Commit a7c81ce3 authored by Paul Mackerras's avatar Paul Mackerras Committed by Michael Ellerman

powerpc/64: Make exception table clearer in __copy_tofrom_user_base

This aims to make the generation of exception table entries for the
loads and stores in __copy_tofrom_user_base clearer and easier to
verify.  Instead of having a series of local labels on the loads and
stores, with a series of corresponding labels later for the exception
handlers, we now use macros to generate exception table entries at the
point of each load and store that could potentially trap.  We do this
with the macros lex (load exception) and stex (store exception).
These macros are used right before the load or store to which they
apply.

Some complexity is introduced by the fact that we have some more work
to do after hitting an exception, because we need to calculate and
return the number of bytes not copied.  The code uses r3 as the
current pointer into the destination buffer, that is, the address of
the first byte of the destination that has not been modified.
However, at various points in the copy loops, r3 can be 4, 8, 16 or 24
bytes behind that point.

To express this offset in an understandable way, we define a symbol
r3_offset which is updated at various points so that it equal to the
difference between the address of the first unmodified byte of the
destination and the value in r3.  (In fact it only needs to be
accurate at the point of each lex or stex macro invocation.)

The rules for updating r3_offset are as follows:

* It starts out at 0
* An addi r3,r3,N instruction decreases r3_offset by N
* A store instruction (stb, sth, stw, std) to N(r3)
  increases r3_offset by the width of the store (1, 2, 4, 8)
* A store with update instruction (stbu, sthu, stwu, stdu) to N(r3)
  sets r3_offset to the width of the store.

There is some trickiness to the way that the lex and stex macros and
the associated exception handlers work.  I would have liked to use
the current value of r3_offset in the name of the symbol used as
the exception handler, as in ".Lld_exc_$(r3_offset)" and then
have symbols .Lld_exc_0, .Lld_exc_8, .Lld_exc_16 etc. corresponding
to the offsets that needed to be added to r3.  However, I couldn't
see a way to do that with gas.

Instead, the exception handler address is .Lld_exc - r3_offset or
.Lst_exc - r3_offset, that is, the distance ahead of .Lld_exc/.Lst_exc
that we start executing is equal to the amount that we need to add to
r3.  This works because r3_offset is always a small multiple of 4,
and our instructions are 4 bytes long.  This means that before
.Lld_exc and .Lst_exc, we have a sequence of instructions that
increments r3 by 4, 8, 16 or 24 depending on where we start.  The
sequence increments r3 by 4 per instruction (on average).

We also replace the exception table for the 4k copy loop by a
macro per load or store.  These loads and stores all use exactly
the same exception handler, which simply resets the argument registers
r3, r4 and r5 to there original values and re-does the whole copy
using the slower loop.
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 81d7b08b
...@@ -20,6 +20,28 @@ ...@@ -20,6 +20,28 @@
#define sHd sld /* Shift towards high-numbered address. */ #define sHd sld /* Shift towards high-numbered address. */
#endif #endif
/*
* These macros are used to generate exception table entries.
* The exception handlers below use the original arguments
* (stored on the stack) and the point where we're up to in
* the destination buffer, i.e. the address of the first
* unmodified byte. Generally r3 points into the destination
* buffer, but the first unmodified byte is at a variable
* offset from r3. In the code below, the symbol r3_offset
* is set to indicate the current offset at each point in
* the code. This offset is then used as a negative offset
* from the exception handler code, and those instructions
* before the exception handlers are addi instructions that
* adjust r3 to point to the correct place.
