Message-ID: <565065E2.2050609@simon.arlott.org.uk>
Date:	Sat, 21 Nov 2015 12:38:58 +0000
From:	Simon Arlott <simon@...e.lp0.eu>
To:	Thomas Gleixner <tglx@...utronix.de>,
	Jason Cooper <jason@...edaemon.net>,
	Marc Zyngier <marc.zyngier@....com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	devicetree@...r.kernel.org,
	Florian Fainelli <f.fainelli@...il.com>,
	Kevin Cernekee <cernekee@...il.com>, linux-mips@...ux-mips.org,
	Jonas Gorski <jogo@...nwrt.org>,
	Ralf Baechle <ralf@...ux-mips.org>
Cc:	Rob Herring <robh@...nel.org>, Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>
Subject: [PATCH 2/2] MIPS: bmips: Add bcm6345-l1 interrupt controller

Add the BCM6345 interrupt controller based on the SMP-capable BCM7038
and the BCM3380 but with packed interrupt registers.

Add the BCM6345 interrupt controller to a list with the existing BCM7038
so that interrupts on CPU1 are not ignored.

Update the maintainers file list for BMIPS to include this driver.

Signed-off-by: Simon Arlott <simon@...e.lp0.eu>
---
Renamed from bcm63168 to bcm6345.

Compared interrupt register word ordering with the bcm7038 driver
which is LE and has the words in LE order, so using ordering that
matches the CPU is appropriate.

Removed unnecessary cpumask memset.

Changed to use only one spinlock.

 MAINTAINERS                      |   1 +
 arch/mips/Kconfig                |   1 +
 arch/mips/bmips/irq.c            |  10 +-
 drivers/irqchip/Kconfig          |   5 +
 drivers/irqchip/Makefile         |   1 +
 drivers/irqchip/irq-bcm6345-l1.c | 366 +++++++++++++++++++++++++++++++++++++++
 6 files changed, 382 insertions(+), 2 deletions(-)
 create mode 100644 drivers/irqchip/irq-bcm6345-l1.c

diff --git a/MAINTAINERS b/MAINTAINERS
index e9caa4b..63bf54a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2373,6 +2373,7 @@ F:	arch/mips/bmips/*
 F:	arch/mips/include/asm/mach-bmips/*
 F:	arch/mips/kernel/*bmips*
 F:	arch/mips/boot/dts/brcm/bcm*.dts*
+F:	drivers/irqchip/irq-bcm63*
 F:	drivers/irqchip/irq-bcm7*
 F:	drivers/irqchip/irq-brcmstb*
 
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e3aa5b0..e536f3f 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -149,6 +149,7 @@ config BMIPS_GENERIC
 	select CSRC_R4K
 	select SYNC_R4K
 	select COMMON_CLK
+	select BCM6345_L1_IRQ
 	select BCM7038_L1_IRQ
 	select BCM7120_L2_IRQ
 	select BRCMSTB_L2_IRQ
diff --git a/arch/mips/bmips/irq.c b/arch/mips/bmips/irq.c
index e7fc6f934..7efefcf 100644
--- a/arch/mips/bmips/irq.c
+++ b/arch/mips/bmips/irq.c
@@ -15,6 +15,12 @@
 #include <asm/irq_cpu.h>
 #include <asm/time.h>
 
+static const struct of_device_id smp_intc_dt_match[] = {
+	{ .compatible = "brcm,bcm7038-l1-intc" },
+	{ .compatible = "brcm,bcm6345-l1-intc" },
+	{}
+};
+
 unsigned int get_c0_compare_int(void)
 {
 	return CP0_LEGACY_COMPARE_IRQ;
@@ -24,8 +30,8 @@ void __init arch_init_irq(void)
 {
 	struct device_node *dn;
 
-	/* Only the STB (bcm7038) controller supports SMP IRQ affinity */
-	dn = of_find_compatible_node(NULL, NULL, "brcm,bcm7038-l1-intc");
+	/* Only these controllers support SMP IRQ affinity */
+	dn = of_find_matching_node(NULL, smp_intc_dt_match);
 	if (dn)
 		of_node_put(dn);
 	else
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 4d7294e..d307bb3 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -65,6 +65,11 @@ config I8259
 	bool
 	select IRQ_DOMAIN
 
