arm64: use alternative auto-nop
Make use of the new alternative_if and alternative_else_nop_endif and
get rid of our homebew NOP sleds, making the code simpler to read.
Note that for cpu_do_switch_mm the ret has been moved out of the
alternative sequence, and in the default case there will be three
additional NOPs executed.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 6880dcc..223d54a 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -150,13 +150,7 @@
ldr x23, [sp, #S_SP] // load return stack pointer
msr sp_el0, x23
#ifdef CONFIG_ARM64_ERRATUM_845719
-alternative_if_not ARM64_WORKAROUND_845719
- nop
- nop
-#ifdef CONFIG_PID_IN_CONTEXTIDR
- nop
-#endif
-alternative_else
+alternative_if ARM64_WORKAROUND_845719
tbz x22, #4, 1f
#ifdef CONFIG_PID_IN_CONTEXTIDR
mrs x29, contextidr_el1
@@ -165,7 +159,7 @@
msr contextidr_el1, xzr
#endif
1:
-alternative_endif
+alternative_else_nop_endif
#endif
.endif
msr elr_el1, x21 // set up the return data
