dmaengine: idxd: add callback support for iaa crypto

Create a lightweight callback interface to allow idxd sub-drivers to
be notified when work sent to idxd wqs has completed.

For a sub-driver to be notified of work completion, it needs to:

- Set the descriptor's 'Request Completion Interrupt'
(IDXD_OP_FLAG_RCI)

- Set the sub-driver desc_complete() callback when registering the
sub-driver e.g.:

struct idxd_device_driver my_drv = {
.probe = my_probe,
.desc_complete = my_complete,
}

- Set the sub-driver-specific context in the sub-driver's descriptor
e.g:

idxd_desc->crypto.req = req;
idxd_desc->crypto.tfm = tfm;
idxd_desc->crypto.src_addr = src_addr;
idxd_desc->crypto.dst_addr = dst_addr;

When the work completes and the completion irq fires, idxd will invoke
the desc_complete() callback with pointers to the descriptor, context,
and completion_type.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

dmaengine: idxd: Export descriptor management functions

To allow idxd sub-drivers to access the descriptor management
functions, export them.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

dmaengine: idxd: Protect int_handle field in hw descriptor

The int_handle field in hw descriptor should also be protected
by wmb() before possibly triggering a DMA read.

Fixes: eb0cf33a91b4 (dmaengine: idxd: move interrupt handle assignment)
Signed-off-by: Guanjun <guanjun@linux.alibaba.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Lijun Pan <lijun.pan@intel.com>
Link: https://lore.kernel.org/r/20231211053704.2725417-2-guanjun@linux.alibaba.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix retry value to be constant for duration of function call

When retries is compared to wq->enqcmds_retries each loop of idxd_enqcmds(),
wq->enqcmds_retries can potentially changed by user. Assign the value
of retries to wq->enqcmds_retries during initialization so it is the
original value set when entering the function.

Fixes: 7930d8553575 ("dmaengine: idxd: add knob for enqcmds retries")
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/165031760154.3658664.1983547716619266558.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: match type for retries var in idxd_enqcmds()

wq->enqcmds_retries is defined as unsigned int. However, retries on the
stack is defined as int. Change retries to unsigned int to compare the same
type.

Fixes: 7930d8553575 ("dmaengine: idxd: add knob for enqcmds retries")
Suggested-by: Thiago Macieira <thiago.macieira@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/165031747059.3658198.6035308204505664375.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: embed irq_entry in idxd_wq struct

With irq_entry already being associated with the wq in a 1:1 relationship,
embed the irq_entry in the idxd_wq struct and remove back pointers for
idxe_wq and idxd_device. In the process of this work, clean up the interrupt
handle assignment so that there's no decision to be made during submit
call on where interrupt handle value comes from. Set the interrupt handle
during irq request initialization time.

irq_entry 0 is designated as special and is tied to the device itself.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163942148362.2412839.12055447853311267866.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add knob for enqcmds retries

Add a sysfs knob to allow tuning of retries for the kernel ENQCMDS
descriptor submission. While on host, it is not as likely that ENQCMDS
return busy during normal operations due to the driver controlling the
number of descriptors allocated for submission. However, when the driver is
operating as a guest driver, the chance of retry goes up significantly due
to sharing a wq with multiple VMs. A default value is provided with the
system admin being able to tune the value on a per WQ basis.

Suggested-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163820629464.2702134.7577370098568297574.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: handle interrupt handle revoked event

"Interrupt handle revoked" is an event that happens when the driver is
running on a guest kernel and the VM is migrated to a new machine.
The device will trigger an interrupt that signals to the guest driver
that the interrupt handles need to be replaced.

The misc irq thread function calls a helper function to handle the
event. The function uses the WQ percpu_ref to quiesce the kernel
submissions. It then replaces the interrupt handles by requesting
interrupt handle command for each I/O MSIX vector. Once the handle is
updated, the driver will unblock the submission path to allow new
submissions.

The submitter will attempt to acquire a percpu_ref before submission. When
the request fails, it will wait on the wq_resurrect 'completion'.

The driver does anticipate the possibility of descriptors being submitted
before the WQ percpu_ref is killed. If a descriptor has already been
submitted, it will return with incorrect interrupt handle status. The
descriptor will be re-submitted with the new interrupt handle on the
completion path. For descriptors with incorrect interrupt handles,
completion interrupt won't be triggered.

