generic: fu740: add workaround for CIP-1200 errata

Instruction TLB can fail to respect a non-global SFENCE thus we need to
flush the TLB using SFENCE.VMA x0, x0

See full description of CIP-1200 in Errata_FU740-C000_20210205 from
https://www.sifive.com/boards/hifive-unmatched

Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

diff --git a/platform/generic/objects.mk b/platform/generic/objects.mk
index d6c8a42..cb15a18 100644 (file)
--- a/platform/generic/objects.mk
+++ b/platform/generic/objects.mk
@@ -9,3 +9,4 @@
 
 platform-objs-y += platform.o
 platform-objs-y += sifive_fu540.o
+platform-objs-y += sifive_fu740.o

diff --git a/platform/generic/platform.c b/platform/generic/platform.c
index 0787d10..0757d87 100644 (file)
--- a/platform/generic/platform.c
+++ b/platform/generic/platform.c
@@ -24,9 +24,11 @@
 #include <sbi_utils/reset/fdt_reset.h>
 
 extern const struct platform_override sifive_fu540;
+extern const struct platform_override sifive_fu740;
 
 static const struct platform_override *special_platforms[] = {
        &sifive_fu540,
+       &sifive_fu740,
 };
 
 static const struct platform_override *generic_plat = NULL;

diff --git a/platform/generic/sifive_fu740.c b/platform/generic/sifive_fu740.c
new file mode 100644 (file)
index 0000000..c8325d3
--- /dev/null
+++ b/platform/generic/sifive_fu740.c
@@ -0,0 +1,36 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 SiFive
+ *
+ * Authors:
+ *   David Abdurachmanov <david.abdurachmanov@sifive.com>
+ */
+
+#include <platform_override.h>
+#include <sbi_utils/fdt/fdt_helper.h>
+#include <sbi_utils/fdt/fdt_fixup.h>
+
+static u64 sifive_fu740_tlbr_flush_limit(const struct fdt_match *match)
+{
+       /*
+        * Needed to address CIP-1200 errata on SiFive FU740
+        * Title: Instruction TLB can fail to respect a non-global SFENCE
+        * Workaround: Flush the TLB using SFENCE.VMA x0, x0
+        * See Errata_FU740-C000_20210205 from
+        * https://www.sifive.com/boards/hifive-unmatched
+        */
+       return 0;
+}
+
+static const struct fdt_match sifive_fu740_match[] = {
+       { .compatible = "sifive,fu740" },
+       { .compatible = "sifive,fu740-c000" },
+       { .compatible = "sifive,hifive-unmatched-a00" },
+       { },
+};
+
+const struct platform_override sifive_fu740 = {
+       .match_table = sifive_fu740_match,
+       .tlbr_flush_limit = sifive_fu740_tlbr_flush_limit,
+};