Now the ARM page tables are always allocated by GFP_ATOMIC parameter,
but the iommu_ops->map() function has been added a gfp_t parameter by
commit 781ca2de89 ("iommu: Add gfp parameter to iommu_ops::map"),
thus io_pgtable_ops->map() should use the gfp parameter passed from
iommu_ops->map() to allocate page pages, which can avoid wasting the
memory allocators atomic pools for some non-atomic contexts.
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/3093df4cb95497aaf713fca623ce4ecebb197c2e.1591930156.git.baolin.wang@linux.alibaba.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Remove the use of dev->archdata.iommu and use the private per-device
pointer provided by IOMMU core code instead.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20200625130836.1916-4-joro@8bytes.org
Fix the following sparse warning:
drivers/iommu/msm_iommu.c:37:1: warning: symbol 'msm_iommu_lock' was not declared.
The msm_iommu_lock has only call site within msm_iommu.c
It should be static
Fixes: 0720d1f052 ("msm: Add MSM IOMMU support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Samuel Zou <zou_wei@huawei.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1589249839-105820-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Convert the MSM IOMMU driver to use the probe_device() and
release_device() call-backs of iommu_ops, so that the iommu core code
does the group and sysfs setup.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200429133712.31431-22-joro@8bytes.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
TTBR1 values have so far been redundant since no users implement any
support for split address spaces. Crucially, though, one of the main
reasons for wanting to do so is to be able to manage each half entirely
independently, e.g. context-switching one set of mappings without
disturbing the other. Thus it seems unlikely that tying two tables
together in a single io_pgtable_cfg would ever be particularly desirable
or useful.
Streamline the configs to just a single conceptual TTBR value
representing the allocated table. This paves the way for future users to
support split address spaces by simply allocating a table and dealing
with the detailed TTBRn logistics themselves.
Tested-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: Drop change to ttbr value]
Signed-off-by: Will Deacon <will@kernel.org>
Add a gfp_t parameter to the iommu_ops::map function.
Remove the needless locking in the AMD iommu driver.
The iommu_ops::map function (or the iommu_map function which calls it)
was always supposed to be sleepable (according to Joerg's comment in
this thread: https://lore.kernel.org/patchwork/patch/977520/ ) and so
should probably have had a "might_sleep()" since it was written. However
currently the dma-iommu api can call iommu_map in an atomic context,
which it shouldn't do. This doesn't cause any problems because any iommu
driver which uses the dma-iommu api uses gfp_atomic in it's
iommu_ops::map function. But doing this wastes the memory allocators
atomic pools.
Signed-off-by: Tom Murphy <murphyt7@tcd.ie>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.
// <smpl>
@@
expression ret;
struct platform_device *E;
@@
ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);
if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>
While we're here, remove braces on if statements that only have one
statement (manually).
Cc: Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
With all the pieces in place, we can finally propagate the
iommu_iotlb_gather structure from the call to unmap() down to the IOMMU
drivers' implementation of ->tlb_add_page(). Currently everybody ignores
it, but the machinery is now there to defer invalidation.
Signed-off-by: Will Deacon <will@kernel.org>
Update the io-pgtable ->unmap() function to take an iommu_iotlb_gather
pointer as an argument, and update the callers as appropriate.
Signed-off-by: Will Deacon <will@kernel.org>
The ->tlb_add_flush() callback in the io-pgtable API now looks a bit
silly:
- It takes a size and a granule, which are always the same
- It takes a 'bool leaf', which is always true
- It only ever flushes a single page
With that in mind, replace it with an optional ->tlb_add_page() callback
that drops the useless parameters.
Signed-off-by: Will Deacon <will@kernel.org>
Hook up ->tlb_flush_walk() and ->tlb_flush_leaf() in drivers using the
io-pgtable API so that we can start making use of them in the page-table
code. For now, they can just wrap the implementations of ->tlb_add_flush
and ->tlb_sync pending future optimisation in each driver.
Signed-off-by: Will Deacon <will@kernel.org>
To allow IOMMU drivers to batch up TLB flushing operations and postpone
them until ->iotlb_sync() is called, extend the prototypes for the
->unmap() and ->iotlb_sync() IOMMU ops callbacks to take a pointer to
the current iommu_iotlb_gather structure.
All affected IOMMU drivers are updated, but there should be no
functional change since the extra parameter is ignored for now.
Signed-off-by: Will Deacon <will@kernel.org>
In preparation for TLB flush gathering in the IOMMU API, rename the
iommu_gather_ops structure in io-pgtable to iommu_flush_ops, which
better describes its purpose and avoids the potential for confusion
between different levels of the API.
