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metag/usercopy: Simplify rapf loop fixup corner case 

The final fixup in the rapf loops must handle a corner case due to the
intermediate decrementing of the destination pointer before writing the
last element to it again and re-incrementing it. This decrement (and the
associated increment in the fixup code) can be easily avoided by using
SETL/SETD with an offset of -8/-4.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
This commit is contained in:
James Hogan 2017-04-04 11:42:35 +01:00
parent 049520dcb3
commit fc1b759ae4
1 changed files with 2 additions and 8 deletions
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10
arch/metag/lib/usercopy.c
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@ -270,8 +270,7 @@
"29: SUB %3, %3, #32\n" \
"30: MGETL D0FrT, D0.5, D0.6, D0.7, [%1++]\n" \
"31: MSETL [%0++], D0FrT, D0.5, D0.6, D0.7\n" \
"32: SUB %0, %0, #8\n" \
"33: SETL [%0++], D0.7, D1.7\n" \
"32: SETL [%0+#-8], D0.7, D1.7\n" \
" SUB %3, %3, #32\n" \
"1: DCACHE [%1+#-64], D0Ar6\n" \
" GETL D0Ar6, D1Ar5, [A0StP+#-40]\n" \
@ -281,7 +280,6 @@
" GETL D0.7, D1.7, [A0StP+#-8]\n" \
" SUB A0StP, A0StP, #40\n" \
" .section .fixup,\"ax\"\n" \
"4: ADD %0, %0, #8\n" \
"3: MOV D0Ar2, TXSTATUS\n" \
" MOV D1Ar1, TXSTATUS\n" \
" AND D1Ar1, D1Ar1, #0xFFFFF8FF\n" \
@ -303,7 +301,6 @@
" .long 30b,3b\n" \
" .long 31b,3b\n" \
" .long 32b,3b\n" \
" .long 33b,4b\n" \
" .previous\n" \
: "=r" (to), "=r" (from), "=r" (ret), "=d" (n) \
: "0" (to), "1" (from), "2" (ret), "3" (n) \
@ -417,8 +414,7 @@
"41: SUB %3, %3, #16\n" \
"42: MGETD D0FrT, D0.5, D0.6, D0.7, [%1++]\n" \
"43: MSETD [%0++], D0FrT, D0.5, D0.6, D0.7\n" \
"44: SUB %0, %0, #4\n" \
"45: SETD [%0++], D0.7\n" \
"44: SETD [%0+#-4], D0.7\n" \
" SUB %3, %3, #16\n" \
"1: DCACHE [%1+#-64], D0Ar6\n" \
" GETL D0Ar6, D1Ar5, [A0StP+#-40]\n" \
@ -428,7 +424,6 @@
" GETL D0.7, D1.7, [A0StP+#-8]\n" \
" SUB A0StP, A0StP, #40\n" \
" .section .fixup,\"ax\"\n" \
"4: ADD %0, %0, #4\n" \
"3: MOV D0Ar2, TXSTATUS\n" \
" MOV D1Ar1, TXSTATUS\n" \
" AND D1Ar1, D1Ar1, #0xFFFFF8FF\n" \
@ -462,7 +457,6 @@
" .long 42b,3b\n" \
" .long 43b,3b\n" \
" .long 44b,3b\n" \
" .long 45b,4b\n" \
" .previous\n" \
: "=r" (to), "=r" (from), "=r" (ret), "=d" (n) \
: "0" (to), "1" (from), "2" (ret), "3" (n) \