linux-dev/drivers/video/fbdev/core/fb_defio.c, branch linus/master

fbdev: Rename pagelist to pagereflist for deferred I/O

2022-05-03T14:04:22Z

Rename various instances of pagelist to pagereflist. The list now stores pageref structures, so the new name is more appropriate. In their write-back helpers, several fbdev drivers refer to the pageref list in struct fb_deferred_io instead of using the one supplied as argument to the function. Convert them over to the supplied one. It's the same instance, so no change of behavior occurs. v4: * fix commit message (Javier) Suggested-by: Sam Ravnborg Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-5-tzimmermann@suse.de

fbdev: Refactor implementation of page_mkwrite

2022-05-03T14:04:22Z

Refactor the page-write handler for deferred I/O. Drivers use the function to let fbdev track written pages of mmap'ed framebuffer memory. v3: * keep locking within track-pages function for readability (Sam) v2: * don't export the helper until we have an external caller Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-4-tzimmermann@suse.de

fbdev: Track deferred-I/O pages in pageref struct

2022-05-03T14:04:22Z

Store the per-page state for fbdev's deferred I/O in struct fb_deferred_io_pageref. Maintain a list of pagerefs for the pages that have to be written back to video memory. Update all affected drivers. As with pages before, fbdev acquires a pageref when an mmaped page of the framebuffer is being written to. It holds the pageref in a list of all currently written pagerefs until it flushes the written pages to video memory. Writeback occurs periodically. After writeback fbdev releases all pagerefs and builds up a new dirty list until the next writeback occurs. Using pagerefs has a number of benefits. For pages of the framebuffer, the deferred I/O code used struct page.lru as an entry into the list of dirty pages. The lru field is owned by the page cache, which makes deferred I/O incompatible with some memory pages (e.g., most notably DRM's GEM SHMEM allocator). struct fb_deferred_io_pageref now provides an entry into a list of dirty framebuffer pages, freeing lru for use with the page cache. Drivers also assumed that struct page.index is the page offset into the framebuffer. This is not true for DRM buffers, which are located at various offset within a mapped area. struct fb_deferred_io_pageref explicitly stores an offset into the framebuffer. struct page.index is now only the page offset into the mapped area. These changes will allow DRM to use fbdev deferred I/O without an intermediate shadow buffer. v3: * use pageref->offset for sorting * fix grammar in comment v2: * minor fixes in commit message Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-3-tzimmermann@suse.de

fbdev: Put mmap for deferred I/O into drivers

2022-05-03T14:04:21Z

The fbdev mmap function fb_mmap() unconditionally overrides the driver's implementation if deferred I/O has been activated. This makes it hard to implement mmap with anything but a vmalloc()'ed software buffer. That is specifically a problem for DRM, where video memory is maintained by a memory manager. Leave the mmap handling to drivers and expect them to call the helper for deferred I/O by thmeselves. v4: * unlock mm_lock in fb_mmap() error path (Dan) v3: * fix warning if fb_mmap is missing (kernel test robot) v2: * print a helpful error message if the defio setup is incorrect (Javier) Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-2-tzimmermann@suse.de