$ find linux/ -type f -name '*.[ch]' | xargs sed -i 's/gather_ops/flush_ops/g'
Signed-off-by: Will Deacon <will@kernel.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 and
only version 2 as published by the free software foundation this
program is distributed in the hope that it will be useful but
without any warranty without even the implied warranty of
merchantability or fitness for a particular purpose see the gnu
general public license for more details you should have received a
copy of the gnu general public license along with this program if
not write to the free software foundation inc 51 franklin street
fifth floor boston ma 02110 1301 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 94 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141334.043630402@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit dccd2304cc ("ARM: 7430/1: sizes.h: move from asm-generic
to <linux/sizes.h>"), <asm/sizes.h> and <asm-generic/sizes.h> are just
wrappers of <linux/sizes.h>.
This commit replaces all <asm/sizes.h> and <asm-generic/sizes.h> to
prepare for the removal.
Link: http://lkml.kernel.org/r/1553267665-27228-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move io-pgtable.h to include/linux/ and export alloc_io_pgtable_ops
and free_io_pgtable_ops. This enables drivers outside drivers/iommu/ to
use the page table library. Specifically, some ARM Mali GPUs use the
ARM page table formats.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: iommu@lists.linux-foundation.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Delete tab aligning a statement with the right hand side of a
preceding assignment rather than the left hand side.
Found with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The Kconfig currently controlling compilation of this code is:
drivers/iommu/Kconfig:config MSM_IOMMU
drivers/iommu/Kconfig: bool "MSM IOMMU Support"
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.
Since module_init was not even used by this driver, the init ordering
remains unchanged with this commit.
We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Cc: iommu@lists.linux-foundation.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Including:
- PASID table handling updates for the Intel VT-d driver. It
implements a global PASID space now so that applications
usings multiple devices will just have one PASID.
- A new config option to make iommu passthroug mode the default.
- New sysfs attribute for iommu groups to export the type of the
default domain.
- A debugfs interface (for debug only) usable by IOMMU drivers
to export internals to user-space.
- R-Car Gen3 SoCs support for the ipmmu-vmsa driver
- The ARM-SMMU now aborts transactions from unknown devices and
devices not attached to any domain.
- Various cleanups and smaller fixes all over the place.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2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=TeYQ
-----END PGP SIGNATURE-----
Merge tag 'iommu-updates-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:
- PASID table handling updates for the Intel VT-d driver. It implements
a global PASID space now so that applications usings multiple devices
will just have one PASID.
- A new config option to make iommu passthroug mode the default.
- New sysfs attribute for iommu groups to export the type of the
default domain.
- A debugfs interface (for debug only) usable by IOMMU drivers to
export internals to user-space.
- R-Car Gen3 SoCs support for the ipmmu-vmsa driver
- The ARM-SMMU now aborts transactions from unknown devices and devices
not attached to any domain.
- Various cleanups and smaller fixes all over the place.
* tag 'iommu-updates-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (42 commits)
iommu/omap: Fix cache flushes on L2 table entries
iommu: Remove the ->map_sg indirection
iommu/arm-smmu-v3: Abort all transactions if SMMU is enabled in kdump kernel
iommu/arm-smmu-v3: Prevent any devices access to memory without registration
iommu/ipmmu-vmsa: Don't register as BUS IOMMU if machine doesn't have IPMMU-VMSA
iommu/ipmmu-vmsa: Clarify supported platforms
iommu/ipmmu-vmsa: Fix allocation in atomic context
iommu: Add config option to set passthrough as default
iommu: Add sysfs attribyte for domain type
iommu/arm-smmu-v3: sync the OVACKFLG to PRIQ consumer register
iommu/arm-smmu: Error out only if not enough context interrupts
iommu/io-pgtable-arm-v7s: Abort allocation when table address overflows the PTE
iommu/io-pgtable-arm: Fix pgtable allocation in selftest
iommu/vt-d: Remove the obsolete per iommu pasid tables
iommu/vt-d: Apply per pci device pasid table in SVA
iommu/vt-d: Allocate and free pasid table
iommu/vt-d: Per PCI device pasid table interfaces
iommu/vt-d: Add for_each_device_domain() helper
iommu/vt-d: Move device_domain_info to header
iommu/vt-d: Apply global PASID in SVA
...
All iommu drivers use the default_iommu_map_sg implementation, and there
is no good reason to ever override it. Just expose it as iommu_map_sg
directly and remove the indirection, specially in our post-spectre world
where indirect calls are horribly expensive.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Now that we use the driver core to stop deferred probe for missing
drivers, IOMMU_OF_DECLARE can be removed.
This is slightly less optimal than having a list of built-in drivers in
that we'll now defer probe twice before giving up. This shouldn't have a
significant impact on boot times as past discussions about deferred
probe have given no evidence of deferred probe having a substantial
impact.
