Pull iommu updates from Joerg Roedel:
"Core changes:
- Fix race conditions in device probe path
- Retire IOMMU bus_ops
- Support for passing custom allocators to page table drivers
- Clean up Kconfig around IOMMU_SVA
- Support for sharing SVA domains with all devices bound to a mm
- Firmware data parsing cleanup
- Tracing improvements for iommu-dma code
- Some smaller fixes and cleanups
ARM-SMMU drivers:
- Device-tree binding updates:
- Add additional compatible strings for Qualcomm SoCs
- Document Adreno clocks for Qualcomm's SM8350 SoC
- SMMUv2:
- Implement support for the ->domain_alloc_paging() callback
- Ensure Secure context is restored following suspend of Qualcomm
SMMU implementation
- SMMUv3:
- Disable stalling mode for the "quiet" context descriptor
- Minor refactoring and driver cleanups
Intel VT-d driver:
- Cleanup and refactoring
AMD IOMMU driver:
- Improve IO TLB invalidation logic
- Small cleanups and improvements
Rockchip IOMMU driver:
- DT binding update to add Rockchip RK3588
Apple DART driver:
- Apple M1 USB4/Thunderbolt DART support
- Cleanups
Virtio IOMMU driver:
- Add support for iotlb_sync_map
- Enable deferred IO TLB flushes"
* tag 'iommu-updates-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (66 commits)
iommu: Don't reserve 0-length IOVA region
iommu/vt-d: Move inline helpers to header files
iommu/vt-d: Remove unused vcmd interfaces
iommu/vt-d: Remove unused parameter of intel_pasid_setup_pass_through()
iommu/vt-d: Refactor device_to_iommu() to retrieve iommu directly
iommu/sva: Fix memory leak in iommu_sva_bind_device()
dt-bindings: iommu: rockchip: Add Rockchip RK3588
iommu/dma: Trace bounce buffer usage when mapping buffers
iommu/arm-smmu: Convert to domain_alloc_paging()
iommu/arm-smmu: Pass arm_smmu_domain to internal functions
iommu/arm-smmu: Implement IOMMU_DOMAIN_BLOCKED
iommu/arm-smmu: Convert to a global static identity domain
iommu/arm-smmu: Reorganize arm_smmu_domain_add_master()
iommu/arm-smmu-v3: Remove ARM_SMMU_DOMAIN_NESTED
iommu/arm-smmu-v3: Master cannot be NULL in arm_smmu_write_strtab_ent()
iommu/arm-smmu-v3: Add a type for the STE
iommu/arm-smmu-v3: disable stall for quiet_cd
iommu/qcom: restore IOMMU state if needed
iommu/arm-smmu-qcom: Add QCM2290 MDSS compatible
iommu/arm-smmu-qcom: Add missing GMU entry to match table
...
Now that the BLOCKED and IDENTITY behaviors are managed with their own
domains change to the domain_alloc_paging() op.
The check for using_legacy_binding is now redundant,
arm_smmu_def_domain_type() always returns IOMMU_DOMAIN_IDENTITY for this
mode, so the core code will never attempt to create a DMA domain in the
first place.
Since commit a4fdd97622 ("iommu: Use flush queue capability") the core
code only passes in IDENTITY/BLOCKED/UNMANAGED/DMA domain types. It will
not pass in IDENTITY or BLOCKED if the global statics exist, so the test
for DMA is also redundant now too.
Call arm_smmu_init_domain_context() early if a dev is available.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v2-c86cc8c2230e+160bb-smmu_newapi_jgg@nvidia.com
[will: Simplify arm_smmu_domain_alloc_paging() since 'cfg' cannot be NULL]
Signed-off-by: Will Deacon <will@kernel.org>
Create a global static identity domain with it's own
arm_smmu_attach_dev_identity() that simply calls
arm_smmu_master_install_s2crs() with the identity parameters.
This is done by giving the attach path for identity its own unique
implementation that simply calls arm_smmu_master_install_s2crs().
