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alpha: switch __copy_user() and __do_clean_user() to normal calling conventions

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They used to need odd calling conventions due to old exception handling
mechanism, the last remnants of which had disappeared back in 2002.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-12-24 20:26:18 -05:00
parent d597580d37
commit 8525023121
5 changed files with 151 additions and 252 deletions
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67
arch/alpha/include/asm/uaccess.h
View File

@ -334,45 +334,17 @@ __asm__ __volatile__("1: stb %r2,%1\n" \
* Complex access routines * Complex access routines
*/ */
/* This little bit of silliness is to get the GP loaded for a function extern long __copy_user(void *to, const void *from, long len);
that ordinarily wouldn't. Otherwise we could have it done by the macro
directly, which can be optimized the linker. */
#ifdef MODULE
#define __module_address(sym) "r"(sym),
#define __module_call(ra, arg, sym) "jsr $" #ra ",(%" #arg ")," #sym
#else
#define __module_address(sym)
#define __module_call(ra, arg, sym) "bsr $" #ra "," #sym " !samegp"
#endif
extern void __copy_user(void); #define __copy_to_user(to, from, n) \
({ \
extern inline long __chk_user_ptr(to); \
__copy_tofrom_user_nocheck(void *to, const void *from, long len) __copy_user((__force void *)(to), (from), (n)); \
{
register void * __cu_to __asm__("$6") = to;
register const void * __cu_from __asm__("$7") = from;
register long __cu_len __asm__("$0") = len;
__asm__ __volatile__(
__module_call(28, 3, __copy_user)
: "=r" (__cu_len), "=r" (__cu_from), "=r" (__cu_to)
: __module_address(__copy_user)
"0" (__cu_len), "1" (__cu_from), "2" (__cu_to)
: "$1", "$2", "$3", "$4", "$5", "$28", "memory");
return __cu_len;
}
#define __copy_to_user(to, from, n) \
({ \
__chk_user_ptr(to); \
__copy_tofrom_user_nocheck((__force void *)(to), (from), (n)); \
}) })
#define __copy_from_user(to, from, n) \ #define __copy_from_user(to, from, n) \
({ \ ({ \
__chk_user_ptr(from); \ __chk_user_ptr(from); \
__copy_tofrom_user_nocheck((to), (__force void *)(from), (n)); \ __copy_user((to), (__force void *)(from), (n)); \
}) })
#define __copy_to_user_inatomic __copy_to_user #define __copy_to_user_inatomic __copy_to_user
@ -382,7 +354,7 @@ extern inline long
copy_to_user(void __user *to, const void *from, long n) copy_to_user(void __user *to, const void *from, long n)
{ {
if (likely(__access_ok((unsigned long)to, n, get_fs()))) if (likely(__access_ok((unsigned long)to, n, get_fs())))
n = __copy_tofrom_user_nocheck((__force void *)to, from, n); n = __copy_user((__force void *)to, from, n);
return n; return n;
} }
@ -397,21 +369,7 @@ copy_from_user(void *to, const void __user *from, long n)
return res; return res;
} }
extern void __do_clear_user(void); extern long __clear_user(void __user *to, long len);
extern inline long
__clear_user(void __user *to, long len)
{
register void __user * __cl_to __asm__("$6") = to;
register long __cl_len __asm__("$0") = len;
__asm__ __volatile__(
__module_call(28, 2, __do_clear_user)
: "=r"(__cl_len), "=r"(__cl_to)
: __module_address(__do_clear_user)
"0"(__cl_len), "1"(__cl_to)
: "$1", "$2", "$3", "$4", "$5", "$28", "memory");
return __cl_len;
}
extern inline long extern inline long
clear_user(void __user *to, long len) clear_user(void __user *to, long len)
@ -421,9 +379,6 @@ clear_user(void __user *to, long len)
return len; return len;
} }
#undef __module_address
#undef __module_call
#define user_addr_max() \ #define user_addr_max() \
(uaccess_kernel() ? ~0UL : TASK_SIZE) (uaccess_kernel() ? ~0UL : TASK_SIZE)

66
arch/alpha/lib/clear_user.S
View File

@ -8,21 +8,6 @@
* right "bytes left to zero" value (and that it is updated only _after_ * right "bytes left to zero" value (and that it is updated only _after_
* a successful copy). There is also some rather minor exception setup * a successful copy). There is also some rather minor exception setup
* stuff. * stuff.
