linux/arch/sparc/lib/NGmemcpy.S
Babu Moger 0ae2d26ffe arch/sparc: Avoid DCTI Couples
Avoid un-intended DCTI Couples. Use of DCTI couples is deprecated.
Also address the "Programming Note" for optimal performance.

Here is the complete text from Oracle SPARC Architecture Specs.

6.3.4.7 DCTI Couples
"A delayed control transfer instruction (DCTI) in the delay slot of
another DCTI is referred to as a “DCTI couple”. The use of DCTI couples
is deprecated in the Oracle SPARC Architecture; no new software should
place a DCTI in the delay slot of another DCTI, because on future Oracle
SPARC Architecture implementations DCTI couples may execute either
slowly or differently than the programmer assumes it will.

SPARC V8 and SPARC V9 Compatibility Note
The SPARC V8 architecture left behavior undefined for a DCTI couple. The
SPARC V9 architecture defined behavior in that case, but as of
UltraSPARC Architecture 2005, use of DCTI couples was deprecated.
Software should not expect high performance from DCTI couples, and
performance of DCTI couples should be expected to decline further in
future processors.

Programming Note
As noted in TABLE 6-5 on page 115, an annulled branch-always
(branch-always with a = 1) instruction is not architecturally a DCTI.
However, since not all implementations make that distinction, for
optimal performance, a DCTI should not be placed in the instruction word
immediately following an annulled branch-always instruction (BA,A or
BPA,A)."

Signed-off-by: Babu Moger <babu.moger@oracle.com>
Reviewed-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-27 21:51:40 -07:00

510 lines
13 KiB
ArmAsm

/* NGmemcpy.S: Niagara optimized memcpy.
*
* Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
*/
#ifdef __KERNEL__
#include <linux/linkage.h>
#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
#ifdef __sparc_v9__
#define SAVE_AMOUNT 128
#else
#define SAVE_AMOUNT 64
#endif
#ifndef STORE_ASI
#define STORE_ASI ASI_BLK_INIT_QUAD_LDD_P
#endif
#ifndef EX_LD
#define EX_LD(x,y) x
#endif
#ifndef EX_ST
#define EX_ST(x,y) 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
#ifndef SIMULATE_NIAGARA_ON_NON_NIAGARA
#define STORE_INIT(src,addr) stxa src, [addr] %asi
#else
#define STORE_INIT(src,addr) stx src, [addr + 0x00]
#endif
#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
#ifndef EX_RETVAL
#define EX_RETVAL(x) x
__restore_asi:
ret
wr %g0, ASI_AIUS, %asi
restore
ENTRY(NG_ret_i2_plus_i4_plus_1)
ba,pt %xcc, __restore_asi
add %i2, %i5, %i0
ENDPROC(NG_ret_i2_plus_i4_plus_1)
ENTRY(NG_ret_i2_plus_g1)