Remove ARM_SMMU_DOMAIN_BYPASS and all checks of IOMMU_DOMAIN_IDENTITY.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v2-c86cc8c2230e+160bb-smmu_newapi_jgg@nvidia.com
[will: Move duplicated autosuspend logic into a helper function]
Signed-off-by: Will Deacon <will@kernel.org>
Make arm_smmu_domain_add_master() not use the smmu_domain to detect the
s2cr configuration, instead pass it in as a parameter. It always returns
zero so make it return void.
Since it no longer really does anything to do with a domain call it
arm_smmu_master_install_s2crs().
This is done to make the next two patches able to re-use this code without
forcing the creation of a struct arm_smmu_domain.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v2-c86cc8c2230e+160bb-smmu_newapi_jgg@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>
In the stall model, invalid transactions were expected to be
stalled and aborted by the IOPF handler.
However, when killing a test case with a huge amount of data, the
accelerator streamline can not stop until all data is consumed
even if the page fault handler reports errors. As a result, the
kill may take a long time, about 10 seconds with numerous iopf
interrupts.
So disable stall for quiet_cd in the non-force stall model, since
force stall model (STALL_MODEL==0b10) requires CD.S must be 1.
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: Wenkai Lin <linwenkai6@hisilicon.com>
Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20231206005727.46150-1-zhangfei.gao@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
In some cases the firmware expects cbndx 1 to be assigned to the GMU,
so we also want the default domain for the GMU to be an identy domain.
This way it does not get a context bank assigned. Without this, both
of_dma_configure() and drm/msm's iommu_domain_attach() will trigger
allocating and configuring a context bank. So GMU ends up attached to
both cbndx 1 and later cbndx 2. This arrangement seemingly confounds
and surprises the firmware if the GPU later triggers a translation
fault, resulting (on sc8280xp / lenovo x13s, at least) in the SMMU
getting wedged and the GPU stuck without memory access.
Cc: stable@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20231210180655.75542-1-robdclark@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
A perfect driver would only call dev_iommu_priv_set() from its probe
callback. We've made it functionally correct to call it from the of_xlate
by adding a lock around that call.
lockdep assert that iommu_probe_device_lock is held to discourage misuse.
Exclude PPC kernels with CONFIG_FSL_PAMU turned on because FSL_PAMU uses a
global static for its priv and abuses priv for its domain.
Remove the pointless stores of NULL, all these are on paths where the core
code will free dev->iommu after the op returns.
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v2-16e4def25ebb+820-iommu_fwspec_p1_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
mm_get_enqcmd_pasid() should be used by architecture code and closely
related to learn the PASID value that the x86 ENQCMD operation should
use for the mm.
For the moment SMMUv3 uses this without any connection to ENQCMD, it
will be cleaned up similar to how the prior patch made VT-d use the
PASID argument of set_dev_pasid().
The motivation is to replace mm->pasid with an iommu private data
structure that is introduced in a later patch.
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20231027000525.1278806-4-tina.zhang@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Always allocate a new arm_smmu_bond in __arm_smmu_sva_bind and remove
the bond refcount since arm_smmu_bond can never be shared across calls
to __arm_smmu_sva_bind.
The iommu framework will not allocate multiple SVA domains for the same
(device/mm) pair, nor will it call set_dev_pasid for a device if a
domain is already attached on the given pasid. There's also a one-to-one
mapping between MM and PASID. __arm_smmu_sva_bind is therefore never
called with the same (device/mm) pair, and so there's no reason to try
and normalize allocations of the arm_smmu_bond struct for a (device/mm)
pair across set_dev_pasid.
Signed-off-by: Michael Shavit <mshavit@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230905194849.v1.2.Id3ab7cf665bcead097654937233a645722a4cce3@changeid
Signed-off-by: Will Deacon <will@kernel.org>
With this change, each master will now own its own CD table instead of
sharing one with other masters attached to the same domain. Attaching a
stage 1 domain installs CD entries into the master's CD table. SVA
writes its CD entries into each master's CD table if the domain is
shared across masters.