+config BCM6345_L1_IRQ
+	bool
+	select GENERIC_IRQ_CHIP
+	select IRQ_DOMAIN
+
 config BCM7038_L1_IRQ
 	bool
 	select GENERIC_IRQ_CHIP
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 177f78f..ded59cf 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o
 obj-$(CONFIG_XTENSA_MX)			+= irq-xtensa-mx.o
 obj-$(CONFIG_IRQ_CROSSBAR)		+= irq-crossbar.o
 obj-$(CONFIG_SOC_VF610)			+= irq-vf610-mscm-ir.o
+obj-$(CONFIG_BCM6345_L1_IRQ)		+= irq-bcm6345-l1.o
 obj-$(CONFIG_BCM7038_L1_IRQ)		+= irq-bcm7038-l1.o
 obj-$(CONFIG_BCM7120_L2_IRQ)		+= irq-bcm7120-l2.o
 obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o
diff --git a/drivers/irqchip/irq-bcm6345-l1.c b/drivers/irqchip/irq-bcm6345-l1.c
new file mode 100644
index 0000000..31a69f4
--- /dev/null
+++ b/drivers/irqchip/irq-bcm6345-l1.c
@@ -0,0 +1,366 @@
+/*
+ * Broadcom BCM6345 style Level 1 interrupt controller driver
+ *
+ * Copyright (C) 2014 Broadcom Corporation
+ * Copyright 2015 Simon Arlott
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This is based on the BCM7038 (which supports SMP) but with a single
+ * enable register instead of separate mask/set/clear registers.
+ *
+ * The BCM3380 has a similar mask/status register layout, but each pair
+ * of words is at separate locations (and SMP is not supported).
+ *
+ * ENABLE/STATUS words are packed next to each other for each CPU:
+ *
+ * BCM6368:
+ *   0x1000_0020: CPU0_W0_ENABLE
+ *   0x1000_0024: CPU0_W1_ENABLE
+ *   0x1000_0028: CPU0_W0_STATUS		IRQs 31-63
+ *   0x1000_002c: CPU0_W1_STATUS		IRQs 0-31
+ *   0x1000_0030: CPU1_W0_ENABLE
+ *   0x1000_0034: CPU1_W1_ENABLE
+ *   0x1000_0038: CPU1_W0_STATUS		IRQs 31-63
+ *   0x1000_003c: CPU1_W1_STATUS		IRQs 0-31
+ *
+ * BCM63168:
+ *   0x1000_0020: CPU0_W0_ENABLE
+ *   0x1000_0024: CPU0_W1_ENABLE
+ *   0x1000_0028: CPU0_W2_ENABLE
+ *   0x1000_002c: CPU0_W3_ENABLE
+ *   0x1000_0030: CPU0_W0_STATUS	IRQs 96-127
+ *   0x1000_0034: CPU0_W1_STATUS	IRQs 64-95
+ *   0x1000_0038: CPU0_W2_STATUS	IRQs 32-63
+ *   0x1000_003c: CPU0_W3_STATUS	IRQs 0-31
+ *   0x1000_0040: CPU1_W0_ENABLE
+ *   0x1000_0044: CPU1_W1_ENABLE
+ *   0x1000_0048: CPU1_W2_ENABLE
+ *   0x1000_004c: CPU1_W3_ENABLE
+ *   0x1000_0050: CPU1_W0_STATUS	IRQs 96-127
+ *   0x1000_0054: CPU1_W1_STATUS	IRQs 64-95
+ *   0x1000_0058: CPU1_W2_STATUS	IRQs 32-63
+ *   0x1000_005c: CPU1_W3_STATUS	IRQs 0-31
+ *
+ * IRQs are numbered in CPU native endian order
+ * (which is big-endian in these examples)
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME	": " fmt
+
+#include <linux/bitops.h>
+#include <linux/cpumask.h>
+#include <linux/kconfig.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/types.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+
+#define IRQS_PER_WORD		32
+#define REG_BYTES_PER_IRQ_WORD	(sizeof(u32) * 2)
+
+struct bcm6345_l1_cpu;
+
+struct bcm6345_l1_chip {
+	raw_spinlock_t		lock;
+	unsigned int		n_words;
+	struct irq_domain	*domain;
+	struct cpumask		cpumask;
+	struct bcm6345_l1_cpu	*cpus[NR_CPUS];
+};
+
+struct bcm6345_l1_cpu {
+	void __iomem		*map_base;
+	unsigned int		parent_irq;
+	u32			enable_cache[];
+};
+
+static inline unsigned int reg_enable(struct bcm6345_l1_chip *intc,
+					   unsigned int word)
+{
+#ifdef __BIG_ENDIAN
+	return (1 * intc->n_words - word - 1) * sizeof(u32);
+#else
+	return (0 * intc->n_words + word) * sizeof(u32);
+#endif
+}
+
+static inline unsigned int reg_status(struct bcm6345_l1_chip *intc,
+				      unsigned int word)
