Workaround for Neoverse N1 erratum 1262888
Neoverse N1 erratum 1262888 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
CPUECTLR_EL1 system register, which disables the MMU hardware prefetcher.
[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html
Change-Id: Ib733d748e32a7ea6a2783f3d5a9c5e13eee01105
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 1ed7ceb..91032c4 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -249,6 +249,9 @@
- ``ERRATA_N1_1262606``: This applies errata 1262606 workaround to Neoverse-N1
CPU. This needs to be enabled only for revision <= r3p0 of the CPU.
+- ``ERRATA_N1_1262888``: This applies errata 1262888 workaround to Neoverse-N1
+ CPU. This needs to be enabled only for revision <= r3p0 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 8f0ecf2..f90aa2e 100644
--- a/include/lib/cpus/aarch64/neoverse_n1.h
+++ b/include/lib/cpus/aarch64/neoverse_n1.h
@@ -31,6 +31,7 @@
#define NEOVERSE_N1_CPUECTLR_EL1 S3_0_C15_C1_4
#define NEOVERSE_N1_WS_THR_L2_MASK (ULL(3) << 24)
+#define NEOVERSE_N1_CPUECTLR_EL1_MM_TLBPF_DIS_BIT (ULL(1) << 51)
/*******************************************************************************
* CPU Auxiliary Control register specific definitions.
diff --git a/lib/cpus/aarch64/neoverse_n1.S b/lib/cpus/aarch64/neoverse_n1.S
index 6004575..d5f2247 100644
--- a/lib/cpus/aarch64/neoverse_n1.S
+++ b/lib/cpus/aarch64/neoverse_n1.S
@@ -266,6 +266,33 @@
endfunc check_errata_1262606
/* --------------------------------------------------
+ * Errata Workaround for Neoverse N1 Errata #1262888
+ * This applies to revision <=r3p0 of Neoverse N1.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------
+ */
+func errata_n1_1262888_wa
+ /* Compare x0 against revision r3p0 */
+ mov x17, x30
+ bl check_errata_1262888
+ cbz x0, 1f
+ mrs x1, NEOVERSE_N1_CPUECTLR_EL1
+ orr x1, x1, NEOVERSE_N1_CPUECTLR_EL1_MM_TLBPF_DIS_BIT
+ msr NEOVERSE_N1_CPUECTLR_EL1, x1
+ isb
+1:
+ ret x17
+endfunc errata_n1_1262888_wa
+
+func check_errata_1262888
+ /* Applies to <=r3p0 */
+ mov x1, #0x30
+ b cpu_rev_var_ls
+endfunc check_errata_1262888
+
+/* --------------------------------------------------
* Errata Workaround for Neoverse N1 Erratum 1315703.
* This applies to revision <= r3p0 of Neoverse N1.
* Inputs:
@@ -348,6 +375,11 @@
bl errata_n1_1262606_wa
#endif
+#if ERRATA_N1_1262888
+ mov x0, x18
+ bl errata_n1_1262888_wa
+#endif
+
#if ERRATA_N1_1315703
mov x0, x18
bl errata_n1_1315703_wa
@@ -417,6 +449,7 @@
report_errata ERRATA_N1_1220197, neoverse_n1, 1220197
report_errata ERRATA_N1_1257314, neoverse_n1, 1257314
report_errata ERRATA_N1_1262606, neoverse_n1, 1262606
+ report_errata ERRATA_N1_1262888, neoverse_n1, 1262888
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 befb45e..2f13696 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -266,6 +266,10 @@
# only to revision <= r3p0 of the Neoverse N1 cpu.
ERRATA_N1_1262606 ?=0
+# Flag to apply erratum 1262888 workaround during reset. This erratum applies
+# only to revision <= r3p0 of the Neoverse N1 cpu.
+ERRATA_N1_1262888 ?=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
@@ -487,6 +491,10 @@
$(eval $(call assert_boolean,ERRATA_N1_1262606))
$(eval $(call add_define,ERRATA_N1_1262606))
+# Process ERRATA_N1_1262888 flag
+$(eval $(call assert_boolean,ERRATA_N1_1262888))
+$(eval $(call add_define,ERRATA_N1_1262888))
+
# Process ERRATA_N1_1315703 flag
$(eval $(call assert_boolean,ERRATA_N1_1315703))
$(eval $(call add_define,ERRATA_N1_1315703))