[PATCH] ARM: add get_user() support for 8 byte types

Rob Clark
2012-11-09T21:18:33Z

From: Rob Clark <rob@ti.com>

A new atomic modeset/pageflip ioctl being developed in DRM requires
get_user() to work for 64bit types (in addition to just put_user()).

Signed-off-by: Rob Clark <rob@ti.com>
---
arch/arm/include/asm/uaccess.h | 25 ++++++++++++++++++++-----
arch/arm/lib/getuser.S | 17 ++++++++++++++++-
2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
index 7e1f760..2e3fdb2 100644
--- a/arch/arm/include/asm/uaccess.h
+++ b/arch/arm/include/asm/uaccess.h
@@ -100,6 +100,7 @@ static inline void set_fs(mm_segment_t fs)
extern int __get_user_1(void *);
extern int __get_user_2(void *);
extern int __get_user_4(void *);
+extern int __get_user_8(void *);

#define __GUP_CLOBBER_1 "lr", "cc"
#ifdef CONFIG_CPU_USE_DOMAINS
@@ -108,6 +109,7 @@ extern int __get_user_4(void *);
#define __GUP_CLOBBER_2 "lr", "cc"
#endif
#define __GUP_CLOBBER_4 "lr", "cc"
+#define __GUP_CLOBBER_8 "lr", "cc"

#define __get_user_x(__r2,__p,__e,__l,__s) \
__asm__ __volatile__ ( \
@@ -122,22 +124,35 @@ extern int __get_user_4(void *);
({ \
unsigned long __limit = current_thread_info()->addr_limit - 1; \
register const typeof(*(p)) __user *__p asm("r0") = (p);\
- register unsigned long __r2 asm("r2"); \
register unsigned long __l asm("r1") = __limit; \
register int __e asm("r0"); \
switch (sizeof(*(__p))) { \
- case 1: \
+ case 1: { \
+ register unsigned long __r2 asm("r2"); \
__get_user_x(__r2, __p, __e, __l, 1); \
+ x = (typeof(*(p))) __r2; \
break; \
- case 2: \
+ } \
+ case 2: { \
+ register unsigned long __r2 asm("r2"); \
__get_user_x(__r2, __p, __e, __l, 2); \
+ x = (typeof(*(p))) __r2; \
break; \
- case 4: \
+ } \
+ case 4: { \
+ register unsigned long __r2 asm("r2"); \
__get_user_x(__r2, __p, __e, __l, 4); \
+ x = (typeof(*(p))) __r2; \
+ break; \
+ } \
+ case 8: { \
+ register unsigned long long __r2 asm("r2"); \
+ __get_user_x(__r2, __p, __e, __l, 8); \
+ x = (typeof(*(p))) __r2; \
break; \
+ } \
default: __e = __get_user_bad(); break; \
} \
- x = (typeof(*(p))) __r2; \
__e; \
})

diff --git a/arch/arm/lib/getuser.S b/arch/arm/lib/getuser.S
index 9b06bb4..d05285c 100644
--- a/arch/arm/lib/getuser.S
+++ b/arch/arm/lib/getuser.S
@@ -18,7 +18,7 @@
* Inputs: r0 contains the address
* r1 contains the address limit, which must be preserved
* Outputs: r0 is the error code
- * r2 contains the zero-extended value
+ * r2, r3 contains the zero-extended value
* lr corrupted
*
* No other registers must be altered. (see <asm/uaccess.h>
@@ -66,6 +66,19 @@ ENTRY(__get_user_4)
mov pc, lr
ENDPROC(__get_user_4)

+ENTRY(__get_user_8)
+ check_uaccess r0, 4, r1, r2, __get_user_bad
+#ifdef CONFIG_THUMB2_KERNEL
+5: TUSER(ldr) r2, [r0]
+6: TUSER(ldr) r3, [r0, #4]
+#else
+5: TUSER(ldr) r2, [r0], #4
+6: TUSER(ldr) r3, [r0]
+#endif
+ mov r0, #0
+ mov pc, lr
+ENDPROC(__get_user_8)
+
__get_user_bad:
mov r2, #0
mov r0, #-EFAULT
@@ -77,4 +90,6 @@ ENDPROC(__get_user_bad)
.long 2b, __get_user_bad
.long 3b, __get_user_bad
.long 4b, __get_user_bad
+ .long 5b, __get_user_bad
+ .long 6b, __get_user_bad
.popsection
--
1.8.0