At the completion of the interrupt handle refresh, the handling function
will call idxd_int_handle_refresh_drain() to issue drain descriptors to
each of the wq with associated interrupt handle. The drain descriptor will have
interrupt request set but without completion record. This will ensure all
descriptors with incorrect interrupt completion handle get drained and
a completion interrupt is triggered for the guest driver to process them.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Co-Developed-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163528420189.3925689.18212568593220415551.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: move interrupt handle assignment

In preparation of supporting interrupt handle revoke event, move the
interrupt handle assignment to right before the descriptor to be submitted.
This allows the interrupt handle revoke logic to assign the latest
interrupt handle on submission.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163528417767.3925689.7730411152122952808.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: int handle management refactoring

Attach int_handle to irq_entry. This removes the separate management of int
handles and reduces the confusion of interating through int handles that is
off by 1 count.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163528417065.3925689.11505755433684476288.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: rework descriptor free path on failure

Refactor the completion function to allow skipping of descriptor freeing on
the submission failure path. This completely removes descriptor freeing
from the submit failure path and leave the responsibility to the caller.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163528416222.3925689.12859769271667814762.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix missed completion on abort path

Ming reported that with the abort path of the descriptor submission, there
can be a window where a completed descriptor can be missed to be completed
by the irq completion thread:

CPU A CPU B
Submit (successful)

Submit (fail)
irq_process_work_list() // empty

llist_abort_desc()
// remove all descs from pending list

irq_process_pending_llist() // empty
exit idxd_wq_thread() with no processing

Add opportunistic descriptor completion in the abort path in order to
remove the missed completion.

Fixes: 6b4b87f2c31a ("dmaengine: idxd: fix submission race window")
Reported-by: Ming Li <ming4.li@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163898288714.443911.16084982766671976640.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: make submit failure path consistent on desc freeing

The submission path for dmaengine API does not do descriptor freeing on
failure. Also, with the abort mechanism, the freeing of descriptor happens
when the abort callback is completed. Therefore free descriptor on all
error paths for submission call to make things consistent. Also remove the
double free that would happen on abort in idxd_dma_tx_submit() call.

Fixes: 6b4b87f2c31a ("dmaengine: idxd: fix submission race window")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162827146072.3459011.10255348500504659810.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: remove interrupt flag for completion list spinlock

The list lock is never acquired in interrupt context. Therefore there is no
need to disable interrupts. Remove interrupt flags for lock operations.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162826417450.3454650.3733188117742416238.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: rotate portal address for better performance

The device submission portal is on a 4k page and any of those 64bit aligned
address on the page can be used for descriptor submission. By rotating the
offset through the 4k range and prevent successive writes to the same MMIO
address, performance improvement is observed through testing.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162681372446.1968485.10634280461681015569.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix wq slot allocation index check

The sbitmap wait and allocate routine checks the index that is returned
from sbitmap_queue_get(). It should be idxd >= 0 as 0 is also a valid
index. This fixes issue where submission path hangs when WQ size is 1.

Fixes: 0705107fcc80 ("dmaengine: idxd: move submission to sbitmap_queue")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162697645067.3478714.506720687816951762.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: assign MSIX vectors to each WQ rather than roundrobin

IOPS increased when changing MSIX vector to per WQ from roundrobin.
Allows descriptor to be completed by the submitter improves caching
locality.

Suggested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Link: https://lore.kernel.org/r/162456717326.1130457.15258077196523268356.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add missing percpu ref put on failure

When enqcmds() fails, exit path is missing a percpu_ref_put(). This can
cause failure on shutdown path when the driver is attempting to quiesce the
wq. Add missing percpu_ref_put() call on the error exit path.

Fixes: 93a40a6d7428 ("dmaengine: idxd: add percpu_ref to descriptor submission path")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162456170168.1121236.7240941044089212312.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix submission race window

Konstantin observed that when descriptors are submitted, the descriptor is
added to the pending list after the submission. This creates a race window
with the slight possibility that the descriptor can complete before it
gets added to the pending list and this window would cause the completion
handler to miss processing the descriptor.

To address the issue, the addition of the descriptor to the pending list
must be done before it gets submitted to the hardware. However, submitting
to swq with ENQCMDS instruction can cause a failure with the condition of
either wq is full or wq is not "active".

With the descriptor allocation being the gate to the wq capacity, it is not
possible to hit a retry with ENQCMDS submission to the swq. The only
possible failure can happen is when wq is no longer "active" due to hw
error and therefore we are moving towards taking down the portal. Given
this is a rare condition and there's no longer concern over I/O
performance, the driver can walk the completion lists in order to retrieve
and abort the descriptor.

The error path will set the descriptor to aborted status. It will take the
work list lock to prevent further processing of worklist. It will do a
delete_all on the pending llist to retrieve all descriptors on the pending
llist. The delete_all action does not require a lock. It will walk through
the acquired llist to find the aborted descriptor while add all remaining
descriptors to the work list since it holds the lock. If it does not find
the aborted descriptor on the llist, it will walk through the work
list. And if it still does not find the descriptor, then it means the
interrupt handler has removed the desc from the llist but is pending on
the work list lock and will process it once the error path releases the
lock.