*/
.macro lex /* exception handler for load */
100: EX_TABLE(100b, .Lld_exc - r3_offset)
.endm
.macro stex /* exception handler for store */
100: EX_TABLE(100b, .Lst_exc - r3_offset)
.endm
.align 7 .align 7
_GLOBAL_TOC(__copy_tofrom_user) _GLOBAL_TOC(__copy_tofrom_user)
#ifdef CONFIG_PPC_BOOK3S_64 #ifdef CONFIG_PPC_BOOK3S_64
...@@ -30,7 +52,7 @@ FTR_SECTION_ELSE ...@@ -30,7 +52,7 @@ FTR_SECTION_ELSE
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_VMX_COPY) ALT_FTR_SECTION_END_IFCLR(CPU_FTR_VMX_COPY)
#endif #endif
_GLOBAL(__copy_tofrom_user_base) _GLOBAL(__copy_tofrom_user_base)
/* first check for a whole page copy on a page boundary */ /* first check for a 4kB copy on a 4kB boundary */
cmpldi cr1,r5,16 cmpldi cr1,r5,16
cmpdi cr6,r5,4096 cmpdi cr6,r5,4096
or r0,r3,r4 or r0,r3,r4
...@@ -59,6 +81,7 @@ ALT_FTR_SECTION_END(CPU_FTR_UNALIGNED_LD_STD | CPU_FTR_CP_USE_DCBTZ, \ ...@@ -59,6 +81,7 @@ ALT_FTR_SECTION_END(CPU_FTR_UNALIGNED_LD_STD | CPU_FTR_CP_USE_DCBTZ, \
CPU_FTR_UNALIGNED_LD_STD) CPU_FTR_UNALIGNED_LD_STD)
.Ldst_aligned: .Ldst_aligned:
addi r3,r3,-16 addi r3,r3,-16
r3_offset = 16
BEGIN_FTR_SECTION BEGIN_FTR_SECTION
andi. r0,r4,7 andi. r0,r4,7
bne .Lsrc_unaligned bne .Lsrc_unaligned
...@@ -66,57 +89,69 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -66,57 +89,69 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
blt cr1,.Ldo_tail /* if < 16 bytes to copy */ blt cr1,.Ldo_tail /* if < 16 bytes to copy */
srdi r0,r5,5 srdi r0,r5,5
cmpdi cr1,r0,0 cmpdi cr1,r0,0
20: ld r7,0(r4) lex; ld r7,0(r4)
220: ld r6,8(r4) lex; ld r6,8(r4)
addi r4,r4,16 addi r4,r4,16
mtctr r0 mtctr r0
andi. r0,r5,0x10 andi. r0,r5,0x10
beq 22f beq 22f
addi r3,r3,16 addi r3,r3,16
r3_offset = 0
addi r4,r4,-16 addi r4,r4,-16
mr r9,r7 mr r9,r7
mr r8,r6 mr r8,r6
beq cr1,72f beq cr1,72f
21: ld r7,16(r4) 21:
221: ld r6,24(r4) lex; ld r7,16(r4)
lex; ld r6,24(r4)
addi r4,r4,32 addi r4,r4,32
70: std r9,0(r3) stex; std r9,0(r3)
270: std r8,8(r3) r3_offset = 8
22: ld r9,0(r4) stex; std r8,8(r3)
222: ld r8,8(r4) r3_offset = 16
71: std r7,16(r3) 22:
271: std r6,24(r3) lex; ld r9,0(r4)
lex; ld r8,8(r4)
stex; std r7,16(r3)
r3_offset = 24
stex; std r6,24(r3)
addi r3,r3,32 addi r3,r3,32
r3_offset = 0
bdnz 21b bdnz 21b
72: std r9,0(r3) 72:
272: std r8,8(r3) stex; std r9,0(r3)
r3_offset = 8
stex; std r8,8(r3)
r3_offset = 16
andi. r5,r5,0xf andi. r5,r5,0xf
beq+ 3f beq+ 3f
addi r4,r4,16 addi r4,r4,16
.Ldo_tail: .Ldo_tail:
addi r3,r3,16 addi r3,r3,16
r3_offset = 0
bf cr7*4+0,246f bf cr7*4+0,246f
244: ld r9,0(r4) lex; ld r9,0(r4)
addi r4,r4,8 addi r4,r4,8
245: std r9,0(r3) stex; std r9,0(r3)
addi r3,r3,8 addi r3,r3,8
246: bf cr7*4+1,1f 246: bf cr7*4+1,1f
