dmaengine: idxd: constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
dsa_device_type, iax_device_type, idxd_wq_device_type, idxd_cdev_file_type,
idxd_cdev_device_type and idxd_group_device_type variables to be constant
structures as well, placing it into read-only memory which can not be
modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20240219-device_cleanup-dmaengine-v1-1-9f72f3cf3587@marliere.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: Remove shadow Event Log head stored in idxd

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: 244da66cda35 ("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>

dmaengine: idxd: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

This is less verbose.

Note that the upper limit of ida_simple_get() is exclusive, but the one of
ida_alloc_range() is inclusive. Sothis change allows one more device.

MINORMASK is ((1U << MINORBITS) - 1), so allowing MINORMASK as a maximum value
makes sense. It is also consistent with other "ida_.*MINORMASK" and
"ida_*MINOR()" usages.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Lijun Pan <lijun.pan@intel.com>
Link: https://lore.kernel.org/r/ac991f5f42112fa782a881d391d447529cbc4a23.1702967302.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: Rename drv_enable/disable_wq to idxd_drv_enable/disable_wq, and export

Rename drv_enable_wq and drv_disable_wq to idxd_drv_enable_wq and
idxd_drv_disable_wq respectively, so that they're no longer too
generic to be exported. This also matches existing naming within the
idxd driver.

And to allow idxd sub-drivers to enable and disable wqs, 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: add wq driver name support for accel-config user tool

With the possibility of multiple wq drivers that can be bound to the wq,
the user config tool accel-config needs a way to know which wq driver to
bind to the wq. Introduce per wq driver_name sysfs attribute where the user
can indicate the driver to be bound to the wq. This allows accel-config to
just bind to the driver using wq->driver_name.

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>
Link: https://lore.kernel.org/r/20230908201045.4115614-1-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: Fix passing freed memory in idxd_cdev_open()

Smatch warns:
drivers/dma/idxd/cdev.c:327:
idxd_cdev_open() warn: 'sva' was already freed.

When idxd_wq_set_pasid() fails, the current code unbinds sva and then
goes to 'failed_set_pasid' where iommu_sva_unbind_device is called
again causing the above warning.
[ device_user_pasid_enabled(idxd) is still true when calling
failed_set_pasid ]

Fix this by removing additional unbind when idxd_wq_set_pasid() fails

Fixes: b022f59725f0 ("dmaengine: idxd: add idxd_copy_cr() to copy user completion record during page fault handling")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230509060716.2830630-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add pid to exported sysfs attribute for opened file

Provide the pid of the application for the opened file. This allows the
monitor daemon to easily correlate which app opened the file and easily
kill the app by pid if that is desired action.

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/20230407203143.2189681-16-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: expose fault counters to sysfs

Expose cr_faults and cr_fault_failures counters to the user space. This
allows a user app to keep track of how many fault the application is
causing with the completion record (CR) and also the number of failures
of the CR writeback. Having a high number of cr_fault_failures is bad as
the app is submitting descriptors with the CR addresses that are bad. User
monitoring daemon may want to consider killing the application as it may be
malicious and attempting to flood the device event log.

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/20230407203143.2189681-15-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add a device to represent the file opened

Embed a struct device for the user file context in order to export sysfs
attributes related with the opened file. Tie the lifetime of the file
context to the device. The sysfs entry will be added under the char device.

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/20230407203143.2189681-14-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add per file user counters for completion record faults

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>

dmaengine: idxd: process user page faults for completion record

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>

dmaengine: idxd: add idxd_copy_cr() to copy user completion record during page fault handling

Define idxd_copy_cr() to copy completion record to fault address in
user address that is found by work queue (wq) and PASID.

It will be used to write the user's completion record that the hardware
device is not able to write due to user completion record page fault.

An xarray is added to associate the PASID and mm with the
struct idxd_user_context so mm can be found by PASID and wq.

It is called when handling the completion record fault in a kernel thread
context. Switch to the mm using kthread_use_vm() and copy the
completion record to the mm via copy_to_user(). Once the copy is
completed, switch back to the current mm using kthread_unuse_mm().

Suggested-by: Christoph Hellwig <hch@infradead.org>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-9-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add per DSA wq workqueue for processing cr faults

Add a workqueue for user submitted completion record fault processing.
The workqueue creation and destruction lifetime will be tied to the user
sub-driver since it will only be used when the wq is a user type.

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/20230407203143.2189681-7-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

mm: replace vma->vm_flags direct modifications with modifier calls

Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.

[akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo]
Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

iommu: Remove SVM_FLAG_SUPERVISOR_MODE support

The current kernel DMA with PASID support is based on the SVA with a flag
SVM_FLAG_SUPERVISOR_MODE. The IOMMU driver binds the kernel memory address
space to a PASID of the device. The device driver programs the device with
kernel virtual address (KVA) for DMA access. There have been security and
functional issues with this approach:

- The lack of IOTLB synchronization upon kernel page table updates.
(vmalloc, module/BPF loading, CONFIG_DEBUG_PAGEALLOC etc.)
- Other than slight more protection, using kernel virtual address (KVA)
has little advantage over physical address. There are also no use
cases yet where DMA engines need kernel virtual addresses for in-kernel
DMA.

This removes SVM_FLAG_SUPERVISOR_MODE support from the IOMMU interface.
The device drivers are suggested to handle kernel DMA with PASID through
the kernel DMA APIs.

The drvdata parameter in iommu_sva_bind_device() and all callbacks is not
needed anymore. Cleanup them as well.

Link: https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Tested-by: Tony Zhu <tony.zhu@intel.com>
Link: https://lore.kernel.org/r/20221031005917.45690-4-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

dmaengine: idxd: Do not enable user type Work Queue without Shared Virtual Addressing

When the idxd_user_drv driver is bound to a Work Queue (WQ) device
without IOMMU or with IOMMU Passthrough without Shared Virtual
Addressing (SVA), the application gains direct access to physical
memory via the device by programming physical address to a submitted
descriptor. This allows direct userspace read and write access to
arbitrary physical memory. This is inconsistent with the security
goals of a good kernel API.

Unlike vfio_pci driver, the IDXD char device driver does not provide any
ways to pin user pages and translate the address from user VA to IOVA or
PA without IOMMU SVA. Therefore the application has no way to instruct the
device to perform DMA function. This makes the char device not usable for
normal application usage.

Since user type WQ without SVA cannot be used for normal application usage
and presents the security issue, bind idxd_user_drv driver and enable user
type WQ only when SVA is enabled (i.e. user PASID is enabled).

Fixes: 448c3de8ac83 ("dmaengine: idxd: create user driver for wq 'device'")
Cc: stable@vger.kernel.org
Suggested-by: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20221014222541.3912195-1-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: Separate user and kernel pasid enabling

The idxd driver always gated the pasid enabling under a single knob and
this assumption is incorrect. The pasid used for kernel operation can be
independently toggled and has no dependency on the user pasid (and vice
versa). Split the two so they are independent "enabled" flags.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/165231431746.986466.5666862038354800551.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: Fix the error handling path in idxd_cdev_register()

If a call to alloc_chrdev_region() fails, the already allocated resources
are leaking.

Add the needed error handling path to fix the leak.

Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/1b5033dcc87b5f2a953c413f0306e883e6114542.1650521591.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: refactor wq driver enable/disable operations

Move the core driver operations from wq driver to the drv_enable_wq() and
drv_disable_wq() functions. The move should reduce the wq driver's
knowledge of the core driver operations and prevent code confusion for
future wq drivers.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/165047301643.3841827.11222723219862233060.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: remove interrupt disable for dev_lock

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>

dmanegine: idxd: add software command status

Enabling device and wq returns standard errno and that does not provide
enough details to indicate what exactly failed. The hardware command status
is only 8bits. Expand the command status to 32bits and use the upper 16
bits to define software errors to provide more details on the exact
failure. Bit 31 will be used to indicate the error is software set as the
driver is using some of the spec defined hardware error as well.

Cc: Ramesh Thomas <ramesh.thomas@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162681373579.1968485.5891788397526827892.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: move dsa_drv support to compatible mode

The original architecture of /sys/bus/dsa invented a scheme whereby
a single entry in the list of bus drivers, /sys/bus/drivers/dsa,
handled all device types and internally routed them to different
different drivers. Those internal drivers were invisible to
userspace.

With the idxd driver transitioned to a proper bus device-driver model,
the legacy behavior needs to be preserved due to it being exposed to
user space via sysfs. Create a compat driver to provide the legacy
behavior for /sys/bus/dsa/drivers/dsa. This should satisfy user
tool accel-config v3.2 or ealier where this behavior is expected.
If the distro has a newer accel-config then the legacy mode does
not need to be enabled.

When the compat driver binds the device (i.e. dsa0) to the dsa driver,
it will be bound to the new idxd_drv. The wq device (i.e. wq0.0) will
be bound to either the dmaengine_drv or the user_drv. The dsa_drv
becomes a routing mechansim for the new drivers. It will not support
additional external drivers that are implemented later.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162637468705.744545.4399080971745974435.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: create user driver for wq 'device'

The original architecture of /sys/bus/dsa invented a scheme whereby a
single entry in the list of bus drivers, /sys/bus/drivers/dsa, handled
all device types and internally routed them to different drivers.
Those internal drivers were invisible to userspace. Now, as
/sys/bus/dsa wants to grow support for alternate drivers for a given
device, for example vfio-mdev instead of kernel-internal-dmaengine, a
proper bus device-driver model is needed. The first step in that process
is separating the existing omnibus/implicit "dsa" driver into proper
individual drivers registered on /sys/bus/dsa. Establish the
idxd_user_drv driver that controls the enabling and disabling of the
wq and also register and unregister a char device to allow user space
to mmap the descriptor submission portal.