+{
+#ifdef __BIG_ENDIAN
+	return (2 * intc->n_words - word - 1) * sizeof(u32);
+#else
+	return (1 * intc->n_words + word) * sizeof(u32);
+#endif
+}
+
+static inline unsigned int cpu_for_irq(struct bcm6345_l1_chip *intc,
+					struct irq_data *d)
+{
+	return cpumask_first_and(&intc->cpumask, irq_data_get_affinity_mask(d));
+}
+
+static void bcm6345_l1_irq_handle(struct irq_desc *desc)
+{
+	struct bcm6345_l1_chip *intc = irq_desc_get_handler_data(desc);
+	struct bcm6345_l1_cpu *cpu;
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned int idx;
+
+#ifdef CONFIG_SMP
+	cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
+#else
+	cpu = intc->cpus[0];
+#endif
+
+	chained_irq_enter(chip, desc);
+
+	for (idx = 0; idx < intc->n_words; idx++) {
+		int base = idx * IRQS_PER_WORD;
+		unsigned long pending;
+		irq_hw_number_t hwirq;
+		unsigned int irq;
+
+		pending = __raw_readl(cpu->map_base + reg_status(intc, idx));
+		pending &= __raw_readl(cpu->map_base + reg_enable(intc, idx));
+
+		for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
+			irq = irq_linear_revmap(intc->domain, base + hwirq);
+			if (irq)
+				do_IRQ(irq);
+			else
+				spurious_interrupt();
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static inline void __bcm6345_l1_unmask(struct irq_data *d)
+{
+	struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+	u32 word = d->hwirq / IRQS_PER_WORD;
+	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
+	unsigned int cpu_idx = cpu_for_irq(intc, d);
+
+	intc->cpus[cpu_idx]->enable_cache[word] |= mask;
+	__raw_writel(intc->cpus[cpu_idx]->enable_cache[word],
+		intc->cpus[cpu_idx]->map_base + reg_enable(intc, word));
+}
+
+static inline void __bcm6345_l1_mask(struct irq_data *d)
+{
+	struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+	u32 word = d->hwirq / IRQS_PER_WORD;
+	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
+	unsigned int cpu_idx = cpu_for_irq(intc, d);
+
+	intc->cpus[cpu_idx]->enable_cache[word] &= ~mask;
+	__raw_writel(intc->cpus[cpu_idx]->enable_cache[word],
+		intc->cpus[cpu_idx]->map_base + reg_enable(intc, word));
+}
+
+static void bcm6345_l1_unmask(struct irq_data *d)
+{
+	struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+	u32 word = d->hwirq / IRQS_PER_WORD;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&intc->lock, flags);
+	__bcm6345_l1_unmask(d);
+	raw_spin_unlock_irqrestore(&intc->lock, flags);
+}
+
+static void bcm6345_l1_mask(struct irq_data *d)
+{
+	struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+	u32 word = d->hwirq / IRQS_PER_WORD;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&intc->lock, flags);
+	__bcm6345_l1_mask(d);
+	raw_spin_unlock_irqrestore(&intc->lock, flags);
+}
+
+static int bcm6345_l1_set_affinity(struct irq_data *d,
+				   const struct cpumask *dest,
+				   bool force)
+{
+	struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+	u32 word = d->hwirq / IRQS_PER_WORD;
+	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
+	unsigned int old_cpu = cpu_for_irq(intc, d);
+	unsigned int new_cpu;
+	struct cpumask valid;
+	unsigned long flags;
+	bool enabled;
+
+	if (!cpumask_and(&valid, &intc->cpumask, dest))
+		return -EINVAL;
+
+	new_cpu = cpumask_any_and(&valid, cpu_online_mask);
+	if (new_cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	dest = cpumask_of(new_cpu);
+
+	raw_spin_lock_irqsave(&intc->lock, flags);
+	if (old_cpu != new_cpu) {
