Commit 1cd95ab8 authored by Al Viro's avatar Al Viro
Browse files

mips: propagate the calling convention change down into __csum_partial_copy_..._user() 



and turn the exception handlers into simply returning 0, which
simplifies the hell out of things in csum_partial.S

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent f863c65c

arch/mips/include/asm/checksum.h

+6 −20
Original line number Diff line number Diff line
@@ -34,25 +34,17 @@ 
 */

__wsum csum_partial(const void *buff, int len, __wsum sum);



__wsum __csum_partial_copy_from_user(const void *src, void *dst,

				     int len, __wsum sum, int *err_ptr);

__wsum __csum_partial_copy_to_user(const void *src, void *dst,

				   int len, __wsum sum, int *err_ptr);

__wsum __csum_partial_copy_from_user(const void __user *src, void *dst, int len);

__wsum __csum_partial_copy_to_user(const void *src, void __user *dst, int len);



#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER

static inline

__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)

{

	__wsum sum = ~0U;

	int err = 0;



	might_fault();



	if (!access_ok(src, len))

		return 0;

	sum = __csum_partial_copy_from_user((__force void *)src, dst,

						     len, sum, &err);

	return err ? 0 : sum;

	return __csum_partial_copy_from_user(src, dst, len);

}



/*
@@ -62,16 +54,10 @@ __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len) 
static inline

__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)

{

	int err = 0;

	__wsum sum = ~0U;



	might_fault();

	if (!access_ok(dst, len))

		return 0;

	sum = __csum_partial_copy_to_user(src,

					   (__force void *)dst,

					   len, sum, &err);

	return err ? 0 : sum;

	return __csum_partial_copy_to_user(src, dst, len);

}



/*
@@ -79,10 +65,10 @@ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len) 
 * we have just one address space, so this is identical to the above)

 */

#define _HAVE_ARCH_CSUM_AND_COPY

__wsum __csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);

__wsum __csum_partial_copy_nocheck(const void *src, void *dst, int len);

static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)

{

	return __csum_partial_copy_nocheck(src, dst, len, 0);

	return __csum_partial_copy_nocheck(src, dst, len);

}



/*

arch/mips/lib/csum_partial.S

+83 −175
Original line number Diff line number Diff line
@@ -308,8 +308,8 @@ EXPORT_SYMBOL(csum_partial) 
/*

 * checksum and copy routines based on memcpy.S

 *

 *	csum_partial_copy_nocheck(src, dst, len, sum)

 *	__csum_partial_copy_kernel(src, dst, len, sum, errp)

 *	csum_partial_copy_nocheck(src, dst, len)

 *	__csum_partial_copy_kernel(src, dst, len)

 *

 * See "Spec" in memcpy.S for details.	Unlike __copy_user, all

 * function in this file use the standard calling convention.
@@ -318,26 +318,11 @@ EXPORT_SYMBOL(csum_partial) 
#define src a0

#define dst a1

#define len a2

#define psum a3

#define sum v0

#define odd t8

#define errptr t9



/*

 * The exception handler for loads requires that:

 *  1- AT contain the address of the byte just past the end of the source

 *     of the copy,

 *  2- src_entry <= src < AT, and

 *  3- (dst - src) == (dst_entry - src_entry),

 * The _entry suffix denotes values when __copy_user was called.

 *

 * (1) is set up up by __csum_partial_copy_from_user and maintained by

 *	not writing AT in __csum_partial_copy

 * (2) is met by incrementing src by the number of bytes copied

 * (3) is met by not doing loads between a pair of increments of dst and src

 *

 * The exception handlers for stores stores -EFAULT to errptr and return.

 * These handlers do not need to overwrite any data.

 * All exception handlers simply return 0.

 */



/* Instruction type */
@@ -358,11 +343,11 @@ EXPORT_SYMBOL(csum_partial) 
 * addr    : Address

 * handler : Exception handler

 */

#define EXC(insn, type, reg, addr, handler)	\

#define EXC(insn, type, reg, addr)		\

	.if \mode == LEGACY_MODE;		\

9:		insn reg, addr;			\

		.section __ex_table,"a";	\

		PTR	9b, handler;		\

		PTR	9b, .L_exc;		\

		.previous;			\

	/* This is enabled in EVA mode */	\

	.else;					\
@@ -371,7 +356,7 @@ EXPORT_SYMBOL(csum_partial) 
		    ((\to == USEROP) && (type == ST_INSN));	\

