parisc: Fix lpa and lpa_user defines

stable inclusion
from stable-v5.10.94
commit eb44b1386af5751e0faec3a06e65078f146f81a7
bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eb44b1386af5751e0faec3a06e65078f146f81a7

--------------------------------

commit db19c6f1 upstream.

While working on the rewrite to the light-weight syscall and futex code, I
experimented with using a hash index based on the user physical address of
atomic variable. This exposed two problems with the lpa and lpa_user defines.

Because of the copy instruction, the pa argument needs to be an early clobber
argument. This prevents gcc from allocating the va and pa arguments to the same
register.

Secondly, the lpa instruction can cause a page fault so we need to catch
exceptions.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Fixes: 116d7533 ("parisc: Use lpa instruction to load physical addresses in driver code")
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

arch/parisc/include/asm/special_insns.h

@@ -5,9 +5,11 @@
 #define lpa(va)	({					\
 	unsigned long pa;				\
 	__asm__ __volatile__(				\
-		"copy %%r0,%0\n\t"	\
-		"lpa %%r0(%1),%0"	\
-		: "=r" (pa)		\
+		"copy %%r0,%0\n"			\
+		"8:\tlpa %%r0(%1),%0\n"			\
+		"9:\n"					\
+		ASM_EXCEPTIONTABLE_ENTRY(8b, 9b)	\
+		: "=&r" (pa)				\
 		: "r" (va)				\
 		: "memory"				\
 	);						\
@@ -17,9 +19,11 @@
 #define lpa_user(va)	({				\
 	unsigned long pa;				\
 	__asm__ __volatile__(				\
-		"copy %%r0,%0\n\t"	\
-		"lpa %%r0(%%sr3,%1),%0"	\
-		: "=r" (pa)		\
+		"copy %%r0,%0\n"			\
+		"8:\tlpa %%r0(%%sr3,%1),%0\n"		\
+		"9:\n"					\
+		ASM_EXCEPTIONTABLE_ENTRY(8b, 9b)	\
+		: "=&r" (pa)				\
 		: "r" (va)				\
 		: "memory"				\
 	);						\