Use list_for_each_entry_safe() to allow iterating through the list and
deleting the entry in the iteration process. The descriptor is freed via
idxd_desc_complete() and there's a slight chance may cause issue for
the list iterator when the descriptor is reused by another thread
without it being deleted from the list.
Fixes: 16e19e1122 ("dmaengine: idxd: Fix list corruption in description completion")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20240603012444.11902-1-lirongqing@baidu.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
drain_workqueue() cannot be called safely in a spinlocked context due to
possible task rescheduling. In the multi-task scenario, calling
queue_work() while drain_workqueue() will lead to a Call Trace as
pushing a work on a draining workqueue is not permitted in spinlocked
context.
Call Trace:
<TASK>
? __warn+0x7d/0x140
? __queue_work+0x2b2/0x440
? report_bug+0x1f8/0x200
? handle_bug+0x3c/0x70
? exc_invalid_op+0x18/0x70
? asm_exc_invalid_op+0x1a/0x20
? __queue_work+0x2b2/0x440
queue_work_on+0x28/0x30
idxd_misc_thread+0x303/0x5a0 [idxd]
? __schedule+0x369/0xb40
? __pfx_irq_thread_fn+0x10/0x10
? irq_thread+0xbc/0x1b0
irq_thread_fn+0x21/0x70
irq_thread+0x102/0x1b0
? preempt_count_add+0x74/0xa0
? __pfx_irq_thread_dtor+0x10/0x10
? __pfx_irq_thread+0x10/0x10
kthread+0x103/0x140
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
The current implementation uses a spinlock to protect event log workqueue
and will lead to the Call Trace due to potential task rescheduling.
To address the locking issue, convert the spinlock to mutex, allowing
the drain_workqueue() to be called in a safe mutex-locked context.
This change ensures proper synchronization when accessing the event log
workqueue, preventing potential Call Trace and improving the overall
robustness of the code.
Fixes: c40bd7d973 ("dmaengine: idxd: process user page faults for completion record")
Signed-off-by: Rex Zhang <rex.zhang@intel.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/20240404223949.2885604-1-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
head is defined in idxd->evl as a shadow of head in the EVLSTATUS register.
There are two issues related to the shadow head:
1. Mismatch between the shadow head and the state of the EVLSTATUS
register:
If Event Log is supported, upon completion of the Enable Device command,
the Event Log head in the variable idxd->evl->head should be cleared to
match the state of the EVLSTATUS register. But the variable is not reset
currently, leading mismatch between the variable and the register state.
The mismatch causes incorrect processing of Event Log entries.
2. Unnecessary shadow head definition:
The shadow head is unnecessary as head can be read directly from the
EVLSTATUS register. Reading head from the register incurs no additional
cost because event log head and tail are always read together and
tail is already read directly from the register as required by hardware.
Remove the shadow Event Log head stored in idxd->evl to address the
mentioned issues.
Fixes: 244da66cda ("dmaengine: idxd: setup event log configuration")
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20240215024931.1739621-1-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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>
Add rate limit to the dev_warn() call in the misc interrupt thread. This
limits dmesg getting spammed if a descriptor submitter is spamming bad
descriptors with invalid completion records and resulting the errors being
continuously reported by the misc interrupt handling thread.