9:			__BUILD_EVA_INSN(insn##e, reg, addr);	\

			.section __ex_table,"a";		\

			PTR	9b, handler;			\

			PTR	9b, .L_exc;			\

			.previous;				\

		.else;						\

			/* EVA without exception */		\
@@ -384,14 +369,14 @@ EXPORT_SYMBOL(csum_partial) 
#ifdef USE_DOUBLE



#define LOADK	ld /* No exception */

#define LOAD(reg, addr, handler)	EXC(ld, LD_INSN, reg, addr, handler)

#define LOADBU(reg, addr, handler)	EXC(lbu, LD_INSN, reg, addr, handler)

#define LOADL(reg, addr, handler)	EXC(ldl, LD_INSN, reg, addr, handler)

#define LOADR(reg, addr, handler)	EXC(ldr, LD_INSN, reg, addr, handler)

#define STOREB(reg, addr, handler)	EXC(sb, ST_INSN, reg, addr, handler)

#define STOREL(reg, addr, handler)	EXC(sdl, ST_INSN, reg, addr, handler)

#define STORER(reg, addr, handler)	EXC(sdr, ST_INSN, reg, addr, handler)

#define STORE(reg, addr, handler)	EXC(sd, ST_INSN, reg, addr, handler)

#define LOAD(reg, addr)		EXC(ld, LD_INSN, reg, addr)

#define LOADBU(reg, addr)	EXC(lbu, LD_INSN, reg, addr)

#define LOADL(reg, addr)	EXC(ldl, LD_INSN, reg, addr)

#define LOADR(reg, addr)	EXC(ldr, LD_INSN, reg, addr)

#define STOREB(reg, addr)	EXC(sb, ST_INSN, reg, addr)

#define STOREL(reg, addr)	EXC(sdl, ST_INSN, reg, addr)

#define STORER(reg, addr)	EXC(sdr, ST_INSN, reg, addr)

#define STORE(reg, addr)	EXC(sd, ST_INSN, reg, addr)

#define ADD    daddu

#define SUB    dsubu

#define SRL    dsrl
@@ -404,14 +389,14 @@ EXPORT_SYMBOL(csum_partial) 
#else



#define LOADK	lw /* No exception */

#define LOAD(reg, addr, handler)	EXC(lw, LD_INSN, reg, addr, handler)

#define LOADBU(reg, addr, handler)	EXC(lbu, LD_INSN, reg, addr, handler)

#define LOADL(reg, addr, handler)	EXC(lwl, LD_INSN, reg, addr, handler)

#define LOADR(reg, addr, handler)	EXC(lwr, LD_INSN, reg, addr, handler)

#define STOREB(reg, addr, handler)	EXC(sb, ST_INSN, reg, addr, handler)

#define STOREL(reg, addr, handler)	EXC(swl, ST_INSN, reg, addr, handler)

#define STORER(reg, addr, handler)	EXC(swr, ST_INSN, reg, addr, handler)

#define STORE(reg, addr, handler)	EXC(sw, ST_INSN, reg, addr, handler)

#define LOAD(reg, addr)		EXC(lw, LD_INSN, reg, addr)

#define LOADBU(reg, addr)	EXC(lbu, LD_INSN, reg, addr)

#define LOADL(reg, addr)	EXC(lwl, LD_INSN, reg, addr)

#define LOADR(reg, addr)	EXC(lwr, LD_INSN, reg, addr)

#define STOREB(reg, addr)	EXC(sb, ST_INSN, reg, addr)

#define STOREL(reg, addr)	EXC(swl, ST_INSN, reg, addr)

#define STORER(reg, addr)	EXC(swr, ST_INSN, reg, addr)

#define STORE(reg, addr)	EXC(sw, ST_INSN, reg, addr)

#define ADD    addu

#define SUB    subu

#define SRL    srl
@@ -450,22 +435,9 @@ EXPORT_SYMBOL(csum_partial) 
	.set	at=v1

#endif



	.macro __BUILD_CSUM_PARTIAL_COPY_USER mode, from, to, __nocheck

	.macro __BUILD_CSUM_PARTIAL_COPY_USER mode, from, to



	PTR_ADDU	AT, src, len	/* See (1) above. */

	/* initialize __nocheck if this the first time we execute this

	 * macro

	 */

#ifdef CONFIG_64BIT

	move	errptr, a4

#else

	lw	errptr, 16(sp)

#endif

	.if \__nocheck == 1

	FEXPORT(__csum_partial_copy_nocheck)

	EXPORT_SYMBOL(__csum_partial_copy_nocheck)

	.endif

	move	sum, zero

	li	sum, -1

	move	odd, zero

	/*

	 * Note: dst & src may be unaligned, len may be 0
@@ -497,31 +469,31 @@ EXPORT_SYMBOL(csum_partial) 
	SUB	len, 8*NBYTES		# subtract here for bgez loop

