Software can use the SPSel operand to write directly to PSTATE.SP.
According to ARM DDI 0487F.b, page D1-2332, writes to PSTATE are
self-synchronizing and no ISB is needed:
"Writes to the PSTATE fields have side-effects on various aspects of the PE
operation. All of these side-effects are guaranteed:
- Not to be visible to earlier instructions in the execution stream.
- To be visible to later instructions in the execution stream."
Signed-off-by: Alexandru Elisei <alexandru.eli...@arm.com>
---
arm/cstart64.S | 1 -
1 file changed, 1 deletion(-)
diff --git a/arm/cstart64.S b/arm/cstart64.S
index 0428014aa58a..fc1930bcdb53 100644
--- a/arm/cstart64.S
+++ b/arm/cstart64.S
@@ -54,7 +54,6 @@ start:
/* set up stack */
mov x4, #1
msr spsel, x4
- isb
adrp x4, stackptr
add sp, x4, :lo12:stackptr
--
2.30.1
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