23: lwz r9,0(r4) lex; lwz r9,0(r4)
addi r4,r4,4 addi r4,r4,4
73: stw r9,0(r3) stex; stw r9,0(r3)
addi r3,r3,4 addi r3,r3,4
1: bf cr7*4+2,2f 1: bf cr7*4+2,2f
44: lhz r9,0(r4) lex; lhz r9,0(r4)
addi r4,r4,2 addi r4,r4,2
74: sth r9,0(r3) stex; sth r9,0(r3)
addi r3,r3,2 addi r3,r3,2
2: bf cr7*4+3,3f 2: bf cr7*4+3,3f
45: lbz r9,0(r4) lex; lbz r9,0(r4)
75: stb r9,0(r3) stex; stb r9,0(r3)
3: li r3,0 3: li r3,0
blr blr
.Lsrc_unaligned: .Lsrc_unaligned:
r3_offset = 16
srdi r6,r5,3 srdi r6,r5,3
addi r5,r5,-16 addi r5,r5,-16
subf r4,r0,r4 subf r4,r0,r4
...@@ -129,58 +164,69 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -129,58 +164,69 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
add r5,r5,r0 add r5,r5,r0
bt cr7*4+0,28f bt cr7*4+0,28f
24: ld r9,0(r4) /* 3+2n loads, 2+2n stores */ lex; ld r9,0(r4) /* 3+2n loads, 2+2n stores */
25: ld r0,8(r4) lex; ld r0,8(r4)
sLd r6,r9,r10 sLd r6,r9,r10
26: ldu r9,16(r4) lex; ldu r9,16(r4)
sHd r7,r0,r11 sHd r7,r0,r11
sLd r8,r0,r10 sLd r8,r0,r10
or r7,r7,r6 or r7,r7,r6
blt cr6,79f blt cr6,79f
27: ld r0,8(r4) lex; ld r0,8(r4)
b 2f b 2f
28: ld r0,0(r4) /* 4+2n loads, 3+2n stores */ 28:
29: ldu r9,8(r4) lex; ld r0,0(r4) /* 4+2n loads, 3+2n stores */
lex; ldu r9,8(r4)
sLd r8,r0,r10 sLd r8,r0,r10
addi r3,r3,-8 addi r3,r3,-8
r3_offset = 24
blt cr6,5f blt cr6,5f
30: ld r0,8(r4) lex; ld r0,8(r4)
sHd r12,r9,r11 sHd r12,r9,r11
sLd r6,r9,r10 sLd r6,r9,r10
31: ldu r9,16(r4) lex; ldu r9,16(r4)
or r12,r8,r12 or r12,r8,r12
sHd r7,r0,r11 sHd r7,r0,r11
sLd r8,r0,r10 sLd r8,r0,r10
addi r3,r3,16 addi r3,r3,16
r3_offset = 8
beq cr6,78f beq cr6,78f
1: or r7,r7,r6 1: or r7,r7,r6
32: ld r0,8(r4) lex; ld r0,8(r4)
76: std r12,8(r3) stex; std r12,8(r3)
r3_offset = 16
2: sHd r12,r9,r11 2: sHd r12,r9,r11
sLd r6,r9,r10 sLd r6,r9,r10
33: ldu r9,16(r4) lex; ldu r9,16(r4)
or r12,r8,r12 or r12,r8,r12
77: stdu r7,16(r3) stex; stdu r7,16(r3)
r3_offset = 8
sHd r7,r0,r11 sHd r7,r0,r11
sLd r8,r0,r10 sLd r8,r0,r10
bdnz 1b bdnz 1b
78: std r12,8(r3) 78:
stex; std r12,8(r3)
r3_offset = 16
or r7,r7,r6 or r7,r7,r6
79: std r7,16(r3) 79:
stex; std r7,16(r3)
r3_offset = 24
5: sHd r12,r9,r11 5: sHd r12,r9,r11
or r12,r8,r12 or r12,r8,r12
80: std r12,24(r3) stex; std r12,24(r3)
r3_offset = 32
bne 6f bne 6f
li r3,0 li r3,0
blr blr
6: cmpwi cr1,r5,8 6: cmpwi cr1,r5,8
addi r3,r3,32 addi r3,r3,32
r3_offset = 0
sLd r9,r9,r10 sLd r9,r9,r10
ble cr1,7f ble cr1,7f
34: ld r0,8(r4) lex; ld r0,8(r4)
sHd r7,r0,r11 sHd r7,r0,r11
or r9,r7,r9 or r9,r7,r9
7: 7:
...@@ -188,7 +234,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -188,7 +234,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
#ifdef __BIG_ENDIAN__ #ifdef __BIG_ENDIAN__
rotldi r9,r9,32 rotldi r9,r9,32