	.align	4

1:

	LOAD(t0, UNIT(0)(src), .Ll_exc\@)

	LOAD(t1, UNIT(1)(src), .Ll_exc_copy\@)

	LOAD(t2, UNIT(2)(src), .Ll_exc_copy\@)

	LOAD(t3, UNIT(3)(src), .Ll_exc_copy\@)

	LOAD(t4, UNIT(4)(src), .Ll_exc_copy\@)

	LOAD(t5, UNIT(5)(src), .Ll_exc_copy\@)

	LOAD(t6, UNIT(6)(src), .Ll_exc_copy\@)

	LOAD(t7, UNIT(7)(src), .Ll_exc_copy\@)

	LOAD(t0, UNIT(0)(src))

	LOAD(t1, UNIT(1)(src))

	LOAD(t2, UNIT(2)(src))

	LOAD(t3, UNIT(3)(src))

	LOAD(t4, UNIT(4)(src))

	LOAD(t5, UNIT(5)(src))

	LOAD(t6, UNIT(6)(src))

	LOAD(t7, UNIT(7)(src))

	SUB	len, len, 8*NBYTES

	ADD	src, src, 8*NBYTES

	STORE(t0, UNIT(0)(dst),	.Ls_exc\@)

	STORE(t0, UNIT(0)(dst))

	ADDC(t0, t1)

	STORE(t1, UNIT(1)(dst),	.Ls_exc\@)

	STORE(t1, UNIT(1)(dst))

	ADDC(sum, t0)

	STORE(t2, UNIT(2)(dst),	.Ls_exc\@)

	STORE(t2, UNIT(2)(dst))

	ADDC(t2, t3)

	STORE(t3, UNIT(3)(dst),	.Ls_exc\@)

	STORE(t3, UNIT(3)(dst))

	ADDC(sum, t2)

	STORE(t4, UNIT(4)(dst),	.Ls_exc\@)

	STORE(t4, UNIT(4)(dst))

	ADDC(t4, t5)

	STORE(t5, UNIT(5)(dst),	.Ls_exc\@)

	STORE(t5, UNIT(5)(dst))

	ADDC(sum, t4)

	STORE(t6, UNIT(6)(dst),	.Ls_exc\@)

	STORE(t6, UNIT(6)(dst))

	ADDC(t6, t7)

	STORE(t7, UNIT(7)(dst),	.Ls_exc\@)

	STORE(t7, UNIT(7)(dst))

	ADDC(sum, t6)

	.set	reorder				/* DADDI_WAR */

	ADD	dst, dst, 8*NBYTES
@@ -541,19 +513,19 @@ EXPORT_SYMBOL(csum_partial) 
	/*

	 * len >= 4*NBYTES

	 */

	LOAD(t0, UNIT(0)(src), .Ll_exc\@)

	LOAD(t1, UNIT(1)(src), .Ll_exc_copy\@)

	LOAD(t2, UNIT(2)(src), .Ll_exc_copy\@)

	LOAD(t3, UNIT(3)(src), .Ll_exc_copy\@)

	LOAD(t0, UNIT(0)(src))

	LOAD(t1, UNIT(1)(src))

	LOAD(t2, UNIT(2)(src))

	LOAD(t3, UNIT(3)(src))

	SUB	len, len, 4*NBYTES

	ADD	src, src, 4*NBYTES

	STORE(t0, UNIT(0)(dst),	.Ls_exc\@)

	STORE(t0, UNIT(0)(dst))

	ADDC(t0, t1)

	STORE(t1, UNIT(1)(dst),	.Ls_exc\@)

	STORE(t1, UNIT(1)(dst))

	ADDC(sum, t0)

	STORE(t2, UNIT(2)(dst),	.Ls_exc\@)

	STORE(t2, UNIT(2)(dst))

	ADDC(t2, t3)

	STORE(t3, UNIT(3)(dst),	.Ls_exc\@)

	STORE(t3, UNIT(3)(dst))

	ADDC(sum, t2)

	.set	reorder				/* DADDI_WAR */

	ADD	dst, dst, 4*NBYTES
@@ -566,10 +538,10 @@ EXPORT_SYMBOL(csum_partial) 
	beq	rem, len, .Lcopy_bytes\@

	 nop

1:

	LOAD(t0, 0(src), .Ll_exc\@)

	LOAD(t0, 0(src))

	ADD	src, src, NBYTES

	SUB	len, len, NBYTES

	STORE(t0, 0(dst), .Ls_exc\@)

	STORE(t0, 0(dst))

	ADDC(sum, t0)

