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| author | David Daney <david.daney@cavium.com> | 2012-06-06 23:00:31 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2012-07-23 13:55:55 +0100 |
| commit | bb0757ebb929d5d6ba484b4313976847285ba280 (patch) | |
| tree | f3a138d260d52fca71d7170e42415235ce6cc46b /arch/mips/lib/memcpy.S | |
| parent | 914f848077fb2ec0ec9c041af9ae1101ed0320f3 (diff) | |
| download | op-kernel-dev-bb0757ebb929d5d6ba484b4313976847285ba280.zip op-kernel-dev-bb0757ebb929d5d6ba484b4313976847285ba280.tar.gz | |
MIPS: Unify memcpy.S and memcpy-inatomic.S
We can save the 451 lines of code that comprise memcpy-inatomic.S at the
expense of a single instruction in the memcpy prolog. We also use an
additional register (t6), so this may cause increased register pressure in
some places as well. But I think the reduced maintenance burden, of not
having two nearly identical implementations, makes it worth it.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/lib/memcpy.S')
| -rw-r--r-- | arch/mips/lib/memcpy.S | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/mips/lib/memcpy.S b/arch/mips/lib/memcpy.S index 56a1f85..65192c0 100644 --- a/arch/mips/lib/memcpy.S +++ b/arch/mips/lib/memcpy.S @@ -183,6 +183,14 @@ #endif /* + * t6 is used as a flag to note inatomic mode. + */ +LEAF(__copy_user_inatomic) + b __copy_user_common + li t6, 1 + END(__copy_user_inatomic) + +/* * A combined memcpy/__copy_user * __copy_user sets len to 0 for success; else to an upper bound of * the number of uncopied bytes. @@ -193,6 +201,8 @@ LEAF(memcpy) /* a0=dst a1=src a2=len */ move v0, dst /* return value */ .L__memcpy: FEXPORT(__copy_user) + li t6, 0 /* not inatomic */ +__copy_user_common: /* * Note: dst & src may be unaligned, len may be 0 * Temps @@ -458,6 +468,7 @@ EXC( lb t1, 0(src), .Ll_exc) LOAD t0, THREAD_BUADDR(t0) # t0 is just past last good address nop SUB len, AT, t0 # len number of uncopied bytes + bnez t6, .Ldone /* Skip the zeroing part if inatomic */ /* * Here's where we rely on src and dst being incremented in tandem, * See (3) above. |
