acks
- Keep header inclusion alphabetically ordered

v5:
- Suspend the MMU/GPU blocks if panthor_fw_resume() fails in
panthor_device_resume()
- Move the pm_runtime_use_autosuspend() call before drm_dev_register()
- Add Liviu's R-b

v4:
- Check drmm_mutex_init() return code
- Fix panthor_device_reset_work() out path
- Fix the race in the unplug logic
- Fix typos
- Unplug blocks when something fails in panthor_device_init()
- Add Steve's R-b

v3:
- Add acks for the MIT+GPL2 relicensing
- Fix 32-bit support
- Shorten the sections protected by panthor_device::pm::mmio_lock to fix
lock ordering issues.
- Rename panthor_device::pm::lock into panthor_device::pm::mmio_lock to
better reflect what this lock is protecting
- Use dev_err_probe()
- Make sure we call drm_dev_exit() when something fails half-way in
panthor_device_reset_work()
- Replace CSF_GPU_LATEST_FLUSH_ID_DEFAULT with a constant '1' and a
comment to explain. Also remove setting the dummy flush ID on suspend.
- Remove drm_WARN_ON() in panthor_exception_name()
- Check pirq->suspended in panthor_xxx_irq_raw_handler()

Co-developed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Steven Price <steven.price@arm.com> # MIT+GPL2 relicensing,Arm
Acked-by: Grant Likely <grant.likely@linaro.org> # MIT+GPL2 relicensing,Linaro
Acked-by: Boris Brezillon <boris.brezillon@collabora.com> # MIT+GPL2 relicensing,Collabora
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240229162230.2634044-4-boris.brezillon@collabora.com