	.set	reorder				/* DADDI_WAR */

	ADD	dst, dst, NBYTES
@@ -592,10 +564,10 @@ EXPORT_SYMBOL(csum_partial) 
	 ADD	t1, dst, len	# t1 is just past last byte of dst

	li	bits, 8*NBYTES

	SLL	rem, len, 3	# rem = number of bits to keep

	LOAD(t0, 0(src), .Ll_exc\@)

	LOAD(t0, 0(src))

	SUB	bits, bits, rem # bits = number of bits to discard

	SHIFT_DISCARD t0, t0, bits

	STREST(t0, -1(t1), .Ls_exc\@)

	STREST(t0, -1(t1))

	SHIFT_DISCARD_REVERT t0, t0, bits

	.set reorder

	ADDC(sum, t0)
@@ -612,12 +584,12 @@ EXPORT_SYMBOL(csum_partial) 
	 * Set match = (src and dst have same alignment)

	 */

#define match rem

	LDFIRST(t3, FIRST(0)(src), .Ll_exc\@)

	LDFIRST(t3, FIRST(0)(src))

	ADD	t2, zero, NBYTES

	LDREST(t3, REST(0)(src), .Ll_exc_copy\@)

	LDREST(t3, REST(0)(src))

	SUB	t2, t2, t1	# t2 = number of bytes copied

	xor	match, t0, t1

	STFIRST(t3, FIRST(0)(dst), .Ls_exc\@)

	STFIRST(t3, FIRST(0)(dst))

	SLL	t4, t1, 3		# t4 = number of bits to discard

	SHIFT_DISCARD t3, t3, t4

	/* no SHIFT_DISCARD_REVERT to handle odd buffer properly */
@@ -639,26 +611,26 @@ EXPORT_SYMBOL(csum_partial) 
 * It's OK to load FIRST(N+1) before REST(N) because the two addresses

 * are to the same unit (unless src is aligned, but it's not).

 */

	LDFIRST(t0, FIRST(0)(src), .Ll_exc\@)

	LDFIRST(t1, FIRST(1)(src), .Ll_exc_copy\@)

	LDFIRST(t0, FIRST(0)(src))

	LDFIRST(t1, FIRST(1)(src))

	SUB	len, len, 4*NBYTES

	LDREST(t0, REST(0)(src), .Ll_exc_copy\@)

	LDREST(t1, REST(1)(src), .Ll_exc_copy\@)

	LDFIRST(t2, FIRST(2)(src), .Ll_exc_copy\@)

	LDFIRST(t3, FIRST(3)(src), .Ll_exc_copy\@)

	LDREST(t2, REST(2)(src), .Ll_exc_copy\@)

	LDREST(t3, REST(3)(src), .Ll_exc_copy\@)

	LDREST(t0, REST(0)(src))

	LDREST(t1, REST(1)(src))

	LDFIRST(t2, FIRST(2)(src))

	LDFIRST(t3, FIRST(3)(src))

	LDREST(t2, REST(2)(src))

	LDREST(t3, REST(3)(src))

	ADD	src, src, 4*NBYTES

#ifdef CONFIG_CPU_SB1

	nop				# improves slotting

#endif

	STORE(t0, UNIT(0)(dst),	.Ls_exc\@)

	STORE(t0, UNIT(0)(dst))

	ADDC(t0, t1)

	STORE(t1, UNIT(1)(dst),	.Ls_exc\@)

	STORE(t1, UNIT(1)(dst))

	ADDC(sum, t0)

	STORE(t2, UNIT(2)(dst),	.Ls_exc\@)

	STORE(t2, UNIT(2)(dst))

	ADDC(t2, t3)

	STORE(t3, UNIT(3)(dst),	.Ls_exc\@)

	STORE(t3, UNIT(3)(dst))

	ADDC(sum, t2)

	.set	reorder				/* DADDI_WAR */

	ADD	dst, dst, 4*NBYTES
@@ -671,11 +643,11 @@ EXPORT_SYMBOL(csum_partial) 
	beq	rem, len, .Lcopy_bytes\@

	 nop

1:

	LDFIRST(t0, FIRST(0)(src), .Ll_exc\@)

	LDREST(t0, REST(0)(src), .Ll_exc_copy\@)

	LDFIRST(t0, FIRST(0)(src))

	LDREST(t0, REST(0)(src))

	ADD	src, src, NBYTES

	SUB	len, len, NBYTES

	STORE(t0, 0(dst), .Ls_exc\@)

	STORE(t0, 0(dst))

	ADDC(sum, t0)