*
* NOTE! This is not directly C-callable, because the calling semantics
* are different:
*
* Inputs:
* length in $0
* destination address in $6
* exception pointer in $7
* return address in $28 (exceptions expect it there)
*
* Outputs:
* bytes left to copy in $0
*
* Clobbers:
* $1,$2,$3,$4,$5,$6
*/ */
#include <asm/export.h> #include <asm/export.h>
@ -38,62 +23,63 @@
.set noreorder .set noreorder
.align 4 .align 4
.globl __do_clear_user .globl __clear_user
.ent __do_clear_user .ent __clear_user
.frame $30, 0, $28 .frame $30, 0, $26
.prologue 0 .prologue 0
$loop: $loop:
and $1, 3, $4 # e0 : and $1, 3, $4 # e0 :
beq $4, 1f # .. e1 : beq $4, 1f # .. e1 :
0: EX( stq_u $31, 0($6) ) # e0 : zero one word 0: EX( stq_u $31, 0($16) ) # e0 : zero one word
subq $0, 8, $0 # .. e1 : subq $0, 8, $0 # .. e1 :
subq $4, 1, $4 # e0 : subq $4, 1, $4 # e0 :
addq $6, 8, $6 # .. e1 : addq $16, 8, $16 # .. e1 :
bne $4, 0b # e1 : bne $4, 0b # e1 :
unop # : unop # :
1: bic $1, 3, $1 # e0 : 1: bic $1, 3, $1 # e0 :
beq $1, $tail # .. e1 : beq $1, $tail # .. e1 :
2: EX( stq_u $31, 0($6) ) # e0 : zero four words 2: EX( stq_u $31, 0($16) ) # e0 : zero four words
subq $0, 8, $0 # .. e1 : subq $0, 8, $0 # .. e1 :
EX( stq_u $31, 8($6) ) # e0 : EX( stq_u $31, 8($16) ) # e0 :
subq $0, 8, $0 # .. e1 : subq $0, 8, $0 # .. e1 :
EX( stq_u $31, 16($6) ) # e0 : EX( stq_u $31, 16($16) ) # e0 :
subq $0, 8, $0 # .. e1 : subq $0, 8, $0 # .. e1 :
EX( stq_u $31, 24($6) ) # e0 : EX( stq_u $31, 24($16) ) # e0 :
subq $0, 8, $0 # .. e1 : subq $0, 8, $0 # .. e1 :
subq $1, 4, $1 # e0 : subq $1, 4, $1 # e0 :
addq $6, 32, $6 # .. e1 : addq $16, 32, $16 # .. e1 :
bne $1, 2b # e1 : bne $1, 2b # e1 :
$tail: $tail:
bne $2, 1f # e1 : is there a tail to do? bne $2, 1f # e1 : is there a tail to do?
ret $31, ($28), 1 # .. e1 : ret $31, ($26), 1 # .. e1 :
1: EX( ldq_u $5, 0($6) ) # e0 : 1: EX( ldq_u $5, 0($16) ) # e0 :
clr $0 # .. e1 : clr $0 # .. e1 :
nop # e1 : nop # e1 :
mskqh $5, $0, $5 # e0 : mskqh $5, $0, $5 # e0 :
EX( stq_u $5, 0($6) ) # e0 : EX( stq_u $5, 0($16) ) # e0 :
ret $31, ($28), 1 # .. e1 : ret $31, ($26), 1 # .. e1 :
__do_clear_user: __clear_user:
and $6, 7, $4 # e0 : find dest misalignment and $17, $17, $0
and $16, 7, $4 # e0 : find dest misalignment
beq $0, $zerolength # .. e1 : beq $0, $zerolength # .. e1 :
addq $0, $4, $1 # e0 : bias counter addq $0, $4, $1 # e0 : bias counter
and $1, 7, $2 # e1 : number of bytes in tail and $1, 7, $2 # e1 : number of bytes in tail
srl $1, 3, $1 # e0 : srl $1, 3, $1 # e0 :
beq $4, $loop # .. e1 : beq $4, $loop # .. e1 :
EX( ldq_u $5, 0($6) ) # e0 : load dst word to mask back in EX( ldq_u $5, 0($16) ) # e0 : load dst word to mask back in
beq $1, $oneword # .. e1 : sub-word store? beq $1, $oneword # .. e1 : sub-word store?
mskql $5, $6, $5 # e0 : take care of misaligned head mskql $5, $16, $5 # e0 : take care of misaligned head
addq $6, 8, $6 # .. e1 : addq $16, 8, $16 # .. e1 :
EX( stq_u $5, -8($6) ) # e0 : EX( stq_u $5, -8($16) ) # e0 :
addq $0, $4, $0 # .. e1 : bytes left -= 8 - misalignment addq $0, $4, $0 # .. e1 : bytes left -= 8 - misalignment
subq $1, 1, $1 # e0 : subq $1, 1, $1 # e0 :
subq $0, 8, $0 # .. e1 : subq $0, 8, $0 # .. e1 :
@ -101,15 +87,15 @@ __do_clear_user:
unop # : unop # :
$oneword: $oneword:
mskql $5, $6, $4 # e0 : mskql $5, $16, $4 # e0 :
mskqh $5, $2, $5 # e0 : mskqh $5, $2, $5 # e0 :
or $5, $4, $5 # e1 : or $5, $4, $5 # e1 :
EX( stq_u $5, 0($6) ) # e0 : EX( stq_u $5, 0($16) ) # e0 :
clr $0 # .. e1 : clr $0 # .. e1 :
$zerolength: $zerolength:
$exception: $exception:
ret $31, ($28), 1 # .. e1 : ret $31, ($26), 1 # .. e1 :
.end __do_clear_user .end __clear_user
EXPORT_SYMBOL(__do_clear_user) EXPORT_SYMBOL(__clear_user)

82
arch/alpha/lib/copy_user.S
View File

@ -9,21 +9,6 @@
* contains the right "bytes left to copy" value (and that it is updated * contains the right "bytes left to copy" value (and that it is updated
* only _after_ a successful copy). There is also some rather minor * only _after_ a successful copy). There is also some rather minor
* exception setup stuff.. * exception setup stuff..
