As of now abbreviations are being used for many state and
execution environment strings. Improve and expand those such that
debug messages are clear.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1617067704-28850-8-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

When moving from SYS_ERROR transition to a different execution
environment, MHI host relies on the BHI register read to spawn
the next image download or wait for READY -> M0 states. The
device can at times move the execution environment to mission
mode when a pass through is expected, which can result in a
stall. Initiate a wait for MHI READY and write M0 such that the
device can proceed with state change event updates for any new
execution environment being entered. This allows us to remove
conditionals in handling firmware load for PBL modes and keeps
the execution environment out of the picture as it can change at
any time.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1617067704-28850-7-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

MHI power up can go through an EDL to Flash Programmer path when
the device has a blank NAND. In those cases, mhi_sync_power_up()
can timeout waiting for a mission mode execution environment.
Allow a successful power up instead by identifying Flash
Programmer as a valid mission mode execution environment with a
purpose to flash the device image contents.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1617067704-28850-6-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

MHI WWAN modems support downloading firmware to NAND or eMMC
using Firehose protocol with process as follows:
1. Modem boots up, enters AMSS execution environment and the
device later enters EDL (Emergency Download) mode through any
mechanism host can use such as a diag command.
2. Modem enters SYS_ERROR, MHI host handles SYS_ERROR transition.
3. EDL image for device to enter 'Flash Programmer' execution
environment is then flashed via BHI interface from host.
4. Modem enters MHI READY -> M0 and sends the Flash Programmer
execution environment change to host.
5. Following that, EDL/FIREHOSE channels (34, 35) are made
available from the host.
6. User space tool for downloading firmware image to modem over
the EDL channels using Firehose protocol. Link to USB flashing
tool: https://git.linaro.org/landing-teams/working/qualcomm/qdl.git/

Make the necessary changes to allow for this sequence to occur and
allow using the Flash Programmer execution environment.
Signed-off-by: NCarl Yin <carl.yin@quectel.com>
Co-developed-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1617067704-28850-5-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Device entering EDL or Emergency Download Mode will be in a
SYS_ERROR MHI state. This requires MHI host to proceed with the
EDL image download over BHI before device can enter an MHI READY
state and proceed with further bootup. Allow this to be handled
by relying on the execution environment check after SYS_ERROR
processing to determine whether to wait for an MHI READY or
download the EDL image over BHI after moving MHI PM state to
Power on Reset internally. This way handling is contained well
within the MHI core driver and helps pave the way for Flash
Programmer execution environment functionality.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1617067704-28850-4-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Currently, the firmware load handler returns after the EDL image
is downloaded. Wait for an MHI READY transition instead as the
specification expects so as to proceed with further bootup such
as device entering Flash Programmer execution environment.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1617067704-28850-3-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Relying on the current execution environment to determine if EDL
image was downloaded should not be done as the execution
environment can change at this point in error cases and we may
misread it. Instead, MHI can rely on the local 'fw_name' variable
as a safer alternative.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1617067704-28850-2-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

We cannot process a power_down if the power state is DISABLED.  There is
no valid mhi_ctxt in that case, so attepting to process the power_down
will likely result in a null pointer dereference.  If the power state is
DISABLED, there is nothing to do anyways, so just bail early.
Signed-off-by: NJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1615409365-8165-1-git-send-email-jhugo@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Currently ENOMEM is returned when MHI ring is full. This error code is
very misleading. Change to EAGAIN instead.
Signed-off-by: NFan Wu <wufan@codeaurora.org>
Signed-off-by: NJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: NHemant Kumar <hemantk@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1615408803-7016-1-git-send-email-jhugo@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

The variables state and ee are being initialized with values that
are never read and are being updated later with a new values. The
initializations are redundant and can be removed.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <mani@kernel.org>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20210311111727.8433-1-colin.king@canonical.comSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

The check to see if we have reset the device after detecting syserr at
power_up is inverted.  wait_for_event_timeout() returns 0 on failure,
and a positive value on success.  The check is looking for non-zero
as a failure, which is likely to incorrectly cause a device init failure
if syserr was detected at power_up.  Fix this.

