[PATCH] MIPS, IRQCHIP: Move i8259 irqchip driver to drivers/irqchip.

[PATCH] MIPS, IRQCHIP: Move i8259 irqchip driver to drivers/irqchip.

[Ralf Baechle]

 arch/mips/Kconfig           |   4 -
 arch/mips/kernel/Makefile   |   1 -
 arch/mips/kernel/i8259.c    | 384 --------------------------------------------
 drivers/irqchip/Kconfig     |   4 +
 drivers/irqchip/Makefile    |   1 +
 drivers/irqchip/irq-i8259.c | 383 +++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 388 insertions(+), 389 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b0a121b..f2ae53a 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1071,10 +1071,6 @@ config HOTPLUG_CPU
 config SYS_SUPPORTS_HOTPLUG_CPU
 	bool
 
-config I8259
-	bool
-	select IRQ_DOMAIN
-
 config MIPS_BONITO64
 	bool
 
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 3f5cf8a..3156c8d 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -61,7 +61,6 @@ obj-$(CONFIG_MIPS_VPE_APSP_API) += rtlx.o
 obj-$(CONFIG_MIPS_VPE_APSP_API_CMP) += rtlx-cmp.o
 obj-$(CONFIG_MIPS_VPE_APSP_API_MT) += rtlx-mt.o
 
