linux_dsm_epyc7002/arch/powerpc/lib/copyuser_64.S
Paul E. McKenney 20151169f1 powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian
The powerpc 64-bit __copy_tofrom_user() function uses shifts to handle
unaligned invocations.  However, these shifts were designed for
big-endian systems: On little-endian systems, they must shift in the
opposite direction.

This commit relies on the C preprocessor to insert the correct shifts
into the assembly code.

[ This is a rare but nasty LE issue. Most of the time we use the POWER7
optimised __copy_tofrom_user_power7 loop, but when it hits an exception
we fall back to the base __copy_tofrom_user loop. - Anton ]

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30 14:02:30 +11:00

675 lines
11 KiB
ArmAsm

/*
* Copyright (C) 2002 Paul Mackerras, IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <asm/processor.h>
#include <asm/ppc_asm.h>
#ifdef __BIG_ENDIAN__
#define sLd sld /* Shift towards low-numbered address. */
#define sHd srd /* Shift towards high-numbered address. */
#else
#define sLd srd /* Shift towards low-numbered address. */
#define sHd sld /* Shift towards high-numbered address. */
#endif
.align 7
_GLOBAL(__copy_tofrom_user)
BEGIN_FTR_SECTION
nop
FTR_SECTION_ELSE
b __copy_tofrom_user_power7
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_VMX_COPY)
_GLOBAL(__copy_tofrom_user_base)
/* first check for a whole page copy on a page boundary */
cmpldi cr1,r5,16
cmpdi cr6,r5,4096
or r0,r3,r4
neg r6,r3 /* LS 3 bits = # bytes to 8-byte dest bdry */
andi. r0,r0,4095
std r3,-24(r1)
crand cr0*4+2,cr0*4+2,cr6*4+2
std r4,-16(r1)
std r5,-8(r1)
dcbt 0,r4
beq .Lcopy_page_4K
andi. r6,r6,7
PPC_MTOCRF(0x01,r5)
blt cr1,.Lshort_copy
/* Below we want to nop out the bne if we're on a CPU that has the
* CPU_FTR_UNALIGNED_LD_STD bit set and the CPU_FTR_CP_USE_DCBTZ bit
* cleared.
* At the time of writing the only CPU that has this combination of bits
* set is Power6.
*/
BEGIN_FTR_SECTION
nop
FTR_SECTION_ELSE
bne .Ldst_unaligned
ALT_FTR_SECTION_END(CPU_FTR_UNALIGNED_LD_STD | CPU_FTR_CP_USE_DCBTZ, \
CPU_FTR_UNALIGNED_LD_STD)
.Ldst_aligned:
addi r3,r3,-16
BEGIN_FTR_SECTION
andi. r0,r4,7
bne .Lsrc_unaligned
END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
blt cr1,.Ldo_tail /* if < 16 bytes to copy */
srdi r0,r5,5
cmpdi cr1,r0,0
20: ld r7,0(r4)
220: ld r6,8(r4)
addi r4,r4,16
mtctr r0
andi. r0,r5,0x10
beq 22f
addi r3,r3,16
addi r4,r4,-16
mr r9,r7
mr r8,r6
beq cr1,72f
21: ld r7,16(r4)
221: ld r6,24(r4)
addi r4,r4,32
70: std r9,0(r3)
270: std r8,8(r3)
22: ld r9,0(r4)
222: ld r8,8(r4)
71: std r7,16(r3)
271: std r6,24(r3)
addi r3,r3,32
bdnz 21b
72: std r9,0(r3)