Fixes: e18d4e9f ("bus: mhi: core: Handle syserr during power_up")
Signed-off-by: NJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1613165243-23359-1-git-send-email-jhugo@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Update debug prints to include local device in the BHI interrupt
handler. This helps show transitions better between MHI states.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1614208985-20851-5-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

In current design, whenever the BHI interrupt is fired, the
execution environment is updated. This can cause race conditions
and impede ongoing power up/down processing. For example, if a
power down is in progress, MHI host updates to a local "disabled"
execution environment. If a BHI interrupt fires later, that value
gets replaced with one from the BHI EE register. This impacts the
controller as it does not expect multiple RDDM execution
environment change status callbacks as an example. Another issue
would be that the device can enter mission mode and the execution
environment is updated, while device creation for SBL channels is
still going on due to slower PM state worker thread run, leading
to multiple attempts at opening the same channel.

Ensure that EE changes are handled only from appropriate places
and occur one after another and handle only PBL modes or RDDM EE
changes as critical events directly from the interrupt handler.
Simplify handling by waiting for SYS ERROR before handling RDDM.
This also makes sure that we use the correct execution environment
to notify the controller driver when the device resets to one of
the PBL execution environments.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614208985-20851-4-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

During full boot chain firmware download, the PM state worker
downloads the AMSS image after a blocking wait for the SBL
execution environment change when running in PBL transition
itself. Improve this design by having the host download the AMSS
image from the SBL transition of PM state worker thread when a
DEV_ST_TRANSITION_SBL is queued instead of the blocking wait.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Link: https://lore.kernel.org/r/1614208985-20851-3-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Currently, client devices are created in SBL or AMSS (mission
mode) and only destroyed after power down or SYS ERROR. When
moving between certain execution environments, such as from SBL
to AMSS, no clean-up is required. This presents an issue where
SBL-specific channels are left open and client drivers now run in
an execution environment where they cannot operate. Fix this by
expanding the mhi_destroy_device() to do an execution environment
specific clean-up if one is requested. Close the gap and destroy
devices in such scenarios that allow SBL client drivers to clean
up once device enters mission mode.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NHemant Kumar <hemantk@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614208985-20851-2-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

MHI suspend/resume are symmetric and balanced procedures. If device is
not in M3 state on a resume, that means something happened behind our
back. In this case resume is aborted and error reported, to let the
controller handle the situation.

This is mainly requested for system wide suspend-resume operation in
PCI context which may lead to power-down/reset of the controller which
will then lose its MHI context. In such cases, PCI driver is supposed
to recover and reinitialize the device.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614960841-20233-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

As per documentation, fields marked as (required) in an MHI
controller structure need to be populated by the controller driver
before calling mhi_register_controller(). Ensure all required
pointers and non-zero fields are present in the controller before
proceeding with the registration.
Signed-off-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1615315490-36017-1-git-send-email-bbhatt@codeaurora.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Use MHI controller device name instead of the 'bus' device name as
debugfs dir name (e.g. /sys/kernel/debug/mhi0). That aligns with
sysfs device name.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Tested-by: NJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NJeffrey Hugo <jhugo@codeaurora.org>
Link: https://lore.kernel.org/r/1613403753-1457-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

mhi_queue returns an error when the doorbell is not accessible in
the current state. This can happen when the device is in non M0
state, like M3, and needs to be waken-up prior ringing the DB. This
case is managed earlier by triggering an asynchronous M3 exit via
controller resume/suspend callbacks, that in turn will cause M0
transition and DB update.

So, since it's not an error but just delaying of doorbell update, there
is no reason to return an error.

This also fixes a use after free error for skb case, indeed a caller
queuing skb will try to free the skb if the queueing fails, but in
that case queueing has been done.

Fixes: a8f75cb3 ("mhi: core: Factorize mhi queuing")
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614336782-5809-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

A recent change created a dedicated workqueue for the state-change work
with WQ_HIGHPRI (no strong reason for that) and WQ_MEM_RECLAIM flags,
but the state-change work (mhi_pm_st_worker) does not guarantee forward
progress under memory pressure, and will even wait on various memory
allocations when e.g. creating devices, loading firmware, etc... The
work is then not part of a memory reclaim path...

