Date: Sat, 22 Aug 2015 15:10:50 +0200
From: Robert Richter <robert.richter@caviumnetworks.com>
To: Marc Zygnier <marc.zyngier@arm.com>, Will Deacon <will.deacon@arm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Jason Cooper <jason@lakedaemon.net>
CC: Ganapatrao Kulkarni <ganapatrao.kulkarni@caviumnetworks.com>,
        Tirumalesh Chalamarla <tirumalesh.chalamarla@caviumnetworks.com>,
        Robert Richter <rric@kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>
Subject: [PATCH] irqchip, gicv3-its, numa: Workaround for Cavium ThunderX
 erratum 23144
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The patch below adds a workaround for gicv3 in a numa environment. It
is on top of my recent gicv3 errata patch submission v4 and Ganapat's
arm64 numa patches for devicetree v5.

Please comment.

Thanks,

-Robert


>From c432820451a46b8d1e299b8bfbfcdcb3b75340e7 Mon Sep 17 00:00:00 2001
From: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Date: Wed, 19 Aug 2015 23:40:05 +0530
Subject: [PATCH] irqchip, gicv3-its, numa: Workaround for Cavium ThunderX erratum
 23144

This implements a workaround for gicv3-its erratum 23144 applicable
for Cavium's ThunderX multinode systems.

The erratum fixes the hang of ITS SYNC command by avoiding inter node
io and collections/cpu mapping. This fix is only applicable for
Cavium's ThunderX dual-socket platforms.

Signed-off-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
[ rric: Reworked errata code, added helper functions, updated commit
  	message. ]

Signed-off-by: Robert Richter <rrichter@cavium.com>
---
 arch/arm64/Kconfig               | 14 +++++++++++
 drivers/irqchip/irq-gic-common.c |  5 ++--
 drivers/irqchip/irq-gic-v3-its.c | 54 ++++++++++++++++++++++++++++++++++------
 3 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3809187ed653..b92b7b70b29b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -421,6 +421,20 @@ config ARM64_ERRATUM_845719
 
 	  If unsure, say Y.
 
+config CAVIUM_ERRATUM_22375
+	bool "Cavium erratum 22375, 24313"
+	depends on NUMA
+	default y
+	help
+		Enable workaround for erratum 22375, 24313.
+
+config CAVIUM_ERRATUM_23144
+	bool "Cavium erratum 23144"
+	depends on NUMA
+	default y
+	help
+		Enable workaround for erratum 23144.
+
 config CAVIUM_ERRATUM_23154
 	bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed"
 	depends on ARCH_THUNDER
diff --git a/drivers/irqchip/irq-gic-common.c b/drivers/irqchip/irq-gic-common.c
index ee789b07f2d1..1dfce64dbdac 100644
--- a/drivers/irqchip/irq-gic-common.c
+++ b/drivers/irqchip/irq-gic-common.c
@@ -24,11 +24,12 @@
 void gic_check_capabilities(u32 iidr, const struct gic_capabilities *cap,
 			void *data)
 {
-	for (; cap->desc; cap++) {
+	for (; cap->init; cap++) {
 		if (cap->iidr != (cap->mask & iidr))
 			continue;
 		cap->init(data);
-		pr_info("%s\n", cap->desc);
+		if (cap->desc)
+			pr_info("%s\n", cap->desc);
 	}
 }
 
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 4bb135721e72..666be39f13a9 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -43,7 +43,8 @@
 #include "irqchip.h"
 
 #define ITS_FLAGS_CMDQ_NEEDS_FLUSHING		(1ULL << 0)
-#define ITS_FLAGS_CAVIUM_THUNDERX		(1ULL << 1)
+#define ITS_WORKAROUND_CAVIUM_22375		(1ULL << 1)
+#define ITS_WORKAROUND_CAVIUM_23144		(1ULL << 2)
 
 #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING	(1 << 0)
 
@@ -76,6 +77,7 @@ struct its_node {
 	struct list_head	its_device_list;
 	u64			flags;
 	u32			ite_size;
+	int			numa_node;
 };
 
 #define ITS_ITT_ALIGN		SZ_256
@@ -609,11 +611,18 @@ static void its_eoi_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;
 	struct its_device *its_dev = irq_data_get_irq_chip_data(d);
 	struct its_collection *target_col;
 	u32 id = its_get_event_id(d);
 
+	if (its_dev->its->flags & ITS_WORKAROUND_CAVIUM_23144) {
+		cpu = cpumask_any_and(mask_val,
+				cpumask_of_node(its_dev->its->numa_node));
+	} else {
+		cpu = cpumask_any_and(mask_val, cpu_online_mask);
+	}
+
 	if (cpu >= nr_cpu_ids)
 		return -EINVAL;
 
@@ -845,7 +854,7 @@ static int its_alloc_tables(struct its_node *its)
 	u64 typer;
 	u32 ids;
 
-	if (its->flags & ITS_FLAGS_CAVIUM_THUNDERX) {
+	if (its->flags & ITS_WORKAROUND_CAVIUM_22375) {
 		/*
 		 * erratum 22375: only alloc 8MB table size
 		 * erratum 24313: ignore memory access type
@@ -1093,6 +1102,11 @@ static void its_cpu_init_lpis(void)
 	dsb(sy);
 }
 
+static inline int numa_node_id_early(void)
+{
+	return MPIDR_AFFINITY_LEVEL(read_cpuid_mpidr(), 2);
+}
+
 static void its_cpu_init_collection(void)
 {
 	struct its_node *its;
@@ -1104,6 +1118,11 @@ static void its_cpu_init_collection(void)
 	list_for_each_entry(its, &its_nodes, entry) {
 		u64 target;
 
+		/* avoid cross node core and its mapping */
+		if ((its->flags & ITS_WORKAROUND_CAVIUM_23144) &&
+			its->numa_node != numa_node_id_early())
+				continue;
+
 		/*
 		 * We now have to bind each collection to its target
 		 * redistributor.
@@ -1372,9 +1391,15 @@ 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);
+	unsigned int cpu;
+
+	if (its_dev->its->flags & ITS_WORKAROUND_CAVIUM_23144)
+		cpu = cpumask_first(cpumask_of_node(its_dev->its->numa_node));
+	else
+		cpu = cpumask_first(cpu_online_mask);
 
 	/* 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] = cpu;
 
 	/* Map the GIC IRQ and event to the device */
 	its_send_mapvi(its_dev, d->hwirq, event);
@@ -1457,16 +1482,31 @@ static int its_force_quiescent(void __iomem *base)
 	}
 }
 
+static inline int its_get_node_thunderx(struct its_node *its)
+{
+	return (its->phys_base >> 44) & 0x3;
+}
+
 static void its_enable_cavium_thunderx(void *data)
 {
-	struct its_node *its = data;
+	struct its_node __maybe_unused *its = data;
 
-	its->flags |= ITS_FLAGS_CAVIUM_THUNDERX;
+#ifdef CONFIG_CAVIUM_ERRATUM_22375
+	its->flags |= ITS_WORKAROUND_CAVIUM_22375;
+	pr_info("ITS: Enabling workaround for 22375, 24313\n");
+#endif
+
+#ifdef CONFIG_CAVIUM_ERRATUM_23144
+	if (num_possible_nodes() > 1) {
+		its->numa_node = its_get_node_thunderx(its);
+		its->flags |= ITS_WORKAROUND_CAVIUM_23144;
+		pr_info("ITS: Enabling workaround for 23144\n");
+	}
+#endif
 }
 
 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

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