-obj-$(CONFIG_I8259)		+= i8259.o
 obj-$(CONFIG_IRQ_CPU_RM7K)	+= irq-rm7000.o
 obj-$(CONFIG_MIPS_MSC)		+= irq-msc01.o
 obj-$(CONFIG_IRQ_TXX9)		+= irq_txx9.o
diff --git a/arch/mips/kernel/i8259.c b/arch/mips/kernel/i8259.c
deleted file mode 100644
index 74f6752..0000000
--- a/arch/mips/kernel/i8259.c
+++ /dev/null
@@ -1,384 +0,0 @@
-/*
- * 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.
- *
- * Code to handle x86 style IRQs plus some generic interrupt stuff.
- *
- * Copyright (C) 1992 Linus Torvalds
- * Copyright (C) 1994 - 2000 Ralf Baechle
- */
-#include <linux/delay.h>
-#include <linux/init.h>
-#include <linux/ioport.h>
-#include <linux/interrupt.h>
-#include <linux/irqdomain.h>
-#include <linux/kernel.h>
-#include <linux/of_irq.h>
-#include <linux/spinlock.h>
-#include <linux/syscore_ops.h>
-#include <linux/irq.h>
-
-#include <asm/i8259.h>
-#include <asm/io.h>
-
-#include "../../drivers/irqchip/irqchip.h"
-
-/*
- * This is the 'legacy' 8259A Programmable Interrupt Controller,
- * present in the majority of PC/AT boxes.
- * plus some generic x86 specific things if generic specifics makes
- * any sense at all.
- * this file should become arch/i386/kernel/irq.c when the old irq.c
- * moves to arch independent land
- */
-
-static int i8259A_auto_eoi = -1;
-DEFINE_RAW_SPINLOCK(i8259A_lock);
-static void disable_8259A_irq(struct irq_data *d);
-static void enable_8259A_irq(struct irq_data *d);
-static void mask_and_ack_8259A(struct irq_data *d);
-static void init_8259A(int auto_eoi);
-
-static struct irq_chip i8259A_chip = {
-	.name			= "XT-PIC",
-	.irq_mask		= disable_8259A_irq,
-	.irq_disable		= disable_8259A_irq,
-	.irq_unmask		= enable_8259A_irq,
-	.irq_mask_ack		= mask_and_ack_8259A,
-};
-
-/*
- * 8259A PIC functions to handle ISA devices:
- */
-
-/*
- * This contains the irq mask for both 8259A irq controllers,
- */
-static unsigned int cached_irq_mask = 0xffff;
-
-#define cached_master_mask	(cached_irq_mask)
-#define cached_slave_mask	(cached_irq_mask >> 8)
-
-static void disable_8259A_irq(struct irq_data *d)
-{
-	unsigned int mask, irq = d->irq - I8259A_IRQ_BASE;
-	unsigned long flags;
-
-	mask = 1 << irq;
-	raw_spin_lock_irqsave(&i8259A_lock, flags);
-	cached_irq_mask |= mask;
-	if (irq & 8)
-		outb(cached_slave_mask, PIC_SLAVE_IMR);
-	else
-		outb(cached_master_mask, PIC_MASTER_IMR);
-	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
-}
-
-static void enable_8259A_irq(struct irq_data *d)
-{
-	unsigned int mask, irq = d->irq - I8259A_IRQ_BASE;
-	unsigned long flags;
-
-	mask = ~(1 << irq);
-	raw_spin_lock_irqsave(&i8259A_lock, flags);
-	cached_irq_mask &= mask;
-	if (irq & 8)
-		outb(cached_slave_mask, PIC_SLAVE_IMR);
-	else
-		outb(cached_master_mask, PIC_MASTER_IMR);
-	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
-}
-
-int i8259A_irq_pending(unsigned int irq)
-{
-	unsigned int mask;
-	unsigned long flags;
-	int ret;
-
-	irq -= I8259A_IRQ_BASE;
-	mask = 1 << irq;
-	raw_spin_lock_irqsave(&i8259A_lock, flags);
-	if (irq < 8)
-		ret = inb(PIC_MASTER_CMD) & mask;
-	else
-		ret = inb(PIC_SLAVE_CMD) & (mask >> 8);
-	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
-
-	return ret;
-}
-
-void make_8259A_irq(unsigned int irq)
-{
-	disable_irq_nosync(irq);
-	irq_set_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
-	enable_irq(irq);
-}
-
-/*
- * This function assumes to be called rarely. Switching between
- * 8259A registers is slow.
- * This has to be protected by the irq controller spinlock
- * before being called.
- */
-static inline int i8259A_irq_real(unsigned int irq)
-{
-	int value;
-	int irqmask = 1 << irq;
-
-	if (irq < 8) {
-		outb(0x0B, PIC_MASTER_CMD);	/* ISR register */
-		value = inb(PIC_MASTER_CMD) & irqmask;
-		outb(0x0A, PIC_MASTER_CMD);	/* back to the IRR register */
-		return value;
-	}
-	outb(0x0B, PIC_SLAVE_CMD);	/* ISR register */
-	value = inb(PIC_SLAVE_CMD) & (irqmask >> 8);
-	outb(0x0A, PIC_SLAVE_CMD);	/* back to the IRR register */
-	return value;
-}
-
-/*
- * Careful! The 8259A is a fragile beast, it pretty
- * much _has_ to be done exactly like this (mask it
- * first, _then_ send the EOI, and the order of EOI
- * to the two 8259s is important!
- */
-static void mask_and_ack_8259A(struct irq_data *d)
-{
-	unsigned int irqmask, irq = d->irq - I8259A_IRQ_BASE;
-	unsigned long flags;
-
-	irqmask = 1 << irq;
-	raw_spin_lock_irqsave(&i8259A_lock, flags);
-	/*
-	 * Lightweight spurious IRQ detection. We do not want
-	 * to overdo spurious IRQ handling - it's usually a sign
-	 * of hardware problems, so we only do the checks we can
-	 * do without slowing down good hardware unnecessarily.
-	 *
-	 * Note that IRQ7 and IRQ15 (the two spurious IRQs
-	 * usually resulting from the 8259A-1|2 PICs) occur
-	 * even if the IRQ is masked in the 8259A. Thus we
-	 * can check spurious 8259A IRQs without doing the