#endif #endif
94: stw r9,0(r3) stex; stw r9,0(r3)
#ifdef __LITTLE_ENDIAN__ #ifdef __LITTLE_ENDIAN__
rotrdi r9,r9,32 rotrdi r9,r9,32
#endif #endif
...@@ -197,7 +243,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -197,7 +243,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
#ifdef __BIG_ENDIAN__ #ifdef __BIG_ENDIAN__
rotldi r9,r9,16 rotldi r9,r9,16
#endif #endif
95: sth r9,0(r3) stex; sth r9,0(r3)
#ifdef __LITTLE_ENDIAN__ #ifdef __LITTLE_ENDIAN__
rotrdi r9,r9,16 rotrdi r9,r9,16
#endif #endif
...@@ -206,7 +252,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -206,7 +252,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
#ifdef __BIG_ENDIAN__ #ifdef __BIG_ENDIAN__
rotldi r9,r9,8 rotldi r9,r9,8
#endif #endif
96: stb r9,0(r3) stex; stb r9,0(r3)
#ifdef __LITTLE_ENDIAN__ #ifdef __LITTLE_ENDIAN__
rotrdi r9,r9,8 rotrdi r9,r9,8
#endif #endif
...@@ -214,47 +260,55 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -214,47 +260,55 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
blr blr
.Ldst_unaligned: .Ldst_unaligned:
r3_offset = 0
PPC_MTOCRF(0x01,r6) /* put #bytes to 8B bdry into cr7 */ PPC_MTOCRF(0x01,r6) /* put #bytes to 8B bdry into cr7 */
subf r5,r6,r5 subf r5,r6,r5
li r7,0 li r7,0
cmpldi cr1,r5,16 cmpldi cr1,r5,16
bf cr7*4+3,1f bf cr7*4+3,1f
35: lbz r0,0(r4) 100: EX_TABLE(100b, .Lld_exc_r7)
81: stb r0,0(r3) lbz r0,0(r4)
100: EX_TABLE(100b, .Lst_exc_r7)
stb r0,0(r3)
addi r7,r7,1 addi r7,r7,1
1: bf cr7*4+2,2f 1: bf cr7*4+2,2f
36: lhzx r0,r7,r4 100: EX_TABLE(100b, .Lld_exc_r7)
82: sthx r0,r7,r3 lhzx r0,r7,r4
100: EX_TABLE(100b, .Lst_exc_r7)
sthx r0,r7,r3
addi r7,r7,2 addi r7,r7,2
2: bf cr7*4+1,3f 2: bf cr7*4+1,3f
37: lwzx r0,r7,r4 100: EX_TABLE(100b, .Lld_exc_r7)
83: stwx r0,r7,r3 lwzx r0,r7,r4
100: EX_TABLE(100b, .Lst_exc_r7)
stwx r0,r7,r3
3: PPC_MTOCRF(0x01,r5) 3: PPC_MTOCRF(0x01,r5)
add r4,r6,r4 add r4,r6,r4
add r3,r6,r3 add r3,r6,r3
b .Ldst_aligned b .Ldst_aligned
.Lshort_copy: .Lshort_copy:
r3_offset = 0
bf cr7*4+0,1f bf cr7*4+0,1f
38: lwz r0,0(r4) lex; lwz r0,0(r4)
39: lwz r9,4(r4) lex; lwz r9,4(r4)
addi r4,r4,8 addi r4,r4,8
84: stw r0,0(r3) stex; stw r0,0(r3)
85: stw r9,4(r3) stex; stw r9,4(r3)
addi r3,r3,8 addi r3,r3,8
1: bf cr7*4+1,2f 1: bf cr7*4+1,2f
40: lwz r0,0(r4) lex; lwz r0,0(r4)
addi r4,r4,4 addi r4,r4,4
86: stw r0,0(r3) stex; stw r0,0(r3)
addi r3,r3,4 addi r3,r3,4
2: bf cr7*4+2,3f 2: bf cr7*4+2,3f
41: lhz r0,0(r4) lex; lhz r0,0(r4)
addi r4,r4,2 addi r4,r4,2
87: sth r0,0(r3) stex; sth r0,0(r3)
addi r3,r3,2 addi r3,r3,2
3: bf cr7*4+3,4f 3: bf cr7*4+3,4f
42: lbz r0,0(r4) lex; lbz r0,0(r4)
88: stb r0,0(r3) stex; stb r0,0(r3)
4: li r3,0 4: li r3,0
blr blr
