kernel/drivers/gpu/drm/i915/i915_gem_execbuffer.c, branch linux-5.1.y

drm/i915: Hack and slash, throttle execbuffer hogs

2019-02-07T16:13:21Z

Apply backpressure to hogs that emit requests faster than the GPU can process them by waiting for their ring to be less than half-full before proceeding with taking the struct_mutex. This is a gross hack to apply throttling backpressure, the long term goal is to remove the struct_mutex contention so that each client naturally waits, preferably in an asynchronous, nonblocking fashion (pipelined operations for the win), for their own resources and never blocks another client within the driver at least. (Realtime priority goals would extend to ensuring that resource contention favours high priority clients as well.) This patch only limits excessive request production and does not attempt to throttle clients that block waiting for eviction (either global GTT or system memory) or any other global resources, see above for the long term goal. No microbenchmarks are harmed (to the best of my knowledge). Testcase: igt/gem_exec_schedule/pi-ringfull-* Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Joonas Lahtinen Cc: John Harrison Reviewed-by: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20190207071829.5574-1-chris@chris-wilson.co.uk

drm/i915: Identify active requests

2019-01-29T19:59:59Z

To allow requests to forgo a common execution timeline, one question we need to be able to answer is "is this request running?". To track whether a request has started on HW, we can emit a breadcrumb at the beginning of the request and check its timeline's HWSP to see if the breadcrumb has advanced past the start of this request. (This is in contrast to the global timeline where we need only ask if we are on the global timeline and if the timeline has advanced past the end of the previous request.) There is still confusion from a preempted request, which has already started but relinquished the HW to a high priority request. For the common case, this discrepancy should be negligible. However, for identification of hung requests, knowing which one was running at the time of the hang will be much more important. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20190129185452.20989-2-chris@chris-wilson.co.uk

drm/i915/gem: Track the rpm wakerefs

2019-01-14T16:18:13Z

Keep track of the temporary rpm wakerefs used for user access to the device, so that we can cancel them upon release and clearly identify any leaks. Signed-off-by: Chris Wilson Cc: Jani Nikula Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-10-chris@chris-wilson.co.uk

drm/i915: Markup paired operations on wakerefs

2019-01-14T16:17:53Z

The majority of runtime-pm operations are bounded and scoped within a function; these are easy to verify that the wakeref are handled correctly. We can employ the compiler to help us, and reduce the number of wakerefs tracked when debugging, by passing around cookies provided by the various rpm_get functions to their rpm_put counterpart. This makes the pairing explicit, and given the required wakeref cookie the compiler can verify that we pass an initialised value to the rpm_put (quite handy for double checking error paths). For regular builds, the compiler should be able to eliminate the unused local variables and the program growth should be minimal. Fwiw, it came out as a net improvement as gcc was able to refactor rpm_get and rpm_get_if_in_use together, v2: Just s/rpm_put/rpm_put_unchecked/ everywhere, leaving the manual mark up for smaller more targeted patches. v3: Mention the cookie in Returns Signed-off-by: Chris Wilson Cc: Jani Nikula Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-2-chris@chris-wilson.co.uk

drm/i915: drop all drmP.h includes

2019-01-09T08:26:36Z

Needs just a few additional includes here and there. Cc: Sam Ravnborg Cc: Daniel Vetter Cc: Laurent Pinchart Acked-by: Daniel Vetter Acked-by: Sam Ravnborg Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20190108082709.3748-1-jani.nikula@intel.com

Merge drm/drm-next into drm-intel-next-queued

2019-01-08T08:50:22Z

Generally catch up with 5.0-rc1, and specifically get the changes: 96d4f267e40f ("Remove 'type' argument from access_ok() function") 0b2c8f8b6b0c ("i915: fix missing user_access_end() in page fault exception case") 594cc251fdd0 ("make 'user_access_begin()' do 'access_ok()'") Signed-off-by: Jani Nikula

make 'user_access_begin()' do 'access_ok()'