*
* NOTE! This is not directly C-callable, because the calling semantics are
* different:
*
* Inputs:
* length in $0
* destination address in $6
* source address in $7
* return address in $28
*
* Outputs:
* bytes left to copy in $0
*
* Clobbers:
* $1,$2,$3,$4,$5,$6,$7
*/ */
#include <asm/export.h> #include <asm/export.h>
@ -49,58 +34,59 @@
.ent __copy_user .ent __copy_user
__copy_user: __copy_user:
.prologue 0 .prologue 0
and $6,7,$3 and $18,$18,$0
and $16,7,$3
beq $0,$35 beq $0,$35
beq $3,$36 beq $3,$36
subq $3,8,$3 subq $3,8,$3
.align 4 .align 4
$37: $37:
EXI( ldq_u $1,0($7) ) EXI( ldq_u $1,0($17) )
EXO( ldq_u $2,0($6) ) EXO( ldq_u $2,0($16) )
extbl $1,$7,$1 extbl $1,$17,$1
mskbl $2,$6,$2 mskbl $2,$16,$2
insbl $1,$6,$1 insbl $1,$16,$1
addq $3,1,$3 addq $3,1,$3
bis $1,$2,$1 bis $1,$2,$1
EXO( stq_u $1,0($6) ) EXO( stq_u $1,0($16) )
subq $0,1,$0 subq $0,1,$0
addq $6,1,$6 addq $16,1,$16
addq $7,1,$7 addq $17,1,$17
beq $0,$41 beq $0,$41
bne $3,$37 bne $3,$37
$36: $36:
and $7,7,$1 and $17,7,$1
bic $0,7,$4 bic $0,7,$4
beq $1,$43 beq $1,$43
beq $4,$48 beq $4,$48
EXI( ldq_u $3,0($7) ) EXI( ldq_u $3,0($17) )
.align 4 .align 4
$50: $50:
EXI( ldq_u $2,8($7) ) EXI( ldq_u $2,8($17) )
subq $4,8,$4 subq $4,8,$4
extql $3,$7,$3 extql $3,$17,$3
extqh $2,$7,$1 extqh $2,$17,$1
bis $3,$1,$1 bis $3,$1,$1
EXO( stq $1,0($6) ) EXO( stq $1,0($16) )
addq $7,8,$7 addq $17,8,$17
subq $0,8,$0 subq $0,8,$0
addq $6,8,$6 addq $16,8,$16
bis $2,$2,$3 bis $2,$2,$3
bne $4,$50 bne $4,$50
$48: $48:
beq $0,$41 beq $0,$41
.align 4 .align 4
$57: $57:
EXI( ldq_u $1,0($7) ) EXI( ldq_u $1,0($17) )
EXO( ldq_u $2,0($6) ) EXO( ldq_u $2,0($16) )
extbl $1,$7,$1 extbl $1,$17,$1
mskbl $2,$6,$2 mskbl $2,$16,$2
insbl $1,$6,$1 insbl $1,$16,$1
bis $1,$2,$1 bis $1,$2,$1
EXO( stq_u $1,0($6) ) EXO( stq_u $1,0($16) )
subq $0,1,$0 subq $0,1,$0
addq $6,1,$6 addq $16,1,$16
addq $7,1,$7 addq $17,1,$17
bne $0,$57 bne $0,$57
br $31,$41 br $31,$41
.align 4 .align 4
@ -108,27 +94,27 @@ $43:
beq $4,$65 beq $4,$65
.align 4 .align 4
$66: $66:
EXI( ldq $1,0($7) ) EXI( ldq $1,0($17) )
subq $4,8,$4 subq $4,8,$4
EXO( stq $1,0($6) ) EXO( stq $1,0($16) )
addq $7,8,$7 addq $17,8,$17
subq $0,8,$0 subq $0,8,$0
addq $6,8,$6 addq $16,8,$16
bne $4,$66 bne $4,$66
$65: $65:
beq $0,$41 beq $0,$41
EXI( ldq $2,0($7) ) EXI( ldq $2,0($17) )
EXO( ldq $1,0($6) ) EXO( ldq $1,0($16) )
mskql $2,$0,$2 mskql $2,$0,$2
mskqh $1,$0,$1 mskqh $1,$0,$1
bis $2,$1,$2 bis $2,$1,$2
EXO( stq $2,0($6) ) EXO( stq $2,0($16) )
bis $31,$31,$0 bis $31,$31,$0
$41: $41:
$35: $35:
$exitin: $exitin:
$exitout: $exitout:
ret $31,($28),1 ret $31,($26),1
.end __copy_user .end __copy_user
EXPORT_SYMBOL(__copy_user) EXPORT_SYMBOL(__copy_user)

84
arch/alpha/lib/ev6-clear_user.S
View File

@ -9,21 +9,6 @@
* a successful copy). There is also some rather minor exception setup * a successful copy). There is also some rather minor exception setup
* stuff. * stuff.
