Commit 24dd85ff authored by Daniel Vetter's avatar Daniel Vetter Committed by Keith Packard

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: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarKeith Packard <keithp@keithp.com>
parent 8ffc0246
...@@ -117,6 +117,8 @@ io_mapping_unmap(void __iomem *vaddr) ...@@ -117,6 +117,8 @@ io_mapping_unmap(void __iomem *vaddr)
#else #else
#include <linux/uaccess.h>
/* this struct isn't actually defined anywhere */ /* this struct isn't actually defined anywhere */
struct io_mapping; struct io_mapping;
...@@ -138,12 +140,14 @@ static inline void __iomem * ...@@ -138,12 +140,14 @@ static inline void __iomem *
io_mapping_map_atomic_wc(struct io_mapping *mapping, io_mapping_map_atomic_wc(struct io_mapping *mapping,
unsigned long offset) unsigned long offset)
{ {
pagefault_disable();
return ((char __force __iomem *) mapping) + offset; return ((char __force __iomem *) mapping) + offset;
} }
static inline void static inline void
io_mapping_unmap_atomic(void __iomem *vaddr) io_mapping_unmap_atomic(void __iomem *vaddr)
{ {
pagefault_enable();
} }
/* Non-atomic map/unmap */ /* Non-atomic map/unmap */
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment