[PATCH v4 5/5] irqchip, gicv3-its: Workaround for Cavium ThunderX errata 22375, 24313

Robert Richter
2015-08-14T18:28:05Z

From: Robert Richter <rrichter@cavium.com>

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.

v3:
* fix erratum to be dependend from iidr

Signed-off-by: Robert Richter <rrichter@cavium.com>
---
drivers/irqchip/irq-gic-v3-its.c | 35 +++++++++++++++++++++++++++++++----
1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 697421e834ee..30459df2ee2c 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"
#include "irqchip.h"

-#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1 << 0)
+#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1ULL << 0)
+#define ITS_FLAGS_CAVIUM_THUNDERX (1ULL << 1)

#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)

@@ -803,9 +804,22 @@ static int its_alloc_tables(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_CAVIUM_THUNDERX) {
+ /*
+ * erratum 22375: only alloc 8MB table size
+ * erratum 24313: ignore memory access type
+ */
+ cache = 0;
+ ids = 0x13; /* 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);
@@ -1391,8 +1405,21 @@ static int its_force_quiescent(void __iomem *base)
}
}

+static void its_enable_cavium_thunderx(void *data)
+{
+ struct its_node *its = data;
+
+ its->flags |= ITS_FLAGS_CAVIUM_THUNDERX;
+}
+
static const struct gic_capabilities its_errata[] = {
{
+ .desc = "ITS: Cavium errata 22375, 24313",
+ .iidr = 0xa100034c, /* ThunderX pass 1.x */
+ .mask = 0xffff0fff,
+ .init = its_enable_cavium_thunderx,
+ },
+ {
}
};

--
2.1.1