Moreover, this causes a warning in check_flush_dependency() since we end
up in code that flushes a non-reclaim workqueue:

[   40.969601] workqueue: WQ_MEM_RECLAIM mhi_hiprio_wq:mhi_pm_st_worker [mhi] is flushing !WQ_MEM_RECLAIM events_highpri:flush_backlog
[   40.969612] WARNING: CPU: 4 PID: 158 at kernel/workqueue.c:2607 check_flush_dependency+0x11c/0x140
[   40.969733] Call Trace:
[   40.969740]  __flush_work+0x97/0x1d0
[   40.969745]  ? wake_up_process+0x15/0x20
[   40.969749]  ? insert_work+0x70/0x80
[   40.969750]  ? __queue_work+0x14a/0x3e0
[   40.969753]  flush_work+0x10/0x20
[   40.969756]  rollback_registered_many+0x1c9/0x510
[   40.969759]  unregister_netdevice_queue+0x94/0x120
[   40.969761]  unregister_netdev+0x1d/0x30
[   40.969765]  mhi_net_remove+0x1a/0x40 [mhi_net]
[   40.969770]  mhi_driver_remove+0x124/0x250 [mhi]
[   40.969776]  device_release_driver_internal+0xf0/0x1d0
[   40.969778]  device_release_driver+0x12/0x20
[   40.969782]  bus_remove_device+0xe1/0x150
[   40.969786]  device_del+0x17b/0x3e0
[   40.969791]  mhi_destroy_device+0x9a/0x100 [mhi]
[   40.969796]  ? mhi_unmap_single_use_bb+0x50/0x50 [mhi]
[   40.969799]  device_for_each_child+0x5e/0xa0
[   40.969804]  mhi_pm_st_worker+0x921/0xf50 [mhi]

Fixes: 8f703978 ("bus: mhi: core: Move to using high priority workqueue")
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614161930-8513-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

When the device is idle it is possible to move it into the lowest MHI
PM state (M3). In that mode, all MHI operations are suspended and the
PCI device can be safely put into PCI D3 state.

The device is then resumed from D3/M3 either because of host initiated
MHI operation (e.g. buffer TX) or because the device (modem) has
triggered wake-up via PME feature (e.g. on incoming data).

Same procedures can be used for system wide or runtime suspend/resume.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614971808-22156-6-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

The PCI core can take care of proper PCI suspend/resume operations, but
this is discarded when the driver saves PCI state by its own. This
currently prevents the PCI core to enable PME (for modem initiated
D3 exit) which is requested for proper runtime pm support.

This change deletes explicit PCI state-saving and state-set from
suspend callback, letting the PCI doing the appropriate work.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614971808-22156-5-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

The wake_db register presence is highly speculative and can fuze MHI
devices. Indeed, currently the wake_db register address is defined at
entry 127 of the 'Channel doorbell array', thus writing to this address
is equivalent to ringing the doorbell for channel 127, causing trouble
with some devics (e.g. SDX24 based modems) that get an unexpected
channel 127 doorbell interrupt.

This change fixes that issue by setting wake get/put as no-op for
pci_generic devices. The wake device sideband mechanism seems really
specific to each device, and is AFAIK not defined by the MHI spec.

It also removes zeroing initialization of wake_db register during MMIO
initialization, the register being set via wake_get/put accessors few
cycles later during M0 transition.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614971808-22156-4-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Add generic info for SDX24 based modems. Also add the FIREHOSE channels
used by the flash-programmer firmware loaded in EDL mode.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614971808-22156-3-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Add support for EM1XXGR-L modems, this modem series is based on SDX24
qcom chip. The modem is mainly based on MBIM protocol for both the
data and control path. The drivers for these channels (mhi-net-mbim and
mhi_uci) are not yet part of the kernel but will be integrated by
different series.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614971808-22156-2-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Not all hardwares need to use the same number of event ring elements.
This change makes this parametrable.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614971808-22156-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

mhi_deinit_chan_ctxt functionthat takes care of unitializing channel
resources, including unmapping coherent MHI areas, can be called
from different path in case of controller unregistering/removal:
 - From a client driver remove callback, via mhi_unprepare_channel
 - From mhi_driver_remove that unitialize all channels

mhi_driver_remove()
|-> driver->remove()
|    |-> mhi_unprepare_channel()
|        |-> mhi_deinit_chan_ctxt()
|...
|-> mhi_deinit_chan_ctxt()

This leads to double dma freeing...

Fix that by preventing deinit for already uninitialized channel.

Link: https://lore.kernel.org/r/1612894264-15956-1-git-send-email-loic.poulain@linaro.org
Fixes: a7f422f2 ("bus: mhi: Fix channel close issue on driver remove")
Reported-by: NKalle Valo <kvalo@codeaurora.org>
Tested-by: NKalle Valo <kvalo@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20210210082538.2494-2-manivannan.sadhasivam@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We met some sporadic modem crashes during high throughput testing, this
has been root caused to a lack of elements in the event ring. Indeed,
the modem is simply crashing when event ring becomes empty.

