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authorAl Viro <viro@zeniv.linux.org.uk>2016-12-25 02:26:18 +0100
committerAl Viro <viro@zeniv.linux.org.uk>2017-03-29 00:23:16 +0200
commit8525023121de4848b5f0a7d867ffeadbc477774d (patch)
treef4b1c2d1575d752963bda2a8836b40becda1eaa2 /arch/alpha/lib/ev6-clear_user.S
parentgeneric ...copy_..._user primitives (diff)
downloadlinux-8525023121de4848b5f0a7d867ffeadbc477774d.tar.xz
linux-8525023121de4848b5f0a7d867ffeadbc477774d.zip
alpha: switch __copy_user() and __do_clean_user() to normal calling conventions
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>
Diffstat (limited to 'arch/alpha/lib/ev6-clear_user.S')
-rw-r--r--arch/alpha/lib/ev6-clear_user.S84
1 files changed, 35 insertions, 49 deletions
diff --git a/arch/alpha/lib/ev6-clear_user.S b/arch/alpha/lib/ev6-clear_user.S
index 05bef6b50598..e179e4757ef8 100644
--- a/arch/alpha/lib/ev6-clear_user.S
+++ b/arch/alpha/lib/ev6-clear_user.S
@@ -9,21 +9,6 @@
* a successful copy). There is also some rather minor exception setup
* 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:
* Compiler Writer's Guide for the Alpha 21264
* abbreviated as 'CWG' in other comments here
@@ -56,14 +41,15 @@
.set noreorder
.align 4
- .globl __do_clear_user
- .ent __do_clear_user
- .frame $30, 0, $28
+ .globl __clear_user
+ .ent __clear_user
+ .frame $30, 0, $26
.prologue 0
# Pipeline info : Slotting & Comments
-__do_clear_user:
- and $6, 7, $4 # .. E .. .. : find dest head misalignment
+__clear_user:
+ and $17, $17, $0
+ and $16, 7, $4 # .. E .. .. : find dest head misalignment
beq $0, $zerolength # U .. .. .. : U L U L
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
- * 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?
- mskql $5, $6, $5 # .. U .. .. : take care of misaligned head
- addq $6, 8, $6 # E .. .. .. : L U U L
+ mskql $5, $16, $5 # .. U .. .. : take care of misaligned head
+ 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 .. :
addq $0, $4, $0 # .. E .. .. : bytes left -= 8 - misalignment
subq $0, 8, $0 # E .. .. .. : U L U L
@@ -93,11 +79,11 @@ __do_clear_user:
* values upon initial entry to the loop
* $1 is number of quadwords to clear (zero is a valid value)
* $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:
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)
blt $4, $trailquad # U .. .. .. : U L U L
@@ -114,21 +100,21 @@ $headalign:
beq $3, $bigalign # U .. .. .. : U L U L : Aligned 0mod64
$alignmod64:
- EX( stq_u $31, 0($6) ) # .. .. .. L
+ EX( stq_u $31, 0($16) ) # .. .. .. L
addq $3, 8, $3 # .. .. E ..
subq $0, 8, $0 # .. E .. ..
nop # E .. .. .. : U L U L
nop # .. .. .. E
subq $1, 1, $1 # .. .. E ..
- addq $6, 8, $6 # .. E .. ..
+ addq $16, 8, $16 # .. E .. ..
blt $3, $alignmod64 # U .. .. .. : U L U L
$bigalign:
/*
* $0 is the number of bytes 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
* 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
@@ -145,39 +131,39 @@ $bigalign:
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... */
$do_wh64:
wh64 ($3) # .. .. .. L1 : memory subsystem hint
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
- addq $6, 128, $3 # E : Target address of wh64
- EX( stq_u $31, 8($6) ) # L :
- EX( stq_u $31, 16($6) ) # L :
+ addq $16, 128, $3 # E : Target address of wh64
+ EX( stq_u $31, 8($16) ) # L :
+ EX( stq_u $31, 16($16) ) # L :
subq $0, 16, $0 # E : U L L U
nop # E :
- EX( stq_u $31, 24($6) ) # L :
- EX( stq_u $31, 32($6) ) # L :
+ EX( stq_u $31, 24($16) ) # L :
+ EX( stq_u $31, 32($16) ) # L :
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 */
subq $0, 16, $0 # E :
- EX( stq_u $31, 40($6) ) # L :
- EX( stq_u $31, 48($6) ) # L :
- cmovlt $5, $6, $3 # E : U L L U : Latency 2, extra mapping cycle
+ EX( stq_u $31, 40($16) ) # L :
+ EX( stq_u $31, 48($16) ) # L :
+ cmovlt $5, $16, $3 # E : U L L U : Latency 2, extra mapping cycle
subq $1, 8, $1 # 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 :
subq $0, 8, $0 # E :
- addq $6, 64, $6 # E :
+ addq $16, 64, $16 # E :
bge $4, $do_wh64 # U : U L U L
$trailquad:
@@ -190,14 +176,14 @@ $trailquad:
beq $1, $trailbytes # U .. .. .. : U L U L : Only 0..7 bytes to go
$onequad:
- EX( stq_u $31, 0($6) ) # .. .. .. L
+ EX( stq_u $31, 0($16) ) # .. .. .. L
subq $1, 1, $1 # .. .. E ..
subq $0, 8, $0 # .. E .. ..
nop # E .. .. .. : U L U L
nop # .. .. .. E
nop # .. .. E ..
- addq $6, 8, $6 # .. E .. ..
+ addq $16, 8, $16 # .. E .. ..
bgt $1, $onequad # U .. .. .. : U L U L
# We have an unknown number of bytes left to go.
@@ -211,9 +197,9 @@ $trailbytes:
# so we will use $0 as the loop counter
# We know for a fact that $0 > 0 zero due to previous context
$onebyte:
- EX( stb $31, 0($6) ) # .. .. .. L
+ EX( stb $31, 0($16) ) # .. .. .. L
subq $0, 1, $0 # .. .. E .. :
- addq $6, 1, $6 # .. E .. .. :
+ addq $16, 1, $16 # .. E .. .. :
bgt $0, $onebyte # U .. .. .. : U L U L
$zerolength:
@@ -221,6 +207,6 @@ $exception: # Destination for exception recovery(?)
nop # .. .. .. E :
nop # .. .. E .. :
nop # .. E .. .. :
- ret $31, ($28), 1 # L0 .. .. .. : L U L U
- .end __do_clear_user
- EXPORT_SYMBOL(__do_clear_user)
+ ret $31, ($26), 1 # L0 .. .. .. : L U L U
+ .end __clear_user
+ EXPORT_SYMBOL(__clear_user)