...@@ -262,48 +316,34 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -262,48 +316,34 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
* exception handlers follow * exception handlers follow
* we have to return the number of bytes not copied * 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 * for an exception on a load, we set the rest of the destination to 0
* Note that the number of bytes of instructions for adjusting r3 needs
* to equal the amount of the adjustment, due to the trick of using
* .Lld_exc - r3_offset as the handler address.
*/ */
136: .Lld_exc_r7:
137:
add r3,r3,r7 add r3,r3,r7
b 1f b .Lld_exc
130:
131: /* adjust by 24 */
addi r3,r3,8 addi r3,r3,8
120: nop
320: /* adjust by 16 */
122:
322:
124:
125:
126:
127:
128:
129:
133:
addi r3,r3,8 addi r3,r3,8
132: nop
/* adjust by 8 */
addi r3,r3,8 addi r3,r3,8
121: nop
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 * Here we have had a fault on a load and r3 points to the first
* unmodified byte of the destination * unmodified byte of the destination. We use the original arguments
* and r3 to work out how much wasn't copied. Since we load some
* distance ahead of the stores, we continue copying byte-by-byte until
* we hit the load fault again in order to copy as much as possible.
*/ */
1: ld r6,-24(r1) .Lld_exc:
ld r6,-24(r1)
ld r4,-16(r1) ld r4,-16(r1)
ld r5,-8(r1) ld r5,-8(r1)
subf r6,r6,r3 subf r6,r6,r3
...@@ -314,9 +354,11 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -314,9 +354,11 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
* first see if we can copy any more bytes before hitting another exception * first see if we can copy any more bytes before hitting another exception
*/ */
mtctr r5 mtctr r5
r3_offset = 0
100: EX_TABLE(100b, .Ldone)
43: lbz r0,0(r4) 43: lbz r0,0(r4)
addi r4,r4,1 addi r4,r4,1
89: stb r0,0(r3) stex; stb r0,0(r3)
addi r3,r3,1 addi r3,r3,1
bdnz 43b bdnz 43b
li r3,0 /* huh? all copied successfully this time? */ li r3,0 /* huh? all copied successfully this time? */
...@@ -325,116 +367,46 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -325,116 +367,46 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
/* /*
* here we have trapped again, amount remaining is in ctr. * here we have trapped again, amount remaining is in ctr.
*/ */
143: mfctr r3 .Ldone:
mfctr r3
blr blr
/* /*
* exception handlers for stores: we just need to work * exception handlers for stores: we just need to work
* out how many bytes weren't copied * out how many bytes weren't copied
* Note that the number of bytes of instructions for adjusting r3 needs
* to equal the amount of the adjustment, due to the trick of using
* .Lst_exc - r3_offset as the handler address.