Merge drm/drm-next into drm-misc-next

2022-04-05T09:06:58Z

Let's start the 5.19 development cycle. Signed-off-by: Maxime Ripard

Merge tag 'drm-next-2022-03-24' of git://anongit.freedesktop.org/drm/drm

2022-03-24T23:19:43Z

Pull drm updates from Dave Airlie: "Lots of work all over, Intel improving DG2 support, amdkfd CRIU support, msm new hw support, and faster fbdev support. dma-buf: - rename dma-buf-map to iosys-map core: - move buddy allocator to core - add pci/platform init macros - improve EDID parser deep color handling - EDID timing type 7 support - add GPD Win Max quirk - add yes/no helpers to string_helpers - flatten syncobj chains - add nomodeset support to lots of drivers - improve fb-helper clipping support - add default property value interface fbdev: - improve fbdev ops speed ttm: - add a backpointer from ttm bo->ttm resource dp: - move displayport headers - add a dp helper module bridge: - anx7625 atomic support, HDCP support panel: - split out panel-lvds and lvds bindings - find panels in OF subnodes privacy: - add chromeos privacy screen support fb: - hot unplug fw fb on forced removal simpledrm: - request region instead of marking ioresource busy - add panel oreintation property udmabuf: - fix oops with 0 pages amdgpu: - power management code cleanup - Enable freesync video mode by default - RAS code cleanup - Improve VRAM access for debug using SDMA - SR-IOV rework special register access and fixes - profiling power state request ioctl - expose IP discovery via sysfs - Cyan skillfish updates - GC 10.3.7, SDMA 5.2.7, DCN 3.1.6 updates - expose benchmark tests via debugfs - add module param to disable XGMI for testing - GPU reset debugfs register dumping support amdkfd: - CRIU support - SDMA queue fixes radeon: - UVD suspend fix - iMac backlight fix i915: - minimal parallel submission for execlists - DG2-G12 subplatform added - DG2 programming workarounds - DG2 accelerated migration support - flat CCS and CCS engine support for XeHP - initial small BAR support - drop fake LMEM support - ADL-N PCH support - bigjoiner updates - introduce VMA resources and async unbinding - register definitions cleanups - multi-FBC refactoring - DG1 OPROM over SPI support - ADL-N platform enabling - opregion mailbox #5 support - DP MST ESI improvements - drm device based logging - async flip optimisation for DG2 - CPU arch abstraction fixes - improve GuC ADS init to work on aarch64 - tweak TTM LRU priority hint - GuC 69.0.3 support - remove short term execbuf pins nouveau: - higher DP/eDP bitrates - backlight fixes msm: - dpu + dp support for sc8180x - dp support for sm8350 - dpu + dsi support for qcm2290 - 10nm dsi phy tuning support - bridge support for dp encoder - gpu support for additional 7c3 SKUs ingenic: - HDMI support for JZ4780 - aux channel EDID support ast: - AST2600 support - add wide screen support - create DP/DVI connectors omapdrm: - fix implicit dma_buf fencing vc4: - add CSC + full range support - better display firmware handoff panfrost: - add initial dual-core GPU support stm: - new revision support - fb handover support mediatek: - transfer display binding document to yaml format. - add mt8195 display device binding. - allow commands to be sent during video mode. - add wait_for_event for crtc disable by cmdq. tegra: - YUV format support rcar-du: - LVDS support for M3-W+ (R8A77961) exynos: - BGR pixel format for FIMD device" * tag 'drm-next-2022-03-24' of git://anongit.freedesktop.org/drm/drm: (1529 commits) drm/i915/display: Do not re-enable PSR after it was marked as not reliable drm/i915/display: Fix HPD short pulse handling for eDP drm/amdgpu: Use drm_mode_copy() drm/radeon: Use drm_mode_copy() drm/amdgpu: Use ternary operator in `vcn_v1_0_start()` drm/amdgpu: Remove pointless on stack mode copies drm/amd/pm: fix indenting in __smu_cmn_reg_print_error() drm/amdgpu/dc: fix typos in comments drm/amdgpu: fix typos in comments drm/amd/pm: fix typos in comments drm/amdgpu: Add stolen reserved memory for MI25 SRIOV. drm/amdgpu: Merge get_reserved_allocation to get_vbios_allocations. drm/amdkfd: evict svm bo worker handle error drm/amdgpu/vcn: fix vcn ring test failure in igt reload test drm/amdgpu: only allow secure submission on rings which support that drm/amdgpu: fixed the warnings reported by kernel test robot drm/amd/display: 3.2.177 drm/amd/display: [FW Promotion] Release 0.0.108.0 drm/amd/display: Add save/restore PANEL_PWRSEQ_REF_DIV2 drm/amd/display: Wait for hubp read line for Pollock ...

fbdev: defio: fix the pagelist corruption

2022-03-18T19:30:02Z

Easily hit the below list corruption: == list_add corruption. prev->next should be next (ffffffffc0ceb090), but was ffffec604507edc8. (prev=ffffec604507edc8). WARNING: CPU: 65 PID: 3959 at lib/list_debug.c:26 __list_add_valid+0x53/0x80 CPU: 65 PID: 3959 Comm: fbdev Tainted: G U RIP: 0010:__list_add_valid+0x53/0x80 Call Trace: fb_deferred_io_mkwrite+0xea/0x150 do_page_mkwrite+0x57/0xc0 do_wp_page+0x278/0x2f0 __handle_mm_fault+0xdc2/0x1590 handle_mm_fault+0xdd/0x2c0 do_user_addr_fault+0x1d3/0x650 exc_page_fault+0x77/0x180 ? asm_exc_page_fault+0x8/0x30 asm_exc_page_fault+0x1e/0x30 RIP: 0033:0x7fd98fc8fad1 == Figure out the race happens when one process is adding &page->lru into the pagelist tail in fb_deferred_io_mkwrite(), another process is re-initializing the same &page->lru in fb_deferred_io_fault(), which is not protected by the lock. This fix is to init all the page lists one time during initialization, it not only fixes the list corruption, but also avoids INIT_LIST_HEAD() redundantly. V2: change "int i" to "unsigned int i" (Geert Uytterhoeven) Signed-off-by: Chuansheng Liu Fixes: 105a940416fc ("fbdev/defio: Early-out if page is already enlisted") Cc: Thomas Zimmermann Cc: Geert Uytterhoeven Reviewed-by: Javier Martinez Canillas Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20220318005003.51810-1-chuansheng.liu@intel.com

