[PATCH v5 5/6] irqchip, gicv3-its: Workaround for Cavium ThunderX errata 22375, 24313

From: Robert Richter
Date: Mon Sep 21 2015 - 16:59:46 EST


From: Robert Richter <rrichter@xxxxxxxxxx>

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 <gkulkarni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Robert Richter <rrichter@xxxxxxxxxx>
---
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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