linux/arch/sparc64/lib/NGmemcpy.S
David S. Miller 24d559cac4 [SPARC64]: store-init needs trailing membar.
The manual says that it is required and we actually have crash reports
where loads see stale data due to not having membars here.

In one case the networking does:

	memset(skb, 0, offsetof(struct sk_buff, truesize));

and then some code later checks skb->nohdr for zero, but it's still
the value that was there before the memset().

Note that arch/sparc64/lib/xor.S already got this right.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-19 13:27:33 -07:00

371 lines
8.2 KiB
ArmAsm

/* NGmemcpy.S: Niagara optimized memcpy.
*
* Copyright (C) 2006 David S. Miller (davem@davemloft.net)
*/
#ifdef __KERNEL__
#include <asm/asi.h>
#include <asm/thread_info.h>
#define GLOBAL_SPARE %g7
#define RESTORE_ASI(TMP) \
ldub [%g6 + TI_CURRENT_DS], TMP; \
wr TMP, 0x0, %asi;
#else
#define GLOBAL_SPARE %g5
#define RESTORE_ASI(TMP) \
wr %g0, ASI_PNF, %asi
#endif
#ifndef STORE_ASI
#define STORE_ASI ASI_BLK_INIT_QUAD_LDD_P
#endif
#ifndef EX_LD
#define EX_LD(x) x
#endif
#ifndef EX_ST
#define EX_ST(x) x
#endif
#ifndef EX_RETVAL
#define EX_RETVAL(x) x
#endif
#ifndef LOAD
#ifndef MEMCPY_DEBUG
#define LOAD(type,addr,dest) type [addr], dest
#else
#define LOAD(type,addr,dest) type##a [addr] 0x80, dest
#endif
#endif
#ifndef LOAD_TWIN
#define LOAD_TWIN(addr_reg,dest0,dest1) \
ldda [addr_reg] ASI_BLK_INIT_QUAD_LDD_P, dest0
#endif
#ifndef STORE
#define STORE(type,src,addr) type src, [addr]
#endif
#ifndef STORE_INIT
#define STORE_INIT(src,addr) stxa src, [addr] %asi
#endif
#ifndef FUNC_NAME
#define FUNC_NAME NGmemcpy
#endif
#ifndef PREAMBLE
#define PREAMBLE
#endif
#ifndef XCC
#define XCC xcc
#endif
.register %g2,#scratch
.register %g3,#scratch
.text
.align 64
.globl FUNC_NAME
.type FUNC_NAME,#function
FUNC_NAME: /* %o0=dst, %o1=src, %o2=len */
srlx %o2, 31, %g2
cmp %g2, 0
tne %xcc, 5
PREAMBLE
mov %o0, GLOBAL_SPARE
cmp %o2, 0
be,pn %XCC, 85f
or %o0, %o1, %o3
cmp %o2, 16
blu,a,pn %XCC, 80f
or %o3, %o2, %o3
/* 2 blocks (128 bytes) is the minimum we can do the block
* copy with. We need to ensure that we'll iterate at least
* once in the block copy loop. At worst we'll need to align
* the destination to a 64-byte boundary which can chew up
* to (64 - 1) bytes from the length before we perform the
* block copy loop.
*/
cmp %o2, (2 * 64)
blu,pt %XCC, 70f
andcc %o3, 0x7, %g0
/* %o0: dst
* %o1: src
* %o2: len (known to be >= 128)
*
* The block copy loops will use %o4/%o5,%g2/%g3 as
* temporaries while copying the data.
*/
LOAD(prefetch, %o1, #one_read)
wr %g0, STORE_ASI, %asi
/* Align destination on 64-byte boundary. */
andcc %o0, (64 - 1), %o4
be,pt %XCC, 2f
sub %o4, 64, %o4
sub %g0, %o4, %o4 ! bytes to align dst
sub %o2, %o4, %o2
1: subcc %o4, 1, %o4
EX_LD(LOAD(ldub, %o1, %g1))
EX_ST(STORE(stb, %g1, %o0))
add %o1, 1, %o1
