From: Robert Richter <[email protected]>

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.

v5:
 * fix table size wrongly allocating only 4MB
 * introduced CAVIUM_ERRATUM_22375 config option
 * added config description
 * introduced ITS_FLAGS_WORKAROUND_CAVIUM_22375

v3:
 * fix erratum to be dependend from iidr

Signed-off-by: Ganapatrao Kulkarni <[email protected]>
Signed-off-by: Robert Richter <[email protected]>
---
 arch/arm64/Kconfig               | 17 +++++++++++++++++
 drivers/irqchip/irq-gic-v3-its.c | 37 +++++++++++++++++++++++++++++++++----
 2 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 2e65757ae7be..08a948f15650 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -331,6 +331,23 @@ config ARM64_ERRATUM_845719
 
          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 5c6023e80f6d..4e9ef1f80c63 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);
@@ -1373,7 +1387,22 @@ 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
        {
        }
 };
-- 
2.1.1

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