* *
* NOTE! This is not directly C-callable, because the calling semantics
* are different:
*
* Inputs:
* length in $0
* destination address in $6
* exception pointer in $7
* return address in $28 (exceptions expect it there)
*
* Outputs:
* bytes left to copy in $0
*
* Clobbers:
* $1,$2,$3,$4,$5,$6
*
* Much of the information about 21264 scheduling/coding comes from: * Much of the information about 21264 scheduling/coding comes from:
* Compiler Writer's Guide for the Alpha 21264 * Compiler Writer's Guide for the Alpha 21264
* abbreviated as 'CWG' in other comments here * abbreviated as 'CWG' in other comments here
@ -56,14 +41,15 @@
.set noreorder .set noreorder
.align 4 .align 4
.globl __do_clear_user .globl __clear_user
.ent __do_clear_user .ent __clear_user
.frame $30, 0, $28 .frame $30, 0, $26
.prologue 0 .prologue 0
# Pipeline info : Slotting & Comments # Pipeline info : Slotting & Comments
__do_clear_user: __clear_user:
and $6, 7, $4 # .. E .. .. : find dest head misalignment and $17, $17, $0
and $16, 7, $4 # .. E .. .. : find dest head misalignment
beq $0, $zerolength # U .. .. .. : U L U L beq $0, $zerolength # U .. .. .. : U L U L
addq $0, $4, $1 # .. .. .. E : bias counter addq $0, $4, $1 # .. .. .. E : bias counter
@ -75,14 +61,14 @@ __do_clear_user:
/* /*
* Head is not aligned. Write (8 - $4) bytes to head of destination * Head is not aligned. Write (8 - $4) bytes to head of destination
* This means $6 is known to be misaligned * This means $16 is known to be misaligned
*/ */
EX( ldq_u $5, 0($6) ) # .. .. .. L : load dst word to mask back in EX( ldq_u $5, 0($16) ) # .. .. .. L : load dst word to mask back in
beq $1, $onebyte # .. .. U .. : sub-word store? beq $1, $onebyte # .. .. U .. : sub-word store?
mskql $5, $6, $5 # .. U .. .. : take care of misaligned head mskql $5, $16, $5 # .. U .. .. : take care of misaligned head
addq $6, 8, $6 # E .. .. .. : L U U L addq $16, 8, $16 # E .. .. .. : L U U L
EX( stq_u $5, -8($6) ) # .. .. .. L : EX( stq_u $5, -8($16) ) # .. .. .. L :
subq $1, 1, $1 # .. .. E .. : subq $1, 1, $1 # .. .. E .. :
addq $0, $4, $0 # .. E .. .. : bytes left -= 8 - misalignment addq $0, $4, $0 # .. E .. .. : bytes left -= 8 - misalignment
subq $0, 8, $0 # E .. .. .. : U L U L subq $0, 8, $0 # E .. .. .. : U L U L
@ -93,11 +79,11 @@ __do_clear_user:
* values upon initial entry to the loop * values upon initial entry to the loop
* $1 is number of quadwords to clear (zero is a valid value) * $1 is number of quadwords to clear (zero is a valid value)
* $2 is number of trailing bytes (0..7) ($2 never used...) * $2 is number of trailing bytes (0..7) ($2 never used...)
* $6 is known to be aligned 0mod8 * $16 is known to be aligned 0mod8
*/ */
$headalign: $headalign:
subq $1, 16, $4 # .. .. .. E : If < 16, we can not use the huge loop subq $1, 16, $4 # .. .. .. E : If < 16, we can not use the huge loop
and $6, 0x3f, $2 # .. .. E .. : Forward work for huge loop and $16, 0x3f, $2 # .. .. E .. : Forward work for huge loop
subq $2, 0x40, $3 # .. E .. .. : bias counter (huge loop) subq $2, 0x40, $3 # .. E .. .. : bias counter (huge loop)
blt $4, $trailquad # U .. .. .. : U L U L blt $4, $trailquad # U .. .. .. : U L U L
@ -114,21 +100,21 @@ $headalign:
beq $3, $bigalign # U .. .. .. : U L U L : Aligned 0mod64 beq $3, $bigalign # U .. .. .. : U L U L : Aligned 0mod64
$alignmod64: $alignmod64:
EX( stq_u $31, 0($6) ) # .. .. .. L EX( stq_u $31, 0($16) ) # .. .. .. L
addq $3, 8, $3 # .. .. E .. addq $3, 8, $3 # .. .. E ..
