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88c6317b36
46 bit addressing enables you to use 4 bits to support some MKTME features, and 3 more bits for Optane support that uses a subset of MTKME for persistent memory. But GTT addressing sticking to 39 bit addressing, thus setting dma_mask_size to 39 fixes below tests : igt@i915_selftest@live@mman igt@kms_big_fb@linear-32bpp-rotate-0 igt@gem_create@create-clear igt@gem_mmap_offset@clear igt@gem_mmap_gtt@cpuset-big-copy In a way solves Gitlab#3142 https://gitlab.freedesktop.org/drm/intel/-/issues/3142, which had following errors : DMAR: DRHD: handling fault status reg 2 DMAR: [DMA Write] Request device [00:02.0] PASID ffffffff fault addr 7effff9000 [fault reason 05] PTE Write access is not set 0x7effff9000 is suspiciously exactly 39 bits, so it seems likely that the HW just ends up masking off those extra bits hence DMA errors. Changes since V2 : - dim checkpatch error solved Changes since V1 : - Added more details to commit message - Matthew Auld Signed-off-by: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@intel.com> Acked-by: Matthew Auld <matthew.auld@intel.com> Signed-off-by: Matthew Auld <matthew.auld@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210708071222.955455-1-tejaskumarx.surendrakumar.upadhyay@intel.com
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.