	.set	reorder				/* DADDI_WAR */

	ADD	dst, dst, NBYTES
@@ -696,11 +668,10 @@ EXPORT_SYMBOL(csum_partial) 
#endif

	move	t2, zero	# partial word

	li	t3, SHIFT_START # shift

/* use .Ll_exc_copy here to return correct sum on fault */

#define COPY_BYTE(N)			\

	LOADBU(t0, N(src), .Ll_exc_copy\@);	\

	LOADBU(t0, N(src));		\

	SUB	len, len, 1;		\

	STOREB(t0, N(dst), .Ls_exc\@);	\

	STOREB(t0, N(dst));		\

	SLLV	t0, t0, t3;		\

	addu	t3, SHIFT_INC;		\

	beqz	len, .Lcopy_bytes_done\@; \
@@ -714,9 +685,9 @@ EXPORT_SYMBOL(csum_partial) 
	COPY_BYTE(4)

	COPY_BYTE(5)

#endif

	LOADBU(t0, NBYTES-2(src), .Ll_exc_copy\@)

	LOADBU(t0, NBYTES-2(src))

	SUB	len, len, 1

	STOREB(t0, NBYTES-2(dst), .Ls_exc\@)

	STOREB(t0, NBYTES-2(dst))

	SLLV	t0, t0, t3

	or	t2, t0

.Lcopy_bytes_done\@:
@@ -753,94 +724,31 @@ EXPORT_SYMBOL(csum_partial) 
#endif

	.set	pop

	.set reorder

	ADDC32(sum, psum)

	jr	ra

	.set noreorder

	.endm



.Ll_exc_copy\@:

	/*

	 * Copy bytes from src until faulting load address (or until a

	 * lb faults)

	 *

	 * When reached by a faulting LDFIRST/LDREST, THREAD_BUADDR($28)

	 * may be more than a byte beyond the last address.

	 * Hence, the lb below may get an exception.

	 *

	 * Assumes src < THREAD_BUADDR($28)

	 */

	LOADK	t0, TI_TASK($28)

	 li	t2, SHIFT_START

	LOADK	t0, THREAD_BUADDR(t0)

1:

	LOADBU(t1, 0(src), .Ll_exc\@)

	ADD	src, src, 1

	sb	t1, 0(dst)	# can't fault -- we're copy_from_user

	SLLV	t1, t1, t2

	addu	t2, SHIFT_INC

	ADDC(sum, t1)

	.set	reorder				/* DADDI_WAR */

	ADD	dst, dst, 1

	bne	src, t0, 1b

	.set	noreorder

.Ll_exc\@:

	LOADK	t0, TI_TASK($28)

	 nop

	LOADK	t0, THREAD_BUADDR(t0)	# t0 is just past last good address

	 nop

	SUB	len, AT, t0		# len number of uncopied bytes

	/*

	 * 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

	.set	push

	.set	noat

#ifndef CONFIG_CPU_DADDI_WORKAROUNDS

	bnez	src, 1b

	 SUB	src, src, 1

#else

	li	v1, 1

	bnez	src, 1b

	 SUB	src, src, v1

#endif

	li	v1, -EFAULT

	b	.Ldone\@

	 sw	v1, (errptr)



.Ls_exc\@:

	li	v0, -1 /* invalid checksum */

	li	v1, -EFAULT

.L_exc:

	jr	ra

	 sw	v1, (errptr)

	.set	pop

	.endm

	 li	v0, 0



FEXPORT(__csum_partial_copy_nocheck)

EXPORT_SYMBOL(__csum_partial_copy_nocheck)

#ifndef CONFIG_EVA

FEXPORT(__csum_partial_copy_to_user)

EXPORT_SYMBOL(__csum_partial_copy_to_user)

FEXPORT(__csum_partial_copy_from_user)

EXPORT_SYMBOL(__csum_partial_copy_from_user)

#endif

__BUILD_CSUM_PARTIAL_COPY_USER LEGACY_MODE USEROP USEROP 1

__BUILD_CSUM_PARTIAL_COPY_USER LEGACY_MODE USEROP USEROP



#ifdef CONFIG_EVA

LEAF(__csum_partial_copy_to_user)

__BUILD_CSUM_PARTIAL_COPY_USER EVA_MODE KERNELOP USEROP 0

__BUILD_CSUM_PARTIAL_COPY_USER EVA_MODE KERNELOP USEROP

END(__csum_partial_copy_to_user)



LEAF(__csum_partial_copy_from_user)

__BUILD_CSUM_PARTIAL_COPY_USER EVA_MODE USEROP KERNELOP 0

__BUILD_CSUM_PARTIAL_COPY_USER EVA_MODE USEROP KERNELOP

END(__csum_partial_copy_from_user)

#endif

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