Also add the device to the devices list before writing the CD to the
table so that SVA will know that the CD needs to be re-written to this
device's CD table as well if it decides to update the CD's ASID
concurrently with this function.
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Michael Shavit <mshavit@google.com>
Link: https://lore.kernel.org/r/20230915211705.v8.6.Ice063dcf87d1b777a72e008d9e3406d2bcf6d876@changeid
Signed-off-by: Will Deacon <will@kernel.org>
Update arm_smmu_write_ctx_desc and downstream functions to operate on
a master instead of an smmu domain. We expect arm_smmu_write_ctx_desc()
to only be called to write a CD entry into a CD table owned by the
master. Under the hood, arm_smmu_write_ctx_desc still fetches the CD
table from the domain that is attached to the master, but a subsequent
commit will move that table's ownership to the master.
Note that this change isn't a nop refactor since SVA will call
arm_smmu_write_ctx_desc in a loop for every master the domain is
attached to despite the fact that they all share the same CD table. This
loop may look weird but becomes necessary when the CD table becomes
per-master in a subsequent commit.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Michael Shavit <mshavit@google.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20230915211705.v8.5.I219054a6cf538df5bb22f4ada2d9933155d6058c@changeid
Signed-off-by: Will Deacon <will@kernel.org>
A domain can be attached to multiple masters with different
master->stall_enabled values. The stall bit of a CD entry should follow
master->stall_enabled and has an inverse relationship with the
STE.S1STALLD bit.
The stall_enabled bit does not depend on any property of the domain, so
move it out of the arm_smmu_domain struct. Move it to the CD table
struct so that it can fully describe how CD entries should be written to
it.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Michael Shavit <mshavit@google.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20230915211705.v8.4.I5aa89c849228794a64146cfe86df21fb71629384@changeid
Signed-off-by: Will Deacon <will@kernel.org>
Remove struct arm_smmu_s1_cfg. This is really just a CD table with a
bit of extra information. Move other attributes of the CD table that
were held there into the existing CD table structure, struct
arm_smmu_ctx_desc_cfg, and replace all usages of arm_smmu_s1_cfg with
arm_smmu_ctx_desc_cfg.
For clarity, use the name "cd_table" for the variables pointing to
arm_smmu_ctx_desc_cfg in the new code instead of cdcfg. A later patch
will make this fully consistent.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Michael Shavit <mshavit@google.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20230915211705.v8.2.I1ef1ed19d7786c8176a0d05820c869e650c8d68f@changeid
Signed-off-by: Will Deacon <will@kernel.org>
arm_smmu_s1_cfg (and by extension arm_smmu_domain) owns both a CD table
and the CD inserted into that table's non-pasid CD entry. This limits
arm_smmu_domain's ability to represent non-pasid domains, where multiple
domains need to be inserted into a common CD table. Rather than describing
an STE entry (which may have multiple domains installed into it with
PASID), a domain should describe a single CD entry instead. This is
precisely the role of arm_smmu_ctx_desc. A subsequent commit will also
move the CD table outside of arm_smmu_domain.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Michael Shavit <mshavit@google.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20230915211705.v8.1.I67ab103c18d882aedc8a08985af1fba70bca084e@changeid
Signed-off-by: Will Deacon <will@kernel.org>
When running an SVA case, the following soft lockup is triggered:
--------------------------------------------------------------------
watchdog: BUG: soft lockup - CPU#244 stuck for 26s!