2019-01-04T20:56:09Z

Originally, the rule used to be that you'd have to do access_ok() separately, and then user_access_begin() before actually doing the direct (optimized) user access. But experience has shown that people then decide not to do access_ok() at all, and instead rely on it being implied by other operations or similar. Which makes it very hard to verify that the access has actually been range-checked. If you use the unsafe direct user accesses, hardware features (either SMAP - Supervisor Mode Access Protection - on x86, or PAN - Privileged Access Never - on ARM) do force you to use user_access_begin(). But nothing really forces the range check. By putting the range check into user_access_begin(), we actually force people to do the right thing (tm), and the range check vill be visible near the actual accesses. We have way too long a history of people trying to avoid them. Signed-off-by: Linus Torvalds

i915: fix missing user_access_end() in page fault exception case

2019-01-04T18:23:10Z

When commit fddcd00a49e9 ("drm/i915: Force the slow path after a user-write error") unified the error handling for various user access problems, it didn't do the user_access_end() that is needed for the unsafe_put_user() case. It's not a huge deal: a missed user_access_end() will only mean that SMAP protection isn't active afterwards, and for the error case we'll be returning to user mode soon enough anyway. But it's wrong, and adding the proper user_access_end() is trivial enough (and doing it for the other error cases where it isn't needed doesn't hurt). I noticed it while doing the same prep-work for changing user_access_begin() that precipitated the access_ok() changes in commit 96d4f267e40f ("Remove 'type' argument from access_ok() function"). Fixes: fddcd00a49e9 ("drm/i915: Force the slow path after a user-write error") Cc: Chris Wilson Cc: Joonas Lahtinen Cc: stable@kernel.org # v4.20 Signed-off-by: Linus Torvalds

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57Z

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds

Merge tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

2019-01-01T23:55:29Z

Pull IOMMU updates from Joerg Roedel: - Page table code for AMD IOMMU now supports large pages where smaller page-sizes were mapped before. VFIO had to work around that in the past and I included a patch to remove it (acked by Alex Williamson) - Patches to unmodularize a couple of IOMMU drivers that would never work as modules anyway. - Work to unify the the iommu-related pointers in 'struct device' into one pointer. This work is not finished yet, but will probably be in the next cycle. - NUMA aware allocation in iommu-dma code - Support for r8a774a1 and r8a774c0 in the Renesas IOMMU driver - Scalable mode support for the Intel VT-d driver - PM runtime improvements for the ARM-SMMU driver - Support for the QCOM-SMMUv2 IOMMU hardware from Qualcom - Various smaller fixes and improvements * tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (78 commits) iommu: Check for iommu_ops == NULL in iommu_probe_device() ACPI/IORT: Don't call iommu_ops->add_device directly iommu/of: Don't call iommu_ops->add_device directly iommu: Consolitate ->add/remove_device() calls iommu/sysfs: Rename iommu_release_device() dmaengine: sh: rcar-dmac: Use device_iommu_mapped() xhci: Use device_iommu_mapped() powerpc/iommu: Use device_iommu_mapped() ACPI/IORT: Use device_iommu_mapped() iommu/of: Use device_iommu_mapped() driver core: Introduce device_iommu_mapped() function iommu/tegra: Use helper functions to access dev->iommu_fwspec iommu/qcom: Use helper functions to access dev->iommu_fwspec iommu/of: Use helper functions to access dev->iommu_fwspec iommu/mediatek: Use helper functions to access dev->iommu_fwspec iommu/ipmmu-vmsa: Use helper functions to access dev->iommu_fwspec iommu/dma: Use helper functions to access dev->iommu_fwspec iommu/arm-smmu: Use helper functions to access dev->iommu_fwspec ACPI/IORT: Use helper functions to access dev->iommu_fwspec iommu: Introduce wrappers around dev->iommu_fwspec ...