bne,pt %XCC, 1b
add %o0, 1, %o0
/* If the source is on a 16-byte boundary we can do
* the direct block copy loop. If it is 8-byte aligned
* we can do the 16-byte loads offset by -8 bytes and the
* init stores offset by one register.
*
* If the source is not even 8-byte aligned, we need to do
* shifting and masking (basically integer faligndata).
*
* The careful bit with init stores is that if we store
* to any part of the cache line we have to store the whole
* cacheline else we can end up with corrupt L2 cache line
* contents. Since the loop works on 64-bytes of 64-byte
* aligned store data at a time, this is easy to ensure.
*/
2:
andcc %o1, (16 - 1), %o4
andn %o2, (64 - 1), %g1 ! block copy loop iterator
sub %o2, %g1, %o2 ! final sub-block copy bytes
be,pt %XCC, 50f
cmp %o4, 8
be,a,pt %XCC, 10f
sub %o1, 0x8, %o1
/* Neither 8-byte nor 16-byte aligned, shift and mask. */
mov %g1, %o4
and %o1, 0x7, %g1
sll %g1, 3, %g1
mov 64, %o3
andn %o1, 0x7, %o1
EX_LD(LOAD(ldx, %o1, %g2))
sub %o3, %g1, %o3
sllx %g2, %g1, %g2
#define SWIVEL_ONE_DWORD(SRC, TMP1, TMP2, PRE_VAL, PRE_SHIFT, POST_SHIFT, DST)\
EX_LD(LOAD(ldx, SRC, TMP1)); \
srlx TMP1, PRE_SHIFT, TMP2; \
or TMP2, PRE_VAL, TMP2; \
EX_ST(STORE_INIT(TMP2, DST)); \
sllx TMP1, POST_SHIFT, PRE_VAL;
1: add %o1, 0x8, %o1
SWIVEL_ONE_DWORD(%o1, %g3, %o5, %g2, %o3, %g1, %o0 + 0x00)
add %o1, 0x8, %o1
SWIVEL_ONE_DWORD(%o1, %g3, %o5, %g2, %o3, %g1, %o0 + 0x08)
add %o1, 0x8, %o1
SWIVEL_ONE_DWORD(%o1, %g3, %o5, %g2, %o3, %g1, %o0 + 0x10)
add %o1, 0x8, %o1
SWIVEL_ONE_DWORD(%o1, %g3, %o5, %g2, %o3, %g1, %o0 + 0x18)
add %o1, 32, %o1
LOAD(prefetch, %o1, #one_read)
sub %o1, 32 - 8, %o1
SWIVEL_ONE_DWORD(%o1, %g3, %o5, %g2, %o3, %g1, %o0 + 0x20)
add %o1, 8, %o1
SWIVEL_ONE_DWORD(%o1, %g3, %o5, %g2, %o3, %g1, %o0 + 0x28)
add %o1, 8, %o1
SWIVEL_ONE_DWORD(%o1, %g3, %o5, %g2, %o3, %g1, %o0 + 0x30)
add %o1, 8, %o1
SWIVEL_ONE_DWORD(%o1, %g3, %o5, %g2, %o3, %g1, %o0 + 0x38)
subcc %o4, 64, %o4
bne,pt %XCC, 1b
add %o0, 64, %o0
#undef SWIVEL_ONE_DWORD
srl %g1, 3, %g1
ba,pt %XCC, 60f
add %o1, %g1, %o1
10: /* Destination is 64-byte aligned, source was only 8-byte
* aligned but it has been subtracted by 8 and we perform
* one twin load ahead, then add 8 back into source when
* we finish the loop.
*/
EX_LD(LOAD_TWIN(%o1, %o4, %o5))
1: add %o1, 16, %o1
EX_LD(LOAD_TWIN(%o1, %g2, %g3))
add %o1, 16 + 32, %o1
LOAD(prefetch, %o1, #one_read)
sub %o1, 32, %o1
EX_ST(STORE_INIT(%o5, %o0 + 0x00)) ! initializes cache line
EX_ST(STORE_INIT(%g2, %o0 + 0x08))
EX_LD(LOAD_TWIN(%o1, %o4, %o5))
add %o1, 16, %o1
EX_ST(STORE_INIT(%g3, %o0 + 0x10))
EX_ST(STORE_INIT(%o4, %o0 + 0x18))
EX_LD(LOAD_TWIN(%o1, %g2, %g3))
add %o1, 16, %o1
EX_ST(STORE_INIT(%o5, %o0 + 0x20))
EX_ST(STORE_INIT(%g2, %o0 + 0x28))
EX_LD(LOAD_TWIN(%o1, %o4, %o5))
EX_ST(STORE_INIT(%g3, %o0 + 0x30))
EX_ST(STORE_INIT(%o4, %o0 + 0x38))
subcc %g1, 64, %g1