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1)
ENTRY(NG_ret_i2_plus_g1_minus_8)
sub %g1, 8, %g1
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_8)
ENTRY(NG_ret_i2_plus_g1_minus_16)
sub %g1, 16, %g1
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_16)
ENTRY(NG_ret_i2_plus_g1_minus_24)
sub %g1, 24, %g1
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_24)
ENTRY(NG_ret_i2_plus_g1_minus_32)
sub %g1, 32, %g1
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_32)
ENTRY(NG_ret_i2_plus_g1_minus_40)
sub %g1, 40, %g1
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_40)
ENTRY(NG_ret_i2_plus_g1_minus_48)
sub %g1, 48, %g1
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_48)
ENTRY(NG_ret_i2_plus_g1_minus_56)
sub %g1, 56, %g1
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_minus_56)
ENTRY(NG_ret_i2_plus_i4)
ba,pt %xcc, __restore_asi
add %i2, %i4, %i0
ENDPROC(NG_ret_i2_plus_i4)
ENTRY(NG_ret_i2_plus_i4_minus_8)
sub %i4, 8, %i4
ba,pt %xcc, __restore_asi
add %i2, %i4, %i0
ENDPROC(NG_ret_i2_plus_i4_minus_8)
ENTRY(NG_ret_i2_plus_8)
ba,pt %xcc, __restore_asi
add %i2, 8, %i0
ENDPROC(NG_ret_i2_plus_8)
ENTRY(NG_ret_i2_plus_4)
ba,pt %xcc, __restore_asi
add %i2, 4, %i0
ENDPROC(NG_ret_i2_plus_4)
ENTRY(NG_ret_i2_plus_1)
ba,pt %xcc, __restore_asi
add %i2, 1, %i0
ENDPROC(NG_ret_i2_plus_1)
ENTRY(NG_ret_i2_plus_g1_plus_1)
add %g1, 1, %g1
ba,pt %xcc, __restore_asi
add %i2, %g1, %i0
ENDPROC(NG_ret_i2_plus_g1_plus_1)
ENTRY(NG_ret_i2)
ba,pt %xcc, __restore_asi
mov %i2, %i0
ENDPROC(NG_ret_i2)
ENTRY(NG_ret_i2_and_7_plus_i4)
and %i2, 7, %i2
ba,pt %xcc, __restore_asi
add %i2, %i4, %i0
ENDPROC(NG_ret_i2_and_7_plus_i4)
#endif
.align 64
.globl FUNC_NAME
.type FUNC_NAME,#function
FUNC_NAME: /* %i0=dst, %i1=src, %i2=len */
PREAMBLE
save %sp, -SAVE_AMOUNT, %sp
srlx %i2, 31, %g2
cmp %g2, 0
tne %xcc, 5
mov %i0, %o0
cmp %i2, 0
be,pn %XCC, 85f
or %o0, %i1, %i3
cmp %i2, 16
blu,a,pn %XCC, 80f
or %i3, %i2, %i3
/* 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 %i2, (2 * 64)
blu,pt %XCC, 70f
andcc %i3, 0x7, %g0
/* %o0: dst
* %i1: src
* %i2: len (known to be >= 128)
*
* The block copy loops will use %i4/%i5,%g2/%g3 as
* temporaries while copying the data.
*/
LOAD(prefetch, %i1, #one_read)
wr %g0, STORE_ASI, %asi
/* Align destination on 64-byte boundary. */
andcc %o0, (64 - 1), %i4
be,pt %XCC, 2f
sub %i4, 64, %i4
sub %g0, %i4, %i4 ! bytes to align dst
sub %i2, %i4, %i2
1: subcc %i4, 1, %i4
EX_LD(LOAD(ldub, %i1, %g1), NG_ret_i2_plus_i4_plus_1)
EX_ST(STORE(stb, %g1, %o0), NG_ret_i2_plus_i4_plus_1)
add %i1, 1, %i1
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 %i1, (16 - 1), %i4
