TTM takes full control over TTM_PL_SYSTEM placed buffers. This makes driver internal usage of TTM_PL_SYSTEM prone to errors because it requires the drivers to manually handle all interactions between TTM which can swap out those buffers whenever it thinks it's the right thing to do and driver. CPU buffers which need to be fenced and shared with accelerators should be placed in driver specific placements that can explicitly handle CPU/accelerator buffer fencing. Currently, apart, from things silently failing nothing is enforcing that requirement which means that it's easy for drivers and new developers to get this wrong. To avoid the confusion we can document this requirement and clarify the solution. This came up during a discussion on dri-devel: https://lore.kernel.org/dri-devel/232f45e9-8748-1243-09bf-56763e6668b3@amd.com Signed-off-by: Zack Rusin <zackr@vmware.com> Cc: Christian König <christian.koenig@amd.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211110145034.487512-1-zackr@vmware.com
Remove the include statement for drm_hashtab.h. It's not required by TTM. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Alex Deucher <alexander.deucher@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211129094841.22499-2-tzimmermann@suse.de
Removed the TTM Huge Page functionnality to address a crash, a timeout fix for udl, CONFIG_FB dependency improvements, a fix for a circular locking depency in imx, a NULL pointer dereference fix for virtio, and a naming collision fix for drm/locking. Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maxime Ripard <maxime@cerno.tech> Link: https://patchwork.freedesktop.org/patch/msgid/20211110082114.vfpkpnecwdfg27lk@gilmour
The huge page functionality in TTM does not work safely because PUD and
PMD entries do not have a special bit.
get_user_pages_fast() considers any page that passed pmd_huge() as
usable:
if (unlikely(pmd_trans_huge(pmd) || pmd_huge(pmd) ||
pmd_devmap(pmd))) {
And vmf_insert_pfn_pmd_prot() unconditionally sets
entry = pmd_mkhuge(pfn_t_pmd(pfn, prot));
eg on x86 the page will be _PAGE_PRESENT | PAGE_PSE.
As such gup_huge_pmd() will try to deref a struct page:
head = try_grab_compound_head(pmd_page(orig), refs, flags);
and thus crash.
Thomas further notices that the drivers are not expecting the struct page
to be used by anything - in particular the refcount incr above will cause
them to malfunction.
Thus everything about this is not able to fully work correctly considering
GUP_fast. Delete it entirely. It can return someday along with a proper
PMD/PUD_SPECIAL bit in the page table itself to gate GUP_fast.
Fixes: 314b6580adc5 ("drm/ttm, drm/vmwgfx: Support huge TTM pagefaults")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Thomas Hellström <thomas.helllstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
[danvet: Update subject per Thomas' &Christian's review]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/0-v2-a44694790652+4ac-ttm_pmd_jgg@nvidia.com
drm-misc-next for 5.16:
UAPI Changes:
Cross-subsystem Changes:
Core Changes:
- fbdev: Fix double-free, Remove unused scrolling acceleration
- locking: improve logging for contented locks without backoff
- dma-buf: Add dma_resv_for_each_fence iterator, and conversion of
users
Driver Changes:
- nouveau: Various code style improvements
- bridge: HPD improvements for lt9611uxc, eDP aux-bus support for
ps8640, lvds-codec data-mapping selection support
- panels: Vivax TPC-9150, Innolux G070Y2-T02, LOGIC Technologies
LTTD800480070-L2RT, Sharp LS060T1SX01,
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014120452.2wicnt6hobu3kbwb@gilmour
Correct the argument name of @placement and added @sg description for ttm_bo_init() and ttm_bo_init_reserved(). Argument @flags was replaced to @placement by Jerome in commit 09855acb1c2e3779f25317ec9a8ffe1b1784a4a8 Argument @sg was added by Dave in commit 129b78bfca591e736e56a294f0e357d73d938f7e Signed-off-by: Amos Kong <amos@sietium.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Dave Airlie <airlied@redhat.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/38eac09bf2ddd6088cc8a126e6bc4792eaa2dc88.1633462176.git.amos@sietium.com Signed-off-by: Christian König <christian.koenig@amd.com>
UAPI Changes: - Add uAPI for using PXP protected objects Mesa changes: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8064 - Add PCI IDs and LMEM discovery/placement uAPI for DG1 Mesa changes: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11584 - Disable engine bonding on Gen12+ except TGL, RKL and ADL-S Cross-subsystem Changes: - Merges 'tip/locking/wwmutex' branch (core kernel tip) - "mei: pxp: export pavp client to me client bus" Core Changes: - Update ttm_move_memcpy for async use (Thomas) Driver Changes: - Enable GuC submission by default on DG1 (Matt B) - Add PXP (Protected Xe Path) support for Gen12 integrated (Daniele, Sean, Anshuman) See "drm/i915/pxp: add PXP documentation" for details! - Remove force_probe protection for ADL-S (Raviteja) - Add base support for XeHP/XeHP SDV (Matt R, Stuart, Lucas) - Handle DRI_PRIME=1 on Intel igfx + Intel dgfx hybrid graphics setup (Tvrtko) - Use Transparent Hugepages when IOMMU is enabled (Tvrtko, Chris) - Implement LMEM backup and restore for suspend / resume (Thomas) - Report INSTDONE_GEOM values in error state for DG2 (Matt R) - Add DG2-specific shadow register table (Matt R) - Update Gen11/Gen12/XeHP shadow register tables (Matt R) - Maintain backward-compatible nested batch behavior on TGL+ (Matt R) - Add new LRI reg offsets for DG2 (Akeem) - Initialize unused MOCS entries to device specific values (Ayaz) - Track and use the correct UC MOCS index on Gen12 (Ayaz) - Add separate MOCS table for Gen12 devices other than TGL/RKL (Ayaz) - Simplify the locking and eliminate some RCU usage (Daniel) - Add some flushing for the 64K GTT path (Matt A) - Mark GPU wedging on driver unregister unrecoverable (Janusz) - Major rework in the GuC codebase, simplify locking and add docs (Matt B) - Add DG1 GuC/HuC firmwares (Daniele, Matt B) - Remember to call i915_sw_fence_fini on guc_state.blocked (Matt A) - Use "gt" forcewake domain name for error messages instead of "blitter" (Matt R) - Drop now duplicate LMEM uAPI RFC kerneldoc section (Daniel) - Fix early tracepoints for requests (Matt A) - Use locked access to ctx->engines in set_priority (Daniel) - Convert gen6/gen7/gen8 read operations to fwtable (Matt R) - Drop gen11/gen12 specific mmio write handlers (Matt R) - Drop gen11 specific mmio read handlers (Matt R) - Use designated initializers for init/exit table (Kees) - Fix syncmap memory leak (Matt B) - Add pretty printing for buddy allocator state debug (Matt A) - Fix potential error pointer dereference in pinned_context() (Dan) - Remove IS_ACTIVE macro (Lucas) - Static code checker fixes (Nathan) - Clean up disabled warnings (Nathan) - Increase timeout in i915_gem_contexts selftests 5x for GuC submission (Matt B) - Ensure wa_init_finish() is called for ctx workaround list (Matt R) - Initialize L3CC table in mocs init (Sreedhar, Ayaz, Ram) - Get PM ref before accessing HW register (Vinay) - Move __i915_gem_free_object to ttm_bo_destroy (Maarten) - Deduplicate frequency dump on debugfs (Lucas) - Make wa list per-gt (Venkata) - Do not define dummy vma in stack (Venkata) - Take pinning into account in __i915_gem_object_is_lmem (Matt B, Thomas) - Do not report currently active engine when describing objects (Tvrtko) - Fix pdfdocs build error by removing nested grid from GuC docs (Akira) - Remove false warning from the rps worker (Tejas) - Flush buffer pools on driver remove (Janusz) - Fix runtime pm handling in i915_gem_shrink (Maarten) - Rework TTM object initialization slightly (Thomas) - Use fixed offset for PTEs location (Michal Wa) - Verify result from CTB (de)register action and improve error messages (Michal Wa) - Fix bug in user proto-context creation that leaked contexts (Matt B) - Re-use Gen11 forcewake read functions on Gen12 (Matt R) - Make shadow tables range-based (Matt R) - Ditch the i915_gem_ww_ctx loop member (Thomas, Maarten) - Use NULL instead of 0 where appropriate (Ville) - Rename pci/debugfs functions to respect file prefix (Jani, Lucas) - Drop guc_communication_enabled (Daniele) - Selftest fixes (Thomas, Daniel, Matt A, Maarten) - Clean up inconsistent indenting (Colin) - Use direction definition DMA_BIDIRECTIONAL instead of PCI_DMA_BIDIRECTIONAL (Cai) - Add "intel_" as prefix in set_mocs_index() (Ayaz) From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/YWAO80MB2eyToYoy@jlahtine-mobl.ger.corp.intel.com Signed-off-by: Dave Airlie <airlied@redhat.com>
In commit:
commit 667a50db0477d47fdff01c666f5ee1ce26b5264c
Author: Thomas Hellstrom <thellstrom@vmware.com>
Date: Fri Jan 3 11:17:18 2014 +0100
drm/ttm: Refuse to fault (prime-) imported pages
we introduced the restriction that imported pages should not be directly
mappable through TTM(this also extends to userptr). In the next patch we
want to introduce a shmem_tt backend, which should follow all the
existing rules with TTM_PAGE_FLAG_EXTERNAL, since it will need to handle
swapping itself, but with the above mapping restriction lifted.
v2(Christian):
- Don't OR together EXTERNAL and EXTERNAL_MAPPABLE in the definition
of EXTERNAL_MAPPABLE, just leave it the caller to handle this
correctly, otherwise we might encounter subtle issues.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210929132629.353541-3-matthew.auld@intel.com
Signed-off-by: Christian König <christian.koenig@amd.com>
Move it to inline kernel-doc, otherwise we can't add empty lines it seems. Also drop the kernel-doc for pages_list, which doesn't seem to exist. v2(Christian): - Add a note that FLAG_SWAPPED shouldn't need to be touched by drivers. - Mention what FLAG_POPULATED does. Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Christian König <christian.koenig@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210929132629.353541-2-matthew.auld@intel.com Signed-off-by: Christian König <christian.koenig@amd.com>
It covers more than just ttm_bo_type_sg usage, like with say dma-buf, since one other user is userptr in amdgpu, and in the future we might have some more. Hence EXTERNAL is likely a more suitable name. v2(Christian): - Rename these to TTM_TT_FLAGS_* - Fix up all the holes in the flag values Suggested-by: Christian König <christian.koenig@amd.com> Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Christian König <christian.koenig@amd.com> Acked-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210929132629.353541-1-matthew.auld@intel.com Signed-off-by: Christian König <christian.koenig@amd.com>