Zeus: apply the MSR SSBS instruction
Zeus supports the SSBS mechanism and also the new MSR instruction to
immediately apply the mitigation. Hence, the new instruction is utilised
in the Zeus-specific reset function.
Change-Id: I962747c28afe85a15207a0eba4146f9a115b27e7
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>
diff --git a/lib/cpus/aarch64/neoverse_zeus.S b/lib/cpus/aarch64/neoverse_zeus.S
index 3d85013..44882b4 100644
--- a/lib/cpus/aarch64/neoverse_zeus.S
+++ b/lib/cpus/aarch64/neoverse_zeus.S
@@ -46,6 +46,16 @@
endfunc neoverse_zeus_errata_report
#endif
+func neoverse_zeus_reset_func
+ mov x19, x30
+
+ /* Disable speculative loads */
+ msr SSBS, xzr
+
+ isb
+ ret x19
+endfunc neoverse_zeus_reset_func
+
/* ---------------------------------------------
* This function provides Neoverse-Zeus specific
* register information for crash reporting.
@@ -66,5 +76,5 @@
endfunc neoverse_zeus_cpu_reg_dump
declare_cpu_ops neoverse_zeus, NEOVERSE_ZEUS_MIDR, \
- CPU_NO_RESET_FUNC, \
+ neoverse_zeus_reset_func, \
neoverse_zeus_core_pwr_dwn
