From bc0629a76726991f97ee88c65b87e99dd94c1dc4 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 1 Nov 2016 10:03:17 +0000 Subject: [PATCH] drm/i915: Track pages pinned due to swizzling quirk If we have a tiled object and an unknown CPU swizzle pattern, we pin the pages to prevent the object from being swapped out (and us corrupting the contents as we do not know the access pattern and so cannot convert it to linear and back to tiled on reuse). This requires us to remember to drop the extra pinning when freeing the object, or else we trigger warnings about the pin leak. In commit fbbd37b36fa5 ("drm/i915: Move object release to a freelist + worker"), the object free path was deferred to a worker, but the unpinning of the quirk, along with marking the object as reclaimable, was left on the immediate path (so that if required we could reclaim the pages under memory pressure as early as possible). However, this split introduced a bug where the pages were no longer being unpinned if they were marked as unneeded. [ 231.800401] WARNING: CPU: 1 PID: 90 at drivers/gpu/drm/i915/i915_gem.c:4275 __i915_gem_free_objects+0x326/0x3c0 [i915] [ 231.800403] WARN_ON(i915_gem_object_has_pinned_pages(obj)) [ 231.800405] Modules linked in: [ 231.800406] snd_hda_intel i915 snd_hda_codec_generic mei_me snd_hda_codec coretemp snd_hwdep mei lpc_ich snd_hda_core snd_pcm e1000e ptp pps_core [last unloaded: i915] [ 231.800426] CPU: 1 PID: 90 Comm: kworker/1:4 Tainted: G U 4.9.0-rc2-CI-CI_DRM_1780+ #1 [ 231.800428] Hardware name: LENOVO 7465CTO/7465CTO, BIOS 6DET44WW (2.08 ) 04/22/2009 [ 231.800456] Workqueue: events __i915_gem_free_work [i915] [ 231.800459] ffffc9000034fc80 ffffffff8142dd65 ffffc9000034fcd0 0000000000000000 [ 231.800465] ffffc9000034fcc0 ffffffff8107e4e6 000010b300000001 0000000000001000 [ 231.800469] ffff88011d3db740 ffff880130ef0000 0000000000000000 ffff880130ef5ea0 [ 231.800474] Call Trace: [ 231.800479] [] dump_stack+0x67/0x92 [ 231.800484] [] __warn+0xc6/0xe0 [ 231.800487] [] warn_slowpath_fmt+0x4a/0x50 [ 231.800491] [] ? kmem_cache_free+0x2dc/0x340 [ 231.800520] [] __i915_gem_free_objects+0x326/0x3c0 [i915] [ 231.800548] [] __i915_gem_free_work+0x2e/0x50 [i915] [ 231.800552] [] process_one_work+0x1ec/0x6b0 [ 231.800555] [] ? process_one_work+0x166/0x6b0 [ 231.800558] [] worker_thread+0x49/0x490 [ 231.800561] [] ? process_one_work+0x6b0/0x6b0 [ 231.800563] [] ? process_one_work+0x6b0/0x6b0 [ 231.800566] [] kthread+0xeb/0x110 [ 231.800569] [] ? kthread_park+0x60/0x60 [ 231.800573] [] ret_from_fork+0x27/0x40 Moving to a separate flag for tracking the quirked pin is overkill for the bug (since we only have to interchange the two tests in i915_gem_free_object) but it does reduce a complicated test on all objects and provide a sanitycheck for uncommon code paths. Fixes: fbbd37b36fa5 ("drm/i915: Move object release to a freelist + worker") Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Reviewed-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/20161101100317.11129-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_drv.h | 6 ++++++ drivers/gpu/drm/i915/i915_gem.c | 21 +++++++++++++-------- drivers/gpu/drm/i915/i915_gem_tiling.c | 9 +++++++-- 3 files changed, 26 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 51360d199263..539106a9c1af 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2304,6 +2304,12 @@ struct drm_i915_gem_object { * pages were last acquired. */ bool dirty:1; + + /** + * This is set if the object has been pinned due to unknown + * swizzling. + */ + bool quirked:1; } mm; /** Breadcrumb of last rendering to the buffer. diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 6c51b21565d6..c9e52f75e1cb 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2324,8 +2324,10 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) i915_gem_object_do_bit_17_swizzle(obj, st); if (i915_gem_object_is_tiled(obj) && - dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) + dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) { __i915_gem_object_pin_pages(obj); + obj->mm.quirked = true; + } return st; @@ -4091,10 +4093,15 @@ i915_gem_madvise_ioctl(struct drm_device *dev, void *data, if (obj->mm.pages && i915_gem_object_is_tiled(obj) && dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) { - if (obj->mm.madv == I915_MADV_WILLNEED) + if (obj->mm.madv == I915_MADV_WILLNEED) { + GEM_BUG_ON(!obj->mm.quirked); __i915_gem_object_unpin_pages(obj); - if (args->madv == I915_MADV_WILLNEED) + obj->mm.quirked = false; + } + if (args->madv == I915_MADV_WILLNEED) { __i915_gem_object_pin_pages(obj); + obj->mm.quirked = true; + } } if (obj->mm.madv != __I915_MADV_PURGED) @@ -4335,14 +4342,12 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj) { struct drm_i915_gem_object *obj = to_intel_bo(gem_obj); + if (obj->mm.quirked) + __i915_gem_object_unpin_pages(obj); + if (discard_backing_storage(obj)) obj->mm.madv = I915_MADV_DONTNEED; - if (obj->mm.pages && obj->mm.madv == I915_MADV_WILLNEED && - to_i915(obj->base.dev)->quirks & QUIRK_PIN_SWIZZLED_PAGES && - i915_gem_object_is_tiled(obj)) - __i915_gem_object_unpin_pages(obj); - /* Before we free the object, make sure any pure RCU-only * read-side critical sections are complete, e.g. * i915_gem_busy_ioctl(). For the corresponding synchronized diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c index 6395e62bd9e4..1577e7810cd6 100644 --- a/drivers/gpu/drm/i915/i915_gem_tiling.c +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c @@ -263,10 +263,15 @@ i915_gem_set_tiling(struct drm_device *dev, void *data, if (obj->mm.pages && obj->mm.madv == I915_MADV_WILLNEED && dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) { - if (args->tiling_mode == I915_TILING_NONE) + if (args->tiling_mode == I915_TILING_NONE) { + GEM_BUG_ON(!obj->mm.quirked); __i915_gem_object_unpin_pages(obj); - if (!i915_gem_object_is_tiled(obj)) + obj->mm.quirked = false; + } + if (!i915_gem_object_is_tiled(obj)) { __i915_gem_object_pin_pages(obj); + obj->mm.quirked = true; + } } mutex_unlock(&obj->mm.lock); -- 2.20.1