It appears that the total number event ring elements is too low given
the performances of the modem (IPA hardware accelerator). This change
increases the number of elements in the hardware event ring to 2048,
which is aligned with what is defined in downstream version:
https://source.codeaurora.org/quic/la/kernel/msm-4.14/tree/arch/arm64/boot/dts/qcom/sm8150-mhi.dtsi?h=msm-4.14#n482

With this change, modem coes not crash anymore.

Note: An event ring element is 16-Byte, so the total memory usage of
a hardware event ring is now 32KB.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1612514195-8257-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Print warning when MHI detects sys error.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NHemant Kumar <hemantk@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1612370382-21643-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Introduce mhi_get_free_desc_count() API to return number
of TREs available to queue buffer. MHI clients can use this
API to know before hand if ring is full without calling queue
API.
Signed-off-by: NHemant Kumar <hemantk@codeaurora.org>
Reviewed-by: NJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1610388462-16322-1-git-send-email-loic.poulain@linaro.orgSigned-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Instead of duplicating queuing procedure in mhi_queue_dma(),
mhi_queue_buf() and mhi_queue_skb(), add a new generic mhi_queue()
as common helper.

Note that the unified mhi_queue align pm_lock locking on mhi_queue_buf
behavior, taking it with irqsave variant (vs _bh for former queue_skb
and queue_dma version).
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

If controller driver has specified the irq_flags, mhi uses this specified
irq_flags. Otherwise, mhi uses default irq_flags.

The purpose of this change is to support one MSI vector for QCA6390.
MHI will use one same MSI vector too in this scenario.

In case of one MSI vector, IRQ_NO_BALANCING is needed when irq handler
is requested. The reason is if irq migration happens, the msi_data may
change too. However, the msi_data is already programmed to QCA6390
hardware during initialization phase. This msi_data inconsistence will
result in crash in kernel.

Another issue is in case of one MSI vector, IRQF_NO_SUSPEND will trigger
WARNINGS because QCA6390 wants to disable the IRQ during the suspend.

To avoid above two issues, QCA6390 driver specifies the irq_flags in case
of one MSI vector when mhi_register_controller is called.
Signed-off-by: NCarl Huang <cjhuang@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

When a shared MSI vector must be used (e.g. when VTd is disabled on
x86_64), each event MSI vector must be set to the shared vector idx.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Hemant Kumar<hemantk@codeaurora.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

The ring element data, though being part of coherent memory, still need
to be performed before updating the ring context to point to this new
element. That can be guaranteed with a memory barrier (dma_wmb).
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

MHI hardware channels are usually the hardware accelerated data path
e.g. IP packets path for modems. This path needs to be optimized for
low latency and high throughput. After several tests on FN980m SDX55
based modem, it seems 1ms is a good default irq_moderation value:

- It allows to reach the maximum download throughput
- It introduces limited latency (5ms is too high)
- It prevents interrupt flooding
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Add support for Diag over MHI. Qualcomm Diag is the qualcomm
diagnostics interface that can be used to collect modem logs,
events, traces, etc. It can be used by tools such QPST or QXDM.

This patch adds the DIAG channels and a dedicated event ring.

Reviewed-by Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

On cold boot, device can take slightly more than 5 seconds to start.
Increase the timeout to prevent MHI power-up issues.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NHemant Kumar <hemantk@codeaurora.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

If the modem crashes for any reason, we may not be able to detect
it at MHI level (MHI registers not reachable anymore).

This patch implements a health-check mechanism to check regularly
that device is alive (MHI layer can communicate with). If device
is not alive (because a crash or unexpected reset), the recovery
procedure is triggered.

Tested successfully with Telit FN980m module.
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: NHemant Kumar <hemantk@codeaurora.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

In AER capable root complex, errors are reported to the host which
can then act accordingly and perform PCI recovering procedure.

This patch enables error reporting and implements error_detected,
slot_reset and resume callbacks.

Reviewed-by Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Add support for system wide suspend/resume. During suspend, MHI
device controller must be put in M3 state and PCI bus in D3 state.

Add a recovery procedure allowing to reinitialize the device in case
of error during resume steps, which can happen if device loses power
(and so its context) while system suspend.

Reviewed-by Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: NLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>