pstate: 83400009 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : arm_smmu_cmdq_issue_cmdlist+0x178/0xa50
lr : arm_smmu_cmdq_issue_cmdlist+0x150/0xa50
sp : ffff8000d83ef290
x29: ffff8000d83ef290 x28: 000000003b9aca00 x27: 0000000000000000
x26: ffff8000d83ef3c0 x25: da86c0812194a0e8 x24: 0000000000000000
x23: 0000000000000040 x22: ffff8000d83ef340 x21: ffff0000c63980c0
x20: 0000000000000001 x19: ffff0000c6398080 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: ffff3000b4a3bbb0
x14: ffff3000b4a30888 x13: ffff3000b4a3cf60 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : ffffc08120e4d6bc
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000048cfa
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 000000000000000a
x2 : 0000000080000000 x1 : 0000000000000000 x0 : 0000000000000001
Call trace:
arm_smmu_cmdq_issue_cmdlist+0x178/0xa50
__arm_smmu_tlb_inv_range+0x118/0x254
arm_smmu_tlb_inv_range_asid+0x6c/0x130
arm_smmu_mm_invalidate_range+0xa0/0xa4
__mmu_notifier_invalidate_range_end+0x88/0x120
unmap_vmas+0x194/0x1e0
unmap_region+0xb4/0x144
do_mas_align_munmap+0x290/0x490
do_mas_munmap+0xbc/0x124
__vm_munmap+0xa8/0x19c
__arm64_sys_munmap+0x28/0x50
invoke_syscall+0x78/0x11c
el0_svc_common.constprop.0+0x58/0x1c0
do_el0_svc+0x34/0x60
el0_svc+0x2c/0xd4
el0t_64_sync_handler+0x114/0x140
el0t_64_sync+0x1a4/0x1a8
--------------------------------------------------------------------
Note that since 6.6-rc1 the arm_smmu_mm_invalidate_range above is renamed
to "arm_smmu_mm_arch_invalidate_secondary_tlbs", yet the problem remains.
The commit 06ff87bae8 ("arm64: mm: remove unused functions and variable
protoypes") fixed a similar lockup on the CPU MMU side. Yet, it can occur
to SMMU too, since arm_smmu_mm_arch_invalidate_secondary_tlbs() is called
typically next to MMU tlb flush function, e.g.
tlb_flush_mmu_tlbonly {
tlb_flush {
__flush_tlb_range {
// check MAX_TLBI_OPS
}
}
mmu_notifier_arch_invalidate_secondary_tlbs {
arm_smmu_mm_arch_invalidate_secondary_tlbs {
// does not check MAX_TLBI_OPS
}
}
}
Clone a CMDQ_MAX_TLBI_OPS from the MAX_TLBI_OPS in tlbflush.h, since in an
SVA case SMMU uses the CPU page table, so it makes sense to align with the
tlbflush code. Then, replace per-page TLBI commands with a single per-asid
TLBI command, if the request size hits this threshold.
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20230920052257.8615-1-nicolinc@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>
Although io-pgtable's non-leaf invalidations are always for full tables,
I missed that SVA also uses non-leaf invalidations, while being at the
mercy of whatever range the MMU notifier throws at it. This means it
definitely wants the previous TTL fix as well, since it also doesn't
know exactly which leaf level(s) may need invalidating, but it can also
give us less-aligned ranges wherein certain corners may lead to building
an invalid command where TTL, Num and Scale are all 0. It should be fine
to handle this by over-invalidating an extra page, since falling back to
a non-range command opens up a whole can of errata-flavoured worms.
