1 files changed, 368 insertions, 0 deletions

diff --git a/kernel/arch/mips/paravirt/paravirt-irq.c b/kernel/arch/mips/paravirt/paravirt-irq.c
new file mode 100644
index 000000000..8987b06c9
--- /dev/null
+++ b/kernel/arch/mips/paravirt/paravirt-irq.c
@@ -0,0 +1,368 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2013 Cavium, Inc.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/cpumask.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+
+#include <asm/io.h>
+
+#define MBOX_BITS_PER_CPU 2
+
+static int cpunum_for_cpu(int cpu)
+{
+#ifdef CONFIG_SMP
+	return cpu_logical_map(cpu);
+#else
+	return get_ebase_cpunum();
+#endif
+}
+
+struct core_chip_data {
+	struct mutex core_irq_mutex;
+	bool current_en;
+	bool desired_en;
+	u8 bit;
+};
+
+static struct core_chip_data irq_core_chip_data[8];
+
+static void irq_core_ack(struct irq_data *data)
+{
+	struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
+	unsigned int bit = cd->bit;
+
+	/*
+	 * We don't need to disable IRQs to make these atomic since
+	 * they are already disabled earlier in the low level
+	 * interrupt code.
+	 */
+	clear_c0_status(0x100 << bit);
+	/* The two user interrupts must be cleared manually. */
+	if (bit < 2)
+		clear_c0_cause(0x100 << bit);
+}
+
+static void irq_core_eoi(struct irq_data *data)
+{
+	struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
+
+	/*
+	 * We don't need to disable IRQs to make these atomic since
+	 * they are already disabled earlier in the low level
+	 * interrupt code.
+	 */
+	set_c0_status(0x100 << cd->bit);
+}
+
+static void irq_core_set_enable_local(void *arg)
+{
+	struct irq_data *data = arg;
+	struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
+	unsigned int mask = 0x100 << cd->bit;
+
+	/*
+	 * Interrupts are already disabled, so these are atomic.
+	 */
+	if (cd->desired_en)
+		set_c0_status(mask);
+	else
+		clear_c0_status(mask);
+
+}
+
+static void irq_core_disable(struct irq_data *data)
+{
+	struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
+	cd->desired_en = false;
+}
+
+static void irq_core_enable(struct irq_data *data)
+{
+	struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
+	cd->desired_en = true;
+}
+
+static void irq_core_bus_lock(struct irq_data *data)
+{
+	struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
+
+	mutex_lock(&cd->core_irq_mutex);
+}
+
+static void irq_core_bus_sync_unlock(struct irq_data *data)
+{
+	struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
+
+	if (cd->desired_en != cd->current_en) {
+		on_each_cpu(irq_core_set_enable_local, data, 1);
+		cd->current_en = cd->desired_en;
+	}
+
+	mutex_unlock(&cd->core_irq_mutex);
+}
+
+static struct irq_chip irq_chip_core = {
+	.name = "Core",
+	.irq_enable = irq_core_enable,
+	.irq_disable = irq_core_disable,
+	.irq_ack = irq_core_ack,
+	.irq_eoi = irq_core_eoi,
+	.irq_bus_lock = irq_core_bus_lock,
+	.irq_bus_sync_unlock = irq_core_bus_sync_unlock,
+
+	.irq_cpu_online = irq_core_eoi,
+	.irq_cpu_offline = irq_core_ack,
+	.flags = IRQCHIP_ONOFFLINE_ENABLED,
+};
+
