Workaround for Neoverse N1 erratum 1130799
Neoverse N1 erratum 1130799 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUACTLR2_EL1 system register.
[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html
Change-Id: I252bc45f9733443ba0503fefe62f50fdea61da6d
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 55109dc..01ee416 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -231,6 +231,9 @@
- ``ERRATA_N1_1073348``: This applies errata 1073348 workaround to Neoverse-N1
CPU. This needs to be enabled only for revision r0p0 and r1p0 of the CPU.
+- ``ERRATA_N1_1130799``: This applies errata 1130799 workaround to Neoverse-N1
+ CPU. This needs to be enabled only for revision <= r2p0 of the CPU.
+
- ``ERRATA_N1_1315703``: This applies errata 1315703 workaround to Neoverse-N1
CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
diff --git a/include/lib/cpus/aarch64/neoverse_n1.h b/include/lib/cpus/aarch64/neoverse_n1.h
index 9048f43..9042d70 100644
--- a/include/lib/cpus/aarch64/neoverse_n1.h
+++ b/include/lib/cpus/aarch64/neoverse_n1.h
@@ -41,6 +41,8 @@
#define NEOVERSE_N1_CPUACTLR2_EL1_BIT_2 (ULL(1) << 2)
#define NEOVERSE_N1_CPUACTLR2_EL1_BIT_16 (ULL(1) << 16)
+#define NEOVERSE_N1_CPUACTLR2_EL1_BIT_59 (ULL(1) << 59)
+
/* Instruction patching registers */
#define CPUPSELR_EL3 S3_6_C15_C8_0
diff --git a/lib/cpus/aarch64/neoverse_n1.S b/lib/cpus/aarch64/neoverse_n1.S
index 2d427b6..31708a4 100644
--- a/lib/cpus/aarch64/neoverse_n1.S
+++ b/lib/cpus/aarch64/neoverse_n1.S
@@ -103,6 +103,33 @@
endfunc check_errata_1073348
/* --------------------------------------------------
+ * Errata Workaround for Neoverse N1 Errata #1130799
+ * This applies to revision <=r2p0 of Neoverse N1.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------
+ */
+func errata_n1_1130799_wa
+ /* Compare x0 against revision r2p0 */
+ mov x17, x30
+ bl check_errata_1130799
+ cbz x0, 1f
+ mrs x1, NEOVERSE_N1_CPUACTLR2_EL1
+ orr x1, x1, NEOVERSE_N1_CPUACTLR2_EL1_BIT_59
+ msr NEOVERSE_N1_CPUACTLR2_EL1, x1
+ isb
+1:
+ ret x17
+endfunc errata_n1_1130799_wa
+
+func check_errata_1130799
+ /* Applies to <=r2p0 */
+ mov x1, #0x20
+ b cpu_rev_var_ls
+endfunc check_errata_1130799
+
+/* --------------------------------------------------
* Errata Workaround for Neoverse N1 Erratum 1315703.
* This applies to revision <= r3p0 of Neoverse N1.
* Inputs:
@@ -155,6 +182,11 @@
bl errata_n1_1073348_wa
#endif
+#if ERRATA_N1_1130799
+ mov x0, x18
+ bl errata_n1_1130799_wa
+#endif
+
#if ERRATA_N1_1315703
mov x0, x18
bl errata_n1_1315703_wa
@@ -218,6 +250,7 @@
*/
report_errata ERRATA_N1_1043202, neoverse_n1, 1043202
report_errata ERRATA_N1_1073348, neoverse_n1, 1073348
+ report_errata ERRATA_N1_1130799, neoverse_n1, 1130799
report_errata ERRATA_N1_1315703, neoverse_n1, 1315703
report_errata ERRATA_DSU_936184, neoverse_n1, dsu_936184
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 0d00d0a..676667b 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -242,6 +242,10 @@
# only to revision r0p0 and r1p0 of the Neoverse N1 cpu.
ERRATA_N1_1073348 ?=0
+# Flag to apply erratum 1130799 workaround during reset. This erratum applies
+# only to revision <= r2p0 of the Neoverse N1 cpu.
+ERRATA_N1_1130799 ?=0
+
# Flag to apply erratum 1315703 workaround during reset. This erratum applies
# to revisions before r3p1 of the Neoverse N1 cpu.
ERRATA_N1_1315703 ?=1
@@ -439,6 +443,10 @@
$(eval $(call assert_boolean,ERRATA_N1_1073348))
$(eval $(call add_define,ERRATA_N1_1073348))
+# Process ERRATA_N1_1130799 flag
+$(eval $(call assert_boolean,ERRATA_N1_1130799))
+$(eval $(call add_define,ERRATA_N1_1130799))
+
# Process ERRATA_N1_1315703 flag
$(eval $(call assert_boolean,ERRATA_N1_1315703))
$(eval $(call add_define,ERRATA_N1_1315703))