The cdev related bits are moved to the cdev driver probe/remove and out of
the drv_enabe/disable_wq() calls. These bits are exclusive to the cdev
operation and not part of the generic enable/disable of the wq device.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162637467578.744545.10203997610072341376.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: add 'struct idxd_dev' as wrapper for conf_dev

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>

dmaengine: idxd: Remove redundant variable cdev_ctx

Variable cdev_ctx is set to '&ictx[wq->idxd->data->type]' but this
value is not used, hence it is a redundant assignment and can be
removed.

Clean up the following clang-analyzer warning:

drivers/dma/idxd/cdev.c:300:2: warning: Value stored to 'cdev_ctx' is
never read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/1620298847-33127-1-git-send-email-jiapeng.chong@linux.alibaba.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: Fix missing error code in idxd_cdev_open()

The error code is missing in this code scenario, add the error code
'-EINVAL' to the return value 'rc'.

Eliminate the follow smatch warning:

drivers/dma/idxd/cdev.c:113 idxd_cdev_open() warn: missing error code
'rc'.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/1622628446-87909-1-git-send-email-jiapeng.chong@linux.alibaba.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: iax bus removal

There is no need to have an additional bus for the IAX device. The removal
of IAX will change user ABI as /sys/bus/iax will no longer exist.
The iax device will be moved to the dsa bus. The device id for dsa and
iax will now be combined rather than unique for each device type in order
to accommodate the iax devices. This is in preparation for fixing the
sub-driver code for idxd. There's no hardware deployment for Sapphire
Rapids platform yet, which means that users have no reason to have
developed scripts against this ABI. There is some exposure to
released versions of accel-config, but those are being fixed up and
an accel-config upgrade is reasonable to get IAX support. As far as
accel-config is concerned IAX support starts when these devices appear
under /sys/bus/dsa, and old accel-config just assumes that an empty /
missing /sys/bus/iax just means a lack of platform support.

Fixes: f25b463883a8 ("dmaengine: idxd: add IAX configuration support in the IDXD driver")
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161852988298.2203940.4529909758034944428.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix cdev setup and free device lifetime issues

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: 42d279f9137a ("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>

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: 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: add work queue drain support

Add wq drain support. When a wq is being released, it needs to wait for
all in-flight operation to complete. A device control function
idxd_wq_drain() has been added to facilitate this. A wq drain call
is added to the char dev on release to make sure all user operations are
complete. A wq drain is also added before the wq is being disabled.

A drain command can take an unpredictable period of time. Interrupt support
for device commands is added to allow waiting on the command to
finish. If a previous command is in progress, the new submitter can block
until the current command is finished before proceeding. The interrupt
based submission will submit the command and then wait until a command
completion interrupt happens to complete. All commands are moved to the
interrupt based command submission except for the device reset during
probe, which will be polled.

Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
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/159319502515.69593.13451647706946040301.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix cdev locking for open and release

add the wq lock in cdev open and release call. This fixes
race conditions observed in the open and close routines.

Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159285824892.64944.2905413694915141834.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: fix off by one on cdev dwq refcount

The refcount check for dedicated workqueue (dwq) is off by one and allows
more than 1 user to open the char device. Fix check so only a single user
can open the device.

Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/158403020187.10208.14117394394540710774.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: check return result from check_vma() in cdev

The returned result from the check_vma() function in the cdev ->mmap() call
needs to be handled. Add the check and returning error.

Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
Reported-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/158264926659.9387.14325163515683047959.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: Fix error handling in idxd_wq_cdev_dev_setup()

We can't call kfree(dev) after calling device_register(dev). The "dev"
pointer has to be freed using put_device().

Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20200205123248.hmtog7qa2eiqaagh@kili.mountain
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idxd: remove set but not used variable 'idxd_cdev'

drivers/dma/idxd/cdev.c: In function idxd_cdev_open:
drivers/dma/idxd/cdev.c:77:20: warning:
variable idxd_cdev set but not used [-Wunused-but-set-variable]

commit 42d279f9137a ("dmaengine: idxd: add char driver to
expose submission portal to userland") involed this.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20200210151855.55044-1-yuehaibing@huawei.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>