drm/i915: Avoid atomic context for error capture

io_mapping_map_atomic/kmap_atomic are occasionally taken in error capture
(if there is no aperture preallocated for the use of error capture), but
the error capture and compression routines are now run in normal
context:

<3> [113.316247] BUG: sleeping function called from invalid context at mm/page_alloc.c:4653
<3> [113.318190] in_atomic(): 1, irqs_disabled(): 0, pid: 678, name: debugfs_test
<4> [113.319900] no locks held by debugfs_test/678.
<3> [113.321002] Preemption disabled at:
<4> [113.321130] [<ffffffffa02506d4>] i915_error_object_create+0x494/0x610 [i915]
<4> [113.327259] Call Trace:
<4> [113.327871] dump_stack+0x67/0x9b
<4> [113.328683] ___might_sleep+0x167/0x250
<4> [113.329618] __alloc_pages_nodemask+0x26b/0x1110
<4> [113.334614] pool_alloc.constprop.19+0x14/0x60 [i915]
<4> [113.335951] compress_page+0x7c/0x100 [i915]
<4> [113.337110] i915_error_object_create+0x4bd/0x610 [i915]
<4> [113.338515] i915_capture_gpu_state+0x384/0x1680 [i915]

However, it is not a good idea to run the slow compression inside atomic
context, so we choose not to.

Fixes: 895d8ebeaa924 ("drm/i915: error capture with no ggtt slot")
Signed-off-by: Bruce Chang <yu.bruce.chang@intel.com>
Reviewed-by: Brian Welty <brian.welty@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191113231104.24208-1-yu.bruce.chang@intel.com

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 1f2f266f26af777a12bd6727d568d4455988f118..7118ecb7f1442526a0893c55c7ef15a11c1022c1 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1029,9 +1029,9 @@ i915_error_object_create(struct drm_i915_private *i915,
                for_each_sgt_daddr(dma, iter, vma->pages) {
                        void __iomem *s;
 
-                       s = io_mapping_map_atomic_wc(&mem->iomap, dma);
+                       s = io_mapping_map_wc(&mem->iomap, dma, PAGE_SIZE);
                        ret = compress_page(compress, (void __force *)s, dst);
-                       io_mapping_unmap_atomic(s);
+                       io_mapping_unmap(s);
                        if (ret)
                                break;
                }
@@ -1043,9 +1043,9 @@ i915_error_object_create(struct drm_i915_private *i915,
 
                        drm_clflush_pages(&page, 1);
 
-                       s = kmap_atomic(page);
+                       s = kmap(page);
                        ret = compress_page(compress, s, dst);
-                       kunmap_atomic(s);
+                       kunmap(s);
 
                        drm_clflush_pages(&page, 1);