Fixes: eb15e7154fbf ("dmaengine: idxd: add interrupt handle request and release support")
Reported-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162628855747.360485.10101925573082466530.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix desc->vector that isn't being updated

Missing update for desc->vector when the wq vector gets updated. This
causes the desc->vector to always be at 0.

Fixes: da435aedb00a ("dmaengine: idxd: fix array index when int_handles are being used")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162628784374.353761.4736602409627820431.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix array index when int_handles are being used

The index to the irq vector should be local and has no relation to
the assigned interrupt handle. Assign the MSIX interrupt index that is
programmed for the descriptor. The interrupt handle only matters when it
comes to hardware descriptor programming.

Fixes: eb15e7154fbf ("dmaengine: idxd: add interrupt handle request and release support")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162456176939.1121476.3366256009925001897.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add interrupt handle request and release support

DSA spec states that when Request Interrupt Handle and Release Interrupt
Handle command bits are set in the CMDCAP register, these device commands
must be supported by the driver.

The interrupt handle is programmed in a descriptor. When Request Interrupt
Handle is not supported, the interrupt handle is the index of the desired
entry in the MSI-X table. When the command is supported, driver must use
the command to obtain a handle to be programmed in the submitted
descriptor.

A requested handle may be revoked. After the handle is revoked, any use of
the handle will result in Invalid Interrupt Handle error.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161894439422.3202472.17579543737810265471.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add percpu_ref to descriptor submission path

Current submission path has no way to restrict the submitter from
stop submiting on shutdown path or wq disable path. This provides a way to
quiesce the submission path.

Modeling after 'struct reqeust_queue' usage of percpu_ref. One of the
abilities of per_cpu reference counting is the ability to stop new
references from being taken while awaiting outstanding references to be
dropped. On wq shutdown, we want to block any new submissions to the kernel
workqueue and quiesce before disabling. The percpu_ref allows us to block
any new submissions and wait for any current submission calls to finish
submitting to the workqueue.

A percpu_ref is embedded in each idxd_wq context to allow control for
individual wq. The wq->wq_active counter is elevated before calling
movdir64b() or enqcmds() to submit a descriptor to the wq and dropped once
the submission call completes. The function is gated by
percpu_ref_tryget_live(). On shutdown with percpu_ref_kill() called, any
new submission would be blocked from acquiring a ref and failed. Once all
references are dropped for the wq, shutdown can continue.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161894438293.3202472.14894701611500822232.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: remove detection of device type

Move all static data type for per device type to an idxd_driver_data data
structure. The data can be attached to the pci_device_id and provided by
the pci probe function. This removes a lot of unnecessary type detection
and setup code.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161852988924.2203940.2787590808682466398.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add IAX configuration support in the IDXD driver

Add support to allow configuration of Intel Analytics Accelerator (IAX) in
addition to the Intel Data Streaming Accelerator (DSA). The IAX hardware
has the same configuration interface as DSA. The main difference
is the type of operations it performs. We can support the DSA and
IAX devices on the same driver with some tweaks.

IAX has a 64B completion record that needs to be 64B aligned, as opposed to
a 32B completion record that is 32B aligned for DSA. IAX also does not
support token management.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/160564555488.1834439.4261958859935360473.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix mapping of portal size

Portal size is 4k. Current code is mapping all 4 portals in a single chunk.
Restrict the mapped portal size to a single portal to ensure that submission
only goes to the intended portal address.

Fixes: c52ca478233c ("dmaengine: idxd: add configuration component of driver")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/160513342642.510187.16450549281618747065.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: Add shared workqueue support

Add shared workqueue support that includes the support of Shared Virtual
memory (SVM) or in similar terms On Demand Paging (ODP). The shared
workqueue uses the enqcmds command in kernel and will respond with retry if
the workqueue is full. Shared workqueue only works when there is PASID
support from the IOMMU.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/160382007499.3911367.26043087963708134.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: move submission to sbitmap_queue

Kill the percpu-rwsem for work submission in favor of an sbitmap_queue.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/159225446631.68253.8860709181621260997.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add char driver to expose submission portal to userland

Create a char device region that will allow acquisition of user portals in
order to allow applications to submit DMA operations. A char device will be
created per work queue that gets exposed. The workqueue type "user"
is used to mark a work queue for user char device. For example if the
workqueue 0 of DSA device 0 is marked for char device, then a device node
of /dev/dsa/wq0.0 will be created.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965026985.73301.976523230037106742.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: connect idxd to dmaengine subsystem

Add plumbing for dmaengine subsystem connection. The driver register a DMA
device per DSA device. The channels are dynamically registered when a
workqueue is configured to be "kernel:dmanegine" type.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965026376.73301.13867988830650740445.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add descriptor manipulation routines

This commit adds helper functions for DSA descriptor allocation,
submission, and free operations.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965025757.73301.12692876585357550065.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>