272: std r8,8(r3)
andi. r5,r5,0xf
beq+ 3f
addi r4,r4,16
.Ldo_tail:
addi r3,r3,16
bf cr7*4+0,246f
244: ld r9,0(r4)
addi r4,r4,8
245: std r9,0(r3)
addi r3,r3,8
246: bf cr7*4+1,1f
23: lwz r9,0(r4)
addi r4,r4,4
73: stw r9,0(r3)
addi r3,r3,4
1: bf cr7*4+2,2f
44: lhz r9,0(r4)
addi r4,r4,2
74: sth r9,0(r3)
addi r3,r3,2
2: bf cr7*4+3,3f
45: lbz r9,0(r4)
75: stb r9,0(r3)
3: li r3,0
blr
.Lsrc_unaligned:
srdi r6,r5,3
addi r5,r5,-16
subf r4,r0,r4
srdi r7,r5,4
sldi r10,r0,3
cmpldi cr6,r6,3
andi. r5,r5,7
mtctr r7
subfic r11,r10,64
add r5,r5,r0
bt cr7*4+0,28f
24: ld r9,0(r4) /* 3+2n loads, 2+2n stores */
25: ld r0,8(r4)
sLd r6,r9,r10
26: ldu r9,16(r4)
sHd r7,r0,r11
sLd r8,r0,r10
or r7,r7,r6
blt cr6,79f
27: ld r0,8(r4)
b 2f
28: ld r0,0(r4) /* 4+2n loads, 3+2n stores */
29: ldu r9,8(r4)
sLd r8,r0,r10
addi r3,r3,-8
blt cr6,5f
30: ld r0,8(r4)
sHd r12,r9,r11
sLd r6,r9,r10
31: ldu r9,16(r4)
or r12,r8,r12
sHd r7,r0,r11
sLd r8,r0,r10
addi r3,r3,16
beq cr6,78f
1: or r7,r7,r6
32: ld r0,8(r4)
76: std r12,8(r3)
2: sHd r12,r9,r11
sLd r6,r9,r10
33: ldu r9,16(r4)
or r12,r8,r12
77: stdu r7,16(r3)
sHd r7,r0,r11
sLd r8,r0,r10
bdnz 1b
78: std r12,8(r3)
or r7,r7,r6
79: std r7,16(r3)
5: sHd r12,r9,r11
or r12,r8,r12
80: std r12,24(r3)
bne 6f
li r3,0
blr
6: cmpwi cr1,r5,8
addi r3,r3,32
sLd r9,r9,r10
ble cr1,7f
34: ld r0,8(r4)
sHd r7,r0,r11
or r9,r7,r9
7:
bf cr7*4+1,1f
#ifdef __BIG_ENDIAN__
rotldi r9,r9,32
#endif
94: stw r9,0(r3)
#ifdef __LITTLE_ENDIAN__
rotrdi r9,r9,32
#endif
addi r3,r3,4
1: bf cr7*4+2,2f
#ifdef __BIG_ENDIAN__
rotldi r9,r9,16
#endif
95: sth r9,0(r3)
#ifdef __LITTLE_ENDIAN__
rotrdi r9,r9,16
#endif
addi r3,r3,2
2: bf cr7*4+3,3f
#ifdef __BIG_ENDIAN__
rotldi r9,r9,8
#endif
96: stb r9,0(r3)
#ifdef __LITTLE_ENDIAN__
rotrdi r9,r9,8
#endif
3: li r3,0
blr
.Ldst_unaligned:
PPC_MTOCRF(0x01,r6) /* put #bytes to 8B bdry into cr7 */
subf r5,r6,r5
li r7,0
cmpldi cr1,r5,16
bf cr7*4+3,1f
35: lbz r0,0(r4)
81: stb r0,0(r3)
addi r7,r7,1
1: bf cr7*4+2,2f
36: lhzx r0,r7,r4
82: sthx r0,r7,r3
addi r7,r7,2
2: bf cr7*4+1,3f
37: lwzx r0,r7,r4
83: stwx r0,r7,r3
3: PPC_MTOCRF(0x01,r5)
add r4,r6,r4
add r3,r6,r3
b .Ldst_aligned
.Lshort_copy:
bf cr7*4+0,1f
38: lwz r0,0(r4)
39: lwz r9,4(r4)
addi r4,r4,8
84: stw r0,0(r3)
85: stw r9,4(r3)
addi r3,r3,8
1: bf cr7*4+1,2f
40: lwz r0,0(r4)
addi r4,r4,4
86: stw r0,0(r3)
addi r3,r3,4
2: bf cr7*4+2,3f
41: lhz r0,0(r4)
addi r4,r4,2
87: sth r0,0(r3)
addi r3,r3,2
3: bf cr7*4+3,4f
42: lbz r0,0(r4)
88: stb r0,0(r3)
4: li r3,0
blr
/*
* exception handlers follow
* we have to return the number of bytes not copied
* for an exception on a load, we set the rest of the destination to 0
*/
136:
137:
add r3,r3,r7
b 1f
130:
131:
