arm64: apply ARM64_ERRATUM_845719 workaround for Brahma-B53 core

The Broadcom Brahma-B53 core is susceptible to the issue described by
ARM64_ERRATUM_845719 so this commit enables the workaround to be applied
when executing on that core.

Since there are now multiple entries to match, we must convert the
existing ARM64_ERRATUM_845719 into an erratum list.
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>

Documentation/arm64/silicon-errata.rst

@@ -91,6 +91,9 @@ stable kernels.
 | ARM            | MMU-500         | #841119,826419  | N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
 +----------------+-----------------+-----------------+-----------------------------+
+| Broadcom       | Brahma-B53      | N/A             | ARM64_ERRATUM_845719        |
++----------------+-----------------+-----------------+-----------------------------+
++----------------+-----------------+-----------------+-----------------------------+
 | Cavium         | ThunderX ITS    | #22375,24313    | CAVIUM_ERRATUM_22375        |
 +----------------+-----------------+-----------------+-----------------------------+
 | Cavium         | ThunderX ITS    | #23144          | CAVIUM_ERRATUM_23144        |

arch/arm64/include/asm/cputype.h

@@ -79,6 +79,7 @@
 #define CAVIUM_CPU_PART_THUNDERX_83XX	0x0A3
 #define CAVIUM_CPU_PART_THUNDERX2	0x0AF
 
+#define BRCM_CPU_PART_BRAHMA_B53	0x100
 #define BRCM_CPU_PART_VULCAN		0x516
 
 #define QCOM_CPU_PART_FALKOR_V1		0x800
@@ -105,6 +106,7 @@
 #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
 #define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
 #define MIDR_CAVIUM_THUNDERX2 MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX2)
+#define MIDR_BRAHMA_B53 MIDR_CPU_MODEL(ARM_CPU_IMP_BRCM, BRCM_CPU_PART_BRAHMA_B53)
 #define MIDR_BRCM_VULCAN MIDR_CPU_MODEL(ARM_CPU_IMP_BRCM, BRCM_CPU_PART_VULCAN)
 #define MIDR_QCOM_FALKOR_V1 MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, QCOM_CPU_PART_FALKOR_V1)
 #define MIDR_QCOM_FALKOR MIDR_CPU_MODEL(ARM_CPU_IMP_QCOM, QCOM_CPU_PART_FALKOR)

arch/arm64/kernel/cpu_errata.c

@@ -743,6 +743,16 @@ static const struct midr_range erratum_1418040_list[] = {
 };
 #endif
 
+#ifdef CONFIG_ARM64_ERRATUM_845719
+static const struct midr_range erratum_845719_list[] = {
+	/* Cortex-A53 r0p[01234] */
+	MIDR_REV_RANGE(MIDR_CORTEX_A53, 0, 0, 4),
+	/* Brahma-B53 r0p[0] */
+	MIDR_REV(MIDR_BRAHMA_B53, 0, 0),
+	{},
+};
+#endif
+
 const struct arm64_cpu_capabilities arm64_errata[] = {
 #ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
 	{
@@ -783,10 +793,9 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 #endif
 #ifdef CONFIG_ARM64_ERRATUM_845719
 	{
-	/* Cortex-A53 r0p[01234] */
 		.desc = "ARM erratum 845719",
 		.capability = ARM64_WORKAROUND_845719,
-		ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A53, 0, 0, 4),
+		ERRATA_MIDR_RANGE_LIST(erratum_845719_list),
 	},
 #endif
 #ifdef CONFIG_CAVIUM_ERRATUM_23154