andn %i2, (64 - 1), %g1 ! block copy loop iterator
be,pt %XCC, 50f
sub %i2, %g1, %i2 ! final sub-block copy bytes
cmp %i4, 8
be,pt %XCC, 10f
sub %i1, %i4, %i1
/* Neither 8-byte nor 16-byte aligned, shift and mask. */
and %i4, 0x7, GLOBAL_SPARE
sll GLOBAL_SPARE, 3, GLOBAL_SPARE
mov 64, %i5
EX_LD(LOAD_TWIN(%i1, %g2, %g3), NG_ret_i2_plus_g1)
sub %i5, GLOBAL_SPARE, %i5
mov 16, %o4
mov 32, %o5
mov 48, %o7
mov 64, %i3
bg,pn %XCC, 9f
nop
#define MIX_THREE_WORDS(WORD1, WORD2, WORD3, PRE_SHIFT, POST_SHIFT, TMP) \
sllx WORD1, POST_SHIFT, WORD1; \
srlx WORD2, PRE_SHIFT, TMP; \
sllx WORD2, POST_SHIFT, WORD2; \
or WORD1, TMP, WORD1; \
srlx WORD3, PRE_SHIFT, TMP; \
or WORD2, TMP, WORD2;
8: EX_LD(LOAD_TWIN(%i1 + %o4, %o2, %o3), NG_ret_i2_plus_g1)
MIX_THREE_WORDS(%g2, %g3, %o2, %i5, GLOBAL_SPARE, %o1)
LOAD(prefetch, %i1 + %i3, #one_read)
EX_ST(STORE_INIT(%g2, %o0 + 0x00), NG_ret_i2_plus_g1)
EX_ST(STORE_INIT(%g3, %o0 + 0x08), NG_ret_i2_plus_g1_minus_8)
EX_LD(LOAD_TWIN(%i1 + %o5, %g2, %g3), NG_ret_i2_plus_g1_minus_16)
MIX_THREE_WORDS(%o2, %o3, %g2, %i5, GLOBAL_SPARE, %o1)
EX_ST(STORE_INIT(%o2, %o0 + 0x10), NG_ret_i2_plus_g1_minus_16)
EX_ST(STORE_INIT(%o3, %o0 + 0x18), NG_ret_i2_plus_g1_minus_24)
EX_LD(LOAD_TWIN(%i1 + %o7, %o2, %o3), NG_ret_i2_plus_g1_minus_32)
MIX_THREE_WORDS(%g2, %g3, %o2, %i5, GLOBAL_SPARE, %o1)
EX_ST(STORE_INIT(%g2, %o0 + 0x20), NG_ret_i2_plus_g1_minus_32)
EX_ST(STORE_INIT(%g3, %o0 + 0x28), NG_ret_i2_plus_g1_minus_40)
EX_LD(LOAD_TWIN(%i1 + %i3, %g2, %g3), NG_ret_i2_plus_g1_minus_48)
add %i1, 64, %i1
MIX_THREE_WORDS(%o2, %o3, %g2, %i5, GLOBAL_SPARE, %o1)
EX_ST(STORE_INIT(%o2, %o0 + 0x30), NG_ret_i2_plus_g1_minus_48)
EX_ST(STORE_INIT(%o3, %o0 + 0x38), NG_ret_i2_plus_g1_minus_56)
subcc %g1, 64, %g1
bne,pt %XCC, 8b
add %o0, 64, %o0
ba,pt %XCC, 60f
add %i1, %i4, %i1
9: EX_LD(LOAD_TWIN(%i1 + %o4, %o2, %o3), NG_ret_i2_plus_g1)
MIX_THREE_WORDS(%g3, %o2, %o3, %i5, GLOBAL_SPARE, %o1)
LOAD(prefetch, %i1 + %i3, #one_read)
EX_ST(STORE_INIT(%g3, %o0 + 0x00), NG_ret_i2_plus_g1)
EX_ST(STORE_INIT(%o2, %o0 + 0x08), NG_ret_i2_plus_g1_minus_8)
EX_LD(LOAD_TWIN(%i1 + %o5, %g2, %g3), NG_ret_i2_plus_g1_minus_16)
MIX_THREE_WORDS(%o3, %g2, %g3, %i5, GLOBAL_SPARE, %o1)
EX_ST(STORE_INIT(%o3, %o0 + 0x10), NG_ret_i2_plus_g1_minus_16)
EX_ST(STORE_INIT(%g2, %o0 + 0x18), NG_ret_i2_plus_g1_minus_24)
EX_LD(LOAD_TWIN(%i1 + %o7, %o2, %o3), NG_ret_i2_plus_g1_minus_32)
MIX_THREE_WORDS(%g3, %o2, %o3, %i5, GLOBAL_SPARE, %o1)
EX_ST(STORE_INIT(%g3, %o0 + 0x20), NG_ret_i2_plus_g1_minus_32)
EX_ST(STORE_INIT(%o2, %o0 + 0x28), NG_ret_i2_plus_g1_minus_40)
