2 files changed, 50 insertions, 4 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 490df449377d..440d906429de 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -348,6 +348,23 @@ config ARM64_ERRATUM_843419
 
           If unsure, say Y.
 
+config CAVIUM_ERRATUM_22375
+        bool "Cavium erratum 22375, 24313"
+        default y
+        help
+          Enable workaround for erratum 22375, 24313.
+
+          This implements two gicv3-its errata workarounds for ThunderX. Both
+          with small impact affecting only ITS table allocation.
+
+            erratum 22375: only alloc 8MB table size
+            erratum 24313: ignore memory access type
+
+          The fixes are in ITS initialization and basically ignore memory access
+          type and table size provided by the TYPER and BASER registers.
+
+          If unsure, say Y.
+
 config CAVIUM_ERRATUM_23154
         bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
         default y
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 82622afc916b..eac44dd28ca1 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -39,7 +39,8 @@
 
 #include "irq-gic-common.h"
 
-#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING           (1 << 0)
+#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING           (1ULL << 0)
+#define ITS_FLAGS_WORKAROUND_CAVIUM_22375       (1ULL << 1)
 
 #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING     (1 << 0)
 
@@ -816,9 +817,22 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
         int i;
         int psz = SZ_64K;
         u64 shr = GITS_BASER_InnerShareable;
-        u64 cache = GITS_BASER_WaWb;
-        u64 typer = readq_relaxed(its->base + GITS_TYPER);
-        u32 ids = GITS_TYPER_DEVBITS(typer);
+        u64 cache;
+        u64 typer;
+        u32 ids;
+
+        if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_22375) {
+                /*
+                 * erratum 22375: only alloc 8MB table size
+                 * erratum 24313: ignore memory access type
+                 */
+                cache   = 0;
+                ids     = 0x14;                 /* 20 bits, 8MB */
+        } else {
+                cache   = GITS_BASER_WaWb;
+                typer   = readq_relaxed(its->base + GITS_TYPER);
+                ids     = GITS_TYPER_DEVBITS(typer);
+        }
 
         for (i = 0; i < GITS_BASER_NR_REGS; i++) {
                 u64 val = readq_relaxed(its->base + GITS_BASER + i * 8);
@@ -1377,7 +1391,22 @@ static int its_force_quiescent(void __iomem *base)
         }
 }
 
+static void __maybe_unused its_enable_quirk_cavium_22375(void *data)
+{
+        struct its_node *its = data;
+
+        its->flags |= ITS_FLAGS_WORKAROUND_CAVIUM_22375;
+}
+
 static const struct gic_quirk its_quirks[] = {
+#ifdef CONFIG_CAVIUM_ERRATUM_22375
+        {
+                .desc   = "ITS: Cavium errata 22375, 24313",
+                .iidr   = 0xa100034c,   /* ThunderX pass 1.x */
+                .mask   = 0xffff0fff,
+                .init   = its_enable_quirk_cavium_22375,
+        },
+#endif
         {
         }
 };