+static void __init irq_init_core(void)
+{
+	int i;
+	int irq;
+	struct core_chip_data *cd;
+
+	/* Start with a clean slate */
+	clear_c0_status(ST0_IM);
+	clear_c0_cause(CAUSEF_IP0 | CAUSEF_IP1);
+
+	for (i = 0; i < ARRAY_SIZE(irq_core_chip_data); i++) {
+		cd = irq_core_chip_data + i;
+		cd->current_en = false;
+		cd->desired_en = false;
+		cd->bit = i;
+		mutex_init(&cd->core_irq_mutex);
+
+		irq = MIPS_CPU_IRQ_BASE + i;
+
+		switch (i) {
+		case 0: /* SW0 */
+		case 1: /* SW1 */
+		case 5: /* IP5 */
+		case 6: /* IP6 */
+		case 7: /* IP7 */
+			irq_set_chip_data(irq, cd);
+			irq_set_chip_and_handler(irq, &irq_chip_core,
+						 handle_percpu_irq);
+			break;
+		default:
+			break;
+		}
+	}
+}
+
+static void __iomem *mips_irq_chip;
+#define MIPS_IRQ_CHIP_NUM_BITS 0
+#define MIPS_IRQ_CHIP_REGS 8
+
+static int mips_irq_cpu_stride;
+static int mips_irq_chip_reg_raw;
+static int mips_irq_chip_reg_src;
+static int mips_irq_chip_reg_en;
+static int mips_irq_chip_reg_raw_w1s;
+static int mips_irq_chip_reg_raw_w1c;
+static int mips_irq_chip_reg_en_w1s;
+static int mips_irq_chip_reg_en_w1c;
+
+static void irq_pci_enable(struct irq_data *data)
+{
+	u32 mask = 1u << data->irq;
+
+	__raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_en_w1s);
+}
+
+static void irq_pci_disable(struct irq_data *data)
+{
+	u32 mask = 1u << data->irq;
+
+	__raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_en_w1c);
+}
+
+static void irq_pci_ack(struct irq_data *data)
+{
+}
+
+static void irq_pci_mask(struct irq_data *data)
+{
+	u32 mask = 1u << data->irq;
+
+	__raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_en_w1c);
+}
+
+static void irq_pci_unmask(struct irq_data *data)
+{
+	u32 mask = 1u << data->irq;
+
+	__raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_en_w1s);
+}
+
+static struct irq_chip irq_chip_pci = {
+	.name = "PCI",
+	.irq_enable = irq_pci_enable,
+	.irq_disable = irq_pci_disable,
+	.irq_ack = irq_pci_ack,
+	.irq_mask = irq_pci_mask,
+	.irq_unmask = irq_pci_unmask,
+};
+
+static void irq_mbox_all(struct irq_data *data,  void __iomem *base)
+{
+	int cpu;
+	unsigned int mbox = data->irq - MIPS_IRQ_MBOX0;
+	u32 mask;
+
+	WARN_ON(mbox >= MBOX_BITS_PER_CPU);
+
+	for_each_online_cpu(cpu) {
+		unsigned int cpuid = cpunum_for_cpu(cpu);
+		mask = 1 << (cpuid * MBOX_BITS_PER_CPU + mbox);
+		__raw_writel(mask, base + (cpuid * mips_irq_cpu_stride));
+	}
+}
+
+static void irq_mbox_enable(struct irq_data *data)
+{
+	irq_mbox_all(data, mips_irq_chip + mips_irq_chip_reg_en_w1s + sizeof(u32));
+}
+
+static void irq_mbox_disable(struct irq_data *data)
+{
+	irq_mbox_all(data, mips_irq_chip + mips_irq_chip_reg_en_w1c + sizeof(u32));
+}
+
+static void irq_mbox_ack(struct irq_data *data)
+{
+	u32 mask;
+	unsigned int mbox = data->irq - MIPS_IRQ_MBOX0;
+
+	WARN_ON(mbox >= MBOX_BITS_PER_CPU);
+
+	mask = 1 << (get_ebase_cpunum() * MBOX_BITS_PER_CPU + mbox);
+	__raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_raw_w1c + sizeof(u32));
+}
+
+void irq_mbox_ipi(int cpu, unsigned int actions)
+{