EX_LD(LOAD_TWIN(%i1 + %i3, %g2, %g3), NG_ret_i2_plus_g1_minus_48)
add %i1, 64, %i1
MIX_THREE_WORDS(%o3, %g2, %g3, %i5, GLOBAL_SPARE, %o1)
EX_ST(STORE_INIT(%o3, %o0 + 0x30), NG_ret_i2_plus_g1_minus_48)
EX_ST(STORE_INIT(%g2, %o0 + 0x38), NG_ret_i2_plus_g1_minus_56)
subcc %g1, 64, %g1
bne,pt %XCC, 9b
add %o0, 64, %o0
ba,pt %XCC, 60f
add %i1, %i4, %i1
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(%i1, %o4, %o5), NG_ret_i2_plus_g1)
mov 16, %o7
mov 32, %g2
mov 48, %g3
mov 64, %o1
1: EX_LD(LOAD_TWIN(%i1 + %o7, %o2, %o3), NG_ret_i2_plus_g1)
LOAD(prefetch, %i1 + %o1, #one_read)
EX_ST(STORE_INIT(%o5, %o0 + 0x00), NG_ret_i2_plus_g1) ! initializes cache line
EX_ST(STORE_INIT(%o2, %o0 + 0x08), NG_ret_i2_plus_g1_minus_8)
EX_LD(LOAD_TWIN(%i1 + %g2, %o4, %o5), NG_ret_i2_plus_g1_minus_16)
EX_ST(STORE_INIT(%o3, %o0 + 0x10), NG_ret_i2_plus_g1_minus_16)
EX_ST(STORE_INIT(%o4, %o0 + 0x18), NG_ret_i2_plus_g1_minus_24)
EX_LD(LOAD_TWIN(%i1 + %g3, %o2, %o3), NG_ret_i2_plus_g1_minus_32)
EX_ST(STORE_INIT(%o5, %o0 + 0x20), NG_ret_i2_plus_g1_minus_32)
EX_ST(STORE_INIT(%o2, %o0 + 0x28), NG_ret_i2_plus_g1_minus_40)
EX_LD(LOAD_TWIN(%i1 + %o1, %o4, %o5), NG_ret_i2_plus_g1_minus_48)
add %i1, 64, %i1
EX_ST(STORE_INIT(%o3, %o0 + 0x30), NG_ret_i2_plus_g1_minus_48)
EX_ST(STORE_INIT(%o4, %o0 + 0x38), NG_ret_i2_plus_g1_minus_56)
subcc %g1, 64, %g1
bne,pt %XCC, 1b
add %o0, 64, %o0
ba,pt %XCC, 60f
add %i1, 0x8, %i1
50: /* Destination is 64-byte aligned, and source is 16-byte
* aligned.
*/
mov 16, %o7
mov 32, %g2
mov 48, %g3
mov 64, %o1
1: EX_LD(LOAD_TWIN(%i1 + %g0, %o4, %o5), NG_ret_i2_plus_g1)
EX_LD(LOAD_TWIN(%i1 + %o7, %o2, %o3), NG_ret_i2_plus_g1)
LOAD(prefetch, %i1 + %o1, #one_read)
EX_ST(STORE_INIT(%o4, %o0 + 0x00), NG_ret_i2_plus_g1) ! initializes cache line
EX_ST(STORE_INIT(%o5, %o0 + 0x08), NG_ret_i2_plus_g1_minus_8)
EX_LD(LOAD_TWIN(%i1 + %g2, %o4, %o5), NG_ret_i2_plus_g1_minus_16)
EX_ST(STORE_INIT(%o2, %o0 + 0x10), NG_ret_i2_plus_g1_minus_16)
EX_ST(STORE_INIT(%o3, %o0 + 0x18), NG_ret_i2_plus_g1_minus_24)
EX_LD(LOAD_TWIN(%i1 + %g3, %o2, %o3), NG_ret_i2_plus_g1_minus_32)
add %i1, 64, %i1
EX_ST(STORE_INIT(%o4, %o0 + 0x20), NG_ret_i2_plus_g1_minus_32)
EX_ST(STORE_INIT(%o5, %o0 + 0x28), NG_ret_i2_plus_g1_minus_40)
EX_ST(STORE_INIT(%o2, %o0 + 0x30), NG_ret_i2_plus_g1_minus_48)
EX_ST(STORE_INIT(%o3, %o0 + 0x38), NG_ret_i2_plus_g1_minus_56)
subcc %g1, 64, %g1
bne,pt %XCC, 1b
add %o0, 64, %o0
/* fall through */
60:
membar #Sync
/* %i2 contains any final bytes still needed to be copied
* over. If anything is left, we copy it one byte at a time.