*/ */
182: .Lst_exc_r7:
183:
add r3,r3,r7 add r3,r3,r7
b 1f b .Lst_exc
371:
180: /* adjust by 24 */
addi r3,r3,8 addi r3,r3,8
171: nop
177: /* adjust by 16 */
179:
addi r3,r3,8 addi r3,r3,8
370: nop
372: /* adjust by 8 */
176:
178:
addi r3,r3,4 addi r3,r3,4
185: /* adjust by 4 */
addi r3,r3,4 addi r3,r3,4
170: .Lst_exc:
172:
345:
173:
174:
175:
181:
184:
186:
187:
188:
189:
194:
195:
196:
1:
ld r6,-24(r1) ld r6,-24(r1)
ld r5,-8(r1) ld r5,-8(r1)
add r6,r6,r5 add r6,r6,r5
subf r3,r3,r6 /* #bytes not copied */ subf r3,r3,r6 /* #bytes not copied in r3 */
blr blr
EX_TABLE(20b,120b)
EX_TABLE(220b,320b)
EX_TABLE(21b,121b)
EX_TABLE(221b,321b)
EX_TABLE(70b,170b)
EX_TABLE(270b,370b)
EX_TABLE(22b,122b)
EX_TABLE(222b,322b)
EX_TABLE(71b,171b)
EX_TABLE(271b,371b)
EX_TABLE(72b,172b)
EX_TABLE(272b,372b)
EX_TABLE(244b,344b)
EX_TABLE(245b,345b)
EX_TABLE(23b,123b)
EX_TABLE(73b,173b)
EX_TABLE(44b,144b)
EX_TABLE(74b,174b)
EX_TABLE(45b,145b)
EX_TABLE(75b,175b)
EX_TABLE(24b,124b)
EX_TABLE(25b,125b)
EX_TABLE(26b,126b)
EX_TABLE(27b,127b)
EX_TABLE(28b,128b)
EX_TABLE(29b,129b)
EX_TABLE(30b,130b)
EX_TABLE(31b,131b)
EX_TABLE(32b,132b)
EX_TABLE(76b,176b)
EX_TABLE(33b,133b)
EX_TABLE(77b,177b)
EX_TABLE(78b,178b)
EX_TABLE(79b,179b)
EX_TABLE(80b,180b)
EX_TABLE(34b,134b)
EX_TABLE(94b,194b)
EX_TABLE(95b,195b)
EX_TABLE(96b,196b)
EX_TABLE(35b,135b)
EX_TABLE(81b,181b)
EX_TABLE(36b,136b)
EX_TABLE(82b,182b)
EX_TABLE(37b,137b)
EX_TABLE(83b,183b)
EX_TABLE(38b,138b)
EX_TABLE(39b,139b)
EX_TABLE(84b,184b)
EX_TABLE(85b,185b)
EX_TABLE(40b,140b)
EX_TABLE(86b,186b)
EX_TABLE(41b,141b)
EX_TABLE(87b,187b)
EX_TABLE(42b,142b)
EX_TABLE(88b,188b)
EX_TABLE(43b,143b)
EX_TABLE(89b,189b)
/* /*
* Routine to copy a whole page of data, optimized for POWER4. * Routine to copy a whole page of data, optimized for POWER4.
* On POWER4 it is more than 50% faster than the simple loop * On POWER4 it is more than 50% faster than the simple loop
* above (following the .Ldst_aligned label). * above (following the .Ldst_aligned label).