addi r3,r3,8
120:
320:
122:
322:
124:
125:
126:
127:
128:
129:
133:
addi r3,r3,8
132:
addi r3,r3,8
121:
321:
344:
134:
135:
138:
139:
140:
141:
142:
123:
144:
145:
/*
* here we have had a fault on a load and r3 points to the first
* unmodified byte of the destination
*/
1: ld r6,-24(r1)
ld r4,-16(r1)
ld r5,-8(r1)
subf r6,r6,r3
add r4,r4,r6
subf r5,r6,r5 /* #bytes left to go */
/*
* first see if we can copy any more bytes before hitting another exception
*/
mtctr r5
43: lbz r0,0(r4)
addi r4,r4,1
89: stb r0,0(r3)
addi r3,r3,1
bdnz 43b
li r3,0 /* huh? all copied successfully this time? */
blr
/*
* here we have trapped again, need to clear ctr bytes starting at r3
*/
143: mfctr r5
li r0,0
mr r4,r3
mr r3,r5 /* return the number of bytes not copied */
1: andi. r9,r4,7
beq 3f
90: stb r0,0(r4)
addic. r5,r5,-1
addi r4,r4,1
bne 1b
blr
3: cmpldi cr1,r5,8
srdi r9,r5,3
andi. r5,r5,7
blt cr1,93f
mtctr r9
91: std r0,0(r4)
addi r4,r4,8
bdnz 91b
93: beqlr
mtctr r5
92: stb r0,0(r4)
addi r4,r4,1
bdnz 92b
blr
/*
* exception handlers for stores: we just need to work
* out how many bytes weren't copied
*/
182:
183:
add r3,r3,r7
b 1f
371:
180:
addi r3,r3,8
171:
177:
addi r3,r3,8
370:
372:
176:
178:
addi r3,r3,4
185:
addi r3,r3,4
170:
172:
345:
173:
174:
175:
179:
181:
184:
186:
187:
188:
189:
194:
195:
196:
1:
ld r6,-24(r1)
ld r5,-8(r1)
add r6,r6,r5
subf r3,r3,r6 /* #bytes not copied */
190:
191:
192:
blr /* #bytes not copied in r3 */
.section __ex_table,"a"
.align 3
.llong 20b,120b
.llong 220b,320b
.llong 21b,121b
.llong 221b,321b
.llong 70b,170b
.llong 270b,370b
.llong 22b,122b
.llong 222b,322b
.llong 71b,171b
.llong 271b,371b
.llong 72b,172b
.llong 272b,372b
.llong 244b,344b
.llong 245b,345b
.llong 23b,123b
.llong 73b,173b
.llong 44b,144b
.llong 74b,174b
.llong 45b,145b
.llong 75b,175b
.llong 24b,124b
.llong 25b,125b
.llong 26b,126b
.llong 27b,127b
.llong 28b,128b
.llong 29b,129b
.llong 30b,130b
.llong 31b,131b
.llong 32b,132b
.llong 76b,176b
.llong 33b,133b
.llong 77b,177b
.llong 78b,178b
.llong 79b,179b
.llong 80b,180b
.llong 34b,134b
.llong 94b,194b
.llong 95b,195b
.llong 96b,196b
.llong 35b,135b
.llong 81b,181b
.llong 36b,136b
.llong 82b,182b
.llong 37b,137b
.llong 83b,183b
.llong 38b,138b
.llong 39b,139b
.llong 84b,184b
.llong 85b,185b
.llong 40b,140b
.llong 86b,186b
.llong 41b,141b
.llong 87b,187b
.llong 42b,142b
.llong 88b,188b
.llong 43b,143b
.llong 89b,189b
.llong 90b,190b
.llong 91b,191b
.llong 92b,192b
.text
/*
* Routine to copy a whole page of data, optimized for POWER4.
* On POWER4 it is more than 50% faster than the simple loop
* above (following the .Ldst_aligned label) but it runs slightly
* slower on POWER3.
