Neoverse N1 Errata Workaround 1542419
Coherent I-cache is causing a prefetch violation where when the core
executes an instruction that has recently been modified, the core might
fetch a stale instruction which violates the ordering of instruction
fetches.
The workaround includes an instruction sequence to implementation
defined registers to trap all EL0 IC IVAU instructions to EL3 and a trap
handler to execute a TLB inner-shareable invalidation to an arbitrary
address followed by a DSB.
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
Change-Id: Ic3b7cbb11cf2eaf9005523ef5578a372593ae4d6
diff --git a/lib/cpus/aarch64/cpu_helpers.S b/lib/cpus/aarch64/cpu_helpers.S
index de1177c..808c7f8 100644
--- a/lib/cpus/aarch64/cpu_helpers.S
+++ b/lib/cpus/aarch64/cpu_helpers.S
@@ -227,6 +227,27 @@
ret
endfunc cpu_rev_var_hs
+/*
+ * Compare the CPU's revision-variant (x0) with a given range (x1 - x2), for errata
+ * application purposes. If the revision-variant is between or includes the given
+ * values, this indicates that errata applies; otherwise not.
+ *
+ * Shall clobber: x0-x4
+ */
+ .globl cpu_rev_var_range
+func cpu_rev_var_range
+ mov x3, #ERRATA_APPLIES
+ mov x4, #ERRATA_NOT_APPLIES
+ cmp x0, x1
+ csel x1, x3, x4, hs
+ cbz x1, 1f
+ cmp x0, x2
+ csel x1, x3, x4, ls
+1:
+ mov x0, x1
+ ret
+endfunc cpu_rev_var_range
+
#if REPORT_ERRATA
/*
* void print_errata_status(void);