mips: get rid of tail-zeroing in primitives (1a4fded6) · Commits · 戴 / test

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

+1 −30

Original line number	Diff line number	Diff line
		@@ -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

+2 −17

Original line number	Diff line number	Diff line
		@@ -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

+0 −49

Original line number	Diff line number	Diff line
		@@ -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)

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