*/
.Lcopy_page_4K:
std r31,-32(1)
std r30,-40(1)
std r29,-48(1)
std r28,-56(1)
std r27,-64(1)
std r26,-72(1)
std r25,-80(1)
std r24,-88(1)
std r23,-96(1)
std r22,-104(1)
std r21,-112(1)
std r20,-120(1)
li r5,4096/32 - 1
addi r3,r3,-8
li r0,5
0: addi r5,r5,-24
mtctr r0
20: ld r22,640(4)
21: ld r21,512(4)
22: ld r20,384(4)
23: ld r11,256(4)
24: ld r9,128(4)
25: ld r7,0(4)
26: ld r25,648(4)
27: ld r24,520(4)
28: ld r23,392(4)
29: ld r10,264(4)
30: ld r8,136(4)
31: ldu r6,8(4)
cmpwi r5,24
1:
32: std r22,648(3)
33: std r21,520(3)
34: std r20,392(3)
35: std r11,264(3)
36: std r9,136(3)
37: std r7,8(3)
38: ld r28,648(4)
39: ld r27,520(4)
40: ld r26,392(4)
41: ld r31,264(4)
42: ld r30,136(4)
43: ld r29,8(4)
44: std r25,656(3)
45: std r24,528(3)
46: std r23,400(3)
47: std r10,272(3)
48: std r8,144(3)
49: std r6,16(3)
50: ld r22,656(4)
51: ld r21,528(4)
52: ld r20,400(4)
53: ld r11,272(4)
54: ld r9,144(4)
55: ld r7,16(4)
56: std r28,664(3)
57: std r27,536(3)
58: std r26,408(3)
59: std r31,280(3)
60: std r30,152(3)
61: stdu r29,24(3)
62: ld r25,664(4)
63: ld r24,536(4)
64: ld r23,408(4)
65: ld r10,280(4)
66: ld r8,152(4)
67: ldu r6,24(4)
bdnz 1b
68: std r22,648(3)
69: std r21,520(3)
70: std r20,392(3)
71: std r11,264(3)
72: std r9,136(3)
73: std r7,8(3)
74: addi r4,r4,640
75: addi r3,r3,648
bge 0b
mtctr r5
76: ld r7,0(4)
77: ld r8,8(4)
78: ldu r9,16(4)
3:
79: ld r10,8(4)
80: std r7,8(3)
81: ld r7,16(4)
82: std r8,16(3)
83: ld r8,24(4)
84: std r9,24(3)
85: ldu r9,32(4)
86: stdu r10,32(3)
bdnz 3b
4:
87: ld r10,8(4)
88: std r7,8(3)
89: std r8,16(3)
90: std r9,24(3)
91: std r10,32(3)
9: ld r20,-120(1)
ld r21,-112(1)
ld r22,-104(1)
ld r23,-96(1)
ld r24,-88(1)
ld r25,-80(1)
ld r26,-72(1)
ld r27,-64(1)
ld r28,-56(1)
ld r29,-48(1)
ld r30,-40(1)
ld r31,-32(1)
li r3,0
blr
/*
* on an exception, reset to the beginning and jump back into the
* standard __copy_tofrom_user
*/
100: ld r20,-120(1)
ld r21,-112(1)
ld r22,-104(1)
ld r23,-96(1)
ld r24,-88(1)
ld r25,-80(1)
ld r26,-72(1)
ld r27,-64(1)
ld r28,-56(1)
ld r29,-48(1)
ld r30,-40(1)
ld r31,-32(1)
ld r3,-24(r1)
ld r4,-16(r1)
li r5,4096
b .Ldst_aligned
.section __ex_table,"a"
.align 3
.llong 20b,100b
.llong 21b,100b
.llong 22b,100b
.llong 23b,100b
.llong 24b,100b
.llong 25b,100b
.llong 26b,100b
.llong 27b,100b
.llong 28b,100b
.llong 29b,100b
.llong 30b,100b
.llong 31b,100b
.llong 32b,100b
.llong 33b,100b
.llong 34b,100b
.llong 35b,100b
.llong 36b,100b
.llong 37b,100b
.llong 38b,100b
.llong 39b,100b
.llong 40b,100b
.llong 41b,100b
.llong 42b,100b
.llong 43b,100b
.llong 44b,100b
.llong 45b,100b
.llong 46b,100b
.llong 47b,100b
.llong 48b,100b
.llong 49b,100b
.llong 50b,100b
.llong 51b,100b
.llong 52b,100b
.llong 53b,100b
.llong 54b,100b
.llong 55b,100b
.llong 56b,100b
.llong 57b,100b
.llong 58b,100b
.llong 59b,100b
.llong 60b,100b
.llong 61b,100b
.llong 62b,100b
.llong 63b,100b
.llong 64b,100b
.llong 65b,100b
.llong 66b,100b
.llong 67b,100b
.llong 68b,100b
.llong 69b,100b
.llong 70b,100b
.llong 71b,100b
.llong 72b,100b
.llong 73b,100b
.llong 74b,100b
.llong 75b,100b
.llong 76b,100b
.llong 77b,100b
.llong 78b,100b
.llong 79b,100b
.llong 80b,100b
.llong 81b,100b
.llong 82b,100b
.llong 83b,100b
.llong 84b,100b
.llong 85b,100b
.llong 86b,100b
.llong 87b,100b
.llong 88b,100b
.llong 89b,100b
.llong 90b,100b
.llong 91b,100b