subq $0, 8, $0 # .. E .. .. subq $0, 8, $0 # .. E .. ..
nop # E .. .. .. : U L U L nop # E .. .. .. : U L U L
nop # .. .. .. E nop # .. .. .. E
subq $1, 1, $1 # .. .. E .. subq $1, 1, $1 # .. .. E ..
addq $6, 8, $6 # .. E .. .. addq $16, 8, $16 # .. E .. ..
blt $3, $alignmod64 # U .. .. .. : U L U L blt $3, $alignmod64 # U .. .. .. : U L U L
$bigalign: $bigalign:
/* /*
* $0 is the number of bytes left * $0 is the number of bytes left
* $1 is the number of quads left * $1 is the number of quads left
* $6 is aligned 0mod64 * $16 is aligned 0mod64
* we know that we'll be taking a minimum of one trip through * we know that we'll be taking a minimum of one trip through
* CWG Section 3.7.6: do not expect a sustained store rate of > 1/cycle * CWG Section 3.7.6: do not expect a sustained store rate of > 1/cycle
* We are _not_ going to update $0 after every single store. That * We are _not_ going to update $0 after every single store. That
@ -145,39 +131,39 @@ $bigalign:
nop # E : nop # E :
nop # E : nop # E :
nop # E : nop # E :
bis $6,$6,$3 # E : U L U L : Initial wh64 address is dest bis $16,$16,$3 # E : U L U L : Initial wh64 address is dest
/* This might actually help for the current trip... */ /* This might actually help for the current trip... */
$do_wh64: $do_wh64:
wh64 ($3) # .. .. .. L1 : memory subsystem hint wh64 ($3) # .. .. .. L1 : memory subsystem hint
subq $1, 16, $4 # .. .. E .. : Forward calculation - repeat the loop? subq $1, 16, $4 # .. .. E .. : Forward calculation - repeat the loop?
EX( stq_u $31, 0($6) ) # .. L .. .. EX( stq_u $31, 0($16) ) # .. L .. ..
subq $0, 8, $0 # E .. .. .. : U L U L subq $0, 8, $0 # E .. .. .. : U L U L
addq $6, 128, $3 # E : Target address of wh64 addq $16, 128, $3 # E : Target address of wh64
EX( stq_u $31, 8($6) ) # L : EX( stq_u $31, 8($16) ) # L :
EX( stq_u $31, 16($6) ) # L : EX( stq_u $31, 16($16) ) # L :
subq $0, 16, $0 # E : U L L U subq $0, 16, $0 # E : U L L U
nop # E : nop # E :
EX( stq_u $31, 24($6) ) # L : EX( stq_u $31, 24($16) ) # L :
EX( stq_u $31, 32($6) ) # L : EX( stq_u $31, 32($16) ) # L :
subq $0, 168, $5 # E : U L L U : two trips through the loop left? subq $0, 168, $5 # E : U L L U : two trips through the loop left?
/* 168 = 192 - 24, since we've already completed some stores */ /* 168 = 192 - 24, since we've already completed some stores */
subq $0, 16, $0 # E : subq $0, 16, $0 # E :
EX( stq_u $31, 40($6) ) # L : EX( stq_u $31, 40($16) ) # L :
EX( stq_u $31, 48($6) ) # L : EX( stq_u $31, 48($16) ) # L :
cmovlt $5, $6, $3 # E : U L L U : Latency 2, extra mapping cycle cmovlt $5, $16, $3 # E : U L L U : Latency 2, extra mapping cycle
subq $1, 8, $1 # E : subq $1, 8, $1 # E :
subq $0, 16, $0 # E : subq $0, 16, $0 # E :
EX( stq_u $31, 56($6) ) # L : EX( stq_u $31, 56($16) ) # L :
nop # E : U L U L nop # E : U L U L
nop # E : nop # E :
subq $0, 8, $0 # E : subq $0, 8, $0 # E :
addq $6, 64, $6 # E : addq $16, 64, $16 # E :
bge $4, $do_wh64 # U : U L U L bge $4, $do_wh64 # U : U L U L
$trailquad: $trailquad:
@ -190,14 +176,14 @@ $trailquad:
beq $1, $trailbytes # U .. .. .. : U L U L : Only 0..7 bytes to go beq $1, $trailbytes # U .. .. .. : U L U L : Only 0..7 bytes to go
$onequad: $onequad:
EX( stq_u $31, 0($6) ) # .. .. .. L EX( stq_u $31, 0($16) ) # .. .. .. L
subq $1, 1, $1 # .. .. E .. subq $1, 1, $1 # .. .. E ..