Reported-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Lijun Pan <lijun.pan@intel.com>
Link: https://lore.kernel.org/r/20230924002347.1117757-1-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
New support:
- Apple admac t8112 device support
- StarFive JH7110 DMA controller
Updates:
- Big pile of idxd updates to support IAA 2.0 device capabilities, DSA
2.0 Event Log and completion record faulting features and new DSA
operations
- at_xdmac supend & resume updates and driver code cleanup
- k3-udma supend & resume support
- k3-psil thread support for J784s4
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Merge tag 'dmaengine-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine
Pull dmaengine updates from Vinod Koul:
"New support:
- Apple admac t8112 device support
- StarFive JH7110 DMA controller
Updates:
- Big pile of idxd updates to support IAA 2.0 device capabilities,
DSA 2.0 Event Log and completion record faulting features and
new DSA operations
- at_xdmac supend & resume updates and driver code cleanup
- k3-udma supend & resume support
- k3-psil thread support for J784s4"
* tag 'dmaengine-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (57 commits)
dmaengine: idxd: add per wq PRS disable
dmaengine: idxd: add pid to exported sysfs attribute for opened file
dmaengine: idxd: expose fault counters to sysfs
dmaengine: idxd: add a device to represent the file opened
dmaengine: idxd: add per file user counters for completion record faults
dmaengine: idxd: process batch descriptor completion record faults
dmaengine: idxd: add descs_completed field for completion record
dmaengine: idxd: process user page faults for completion record
dmaengine: idxd: add idxd_copy_cr() to copy user completion record during page fault handling
dmaengine: idxd: create kmem cache for event log fault items
dmaengine: idxd: add per DSA wq workqueue for processing cr faults
dmanegine: idxd: add debugfs for event log dump
dmaengine: idxd: add interrupt handling for event log
dmaengine: idxd: setup event log configuration
dmaengine: idxd: add event log size sysfs attribute
dmaengine: idxd: make misc interrupt one shot
dt-bindings: dma: snps,dw-axi-dmac: constrain the items of resets for JH7110 dma
dt-bindings: dma: Drop unneeded quotes
dmaengine: at_xdmac: align declaration of ret with the rest of variables
dmaengine: at_xdmac: add a warning message regarding for unpaused channels
...
Add counters per opened file for the char device in order to keep track how
many completion record faults occurred and how many of those faults failed
the writeback by the driver after attempt to fault in the page. The
counters are managed by xarray that associates the PASID with
struct idxd_user_context.
Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-13-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add event log processing for faulting of user batch descriptor completion
record.
When encountering an event log entry for a page fault on a completion
record, the driver is expected to do the following:
1. If the "first error in batch" bit in event log entry error info is
set, discard any previously recorded errors associated with the
"batch identifier".
2. Fix the page fault according to the fault address in the event log. If
successful, write the completion record to the fault address in user space.
3. If an error is encountered while writing the completion record and it is
associated to a descriptor in the batch, the driver associates the error
with the batch identifier of the event log entry and tracks it until the
event log entry for the corresponding batch desc is encountered.
While processing an event log entry for a batch descriptor with error
indicating that one or more descs in the batch had event log entries,
the driver will do the following before writing the batch completion
record:
1. If the status field of the completion record is 0x1, the driver will
change it to error code 0x5 (one or more operations in batch completed
with status not successful) and changes the result field to 1.
2. If the status is error code 0x6 (page fault on batch descriptor list
address), change the result field to 1.
3. If status is any other value, the completion record is not changed.
4. Clear the recorded error in preparation for next batch with same batch
identifier.
The result field is for user software to determine whether to set the
"Batch Error" flag bit in the descriptor for continuation of partial
batch descriptor completion. See DSA spec 2.0 for additional information.
If no error has been recorded for the batch, the batch completion record is
written to user space as is.
Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-12-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
DSA supports page fault handling through PRS. However, the DMA engine
that's processing the descriptor is blocked until the PRS response is
received. Other workqueues sharing the engine are also blocked.
Page fault handing by the driver with PRS disabled can be used to
mitigate the stalling.
With PRS disabled while ATS remain enabled, DSA handles page faults on
a completion record by reporting an event in the event log. In this
instance, the descriptor is completed and the event log contains the
completion record address and the contents of the completion record. Add
support to the event log handling code to fault in the completion record
and copy the content of the completion record to user memory.
A bitmap is introduced to keep track of discarded event log entries. When
the user process initiates ->release() of the char device, it no longer is
interested in any remaining event log entries tied to the relevant wq and
PASID. The driver will mark the event log entry index in the bitmap. Upon
encountering the entries during processing, the event log handler will just
clear the bitmap bit and skip the entry rather than attempt to process the
event log entry.
Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-10-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
An event log interrupt is raised in the misc interrupt INTCAUSE register
when an event is written by the hardware. Add basic event log processing
support to the interrupt handler. The event log is a ring where the
hardware owns the tail and the software owns the head. The hardware will
advance the tail index when an additional event has been pushed to memory.
The software will process the log entry and then advances the head. The
log is full when (tail + 1) % log_size = head. The hardware will stop
writing when the log is full. The user is expected to create a log size
large enough to handle all the expected events.
Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-5-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Current code continuously processes the interrupt as long as the hardware
is setting the status bit. There's no reason to do that since the threaded
handler will get called again if another interrupt is asserted.
Also through testing, it has shown that if a misprogrammed (or malicious)
agent can continuously submit descriptors with bad completion record and
causes errors to be reported via the misc interrupt. Continuous processing
by the thread can cause software hang watchdog to kick off since the thread
isn't giving up the CPU.
Reported-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-2-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
INVALID_IOASID and IOMMU_PASID_INVALID are duplicated. Rename
INVALID_IOASID and consolidate since we are moving away from IOASID
infrastructure.
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Link: https://lore.kernel.org/r/20230322200803.869130-7-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Since fault processing code has been removed, struct idxd_fault is not used any
more and can be removed as well.
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20220928014747.106808-1-yuancan@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Now that idxd_wq_disable_cleanup() sets the workqueue state to
IDXD_WQ_DISABLED, use a bitmap to track which workqueues have been
enabled. This will then be used to determine which workqueues
should be re-enabled when attempting a software reset to recover
from a device halt state.
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20220928154856.623545-3-jsnitsel@redhat.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
idxd_device_clear_state() now grabs the idxd->dev_lock
itself, so don't grab the lock prior to calling it.
This was seen in testing after dmar fault occurred on system,
resulting in lockup stack traces.
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Fixes: cf4ac3fef3 ("dmaengine: idxd: fix lockdep warning on device driver removal")
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20220823163709.2102468-1-jsnitsel@redhat.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Change the driver where WQ interrupt is requested only when wq is being
enabled. This new scheme set things up so that request_threaded_irq() is
only called when a kernel wq type is being enabled. This also sets up for
future interrupt request where different interrupt handler such as wq
occupancy interrupt can be setup instead of the wq completion interrupt.
Not calling request_irq() until the WQ actually needs an irq also prevents
wasting of CPU irq vectors on x86 systems, which is a limited resource.
idxd_flush_pending_descs() is moved to device.c since descriptor flushing
is now part of wq disable rather than shutdown().
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163942149487.2412839.6691222855803875848.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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>
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>
Dan reports that smatch has found idxd_wq_quiesce() is being called inside
the idxd->dev_lock. idxd_wq_quiesce() calls wait_for_completion() and
therefore it can sleep. Move the call outside of the spinlock as it does
not need device lock.
Fixes: 5b0c68c473 ("dmaengine: idxd: support reporting of halt interrupt")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163716858508.1721911.15051495873516709923.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
"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>
Handle a descriptor that has been marked with invalid interrupt handle
error in status. Create a work item that will resubmit the descriptor. This
typically happens when the driver has handled the revoke interrupt handle
event and has a new interrupt handle.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163528419601.3925689.4166517602890523193.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The helper is called at the completion of the interrupt handle refresh
event. It issues 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>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163528418315.3925689.7944718440052849626.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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>
Using list_move_tail() instead of list_del() + list_add_tail()
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20210908092826.67765-1-cuibixuan@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The spinlock is not being used in hard interrupt context. There is no need
to disable irq when acquiring the lock. The interrupt thread handler also
is not in bottom half context, therefore we can also remove disabling of
the bh. Convert all dev_lock acquisition to plain spin_lock() calls.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162984026772.1939166.11504067782824765879.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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>
The interrupt thread handler currently loops forever to process outstanding
completions. This causes either an "irq X: nobody cared" kernel splat or
the NMI watchdog kicks in due to running too long in the function. The irq
thread handler is expected to run again after exiting if there are
interrupts fired while the thread handler is running. So the handler code
can process all the completed I/O in a single pass and exit without losing
the follow on completed I/O.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162802977005.3084234.11836261157026497585.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Coverity static analysis of linux-next found issue.
The check (status == IDXD_COMP_DESC_ABORT) is always false since status
was previously masked with 0x7f and IDXD_COMP_DESC_ABORT is 0xff.
Fixes: 6b4b87f2c3 ("dmaengine: idxd: fix submission race window")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162698465160.3560828.18173186265683415384.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Kernel memory are pinned and will not cause faults. Since the driver
does not support interrupts for user descriptors, no fault errors are
expected to come through the misc interrupt. Remove dead code.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162630502789.631986.10591230961790023856.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add a 'struct idxd_dev' that wraps the 'struct device' for idxd conf_dev
that registers with the dsa bus. This is introduced in order to deal with
multiple different types of 'devices' that are registered on the dsa_bus
when the compat driver needs to route them to the correct driver to attach.
The bind() call now can determine the type of device and then do the
appropriate driver matching.
Reviewed-by Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162637460065.744545.584492831446090984.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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: eb15e7154f ("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>
The previous state cleanup patch only performed wq state cleanups. This
does not go far enough as when device is disabled or reset, the state
for groups and engines must also be cleaned up. Add additional state
cleanup beyond wq cleanup. Tie those cleanups directly to device
disable and reset, and wq disable and reset.
Fixes: da32b28c95 ("dmaengine: idxd: cleanup workqueue config after disabling")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162285154108.2096632.5572805472362321307.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add the code needed in the main IDXD driver to interface with the IDXD
perfmon implementation.
[ Based on work originally by Jing Lin. ]
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Link: https://lore.kernel.org/r/a5564a5583911565d31c2af9234218c5166c4b2c.1619276133.git.zanussi@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Remove interrupt masking and just let the hard irq handler keep
firing for new events. This is less of a performance impact vs
the MMIO readback inside the pci_msi_{mask,unmas}_irq(). Especially
with a loaded system those flushes can be stuck behind large amounts
of MMIO writes to flush. When guest kernel is running on top of VFIO
mdev, mask/unmask causes a vmexit each time and is not desirable.
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/161894523436.3210025.1834640110556139277.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The char device setup and cleanup has device lifetime issues regarding when
parts are initialized and cleaned up. The initialization of struct device is
done incorrectly. device_initialize() needs to be called on the 'struct
device' and then additional changes can be added. The ->release() function
needs to be setup via device_type before dev_set_name() to allow proper
cleanup. The change re-parents the cdev under the wq->conf_dev to get
natural reference inheritance. No known dependency on the old device path exists.
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Fixes: 42d279f913 ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/161852987721.2203940.1478218825576630810.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Remove devm_* allocation and fix wq->conf_dev 'struct device' lifetime.
Address issues flagged by CONFIG_DEBUG_KOBJECT_RELEASE. Add release
functions in order to free the allocated memory for the wq context at
device destruction time.
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Fixes: bfe1d56091 ("dmaengine: idxd: Init and probe for Intel data accelerators")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161852985907.2203940.6840120734115043753.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Current code blindly writes over the SWERR and the OVERFLOW bits. Write
back the bits actually read instead so the driver avoids clobbering the
OVERFLOW bit that comes after the register is read.
Fixes: bfe1d56091 ("dmaengine: idxd: Init and probe for Intel data accelerators")
Reported-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161352082229.3511254.1002151220537623503.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Nikhil reported the misc interrupt handler can sometimes miss handling
the command interrupt when an error interrupt happens near the same time.
Have the irq handling thread continue to process the misc interrupts until
all interrupts are processed. This is a low usage interrupt and is not
expected to handle high volume traffic. Therefore there is no concern of
this thread running for a long time.
Fixes: 0d5c10b4c8 ("dmaengine: idxd: add work queue drain support")
Reported-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161074755329.2183844.13295528344116907983.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add code to "complete" a descriptor when the descriptor or its completion
address hit a fault error when SVA mode is being used. This error can be
triggered due to bad programming by the user. A lock is introduced in order
to protect the descriptor completion lists since the fault handler will run
from the system work queue after being scheduled in the interrupt handler.
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/160382008092.3911367.12766483427643278985.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Switch driver to use MSIX mask and unmask instead of the ignore bit.
When ignore bit is cleared, we must issue an MMIO read to ensure writes
have all arrived and check and process any additional completions. The
ignore bit does not queue up any pending MSIX interrupts. The mask bit
however does. Use API call from interrupt subsystem to mask MSIX
interrupt since the hardware does not have convenient mask bit register.
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159319517621.70410.11816465052708900506.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
