[PATCH v4] irqchip, gicv3-its, numa: Enable workaround for Cavium thunderx erratum 23144

From: Ganapatrao Kulkarni
Date: Wed Mar 16 2016 - 09:11:28 EST


The erratum fixes the hang of ITS SYNC command by avoiding inter node
io and collections/cpu mapping on thunderx dual-socket platform.

This fix is only applicable for Cavium's ThunderX dual-socket platform.

This is based on NUMA v15 series.
http://comments.gmane.org/gmane.linux.kernel/2172411

v4:
updated silicon-errata.txt
updated as per Robert Richter review comment.

v3:
updatated as per Marc Zyngier's review comments.
http://www.spinics.net/lists/arm-kernel/msg443462.html

v2:
updatated as per Marc Zyngier's review comments.

Reviewed-by: Robert Richter <rrichter@xxxxxxxxxx>
Signed-off-by: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxxxxxxxxxx>
---
Documentation/arm64/silicon-errata.txt | 1 +
arch/arm64/Kconfig | 9 +++++++
drivers/irqchip/irq-gic-v3-its.c | 48 ++++++++++++++++++++++++++++++++--
3 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 58b71dd..5e620a0 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -55,4 +55,5 @@ stable kernels.
| ARM | Cortex-A57 | #834220 | ARM64_ERRATUM_834220 |
| | | | |
| Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 |
+| Cavium | ThunderX ITS | #23144 | CAVIUM_ERRATUM_23144 |
| Cavium | ThunderX GICv3 | #23154 | CAVIUM_ERRATUM_23154 |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 8cc6228..57595f7 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -422,6 +422,15 @@ config CAVIUM_ERRATUM_22375

If unsure, say Y.

+config CAVIUM_ERRATUM_23144
+ bool "Cavium erratum 23144: ITS SYNC hang on dual socket system"
+ depends on NUMA
+ default y
+ help
+ ITS SYNC command hang for cross node io and collections/cpu mapping.
+
+ 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 3926179..35ab325 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -41,6 +41,7 @@

#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1ULL << 0)
#define ITS_FLAGS_WORKAROUND_CAVIUM_22375 (1ULL << 1)
+#define ITS_FLAGS_WORKAROUND_CAVIUM_23144 (1ULL << 2)

#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)

@@ -74,6 +75,7 @@ struct its_node {
struct list_head its_device_list;
u64 flags;
u32 ite_size;
+ int numa_node;
};

#define ITS_ITT_ALIGN SZ_256
@@ -605,11 +607,21 @@ static void its_unmask_irq(struct irq_data *d)
static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
bool force)
{
- unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
+ unsigned int cpu;
+ const struct cpumask *cpu_mask = cpu_online_mask;
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
struct its_collection *target_col;
u32 id = its_get_event_id(d);

+ /* lpi cannot be routed to a redistributor that is on a foreign node */
+ if (its_dev->its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
+ cpu_mask = cpumask_of_node(its_dev->its->numa_node);
+ if (!cpumask_intersects(mask_val, cpu_mask))
+ return -EINVAL;
+ }
+
+ cpu = cpumask_any_and(mask_val, cpu_mask);
+
if (cpu >= nr_cpu_ids)
return -EINVAL;

@@ -1090,6 +1102,16 @@ static void its_cpu_init_collection(void)
list_for_each_entry(its, &its_nodes, entry) {
u64 target;

+ /* avoid cross node collections and its mapping */
+ if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
+ struct device_node *cpu_node;
+
+ cpu_node = of_get_cpu_node(cpu, NULL);
+ if (its->numa_node != NUMA_NO_NODE &&
+ its->numa_node != of_node_to_nid(cpu_node))
+ continue;
+ }
+
/*
* We now have to bind each collection to its target
* redistributor.
@@ -1317,9 +1339,14 @@ static void its_irq_domain_activate(struct irq_domain *domain,
{
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
u32 event = its_get_event_id(d);
+ const struct cpumask *cpu_mask = cpu_online_mask;
+
+ /* get the cpu_mask of local node */
+ if (IS_ENABLED(CONFIG_NUMA))
+ cpu_mask = cpumask_of_node(its_dev->its->numa_node);

/* Bind the LPI to the first possible CPU */
- its_dev->event_map.col_map[event] = cpumask_first(cpu_online_mask);
+ its_dev->event_map.col_map[event] = cpumask_first(cpu_mask);

/* Map the GIC IRQ and event to the device */
its_send_mapvi(its_dev, d->hwirq, event);
@@ -1409,6 +1436,13 @@ static void __maybe_unused its_enable_quirk_cavium_22375(void *data)
its->flags |= ITS_FLAGS_WORKAROUND_CAVIUM_22375;
}

+static void __maybe_unused its_enable_quirk_cavium_23144(void *data)
+{
+ struct its_node *its = data;
+
+ its->flags |= ITS_FLAGS_WORKAROUND_CAVIUM_23144;
+}
+
static const struct gic_quirk its_quirks[] = {
#ifdef CONFIG_CAVIUM_ERRATUM_22375
{
@@ -1418,6 +1452,15 @@ static const struct gic_quirk its_quirks[] = {
.init = its_enable_quirk_cavium_22375,
},
#endif
+
+#ifdef CONFIG_CAVIUM_ERRATUM_23144
+ {
+ .desc = "ITS: Cavium erratum 23144",
+ .iidr = 0xa100034c, /* ThunderX pass 1.x */
+ .mask = 0xffff0fff,
+ .init = its_enable_quirk_cavium_23144,
+ },
+#endif
{
}
};
@@ -1480,6 +1523,7 @@ static int __init its_probe(struct device_node *node,
its->base = its_base;
its->phys_base = res.start;
its->ite_size = ((readl_relaxed(its_base + GITS_TYPER) >> 4) & 0xf) + 1;
+ its->numa_node = of_node_to_nid(node);

its->cmd_base = kzalloc(ITS_CMD_QUEUE_SZ, GFP_KERNEL);
if (!its->cmd_base) {
--
1.8.1.4