subq $0, 8, $0 # .. E .. .. subq $0, 8, $0 # .. E .. ..
nop # E .. .. .. : U L U L nop # E .. .. .. : U L U L
nop # .. .. .. E nop # .. .. .. E
nop # .. .. E .. nop # .. .. E ..
addq $6, 8, $6 # .. E .. .. addq $16, 8, $16 # .. E .. ..
bgt $1, $onequad # U .. .. .. : U L U L bgt $1, $onequad # U .. .. .. : U L U L
# We have an unknown number of bytes left to go. # We have an unknown number of bytes left to go.
@ -211,9 +197,9 @@ $trailbytes:
# so we will use $0 as the loop counter # so we will use $0 as the loop counter
# We know for a fact that $0 > 0 zero due to previous context # We know for a fact that $0 > 0 zero due to previous context
$onebyte: $onebyte:
EX( stb $31, 0($6) ) # .. .. .. L EX( stb $31, 0($16) ) # .. .. .. L
subq $0, 1, $0 # .. .. E .. : subq $0, 1, $0 # .. .. E .. :
addq $6, 1, $6 # .. E .. .. : addq $16, 1, $16 # .. E .. .. :
bgt $0, $onebyte # U .. .. .. : U L U L bgt $0, $onebyte # U .. .. .. : U L U L
$zerolength: $zerolength:
@ -221,6 +207,6 @@ $exception: # Destination for exception recovery(?)
nop # .. .. .. E : nop # .. .. .. E :
nop # .. .. E .. : nop # .. .. E .. :
nop # .. E .. .. : nop # .. E .. .. :
ret $31, ($28), 1 # L0 .. .. .. : L U L U ret $31, ($26), 1 # L0 .. .. .. : L U L U
.end __do_clear_user .end __clear_user
EXPORT_SYMBOL(__do_clear_user) EXPORT_SYMBOL(__clear_user)

104
arch/alpha/lib/ev6-copy_user.S
View File

@ -12,21 +12,6 @@
* only _after_ a successful copy). There is also some rather minor * only _after_ a successful copy). There is also some rather minor
* exception setup stuff.. * exception setup stuff..
* *
* NOTE! This is not directly C-callable, because the calling semantics are
* different:
*
* Inputs:
* length in $0
* destination address in $6
* source address in $7
* return address in $28
*
* Outputs:
* bytes left to copy in $0
*
* Clobbers:
* $1,$2,$3,$4,$5,$6,$7
*
* Much of the information about 21264 scheduling/coding comes from: * Much of the information about 21264 scheduling/coding comes from:
* Compiler Writer's Guide for the Alpha 21264 * Compiler Writer's Guide for the Alpha 21264
* abbreviated as 'CWG' in other comments here * abbreviated as 'CWG' in other comments here
@ -60,10 +45,11 @@
# Pipeline info: Slotting & Comments # Pipeline info: Slotting & Comments
__copy_user: __copy_user:
.prologue 0 .prologue 0
subq $0, 32, $1 # .. E .. .. : Is this going to be a small copy? andq $18, $18, $0
subq $18, 32, $1 # .. E .. .. : Is this going to be a small copy?
beq $0, $zerolength # U .. .. .. : U L U L beq $0, $zerolength # U .. .. .. : U L U L
and $6,7,$3 # .. .. .. E : is leading dest misalignment and $16,7,$3 # .. .. .. E : is leading dest misalignment
ble $1, $onebyteloop # .. .. U .. : 1st branch : small amount of data ble $1, $onebyteloop # .. .. U .. : 1st branch : small amount of data
beq $3, $destaligned # .. U .. .. : 2nd (one cycle fetcher stall) beq $3, $destaligned # .. U .. .. : 2nd (one cycle fetcher stall)
subq $3, 8, $3 # E .. .. .. : L U U L : trip counter subq $3, 8, $3 # E .. .. .. : L U U L : trip counter
@ -73,17 +59,17 @@ __copy_user:
* We know we have at least one trip through this loop * We know we have at least one trip through this loop
*/ */
$aligndest: $aligndest:
EXI( ldbu $1,0($7) ) # .. .. .. L : Keep loads separate from stores EXI( ldbu $1,0($17) ) # .. .. .. L : Keep loads separate from stores
addq $6,1,$6 # .. .. E .. : Section 3.8 in the CWG addq $16,1,$16 # .. .. E .. : Section 3.8 in the CWG
addq $3,1,$3 # .. E .. .. : addq $3,1,$3 # .. E .. .. :
nop # E .. .. .. : U L U L nop # E .. .. .. : U L U L
/* /*
* the -1 is to compensate for the inc($6) done in a previous quadpack * the -1 is to compensate for the inc($16) done in a previous quadpack
