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>

1 files changed, 0 insertions, 49 deletions

diff --git a/arch/tile/lib/usercopy_64.S b/arch/tile/lib/usercopy_64.S
index 2ff44f87b78e..adb2dbbc70cd 100644
--- a/arch/tile/lib/usercopy_64.S
+++ b/arch/tile/lib/usercopy_64.S
@@ -19,55 +19,6 @@
 
 /* Access user memory, but use MMU to avoid propagating kernel exceptions. */
 
-	.pushsection .fixup,"ax"
-
-get_user_fault:
-	{ movei r1, -EFAULT; move r0, zero }
-	jrp lr
-	ENDPROC(get_user_fault)
-
-put_user_fault:
-	{ movei r0, -EFAULT; jrp lr }
-	ENDPROC(put_user_fault)
-
-	.popsection
-
-/*
- * __get_user_N functions take a pointer in r0, and return 0 in r1
- * on success, with the value in r0; or else -EFAULT in r1.
- */
-#define __get_user_N(bytes, LOAD) \
-	STD_ENTRY(__get_user_##bytes); \
-1:	{ LOAD r0, r0; move r1, zero }; \
-	jrp lr; \
-	STD_ENDPROC(__get_user_##bytes); \
-	.pushsection __ex_table,"a"; \
-	.quad 1b, get_user_fault; \
-	.popsection
-
-__get_user_N(1, ld1u)
-__get_user_N(2, ld2u)
-__get_user_N(4, ld4u)
-__get_user_N(8, ld)
-
-/*
- * __put_user_N functions take a value in r0 and a pointer in r1,
- * and return 0 in r0 on success or -EFAULT on failure.
- */
-#define __put_user_N(bytes, STORE) \
-	STD_ENTRY(__put_user_##bytes); \
-1:	{ STORE r1, r0; move r0, zero }; \
-	jrp lr; \
-	STD_ENDPROC(__put_user_##bytes); \
-	.pushsection __ex_table,"a"; \
-	.quad 1b, put_user_fault; \
-	.popsection
-
-__put_user_N(1, st1)
-__put_user_N(2, st2)
-__put_user_N(4, st4)
-__put_user_N(8, st)
-
 /*
  * strnlen_user_asm takes the pointer in r0, and the length bound in r1.
  * It returns the length, including the terminating NUL, or zero on exception.