mips: get rid of tail-zeroing in primitives

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/mips/cavium-octeon/octeon-memcpy.S

@@ -139,15 +139,6 @@
 	.set	noreorder
 	.set	noat
 
-/*
- * t7 is used as a flag to note inatomic mode.
- */
-LEAF(__copy_user_inatomic)
-EXPORT_SYMBOL(__copy_user_inatomic)
-	b	__copy_user_common
-	 li	t7, 1
-	END(__copy_user_inatomic)
-
 /*
  * A combined memcpy/__copy_user
  * __copy_user sets len to 0 for success; else to an upper bound of
@@ -161,8 +152,6 @@ EXPORT_SYMBOL(memcpy)
 __memcpy:
 FEXPORT(__copy_user)
 EXPORT_SYMBOL(__copy_user)
-	li	t7, 0				/* not inatomic */
-__copy_user_common:
 	/*
 	 * Note: dst & src may be unaligned, len may be 0
 	 * Temps
@@ -414,25 +403,7 @@ l_exc:
 	LOAD	t0, TI_TASK($28)
 	LOAD	t0, THREAD_BUADDR(t0)	# t0 is just past last good address
 	SUB	len, AT, t0		# len number of uncopied bytes
-	bnez	t7, 2f		/* Skip the zeroing out part if inatomic */
-	/*
-	 * Here's where we rely on src and dst being incremented in tandem,
-	 *   See (3) above.
-	 * dst += (fault addr - src) to put dst at first byte to clear
-	 */
-	ADD	dst, t0			# compute start address in a1
-	SUB	dst, src
-	/*
-	 * Clear len bytes starting at dst.  Can't call __bzero because it
-	 * might modify len.  An inefficient loop for these rare times...
-	 */
-	beqz	len, done
-	 SUB	src, len, 1
-1:	sb	zero, 0(dst)
-	ADD	dst, dst, 1
-	bnez	src, 1b
-	 SUB	src, src, 1
-2:	jr	ra
+	jr	ra
 	 nop
 
 

arch/mips/include/asm/uaccess.h

@@ -841,9 +841,6 @@ extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 #define __invoke_copy_from_kernel(to, from, n)				\
 	__invoke_copy_from(__copy_user, to, from, n)
 
-#define __invoke_copy_from_kernel_inatomic(to, from, n)			\
-	__invoke_copy_from(__copy_user_inatomic, to, from, n)
-
 #define __invoke_copy_to_kernel(to, from, n)				\
 	__invoke_copy_to(__copy_user, to, from, n)
 
@@ -854,9 +851,6 @@ extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 #define __invoke_copy_from_user(to, from, n)				\
 	__invoke_copy_from(__copy_user, to, from, n)
 
-#define __invoke_copy_from_user_inatomic(to, from, n)			\
-	__invoke_copy_from(__copy_user_inatomic, to, from, n)
-
 #define __invoke_copy_to_user(to, from, n)				\
 	__invoke_copy_to(__copy_user, to, from, n)
 
@@ -867,8 +861,6 @@ extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 
 /* EVA specific functions */
 
-extern size_t __copy_user_inatomic_eva(void *__to, const void *__from,
-				       size_t __n);
 extern size_t __copy_from_user_eva(void *__to, const void *__from,
 				   size_t __n);
 extern size_t __copy_to_user_eva(void *__to, const void *__from,
@@ -882,9 +874,6 @@ extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
 #define __invoke_copy_from_user(to, from, n)				\
 	__invoke_copy_from(__copy_from_user_eva, to, from, n)
 
-#define __invoke_copy_from_user_inatomic(to, from, n)			\
-	__invoke_copy_from(__copy_user_inatomic_eva, to, from, n)
-
 #define __invoke_copy_to_user(to, from, n)				\
 	__invoke_copy_to(__copy_to_user_eva, to, from, n)
 
@@ -930,8 +919,6 @@ extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
 	__cu_len;							\
 })
 
-extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
-
 #define __copy_to_user_inatomic(to, from, n)				\
 ({									\
 	void __user *__cu_to;						\
@@ -966,12 +953,10 @@ extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
 	check_object_size(__cu_to, __cu_len, false);			\
 									\
 	if (eva_kernel_access())					\
-		__cu_len = __invoke_copy_from_kernel_inatomic(__cu_to,	\
-							      __cu_from,\
+		__cu_len = __invoke_copy_from_kernel(__cu_to, __cu_from,\
 							      __cu_len);\
 	else								\
-		__cu_len = __invoke_copy_from_user_inatomic(__cu_to,	\
-							    __cu_from,	\
+		__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,	\
 							    __cu_len);	\
 	__cu_len;							\
 })

arch/mips/lib/memcpy.S

@@ -562,39 +562,9 @@
 	LOADK	t0, THREAD_BUADDR(t0)	# t0 is just past last good address
 	 nop
 	SUB	len, AT, t0		# len number of uncopied bytes
-	bnez	t6, .Ldone\@	/* Skip the zeroing part if inatomic */
-	/*
-	 * Here's where we rely on src and dst being incremented in tandem,
-	 *   See (3) above.
-	 * dst += (fault addr - src) to put dst at first byte to clear
-	 */
-	ADD	dst, t0			# compute start address in a1
-	SUB	dst, src
-	/*
-	 * Clear len bytes starting at dst.  Can't call __bzero because it
-	 * might modify len.  An inefficient loop for these rare times...
-	 */
-	.set	reorder				/* DADDI_WAR */
-	SUB	src, len, 1
-	beqz	len, .Ldone\@
-	.set	noreorder
-1:	sb	zero, 0(dst)
-	ADD	dst, dst, 1
-#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
-	bnez	src, 1b
-	 SUB	src, src, 1
-#else
-	.set	push
-	.set	noat
-	li	v1, 1
-	bnez	src, 1b
-	 SUB	src, src, v1
-	.set	pop
-#endif
 	jr	ra
 	 nop
 
-
 #define SEXC(n)							\
 	.set	reorder;			/* DADDI_WAR */ \
 .Ls_exc_p ## n ## u\@:						\
@@ -672,15 +642,6 @@ LEAF(__rmemcpy)					/* a0=dst a1=src a2=len */
 	 move	a2, zero
 	END(__rmemcpy)
 
-/*
- * t6 is used as a flag to note inatomic mode.
- */
-LEAF(__copy_user_inatomic)
-EXPORT_SYMBOL(__copy_user_inatomic)
-	b	__copy_user_common
-	li	t6, 1
-	END(__copy_user_inatomic)
-
 /*
  * A combined memcpy/__copy_user
  * __copy_user sets len to 0 for success; else to an upper bound of
@@ -694,8 +655,6 @@ EXPORT_SYMBOL(memcpy)
 .L__memcpy:
 FEXPORT(__copy_user)
 EXPORT_SYMBOL(__copy_user)
-	li	t6, 0	/* not inatomic */
-__copy_user_common:
 	/* Legacy Mode, user <-> user */
 	__BUILD_COPY_USER LEGACY_MODE USEROP USEROP
 
@@ -708,20 +667,12 @@ __copy_user_common:
  * space
  */
 
-LEAF(__copy_user_inatomic_eva)
-EXPORT_SYMBOL(__copy_user_inatomic_eva)
-	b       __copy_from_user_common
-	li	t6, 1
-	END(__copy_user_inatomic_eva)
-
 /*
  * __copy_from_user (EVA)
  */
 
 LEAF(__copy_from_user_eva)
 EXPORT_SYMBOL(__copy_from_user_eva)
-	li	t6, 0	/* not inatomic */
-__copy_from_user_common:
 	__BUILD_COPY_USER EVA_MODE USEROP KERNELOP
 END(__copy_from_user_eva)