Testing shown that when a wq mode is setup to be dedicated and then torn
down and reconfigured to shared, the wq configured end up being dedicated
anyays. The root cause is when idxd_device_wqs_clear_state() gets called
during idxd_driver removal, idxd_wq_disable_cleanup() does not get called
vs when the wq driver is removed first. The check of wq state being
"enabled" causes the cleanup to be bypassed. However, idxd_driver->remove()
releases all wq drivers. So the wqs goes to "disabled" state and will never
be "enabled". By that point, the driver has no idea if the wq was
previously configured or clean. So force call idxd_wq_disable_cleanup() on
all wqs always to make sure everything gets cleaned up.
Reported-by: Tony Zhu <tony.zhu@intel.com>
Tested-by: Tony Zhu <tony.zhu@intel.com>
Fixes: 0dcfe41e9a ("dmanegine: idxd: cleanup all device related bits after disabling device")
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/20220628230056.2527816-1-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull dmaengine updates from Vinod Koul:
"Nothing special, this includes a couple of new device support and new
driver support and bunch of driver updates.
New support:
- Tegra gpcdma driver support
- Qualcomm SM8350, Sm8450 and SC7280 device support
- Renesas RZN1 dma and platform support
Updates:
- stm32 device pause/resume support and updates
- DMA memset ops Documentation and usage clarification
- deprecate '#dma-channels' & '#dma-requests' bindings
- driver updates for stm32, ptdma idsx etc"
* tag 'dmaengine-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (87 commits)
dmaengine: idxd: make idxd_wq_enable() return 0 if wq is already enabled
dmaengine: sun6i: Add support for the D1 variant
dmaengine: sun6i: Add support for 34-bit physical addresses
dmaengine: sun6i: Do not use virt_to_phys
dt-bindings: dma: sun50i-a64: Add compatible for D1
dmaengine: tegra: Remove unused switch case
dmaengine: tegra: Fix uninitialized variable usage
dmaengine: stm32-dma: add device_pause/device_resume support
dmaengine: stm32-dma: rename pm ops before dma pause/resume introduction
dmaengine: stm32-dma: pass DMA_SxSCR value to stm32_dma_handle_chan_done()
dmaengine: stm32-dma: introduce stm32_dma_sg_inc to manage chan->next_sg
dmaengine: stm32-dmamux: avoid reset of dmamux if used by coprocessor
dmaengine: qcom: gpi: Add support for sc7280
dt-bindings: dma: pl330: Add power-domains
dmaengine: stm32-mdma: use dev_dbg on non-busy channel spurious it
dmaengine: stm32-mdma: fix chan initialization in stm32_mdma_irq_handler()
dmaengine: stm32-mdma: remove GISR1 register
dmaengine: ti: deprecate '#dma-channels'
dmaengine: mmp: deprecate '#dma-channels'
dmaengine: pxa: deprecate '#dma-channels' and '#dma-requests'
...
The driver currently programs the system pasid to the WQ preemptively when
system pasid is enabled. Given that a dwq will reprogram the pasid and
possibly a different pasid, the programming is not necessary. The pasid_en
bit can be set for swq as it does not need pasid programming but
needs the pasid_en bit. Remove system pasid programming on device config
write. Add pasid programming for kernel wq type on wq driver enable. The
char dev driver already reprograms the dwq on ->open() call so there's no
change.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/164935607115.1660372.6734518676950372366.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The following sysfs attributes will be obsolete due to the name change of
tokens to read buffers:
max_tokens
token_limit
group/tokens_allowed
group/tokens_reserved
group/use_token_limit
Create new entries and have old entry print warning of deprecation.
New attributes to replace the token ones:
max_read_buffers
read_buffer_limit
group/read_buffers_allowed
group/read_buffers_reserved
group/use_read_buffer_limit
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163951339488.2988321.2424012059911316373.stgit@djiang5-desk3.ch.intel.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>
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: 6b4b87f2c3 ("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>
"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>
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>
