From 24dd85ff723f142093f44244764b9b5c152235b8 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 28 Sep 2011 11:57:23 +0200 Subject: [PATCH] io-mapping: ensure io_mapping_map_atomic _is_ atomic For the !HAVE_ATOMIC_IOMAP case the stub functions did not call pagefault_disable/_enable. The i915 driver relies on the map actually being atomic, otherwise it can deadlock with it's own pagefault handler in the gtt pwrite fastpath. This is exercised by gem_mmap_gtt from the intel-gpu-toosl gem testsuite. v2: Chris Wilson noted the lack of an include. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38115 Cc: stable@kernel.org Signed-off-by: Daniel Vetter Reviewed-by: Chris Wilson Signed-off-by: Keith Packard --- include/linux/io-mapping.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index 8cdcc2a199ad..1feeb5263565 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -117,6 +117,8 @@ io_mapping_unmap(void __iomem *vaddr) #else +#include + /* this struct isn't actually defined anywhere */ struct io_mapping; @@ -138,12 +140,14 @@ static inline void __iomem * io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) { + pagefault_disable(); return ((char __force __iomem *) mapping) + offset; } static inline void io_mapping_unmap_atomic(void __iomem *vaddr) { + pagefault_enable(); } /* Non-atomic map/unmap */ -- 2.20.1