arch/tile: optimize get_user/put_user and friends
authorChris Metcalf <cmetcalf@tilera.com>
Thu, 29 Mar 2012 17:39:51 +0000 (13:39 -0400)
committerChris Metcalf <cmetcalf@tilera.com>
Fri, 25 May 2012 16:48:23 +0000 (12:48 -0400)
commit47d632f9f8f3ed62b21f725e98b726d65769b6d7
tree9599e3a0106ee320b293be1dbc2d4dbb93b6e1ff
parent1efea40d4172a2a475ccb29b59d6221e9d0c174b
arch/tile: optimize get_user/put_user and friends

Use direct load/store for the get_user/put_user.

Previously, we would call out to a helper routine that would do the
appropriate thing and then return, handling the possible exception
internally.  Now we inline the load or store, along with a "we succeeded"
indication in a register; if the load or store faults, we write a
"we failed" indication into the same register and then return to the
following instruction.  This is more efficient and gives us more compact
code, as well as being more in line with what other architectures do.

The special futex assembly source file for TILE-Gx also disappears in
this change; we just use the same inlining idiom there as well, putting
the appropriate atomic operations directly into futex_atomic_op_inuser()
(and thus into the FUTEX_WAIT function).

The underlying atomic copy_from_user, copy_to_user functions were
renamed using the (cryptic) x86 convention as copy_from_user_ll and
copy_to_user_ll.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
arch/tile/include/asm/atomic_32.h
arch/tile/include/asm/futex.h
arch/tile/include/asm/uaccess.h
arch/tile/kernel/Makefile
arch/tile/lib/atomic_32.c
arch/tile/lib/exports.c
arch/tile/lib/usercopy_32.S
arch/tile/lib/usercopy_64.S