*/ */
.macro exc
100: EX_TABLE(100b, .Labort)
.endm
.Lcopy_page_4K: .Lcopy_page_4K:
std r31,-32(1) std r31,-32(1)
std r30,-40(1) std r30,-40(1)
...@@ -453,86 +425,86 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -453,86 +425,86 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
li r0,5 li r0,5
0: addi r5,r5,-24 0: addi r5,r5,-24
mtctr r0 mtctr r0
20: ld r22,640(4) exc; ld r22,640(4)
21: ld r21,512(4) exc; ld r21,512(4)
22: ld r20,384(4) exc; ld r20,384(4)
23: ld r11,256(4) exc; ld r11,256(4)
24: ld r9,128(4) exc; ld r9,128(4)
25: ld r7,0(4) exc; ld r7,0(4)
26: ld r25,648(4) exc; ld r25,648(4)
27: ld r24,520(4) exc; ld r24,520(4)
28: ld r23,392(4) exc; ld r23,392(4)
29: ld r10,264(4) exc; ld r10,264(4)
30: ld r8,136(4) exc; ld r8,136(4)
31: ldu r6,8(4) exc; ldu r6,8(4)
cmpwi r5,24 cmpwi r5,24
1: 1:
32: std r22,648(3) exc; std r22,648(3)
33: std r21,520(3) exc; std r21,520(3)
34: std r20,392(3) exc; std r20,392(3)
35: std r11,264(3) exc; std r11,264(3)
36: std r9,136(3) exc; std r9,136(3)
37: std r7,8(3) exc; std r7,8(3)
38: ld r28,648(4) exc; ld r28,648(4)
39: ld r27,520(4) exc; ld r27,520(4)
40: ld r26,392(4) exc; ld r26,392(4)
41: ld r31,264(4) exc; ld r31,264(4)
42: ld r30,136(4) exc; ld r30,136(4)
43: ld r29,8(4) exc; ld r29,8(4)
44: std r25,656(3) exc; std r25,656(3)
45: std r24,528(3) exc; std r24,528(3)
46: std r23,400(3) exc; std r23,400(3)
47: std r10,272(3) exc; std r10,272(3)
48: std r8,144(3) exc; std r8,144(3)
49: std r6,16(3) exc; std r6,16(3)
50: ld r22,656(4) exc; ld r22,656(4)
51: ld r21,528(4) exc; ld r21,528(4)
52: ld r20,400(4) exc; ld r20,400(4)
53: ld r11,272(4) exc; ld r11,272(4)
54: ld r9,144(4) exc; ld r9,144(4)
55: ld r7,16(4) exc; ld r7,16(4)
56: std r28,664(3) exc; std r28,664(3)
57: std r27,536(3) exc; std r27,536(3)
58: std r26,408(3) exc; std r26,408(3)
59: std r31,280(3) exc; std r31,280(3)
60: std r30,152(3) exc; std r30,152(3)
61: stdu r29,24(3) exc; stdu r29,24(3)
62: ld r25,664(4) exc; ld r25,664(4)
63: ld r24,536(4) exc; ld r24,536(4)
64: ld r23,408(4) exc; ld r23,408(4)
65: ld r10,280(4) exc; ld r10,280(4)
66: ld r8,152(4) exc; ld r8,152(4)
67: ldu r6,24(4) exc; ldu r6,24(4)
bdnz 1b bdnz 1b
68: std r22,648(3) exc; std r22,648(3)
69: std r21,520(3) exc; std r21,520(3)
70: std r20,392(3) exc; std r20,392(3)
71: std r11,264(3) exc; std r11,264(3)
72: std r9,136(3) exc; std r9,136(3)
73: std r7,8(3) exc; std r7,8(3)
74: addi r4,r4,640 addi r4,r4,640
75: addi r3,r3,648 addi r3,r3,648
bge 0b bge 0b
mtctr r5 mtctr r5
76: ld r7,0(4) exc; ld r7,0(4)
77: ld r8,8(4) exc; ld r8,8(4)
78: ldu r9,16(4) exc; ldu r9,16(4)
3: 3:
79: ld r10,8(4) exc; ld r10,8(4)
80: std r7,8(3) exc; std r7,8(3)