bne,pt %XCC, 1b
add %o0, 64, %o0
ba,pt %XCC, 60f
add %o1, 0x8, %o1
50: /* Destination is 64-byte aligned, and source is 16-byte
* aligned.
*/
1: EX_LD(LOAD_TWIN(%o1, %o4, %o5))
add %o1, 16, %o1
EX_LD(LOAD_TWIN(%o1, %g2, %g3))
add %o1, 16 + 32, %o1
LOAD(prefetch, %o1, #one_read)
sub %o1, 32, %o1
EX_ST(STORE_INIT(%o4, %o0 + 0x00)) ! initializes cache line
EX_ST(STORE_INIT(%o5, %o0 + 0x08))
EX_LD(LOAD_TWIN(%o1, %o4, %o5))
add %o1, 16, %o1
EX_ST(STORE_INIT(%g2, %o0 + 0x10))
EX_ST(STORE_INIT(%g3, %o0 + 0x18))
EX_LD(LOAD_TWIN(%o1, %g2, %g3))
add %o1, 16, %o1
EX_ST(STORE_INIT(%o4, %o0 + 0x20))
EX_ST(STORE_INIT(%o5, %o0 + 0x28))
EX_ST(STORE_INIT(%g2, %o0 + 0x30))
EX_ST(STORE_INIT(%g3, %o0 + 0x38))
subcc %g1, 64, %g1
bne,pt %XCC, 1b
add %o0, 64, %o0
/* fall through */
60:
membar #Sync
/* %o2 contains any final bytes still needed to be copied
* over. If anything is left, we copy it one byte at a time.
*/
RESTORE_ASI(%o3)
brz,pt %o2, 85f
sub %o0, %o1, %o3
ba,a,pt %XCC, 90f
.align 64
70: /* 16 < len <= 64 */
bne,pn %XCC, 75f
sub %o0, %o1, %o3
72:
andn %o2, 0xf, %o4
and %o2, 0xf, %o2
1: subcc %o4, 0x10, %o4
EX_LD(LOAD(ldx, %o1, %o5))
add %o1, 0x08, %o1
EX_LD(LOAD(ldx, %o1, %g1))
sub %o1, 0x08, %o1
EX_ST(STORE(stx, %o5, %o1 + %o3))
add %o1, 0x8, %o1
EX_ST(STORE(stx, %g1, %o1 + %o3))
bgu,pt %XCC, 1b
add %o1, 0x8, %o1
73: andcc %o2, 0x8, %g0
be,pt %XCC, 1f
nop
sub %o2, 0x8, %o2
EX_LD(LOAD(ldx, %o1, %o5))
EX_ST(STORE(stx, %o5, %o1 + %o3))
add %o1, 0x8, %o1
1: andcc %o2, 0x4, %g0
be,pt %XCC, 1f
nop
sub %o2, 0x4, %o2
EX_LD(LOAD(lduw, %o1, %o5))
EX_ST(STORE(stw, %o5, %o1 + %o3))
add %o1, 0x4, %o1
1: cmp %o2, 0
be,pt %XCC, 85f
nop
ba,pt %xcc, 90f
nop
75:
andcc %o0, 0x7, %g1
sub %g1, 0x8, %g1
be,pn %icc, 2f
sub %g0, %g1, %g1
sub %o2, %g1, %o2
1: subcc %g1, 1, %g1
EX_LD(LOAD(ldub, %o1, %o5))
EX_ST(STORE(stb, %o5, %o1 + %o3))
bgu,pt %icc, 1b
add %o1, 1, %o1
2: add %o1, %o3, %o0
andcc %o1, 0x7, %g1
bne,pt %icc, 8f
sll %g1, 3, %g1
cmp %o2, 16
bgeu,pt %icc, 72b
nop
ba,a,pt %xcc, 73b
8: mov 64, %o3
andn %o1, 0x7, %o1
EX_LD(LOAD(ldx, %o1, %g2))
sub %o3, %g1, %o3
andn %o2, 0x7, %o4
sllx %g2, %g1, %g2
1: add %o1, 0x8, %o1
EX_LD(LOAD(ldx, %o1, %g3))
subcc %o4, 0x8, %o4
srlx %g3, %o3, %o5
or %o5, %g2, %o5
EX_ST(STORE(stx, %o5, %o0))
add %o0, 0x8, %o0
bgu,pt %icc, 1b
sllx %g3, %g1, %g2
srl %g1, 3, %g1
andcc %o2, 0x7, %o2
be,pn %icc, 85f
add %o1, %g1, %o1
ba,pt %xcc, 90f
sub %o0, %o1, %o3
.align 64
80: /* 0 < len <= 16 */
andcc %o3, 0x3, %g0
bne,pn %XCC, 90f
sub %o0, %o1, %o3
1:
subcc %o2, 4, %o2
EX_LD(LOAD(lduw, %o1, %g1))
EX_ST(STORE(stw, %g1, %o1 + %o3))
bgu,pt %XCC, 1b
add %o1, 4, %o1
85: retl
mov EX_RETVAL(GLOBAL_SPARE), %o0
.align 32
90:
subcc %o2, 1, %o2
EX_LD(LOAD(ldub, %o1, %g1))
EX_ST(STORE(stb, %g1, %o1 + %o3))
bgu,pt %XCC, 90b
add %o1, 1, %o1
retl
mov EX_RETVAL(GLOBAL_SPARE), %o0
.size FUNC_NAME, .-FUNC_NAME