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MIPS: Octeon: Implement Octeon specific __copy_user_inatomic

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The generic version seems to prefetch past the end of memory.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3929/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
David Daney 2012-06-06 14:50:17 -07:00 committed by Ralf Baechle
parent 497e5ff03f
commit 914f848077
1 changed files with 12 additions and 4 deletions
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16
arch/mips/cavium-octeon/octeon-memcpy.S
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@ -163,6 +163,14 @@
.set noreorder .set noreorder
.set noat .set noat
/*
* t7 is used as a flag to note inatomic mode.
*/
LEAF(__copy_user_inatomic)
b __copy_user_common
li t7, 1
END(__copy_user_inatomic)
/* /*
* A combined memcpy/__copy_user * A combined memcpy/__copy_user
* __copy_user sets len to 0 for success; else to an upper bound of * __copy_user sets len to 0 for success; else to an upper bound of
@ -174,6 +182,8 @@ LEAF(memcpy) /* a0=dst a1=src a2=len */
move v0, dst /* return value */ move v0, dst /* return value */
__memcpy: __memcpy:
FEXPORT(__copy_user) FEXPORT(__copy_user)
li t7, 0 /* not inatomic */
__copy_user_common:
/* /*
* Note: dst & src may be unaligned, len may be 0 * Note: dst & src may be unaligned, len may be 0
* Temps * Temps
@ -412,7 +422,6 @@ l_exc_copy:
* Assumes src < THREAD_BUADDR($28) * Assumes src < THREAD_BUADDR($28)
*/ */
LOAD t0, TI_TASK($28) LOAD t0, TI_TASK($28)
nop
LOAD t0, THREAD_BUADDR(t0) LOAD t0, THREAD_BUADDR(t0)
1: 1:
EXC( lb t1, 0(src), l_exc) EXC( lb t1, 0(src), l_exc)
@ -422,10 +431,9 @@ EXC( lb t1, 0(src), l_exc)
ADD dst, dst, 1 ADD dst, dst, 1
l_exc: l_exc:
LOAD t0, TI_TASK($28) LOAD t0, TI_TASK($28)
nop
LOAD t0, THREAD_BUADDR(t0) # t0 is just past last good address LOAD t0, THREAD_BUADDR(t0) # t0 is just past last good address
nop
SUB len, AT, t0 # len number of uncopied bytes SUB len, AT, t0 # len number of uncopied bytes
bnez t7, 2f /* Skip the zeroing out part if inatomic */
/* /*
* Here's where we rely on src and dst being incremented in tandem, * Here's where we rely on src and dst being incremented in tandem,
* See (3) above. * See (3) above.
@ -443,7 +451,7 @@ l_exc:
ADD dst, dst, 1 ADD dst, dst, 1
bnez src, 1b bnez src, 1b
SUB src, src, 1 SUB src, src, 1
jr ra 2: jr ra
nop nop