* which allows us zero dependencies within either quadpack in the loop * which allows us zero dependencies within either quadpack in the loop
*/ */
EXO( stb $1,-1($6) ) # .. .. .. L : EXO( stb $1,-1($16) ) # .. .. .. L :
addq $7,1,$7 # .. .. E .. : Section 3.8 in the CWG addq $17,1,$17 # .. .. E .. : Section 3.8 in the CWG
subq $0,1,$0 # .. E .. .. : subq $0,1,$0 # .. E .. .. :
bne $3, $aligndest # U .. .. .. : U L U L bne $3, $aligndest # U .. .. .. : U L U L
@ -92,29 +78,29 @@ $aligndest:
* If we arrived via branch, we have a minimum of 32 bytes * If we arrived via branch, we have a minimum of 32 bytes
*/ */
$destaligned: $destaligned:
and $7,7,$1 # .. .. .. E : Check _current_ source alignment and $17,7,$1 # .. .. .. E : Check _current_ source alignment
bic $0,7,$4 # .. .. E .. : number bytes as a quadword loop bic $0,7,$4 # .. .. E .. : number bytes as a quadword loop
EXI( ldq_u $3,0($7) ) # .. L .. .. : Forward fetch for fallthrough code EXI( ldq_u $3,0($17) ) # .. L .. .. : Forward fetch for fallthrough code
beq $1,$quadaligned # U .. .. .. : U L U L beq $1,$quadaligned # U .. .. .. : U L U L
/* /*
* In the worst case, we've just executed an ldq_u here from 0($7) * In the worst case, we've just executed an ldq_u here from 0($17)
* and we'll repeat it once if we take the branch * and we'll repeat it once if we take the branch
*/ */
/* Misaligned quadword loop - not unrolled. Leave it that way. */ /* Misaligned quadword loop - not unrolled. Leave it that way. */
$misquad: $misquad:
EXI( ldq_u $2,8($7) ) # .. .. .. L : EXI( ldq_u $2,8($17) ) # .. .. .. L :
subq $4,8,$4 # .. .. E .. : subq $4,8,$4 # .. .. E .. :
extql $3,$7,$3 # .. U .. .. : extql $3,$17,$3 # .. U .. .. :
extqh $2,$7,$1 # U .. .. .. : U U L L extqh $2,$17,$1 # U .. .. .. : U U L L
bis $3,$1,$1 # .. .. .. E : bis $3,$1,$1 # .. .. .. E :
EXO( stq $1,0($6) ) # .. .. L .. : EXO( stq $1,0($16) ) # .. .. L .. :
addq $7,8,$7 # .. E .. .. : addq $17,8,$17 # .. E .. .. :
subq $0,8,$0 # E .. .. .. : U L L U subq $0,8,$0 # E .. .. .. : U L L U
addq $6,8,$6 # .. .. .. E : addq $16,8,$16 # .. .. .. E :
bis $2,$2,$3 # .. .. E .. : bis $2,$2,$3 # .. .. E .. :
nop # .. E .. .. : nop # .. E .. .. :
bne $4,$misquad # U .. .. .. : U L U L bne $4,$misquad # U .. .. .. : U L U L
@ -125,8 +111,8 @@ $misquad:
beq $0,$zerolength # U .. .. .. : U L U L beq $0,$zerolength # U .. .. .. : U L U L
/* We know we have at least one trip through the byte loop */ /* We know we have at least one trip through the byte loop */
EXI ( ldbu $2,0($7) ) # .. .. .. L : No loads in the same quad EXI ( ldbu $2,0($17) ) # .. .. .. L : No loads in the same quad
addq $6,1,$6 # .. .. E .. : as the store (Section 3.8 in CWG) addq $16,1,$16 # .. .. E .. : as the store (Section 3.8 in CWG)
nop # .. E .. .. : nop # .. E .. .. :
br $31, $dirtyentry # L0 .. .. .. : L U U L br $31, $dirtyentry # L0 .. .. .. : L U U L
/* Do the trailing byte loop load, then hop into the store part of the loop */ /* Do the trailing byte loop load, then hop into the store part of the loop */
@ -136,8 +122,8 @@ $misquad:
* Based upon the usage context, it's worth the effort to unroll this loop * Based upon the usage context, it's worth the effort to unroll this loop
* $0 - number of bytes to be moved * $0 - number of bytes to be moved
* $4 - number of bytes to move as quadwords * $4 - number of bytes to move as quadwords
* $6 is current destination address * $16 is current destination address
* $7 is current source address * $17 is current source address
*/ */
$quadaligned: $quadaligned:
subq $4, 32, $2 # .. .. .. E : do not unroll for small stuff subq $4, 32, $2 # .. .. .. E : do not unroll for small stuff
@ -155,29 +141,29 @@ $quadaligned:
* instruction memory hint instruction). * instruction memory hint instruction).