*/
RESTORE_ASI(%i3)
brz,pt %i2, 85f
sub %o0, %i1, %i3
ba,a,pt %XCC, 90f
nop
.align 64
70: /* 16 < len <= 64 */
bne,pn %XCC, 75f
sub %o0, %i1, %i3
72:
andn %i2, 0xf, %i4
and %i2, 0xf, %i2
1: subcc %i4, 0x10, %i4
EX_LD(LOAD(ldx, %i1, %o4), NG_ret_i2_plus_i4)
add %i1, 0x08, %i1
EX_LD(LOAD(ldx, %i1, %g1), NG_ret_i2_plus_i4)
sub %i1, 0x08, %i1
EX_ST(STORE(stx, %o4, %i1 + %i3), NG_ret_i2_plus_i4)
add %i1, 0x8, %i1
EX_ST(STORE(stx, %g1, %i1 + %i3), NG_ret_i2_plus_i4_minus_8)
bgu,pt %XCC, 1b
add %i1, 0x8, %i1
73: andcc %i2, 0x8, %g0
be,pt %XCC, 1f
nop
sub %i2, 0x8, %i2
EX_LD(LOAD(ldx, %i1, %o4), NG_ret_i2_plus_8)
EX_ST(STORE(stx, %o4, %i1 + %i3), NG_ret_i2_plus_8)
add %i1, 0x8, %i1
1: andcc %i2, 0x4, %g0
be,pt %XCC, 1f
nop
sub %i2, 0x4, %i2
EX_LD(LOAD(lduw, %i1, %i5), NG_ret_i2_plus_4)
EX_ST(STORE(stw, %i5, %i1 + %i3), NG_ret_i2_plus_4)
add %i1, 0x4, %i1
1: cmp %i2, 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 %i2, %g1, %i2
1: subcc %g1, 1, %g1
EX_LD(LOAD(ldub, %i1, %i5), NG_ret_i2_plus_g1_plus_1)
EX_ST(STORE(stb, %i5, %i1 + %i3), NG_ret_i2_plus_g1_plus_1)
bgu,pt %icc, 1b
add %i1, 1, %i1
2: add %i1, %i3, %o0
andcc %i1, 0x7, %g1
bne,pt %icc, 8f
sll %g1, 3, %g1
cmp %i2, 16
bgeu,pt %icc, 72b
nop
ba,a,pt %xcc, 73b
8: mov 64, %i3
andn %i1, 0x7, %i1
EX_LD(LOAD(ldx, %i1, %g2), NG_ret_i2)
sub %i3, %g1, %i3
andn %i2, 0x7, %i4
sllx %g2, %g1, %g2
1: add %i1, 0x8, %i1
EX_LD(LOAD(ldx, %i1, %g3), NG_ret_i2_and_7_plus_i4)
subcc %i4, 0x8, %i4
srlx %g3, %i3, %i5
or %i5, %g2, %i5
EX_ST(STORE(stx, %i5, %o0), NG_ret_i2_and_7_plus_i4)
add %o0, 0x8, %o0
bgu,pt %icc, 1b
sllx %g3, %g1, %g2
srl %g1, 3, %g1
andcc %i2, 0x7, %i2
be,pn %icc, 85f
add %i1, %g1, %i1
ba,pt %xcc, 90f
sub %o0, %i1, %i3
.align 64
80: /* 0 < len <= 16 */
andcc %i3, 0x3, %g0
bne,pn %XCC, 90f
sub %o0, %i1, %i3
1:
subcc %i2, 4, %i2
EX_LD(LOAD(lduw, %i1, %g1), NG_ret_i2_plus_4)
EX_ST(STORE(stw, %g1, %i1 + %i3), NG_ret_i2_plus_4)
bgu,pt %XCC, 1b
add %i1, 4, %i1
85: ret
restore EX_RETVAL(%i0), %g0, %o0
.align 32
90:
subcc %i2, 1, %i2
EX_LD(LOAD(ldub, %i1, %g1), NG_ret_i2_plus_1)
EX_ST(STORE(stb, %g1, %i1 + %i3), NG_ret_i2_plus_1)
bgu,pt %XCC, 90b
add %i1, 1, %i1
ret
restore EX_RETVAL(%i0), %g0, %o0
.size FUNC_NAME, .-FUNC_NAME