fb_defio: Use noop_dirty_folio()

2022-03-16T17:37:05Z

Remove the custom implementation of set_page_dirty. Signed-off-by: Matthew Wilcox (Oracle) Tested-by: Damien Le Moal Acked-by: Damien Le Moal Tested-by: Mike Marshall # orangefs Tested-by: David Howells # afs

fbdev: Don't sort deferred-I/O pages by default

2022-02-16T15:41:45Z

Fbdev's deferred I/O sorts all dirty pages by default, which incurs a significant overhead. Make the sorting step optional and update the few drivers that require it. Use a FIFO list by default. Most fbdev drivers with deferred I/O build a bounding rectangle around the dirty pages or simply flush the whole screen. The only two affected DRM drivers, generic fbdev and vmwgfx, both use a bounding rectangle. In those cases, the exact order of the pages doesn't matter. The other drivers look at the page index or handle pages one-by-one. The patch sets the sort_pagelist flag for those, even though some of them would probably work correctly without sorting. Driver maintainers should update their driver accordingly. Sorting pages by memory offset for deferred I/O performs an implicit bubble-sort step on the list of dirty pages. The algorithm goes through the list of dirty pages and inserts each new page according to its index field. Even worse, list traversal always starts at the first entry. As video memory is most likely updated scanline by scanline, the algorithm traverses through the complete list for each updated page. For example, with 1024x768x32bpp each page covers exactly one scanline. Writing a single screen update from top to bottom requires updating 768 pages. With an average list length of 384 entries, a screen update creates (768 * 384 =) 294912 compare operation. Fix this by making the sorting step opt-in and update the few drivers that require it. All other drivers work with unsorted page lists. Pages are appended to the list. Therefore, in the common case of writing the framebuffer top to bottom, pages are still sorted by offset, which may have a positive effect on performance. Playing a video [1] in mplayer's benchmark mode shows the difference (i7-4790, FullHD, simpledrm, kernel with debugging). mplayer -benchmark -nosound -vo fbdev ./big_buck_bunny_720p_stereo.ogg With sorted page lists: BENCHMARKs: VC: 32.960s VO: 73.068s A: 0.000s Sys: 2.413s = 108.441s BENCHMARK%: VC: 30.3947% VO: 67.3802% A: 0.0000% Sys: 2.2251% = 100.0000% With unsorted page lists: BENCHMARKs: VC: 31.005s VO: 42.889s A: 0.000s Sys: 2.256s = 76.150s BENCHMARK%: VC: 40.7156% VO: 56.3219% A: 0.0000% Sys: 2.9625% = 100.0000% VC shows the overhead of video decoding, VO shows the overhead of the video output. Using unsorted page lists reduces the benchmark's run time by ~32s/~25%. v2: * Make sorted pagelists the special case (Sam) * Comment on drivers' use of pagelist (Sam) * Warn about the overhead in comment Signed-off-by: Thomas Zimmermann Acked-by: Sam Ravnborg Acked-by: Andy Shevchenko Link: https://download.blender.org/peach/bigbuckbunny_movies/big_buck_bunny_720p_stereo.ogg # [1] Link: https://patchwork.freedesktop.org/patch/msgid/20220211094640.21632-3-tzimmermann@suse.de

fbdev/defio: Early-out if page is already enlisted

2022-02-16T15:41:19Z

Return early if a page is already in the list of dirty pages for deferred I/O. This can be detected if the page's list head is not empty. Keep the list head initialized while the page is not enlisted to make this work reliably. v2: * update comment and fix spelling (Sam) Signed-off-by: Thomas Zimmermann Acked-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20220211094640.21632-2-tzimmermann@suse.de