81: ld r7,16(4) exc; ld r7,16(4)
82: std r8,16(3) exc; std r8,16(3)
83: ld r8,24(4) exc; ld r8,24(4)
84: std r9,24(3) exc; std r9,24(3)
85: ldu r9,32(4) exc; ldu r9,32(4)
86: stdu r10,32(3) exc; stdu r10,32(3)
bdnz 3b bdnz 3b
4: 4:
87: ld r10,8(4) exc; ld r10,8(4)
88: std r7,8(3) exc; std r7,8(3)
89: std r8,16(3) exc; std r8,16(3)
90: std r9,24(3) exc; std r9,24(3)
91: std r10,32(3) exc; std r10,32(3)
9: ld r20,-120(1) 9: ld r20,-120(1)
ld r21,-112(1) ld r21,-112(1)
ld r22,-104(1) ld r22,-104(1)
...@@ -552,7 +524,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -552,7 +524,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
* on an exception, reset to the beginning and jump back into the * on an exception, reset to the beginning and jump back into the
* standard __copy_tofrom_user * standard __copy_tofrom_user
*/ */
100: ld r20,-120(1) .Labort:
ld r20,-120(1)
ld r21,-112(1) ld r21,-112(1)
ld r22,-104(1) ld r22,-104(1)
ld r23,-96(1) ld r23,-96(1)
...@@ -568,78 +541,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD) ...@@ -568,78 +541,4 @@ END_FTR_SECTION_IFCLR(CPU_FTR_UNALIGNED_LD_STD)
ld r4,-16(r1) ld r4,-16(r1)
li r5,4096 li r5,4096
b .Ldst_aligned b .Ldst_aligned
EX_TABLE(20b,100b)
EX_TABLE(21b,100b)
EX_TABLE(22b,100b)
EX_TABLE(23b,100b)
EX_TABLE(24b,100b)
EX_TABLE(25b,100b)
EX_TABLE(26b,100b)
EX_TABLE(27b,100b)
EX_TABLE(28b,100b)
EX_TABLE(29b,100b)
EX_TABLE(30b,100b)
EX_TABLE(31b,100b)
EX_TABLE(32b,100b)
EX_TABLE(33b,100b)
EX_TABLE(34b,100b)
EX_TABLE(35b,100b)
EX_TABLE(36b,100b)
EX_TABLE(37b,100b)
EX_TABLE(38b,100b)
EX_TABLE(39b,100b)
EX_TABLE(40b,100b)
EX_TABLE(41b,100b)
EX_TABLE(42b,100b)
EX_TABLE(43b,100b)
EX_TABLE(44b,100b)
EX_TABLE(45b,100b)
EX_TABLE(46b,100b)
EX_TABLE(47b,100b)
EX_TABLE(48b,100b)
EX_TABLE(49b,100b)
EX_TABLE(50b,100b)
EX_TABLE(51b,100b)
EX_TABLE(52b,100b)
EX_TABLE(53b,100b)
EX_TABLE(54b,100b)
EX_TABLE(55b,100b)
EX_TABLE(56b,100b)
EX_TABLE(57b,100b)
EX_TABLE(58b,100b)
EX_TABLE(59b,100b)
EX_TABLE(60b,100b)
EX_TABLE(61b,100b)
EX_TABLE(62b,100b)
EX_TABLE(63b,100b)
EX_TABLE(64b,100b)
EX_TABLE(65b,100b)
EX_TABLE(66b,100b)
EX_TABLE(67b,100b)
EX_TABLE(68b,100b)
EX_TABLE(69b,100b)
EX_TABLE(70b,100b)
EX_TABLE(71b,100b)
EX_TABLE(72b,100b)
EX_TABLE(73b,100b)
EX_TABLE(74b,100b)
EX_TABLE(75b,100b)
EX_TABLE(76b,100b)
EX_TABLE(77b,100b)
EX_TABLE(78b,100b)
EX_TABLE(79b,100b)
EX_TABLE(80b,100b)
EX_TABLE(81b,100b)
EX_TABLE(82b,100b)
EX_TABLE(83b,100b)
EX_TABLE(84b,100b)
EX_TABLE(85b,100b)
EX_TABLE(86b,100b)
EX_TABLE(87b,100b)
EX_TABLE(88b,100b)
EX_TABLE(89b,100b)
EX_TABLE(90b,100b)
EX_TABLE(91b,100b)
EXPORT_SYMBOL(__copy_tofrom_user) EXPORT_SYMBOL(__copy_tofrom_user)
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