c45e788d95
Before we execute a batch, we must first issue any and all TLB invalidations so that batch picks up the new page table entries. Tigerlake's preparser is weakening our post-sync CS_STALL inside the invalidate pipe-control and allowing the loading of the batch buffer before we have setup its page table (and so it loads the wrong page and executes indefinitely). The igt_cs_tlb indicates that this issue can only be observed on rcs, even though the preparser is common to all engines. Alternatively, we could do TLB shootdown via mmio on updating the GTT. By inserting the pre-parser disable inside EMIT_INVALIDATE, we will also accidentally fixup execution that writes into subsequent batches, such as gem_exec_whisper and even relocations performed on the GPU. We should be careful not to allow this disable to become baked into the uABI! The issue is that if userspace relies on our disabling of the HW optimisation, when we are ready to enable that optimisation, userspace will then be broken... Testcase: igt/i915_selftests/live_gtt/igt_cs_tlb Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111753 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190919151811.9526-1-chris@chris-wilson.co.uk |
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|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.