Fixes: 6833b8f2e1 ("iommu/arm-smmu-v3: Set TTL invalidation hint better")
Reported-by: Rui Zhu <zhurui3@huawei.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b99cfe71af2bd93a8a2930f20967fb2a4f7748dd.1694432734.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Pull iommu updates from Joerg Roedel:
"Core changes:
- Consolidate probe_device path
- Make the PCI-SAC IOVA allocation trick PCI-only
AMD IOMMU:
- Consolidate PPR log handling
- Interrupt handling improvements
- Refcount fixes for amd_iommu_v2 driver
Intel VT-d driver:
- Enable idxd device DMA with pasid through iommu dma ops
- Lift RESV_DIRECT check from VT-d driver to core
- Miscellaneous cleanups and fixes
ARM-SMMU drivers:
- Device-tree binding updates:
- Add additional compatible strings for Qualcomm SoCs
- Allow ASIDs to be configured in the DT to work around Qualcomm's
broken hypervisor
- Fix clocks for Qualcomm's MSM8998 SoC
- SMMUv2:
- Support for Qualcomm's legacy firmware implementation featured
on at least MSM8956 and MSM8976
- Match compatible strings for Qualcomm SM6350 and SM6375 SoC
variants
- SMMUv3:
- Use 'ida' instead of a bitmap for VMID allocation
- Rockchip IOMMU:
- Lift page-table allocation restrictions on newer hardware
- Mediatek IOMMU:
- Add MT8188 IOMMU Support
- Renesas IOMMU:
- Allow PCIe devices
.. and the usual set of cleanups an smaller fixes"
* tag 'iommu-updates-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (64 commits)
iommu: Explicitly include correct DT includes
iommu/amd: Remove unused declarations
iommu/arm-smmu-qcom: Add SM6375 SMMUv2
iommu/arm-smmu-qcom: Add SM6350 DPU compatible
iommu/arm-smmu-qcom: Add SM6375 DPU compatible
iommu/arm-smmu-qcom: Sort the compatible list alphabetically
dt-bindings: arm-smmu: Fix MSM8998 clocks description
iommu/vt-d: Remove unused extern declaration dmar_parse_dev_scope()
iommu/vt-d: Fix to convert mm pfn to dma pfn
iommu/vt-d: Fix to flush cache of PASID directory table
iommu/vt-d: Remove rmrr check in domain attaching device path
iommu: Prevent RESV_DIRECT devices from blocking domains
dmaengine/idxd: Re-enable kernel workqueue under DMA API
iommu/vt-d: Add set_dev_pasid callback for dma domain
iommu/vt-d: Prepare for set_dev_pasid callback
iommu/vt-d: Make prq draining code generic
iommu/vt-d: Remove pasid_mutex
iommu/vt-d: Add domain_flush_pasid_iotlb()
iommu: Move global PASID allocation from SVA to core
iommu: Generalize PASID 0 for normal DMA w/o PASID
...
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20230714174640.4058404-1-robh@kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
PCIe Process address space ID (PASID) is used to tag DMA traffic, it
provides finer grained isolation than requester ID (RID).
For each device/RID, 0 is a special PASID for the normal DMA (no
PASID). This is universal across all architectures that supports PASID,
therefore warranted to be reserved globally and declared in the common
header. Consequently, we can avoid the conflict between different PASID
use cases in the generic code. e.g. SVA and DMA API with PASIDs.
This paved away for device drivers to choose global PASID policy while
continue doing normal DMA.
Noting that VT-d could support none-zero RID/NO_PASID, but currently not
used.
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Link: https://lore.kernel.org/r/20230802212427.1497170-2-jacob.jun.pan@linux.intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
On some SoCs like MSM8956, MSM8976 and others, secure contexts are
also secured: these get programmed by the bootloader or TZ (as usual)
but their "interesting" registers are locked out by the hypervisor,
disallowing direct register writes from Linux and, in many cases,
completely disallowing the reprogramming of TTBR, TCR, MAIR and other
registers including, but not limited to, resetting contexts.
This is referred downstream as a "v2" IOMMU but this is effectively
a "v2 firmware configuration" instead.
Luckily, the described behavior of version 2 is effective only on
secure contexts and not on non-secure ones: add support for that,
finally getting a completely working IOMMU on at least MSM8956/76.
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
[Marijn: Rebased over next-20221111]
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230622092742.74819-7-angelogioacchino.delregno@collabora.com
Signed-off-by: Will Deacon <will@kernel.org>
This driver was indexing the contexts by asid-1, which is probably
done under the assumption that the first ASID is always 1.
Unfortunately this is not always true: at least for MSM8956 and
MSM8976's GPU IOMMU, the gpu_user context's ASID number is zero.
To allow using a zero asid number, index the contexts by `asid`
instead of by `asid - 1`.
While at it, also enhance human readability by renaming the
`num_ctxs` member of struct qcom_iommu_dev to `max_asid`.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230622092742.74819-5-angelogioacchino.delregno@collabora.com
Signed-off-by: Will Deacon <will@kernel.org>