+		enabled = intc->cpus[old_cpu]->enable_cache[word] & mask;
+		if (enabled)
+			__bcm6345_l1_mask(d);
+		cpumask_copy(irq_data_get_affinity_mask(d), dest);
+		if (enabled)
+			__bcm6345_l1_unmask(d);
+	} else {
+		cpumask_copy(irq_data_get_affinity_mask(d), dest);
+	}
+	raw_spin_unlock_irqrestore(&intc->lock, flags);
+
+	return IRQ_SET_MASK_OK_NOCOPY;
+}
+
+static int __init bcm6345_l1_init_one(struct device_node *dn,
+				      unsigned int idx,
+				      struct bcm6345_l1_chip *intc)
+{
+	struct resource res;
+	resource_size_t sz;
+	struct bcm6345_l1_cpu *cpu;
+	unsigned int i, n_words;
+
+	if (of_address_to_resource(dn, idx, &res))
+		return -EINVAL;
+	sz = resource_size(&res);
+	n_words = sz / REG_BYTES_PER_IRQ_WORD;
+
+	if (!intc->n_words)
+		intc->n_words = n_words;
+	else if (intc->n_words != n_words)
+		return -EINVAL;
+
+	cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
+					GFP_KERNEL);
+	if (!cpu)
+		return -ENOMEM;
+
+	cpu->map_base = ioremap(res.start, sz);
+	if (!cpu->map_base)
+		return -ENOMEM;
+
+	for (i = 0; i < n_words; i++) {
+		cpu->enable_cache[i] = 0;
+		__raw_writel(0, cpu->map_base + reg_enable(intc, i));
+	}
+
+	cpu->parent_irq = irq_of_parse_and_map(dn, idx);
+	if (!cpu->parent_irq) {
+		pr_err("failed to map parent interrupt %d\n", cpu->parent_irq);
+		return -EINVAL;
+	}
+	irq_set_chained_handler_and_data(cpu->parent_irq,
+						bcm6345_l1_irq_handle, intc);
+
+	return 0;
+}
+
+static struct irq_chip bcm6345_l1_irq_chip = {
+	.name			= "bcm6345-l1",
+	.irq_mask		= bcm6345_l1_mask,
+	.irq_unmask		= bcm6345_l1_unmask,
+	.irq_set_affinity	= bcm6345_l1_set_affinity,
+};
+
+static int bcm6345_l1_map(struct irq_domain *d, unsigned int virq,
+			  irq_hw_number_t hw_irq)
+{
+	irq_set_chip_and_handler(virq,
+		&bcm6345_l1_irq_chip, handle_percpu_irq);
+	irq_set_chip_data(virq, d->host_data);
+	return 0;
+}
+
+static const struct irq_domain_ops bcm6345_l1_domain_ops = {
+	.xlate			= irq_domain_xlate_onecell,
+	.map			= bcm6345_l1_map,
+};
+
+static int __init bcm6345_l1_of_init(struct device_node *dn,
+			      struct device_node *parent)
+{
+	struct bcm6345_l1_chip *intc;
+	unsigned int idx;
+	int ret;
+
+	intc = kzalloc(sizeof(*intc), GFP_KERNEL);
+	if (!intc)
+		return -ENOMEM;
+
+	for_each_possible_cpu(idx) {
+		ret = bcm6345_l1_init_one(dn, idx, intc);
+		if (ret)
+			pr_err("failed to init intc L1 for cpu %d: %d\n",
+				idx, ret);
+		else
+			cpumask_set_cpu(idx, &intc->cpumask);
+	}
+
+	if (!cpumask_weight(&intc->cpumask)) {
+		ret = -ENODEV;
+		goto out_free;
+	}
+
+	raw_spin_lock_init(&intc->lock);
+
+	intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
+					     &bcm6345_l1_domain_ops,
+					     intc);
+	if (!intc->domain) {
+		ret = -ENOMEM;
+		goto out_unmap;
+	}
+
+	pr_info("registered BCM6345 L1 intc (IRQs: %d)\n",
+			IRQS_PER_WORD * intc->n_words);
+	for_each_cpu(idx, &intc->cpumask) {
+		struct bcm6345_l1_cpu *cpu = intc->cpus[idx];
+
+		pr_info("  CPU%u at MMIO 0x%p (irq = %d)\n", idx,
+				cpu->map_base, cpu->parent_irq);
+	}
+
+	return 0;
+
+out_unmap:
+	for_each_possible_cpu(idx) {
+		struct bcm6345_l1_cpu *cpu = intc->cpus[idx];
+
+		if (cpu) {
+			if (cpu->map_base)
+				iounmap(cpu->map_base);
+			kfree(cpu);
+		}
+	}
+out_free:
+	kfree(intc);
+	return ret;
+}
+
+IRQCHIP_DECLARE(bcm6345_l1, "brcm,bcm6345-l1-intc", bcm6345_l1_of_init);
-- 
2.1.4

-- 
Simon Arlott
--
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