+	unsigned int cpuid = cpunum_for_cpu(cpu);
+	u32 mask;
+
+	WARN_ON(actions >= (1 << MBOX_BITS_PER_CPU));
+
+	mask = actions << (cpuid * MBOX_BITS_PER_CPU);
+	__raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_raw_w1s + sizeof(u32));
+}
+
+static void irq_mbox_cpu_onoffline(struct irq_data *data,  void __iomem *base)
+{
+	unsigned int mbox = data->irq - MIPS_IRQ_MBOX0;
+	unsigned int cpuid = get_ebase_cpunum();
+	u32 mask;
+
+	WARN_ON(mbox >= MBOX_BITS_PER_CPU);
+
+	mask = 1 << (cpuid * MBOX_BITS_PER_CPU + mbox);
+	__raw_writel(mask, base + (cpuid * mips_irq_cpu_stride));
+
+}
+
+static void irq_mbox_cpu_online(struct irq_data *data)
+{
+	irq_mbox_cpu_onoffline(data, mips_irq_chip + mips_irq_chip_reg_en_w1s + sizeof(u32));
+}
+
+static void irq_mbox_cpu_offline(struct irq_data *data)
+{
+	irq_mbox_cpu_onoffline(data, mips_irq_chip + mips_irq_chip_reg_en_w1c + sizeof(u32));
+}
+
+static struct irq_chip irq_chip_mbox = {
+	.name = "MBOX",
+	.irq_enable = irq_mbox_enable,
+	.irq_disable = irq_mbox_disable,
+	.irq_ack = irq_mbox_ack,
+	.irq_cpu_online = irq_mbox_cpu_online,
+	.irq_cpu_offline = irq_mbox_cpu_offline,
+	.flags = IRQCHIP_ONOFFLINE_ENABLED,
+};
+
+static void __init irq_pci_init(void)
+{
+	int i, stride;
+	u32 num_bits;
+
+	mips_irq_chip = ioremap(0x1e010000, 4096);
+
+	num_bits = __raw_readl(mips_irq_chip + MIPS_IRQ_CHIP_NUM_BITS);
+	stride = 8 * (1 + ((num_bits - 1) / 64));
+
+
+	pr_notice("mips_irq_chip: %u bits, reg stride: %d\n", num_bits, stride);
+	mips_irq_chip_reg_raw		= MIPS_IRQ_CHIP_REGS + 0 * stride;
+	mips_irq_chip_reg_raw_w1s	= MIPS_IRQ_CHIP_REGS + 1 * stride;
+	mips_irq_chip_reg_raw_w1c	= MIPS_IRQ_CHIP_REGS + 2 * stride;
+	mips_irq_chip_reg_src		= MIPS_IRQ_CHIP_REGS + 3 * stride;
+	mips_irq_chip_reg_en		= MIPS_IRQ_CHIP_REGS + 4 * stride;
+	mips_irq_chip_reg_en_w1s	= MIPS_IRQ_CHIP_REGS + 5 * stride;
+	mips_irq_chip_reg_en_w1c	= MIPS_IRQ_CHIP_REGS + 6 * stride;
+	mips_irq_cpu_stride		= stride * 4;
+
+	for (i = 0; i < 4; i++)
+		irq_set_chip_and_handler(i + MIPS_IRQ_PCIA, &irq_chip_pci, handle_level_irq);
+
+	for (i = 0; i < 2; i++)
+		irq_set_chip_and_handler(i + MIPS_IRQ_MBOX0, &irq_chip_mbox, handle_percpu_irq);
+
+
+	set_c0_status(STATUSF_IP2);
+}
+
+static void irq_pci_dispatch(void)
+{
+	unsigned int cpuid = get_ebase_cpunum();
+	u32 en;
+
+	en = __raw_readl(mips_irq_chip + mips_irq_chip_reg_src +
+			(cpuid * mips_irq_cpu_stride));
+
+	if (!en) {
+		en = __raw_readl(mips_irq_chip + mips_irq_chip_reg_src + (cpuid * mips_irq_cpu_stride) + sizeof(u32));
+		en = (en >> (2 * cpuid)) & 3;
+
+		if (!en)
+			spurious_interrupt();
+		else
+			do_IRQ(__ffs(en) + MIPS_IRQ_MBOX0);	/* MBOX type */
+	} else {
+		do_IRQ(__ffs(en));
+	}
+}
+
+
+void __init arch_init_irq(void)
+{
+	irq_init_core();
+	irq_pci_init();
+}
+
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
+	int ip;
+
+	if (unlikely(!pending)) {
+		spurious_interrupt();
+		return;
+	}
+
+	ip = ffs(pending) - 1 - STATUSB_IP0;
+	if (ip == 2)
+		irq_pci_dispatch();
+	else
+		do_IRQ(MIPS_CPU_IRQ_BASE + ip);
+}