*/ */
$unroll4: $unroll4:
EXI( ldq $1,0($7) ) # .. .. .. L EXI( ldq $1,0($17) ) # .. .. .. L
EXI( ldq $2,8($7) ) # .. .. L .. EXI( ldq $2,8($17) ) # .. .. L ..
subq $4,32,$4 # .. E .. .. subq $4,32,$4 # .. E .. ..
nop # E .. .. .. : U U L L nop # E .. .. .. : U U L L
addq $7,16,$7 # .. .. .. E addq $17,16,$17 # .. .. .. E
EXO( stq $1,0($6) ) # .. .. L .. EXO( stq $1,0($16) ) # .. .. L ..
EXO( stq $2,8($6) ) # .. L .. .. EXO( stq $2,8($16) ) # .. L .. ..
subq $0,16,$0 # E .. .. .. : U L L U subq $0,16,$0 # E .. .. .. : U L L U
addq $6,16,$6 # .. .. .. E addq $16,16,$16 # .. .. .. E
EXI( ldq $1,0($7) ) # .. .. L .. EXI( ldq $1,0($17) ) # .. .. L ..
EXI( ldq $2,8($7) ) # .. L .. .. EXI( ldq $2,8($17) ) # .. L .. ..
subq $4, 32, $3 # E .. .. .. : U U L L : is there enough for another trip? subq $4, 32, $3 # E .. .. .. : U U L L : is there enough for another trip?
EXO( stq $1,0($6) ) # .. .. .. L EXO( stq $1,0($16) ) # .. .. .. L
EXO( stq $2,8($6) ) # .. .. L .. EXO( stq $2,8($16) ) # .. .. L ..
subq $0,16,$0 # .. E .. .. subq $0,16,$0 # .. E .. ..
addq $7,16,$7 # E .. .. .. : U L L U addq $17,16,$17 # E .. .. .. : U L L U
nop # .. .. .. E nop # .. .. .. E
nop # .. .. E .. nop # .. .. E ..
addq $6,16,$6 # .. E .. .. addq $16,16,$16 # .. E .. ..
bgt $3,$unroll4 # U .. .. .. : U L U L bgt $3,$unroll4 # U .. .. .. : U L U L
nop nop
@ -186,14 +172,14 @@ $unroll4:
beq $4, $noquads beq $4, $noquads
$onequad: $onequad:
EXI( ldq $1,0($7) ) EXI( ldq $1,0($17) )
subq $4,8,$4 subq $4,8,$4
addq $7,8,$7 addq $17,8,$17
nop nop
EXO( stq $1,0($6) ) EXO( stq $1,0($16) )
subq $0,8,$0 subq $0,8,$0
addq $6,8,$6 addq $16,8,$16
bne $4,$onequad bne $4,$onequad
$noquads: $noquads:
@ -207,23 +193,23 @@ $noquads:
* There's no point in doing a lot of complex alignment calculations to try to * There's no point in doing a lot of complex alignment calculations to try to
* to quadword stuff for a small amount of data. * to quadword stuff for a small amount of data.
* $0 - remaining number of bytes left to copy * $0 - remaining number of bytes left to copy
* $6 - current dest addr * $16 - current dest addr
* $7 - current source addr * $17 - current source addr
*/ */
$onebyteloop: $onebyteloop:
EXI ( ldbu $2,0($7) ) # .. .. .. L : No loads in the same quad EXI ( ldbu $2,0($17) ) # .. .. .. L : No loads in the same quad
addq $6,1,$6 # .. .. E .. : as the store (Section 3.8 in CWG) addq $16,1,$16 # .. .. E .. : as the store (Section 3.8 in CWG)
nop # .. E .. .. : nop # .. E .. .. :
nop # E .. .. .. : U L U L nop # E .. .. .. : U L U L
$dirtyentry: $dirtyentry:
/* /*
* the -1 is to compensate for the inc($6) done in a previous quadpack * the -1 is to compensate for the inc($16) done in a previous quadpack
* which allows us zero dependencies within either quadpack in the loop * which allows us zero dependencies within either quadpack in the loop
*/ */
EXO ( stb $2,-1($6) ) # .. .. .. L : EXO ( stb $2,-1($16) ) # .. .. .. L :
addq $7,1,$7 # .. .. E .. : quadpack as the load addq $17,1,$17 # .. .. E .. : quadpack as the load
subq $0,1,$0 # .. E .. .. : change count _after_ copy subq $0,1,$0 # .. E .. .. : change count _after_ copy
bgt $0,$onebyteloop # U .. .. .. : U L U L bgt $0,$onebyteloop # U .. .. .. : U L U L
@ -233,7 +219,7 @@ $exitout: # Destination for exception recovery(?)
nop # .. .. .. E nop # .. .. .. E
nop # .. .. E .. nop # .. .. E ..
nop # .. E .. .. nop # .. E .. ..
ret $31,($28),1 # L0 .. .. .. : L U L U ret $31,($26),1 # L0 .. .. .. : L U L U
.end __copy_user .end __copy_user
EXPORT_SYMBOL(__copy_user) EXPORT_SYMBOL(__copy_user)