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authorMax Filippov <jcmvbkbc@gmail.com>2020-07-31 12:38:05 -0700
committerMax Filippov <jcmvbkbc@gmail.com>2020-07-31 14:15:57 -0700
commita0fc1436f1f4f84e93144480bf30e0c958d135b6 (patch)
tree3b2aef37c8000b3ae4a6f205f35c6e0c4dbf53f0 /arch/xtensa/include
parent6d65d3769d1910379e1cfa61ebf387efc6bfb22c (diff)
xtensa: add missing exclusive access state management
The result of the s32ex opcode is recorded in the ATOMCTL special register and must be retrieved with the getex opcode. Context switch between s32ex and getex may trash the ATOMCTL register and result in duplicate update or missing update of the atomic variable. Add atomctl8 field to the struct thread_info and use getex to swap ATOMCTL bit 8 as a part of context switch. Clear exclusive access monitor on kernel entry. Cc: stable@vger.kernel.org Fixes: f7c34874f04a ("xtensa: add exclusive atomics support") Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/include')
-rw-r--r--arch/xtensa/include/asm/thread_info.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h
index 8918f0f20c53..6acbbe0d87d3 100644
--- a/arch/xtensa/include/asm/thread_info.h
+++ b/arch/xtensa/include/asm/thread_info.h
@@ -55,6 +55,10 @@ struct thread_info {
mm_segment_t addr_limit; /* thread address space */
unsigned long cpenable;
+#if XCHAL_HAVE_EXCLUSIVE
+ /* result of the most recent exclusive store */
+ unsigned long atomctl8;
+#endif
/* Allocate storage for extra user states and coprocessor states. */
#if XTENSA_HAVE_COPROCESSORS