drm/i915/mtl/gsc: Add a gsc_info debugfs

Add a new debugfs to dump information about the GSC. This includes:

- the FW path and SW tracking status;
- the release, security and compatibility versions;
- the HECI1 status registers.

Note that those are the same registers that the mei driver dumps in
their own status sysfs on DG2 (where mei owns the GSC).

To make it simpler to loop through the status register, the code has
been update to use a PICK macro and the existing code using the regs had
been adapted to match.

v2: fix includes and copyright dates (Alan)
v3: actually fix the includes

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230612181529.2222451-5-daniele.ceraolospurio@intel.com

drm/i915/mtl/gsc: extract release and security versions from the gsc binary

The release and security versions of the GSC binary are not used at
runtime to decide interface compatibility (there is a separate version
for that), but they're still useful for debug, so it is still worth
extracting them and printing them out in dmesg.

To get to these version, we need to navigate through various headers in
the binary. See in-code comment for details.

v2: fix and improve size checks when crawling the binary header, add
comment about the different version, wrap the partition base/offset
pairs in the GSC header in a struct (Alan)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230612181529.2222451-3-daniele.ceraolospurio@intel.com

drm/i915/gsc: fixes and updates for GSC memory allocation

A few fixes/updates are required around the GSC memory allocation and it
is easier to do them all at the same time. The changes are as follows:

1 - Switch the memory allocation to stolen memory. We need to avoid
accesses from GSC FW to normal memory after the suspend function has
completed and to do so we can either switch to using stolen or make sure
the GSC is gone to sleep before the end of the suspend function. Given
that the GSC waits for a bit before going idle even if there are no
pending operations, it is easier and quicker to just use stolen memory.

2 - Reduce the GSC allocation size to 4MBs, which is the POR requirement.
The 8MBs were needed only for early FW and I had misunderstood that as
being the expected POR size when I sent the original patch.

3 - Perma-map the GSC allocation. This isn't required immediately, but it
will be needed later to be able to quickly extract the GSC logs, which are
inside the allocation. Since the mapping code needs to be rewritten due to
switching to stolen, it makes sense to do the switch immediately to avoid
having to change it again later.

Note that the explicit setting of CACHE_NONE for Wa_22016122933 has been
dropped because that's the default setting for stolen memory on !LLC
platforms.

v2: only memset the memory we're not overwriting (Alan)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230612181529.2222451-2-daniele.ceraolospurio@intel.com

drm/i915/gsc: add support for GSC proxy interrupt

The GSC notifies us of a proxy request via the HECI2 interrupt. The
interrupt must be enabled both in the HECI layer and in our usual gt irq
programming; for the latter, the interrupt is enabled via the same enable
register as the GSC CS, but it does have its own mask register. When the
interrupt is received, we also need to de-assert it in both layers.

The handling of the proxy request is deferred to the same worker that we
use for GSC load. New flags have been added to distinguish between the
init case and the proxy interrupt.

v2: Make sure not to set the reset bit when enabling/disabling the GSC
interrupts, fix defines (Alan)

v3: rebase on proxy status register check

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230502163854.317653-5-daniele.ceraolospurio@intel.com

drm/i915/gsc: add initial support for GSC proxy

The GSC uC needs to communicate with the CSME to perform certain
operations. Since the GSC can't perform this communication directly
on platforms where it is integrated in GT, i915 needs to transfer the
messages from GSC to CSME and back.
The proxy flow is as follow:
1 - i915 submits a request to GSC asking for the message to CSME
2 - GSC replies with the proxy header + payload for CSME
3 - i915 sends the reply from GSC as-is to CSME via the mei proxy
component
4 - CSME replies with the proxy header + payload for GSC
5 - i915 submits a request to GSC with the reply from CSME
6 - GSC replies either with a new header + payload (same as step 2,
so we restart from there) or with an end message.

After GSC load, i915 is expected to start the first proxy message chain,
while all subsequent ones will be triggered by the GSC via interrupt.

To communicate with the CSME, we use a dedicated mei component, which
means that we need to wait for it to bind before we can initialize the
proxies. This usually happens quite fast, but given that there is a
chance that we'll have to wait a few seconds the GSC work has been moved
to a dedicated WQ to not stall other processes.

v2: fix code style, includes and variable naming (Alan)
v3: add extra check for proxy status, fix includes and comments

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230502163854.317653-4-daniele.ceraolospurio@intel.com

drm/i915/gsc: Fix race between HW init and GSC FW load

The GSC FW load is a slow process (up to 250 ms), so we defer it to a
dedicated worker to avoid stalling the init flow for that long. However,
we currently start this worker before the HW init is complete, so there
is a chance that the GSC loading code submits to the HW before the
engine initialization has completed. We can easily fix this by starting
the thread later in the gt_resume flow.
From this later spot, the GSC code can still race with the default
submission code; we functionally don't care who wins the race (the GSC
load doesn't need any state), but since the whole point of the separate
worker is to make the main thread faster, we prefer the default
submission code to run first. Therefore, make an exception for driver
probe and only and start the gsc load from uc_init_late.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230223172120.3304293-3-daniele.ceraolospurio@intel.com

drm/i915/gsc: flush the GSC worker before wedging on unload

If we unload the driver and wedge before the GSC worker is complete,
the worker will hit an error on its submission to the GSC engine and
then exit. This is hard to hit for a user, but it is reproducible
with skipping selftests. The error is handled gracefully by the
worker, so there are no functional issues, but we still end up with
an error message in dmesg, which is something we want to avoid as
this is a supported scenario. We could modify the worker to better
handle a wedging occurring during its execution, but that gets
complicated for a couple of reasons:
- We do want the error on runtime wedging, because there are
implications for subsystems outside of GT (i.e., PXP, HDCP), it's
only the error on driver unload that we want to silence.
- The worker is responsible for multiple submissions (GSC FW load,
HuC auth, SW proxy), so all of those will have to be adapted to
handle the wedged_on_fini scenario.
Therefore, it's much simpler to just wait for the worker to be done
before wedging on driver removal, also considering that the worker
will likely already be idle in the great majority of non-selftest
scenarios.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230223172120.3304293-2-daniele.ceraolospurio@intel.com

drm/i915/gsc: GSC firmware loading

GSC FW is loaded by submitting a dedicated command via the GSC engine.
The memory area used for loading the FW is then re-purposed as local
memory for the GSC itself, so we use a separate allocation instead of
using the one where we keep the firmware stored for reload.

The GSC is not reset as part of GT reset, so we only need to load it on
first boot and S3/S4 exit.

v2: use REG_* for register fields definitions (Rodrigo), move to WQ
immediately

v3: mark worker function as static

Bspec: 63347, 65346
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221208200521.2928378-4-daniele.ceraolospurio@intel.com

drm/i915/uc: Introduce GSC FW

On MTL the GSC FW needs to be loaded on the media GT by the graphics
driver. We're going to treat it like a new uc_fw, so add the initial
defs and init/fini functions for it.

Similarly to the other FWs, the GSC FW path can be overridden via
modparam. The modparam can also be used to disable the GSC FW loading by
setting it to an empty string.

Note that the new structure has been called intel_gsc_uc to avoid
confusion with the existing intel_gsc, which instead represents the heci
gsc interfaces.

v2: re-order Makefile list to be properly sorted (Jani, Alan), better
comment (alan)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221208200521.2928378-2-daniele.ceraolospurio@intel.com