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: iommu@lists.linux-foundation.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: devicetree@vger.kernel.org
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that no more drivers rely on arbitrary early initialisation via an
of_iommu_init_fn hook, let's clean up the redundant remnants. The
IOMMU_OF_DECLARE() macro needs to remain for now, as the probe-deferral
mechanism has no other nice way to detect built-in drivers before they
have registered themselves, such that it can make the right decision.
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Since the MSM IOMMU driver now probes via DT exclusively rather than
platform data, dependent masters should be deferred until the IOMMU
itself is ready. Thus we can do away with the early initialisation
hook to unconditionally claim the bus ops, and instead do that only
once an IOMMU is actually probed. Furthermore, this should also make
the driver safe for multiplatform kernels on non-MSM SoCs.
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
As the last step to making groups mandatory, clean up the remaining
drivers by adding basic support. Whilst it may not perfectly reflect the
isolation capabilities of the hardware, using generic_device_group()
should at least maintain existing behaviour with respect to the API.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
And also move its remaining functionality to
iommu_device_register() and 'struct iommu_device'.
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This iommu uses the armv7 short descriptor format. So use the
generic ARMV7S pagetable ops instead of rewriting the same stuff
in the driver.
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Tested-by: Archit Taneja <architt@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This adds the xlate callback which gets invoked during
device registration from DT. The master devices gets added
through this.
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Tested-by: Archit Taneja <architt@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
There are only two functions left in msm_iommu_dev.c. Move it to
msm_iommu.c and delete the file.
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Tested-by: Archit Taneja <architt@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The driver currently works based on platform data. Remove this
and add support for DT. A single master can have multiple ports
connected to more than one iommu.
master
|
|
|
------------------------
| |
IOMMU0 IOMMU1
| |
ctx0 ctx1 ctx0 ctx1
This association of master and iommus/contexts were previously
represented by platform data parent/child device details. The client
drivers were responsible for programming all of the iommus/contexts
for the device. Now while adapting to generic DT bindings we maintain the
list of iommus, contexts that each master domain is connected to and
program all of them on attach/detach.
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Tested-by: Archit Taneja <architt@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Mapping and unmapping are more often than not in the critical path.
map_sg allows IOMMU driver implementations to optimize the process
of mapping buffers into the IOMMU page tables.
Instead of mapping a buffer one page at a time and requiring potentially
expensive TLB operations for each page, this function allows the driver
to map all pages in one go and defer TLB maintenance until after all
pages have been mapped.
Additionally, the mapping operation would be faster in general since
clients does not have to keep calling map API over and over again for
each physically contiguous chunk of memory that needs to be mapped to a
virtually contiguous region.
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
A semantic patch approach was proposed with the subject
"[PATCH with Coccinelle?] Deletion of unnecessary checks
before specific function calls" on 2014-03-05.
https://lkml.org/lkml/2014/3/5/344http://article.gmane.org/gmane.comp.version-control.coccinelle/3513/
This patch pattern application was repeated with the help of
the software "Coccinelle 1.0.0-rc22" on the source files for
Linux 3.17.1. An extract of the automatically generated
update suggestions is shown here.
It was determined that the affected source code places call
functions which perform input parameter validation already.
It is therefore not needed that a similar safety check is
repeated at the call site.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This structure is read-only data and should never be modified.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Two header files exist in mach-msm's include/mach directory that
are only used by the MSM iommu driver. Move these files to the
iommu driver directory and prefix them with "msm_". This allows
us to compile the MSM iommu driver on multi-platform kernels.
Acked-by: Joerg Roedel <joro@8bytes.org>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
This is required in case of PAMU, as it can support a window size of up
to 64G (even on 32bit).
Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Error handling in msm_iommu_unmap() is broken. On some error
conditions retval is set to a non-zero value which causes
the function to return 'len' at the end. This hides the
error from the user. Zero should be returned in those error
cases.
Cc: David Brown <davidb@codeaurora.org>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Cc: stable@vger.kernel.org # >= 3.1
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Acked-by: David Brown <davidb@codeaurora.org>
Let the IOMMU core know we support 4KiB, 64KiB, 1MiB and 16MiB page sizes.
This way the IOMMU core can split any arbitrary-sized physically
contiguous regions (that it needs to map) as needed.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: David Brown <davidb@codeaurora.org>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Express sizes in bytes rather than in page order, to eliminate the
size->order->size conversions we have whenever the IOMMU API is calling
the low level drivers' map/unmap methods.
Adopt all existing drivers.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <Joerg.Roedel@amd.com>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Cc: KyongHo Cho <pullip.cho@samsung.com>
Cc: Hiroshi DOYU <hdoyu@nvidia.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Convert the MSM IOMMU driver for ARM to use the new
interface for publishing the iommu_ops.
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
