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Diffstat (limited to 'arch/arm64/lib/clear_user.S')
-rw-r--r--arch/arm64/lib/clear_user.S25
1 files changed, 21 insertions, 4 deletions
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index a5a5f5b97b17..de9a303b6ad0 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -17,14 +17,27 @@
* Alignment fixed up by hardware.
*/
- .p2align 4
- // Alignment is for the loop, but since the prologue (including BTI)
- // is also 16 bytes we can keep any padding outside the function
SYM_FUNC_START(__arch_clear_user)
add x2, x0, x1
+
+#ifdef CONFIG_AS_HAS_MOPS
+ .arch_extension mops
+alternative_if_not ARM64_HAS_MOPS
+ b .Lno_mops
+alternative_else_nop_endif
+
+USER(9f, setpt [x0]!, x1!, xzr)
+USER(6f, setmt [x0]!, x1!, xzr)
+USER(6f, setet [x0]!, x1!, xzr)
+ mov x0, #0
+ ret
+.Lno_mops:
+#endif
+
subs x1, x1, #8
b.mi 2f
-1:
+
+1: .p2align 4
USER(9f, sttr xzr, [x0])
add x0, x0, #8
subs x1, x1, #8
@@ -47,6 +60,10 @@ USER(7f, sttrb wzr, [x2, #-1])
ret
// Exception fixups
+6: b.cs 9f
+ // Registers are in Option A format
+ add x0, x0, x1
+ b 9f
7: sub x0, x2, #5 // Adjust for faulting on the final byte...
8: add x0, x0, #4 // ...or the second word of the 4-7 byte case
9: sub x0, x2, x0