-	 * quite slow i8259A_irq_real() call for every IRQ.
-	 * This does not cover 100% of spurious interrupts,
-	 * but should be enough to warn the user that there
-	 * is something bad going on ...
-	 */
-	if (cached_irq_mask & irqmask)
-		goto spurious_8259A_irq;
-	cached_irq_mask |= irqmask;
-
-handle_real_irq:
-	if (irq & 8) {
-		inb(PIC_SLAVE_IMR);	/* DUMMY - (do we need this?) */
-		outb(cached_slave_mask, PIC_SLAVE_IMR);
-		outb(0x60+(irq&7), PIC_SLAVE_CMD);/* 'Specific EOI' to slave */
-		outb(0x60+PIC_CASCADE_IR, PIC_MASTER_CMD); /* 'Specific EOI' to master-IRQ2 */
-	} else {
-		inb(PIC_MASTER_IMR);	/* DUMMY - (do we need this?) */
-		outb(cached_master_mask, PIC_MASTER_IMR);
-		outb(0x60+irq, PIC_MASTER_CMD); /* 'Specific EOI to master */
-	}
-	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
-	return;
-
-spurious_8259A_irq:
-	/*
-	 * this is the slow path - should happen rarely.
-	 */
-	if (i8259A_irq_real(irq))
-		/*
-		 * oops, the IRQ _is_ in service according to the
-		 * 8259A - not spurious, go handle it.
-		 */
-		goto handle_real_irq;
-
-	{
-		static int spurious_irq_mask;
-		/*
-		 * At this point we can be sure the IRQ is spurious,
-		 * lets ACK and report it. [once per IRQ]
-		 */
-		if (!(spurious_irq_mask & irqmask)) {
-			printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);
-			spurious_irq_mask |= irqmask;
-		}
-		atomic_inc(&irq_err_count);
-		/*
-		 * Theoretically we do not have to handle this IRQ,
-		 * but in Linux this does not cause problems and is
-		 * simpler for us.
-		 */
-		goto handle_real_irq;
-	}
-}
-
-static void i8259A_resume(void)
-{
-	if (i8259A_auto_eoi >= 0)
-		init_8259A(i8259A_auto_eoi);
-}
-
-static void i8259A_shutdown(void)
-{
-	/* Put the i8259A into a quiescent state that
-	 * the kernel initialization code can get it
-	 * out of.
-	 */
-	if (i8259A_auto_eoi >= 0) {
-		outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */
-		outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */
-	}
-}
-
-static struct syscore_ops i8259_syscore_ops = {
-	.resume = i8259A_resume,
-	.shutdown = i8259A_shutdown,
-};
-
-static int __init i8259A_init_sysfs(void)
-{
-	register_syscore_ops(&i8259_syscore_ops);
-	return 0;
-}
-
-device_initcall(i8259A_init_sysfs);
-
-static void init_8259A(int auto_eoi)
-{
-	unsigned long flags;
-
-	i8259A_auto_eoi = auto_eoi;
-
-	raw_spin_lock_irqsave(&i8259A_lock, flags);
-
-	outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */
-	outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */
-
-	/*
-	 * outb_p - this has to work on a wide range of PC hardware.
-	 */
-	outb_p(0x11, PIC_MASTER_CMD);	/* ICW1: select 8259A-1 init */
-	outb_p(I8259A_IRQ_BASE + 0, PIC_MASTER_IMR);	/* ICW2: 8259A-1 IR0 mapped to I8259A_IRQ_BASE + 0x00 */
-	outb_p(1U << PIC_CASCADE_IR, PIC_MASTER_IMR);	/* 8259A-1 (the master) has a slave on IR2 */
-	if (auto_eoi)	/* master does Auto EOI */
-		outb_p(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR);
-	else		/* master expects normal EOI */
-		outb_p(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);
-
-	outb_p(0x11, PIC_SLAVE_CMD);	/* ICW1: select 8259A-2 init */
-	outb_p(I8259A_IRQ_BASE + 8, PIC_SLAVE_IMR);	/* ICW2: 8259A-2 IR0 mapped to I8259A_IRQ_BASE + 0x08 */
-	outb_p(PIC_CASCADE_IR, PIC_SLAVE_IMR);	/* 8259A-2 is a slave on master's IR2 */
-	outb_p(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR); /* (slave's support for AEOI in flat mode is to be investigated) */
-	if (auto_eoi)
-		/*
-		 * In AEOI mode we just have to mask the interrupt
-		 * when acking.
-		 */
-		i8259A_chip.irq_mask_ack = disable_8259A_irq;
-	else
-		i8259A_chip.irq_mask_ack = mask_and_ack_8259A;
-
-	udelay(100);		/* wait for 8259A to initialize */
-
-	outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
-	outb(cached_slave_mask, PIC_SLAVE_IMR);	  /* restore slave IRQ mask */
-
-	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
-}
-
-/*
- * IRQ2 is cascade interrupt to second interrupt controller
- */
-static struct irqaction irq2 = {
-	.handler = no_action,
-	.name = "cascade",
-	.flags = IRQF_NO_THREAD,
-};
-
-static struct resource pic1_io_resource = {
-	.name = "pic1",
-	.start = PIC_MASTER_CMD,
-	.end = PIC_MASTER_IMR,
-	.flags = IORESOURCE_BUSY
-};
-
-static struct resource pic2_io_resource = {
-	.name = "pic2",
-	.start = PIC_SLAVE_CMD,
-	.end = PIC_SLAVE_IMR,
-	.flags = IORESOURCE_BUSY
-};
-
-static int i8259A_irq_domain_map(struct irq_domain *d, unsigned int virq,
-				 irq_hw_number_t hw)
-{
-	irq_set_chip_and_handler(virq, &i8259A_chip, handle_level_irq);
-	irq_set_probe(virq);
-	return 0;
-}
-
-static struct irq_domain_ops i8259A_ops = {
-	.map = i8259A_irq_domain_map,
-	.xlate = irq_domain_xlate_onecell,
-};
-
-/*
- * On systems with i8259-style interrupt controllers we assume for
- * driver compatibility reasons interrupts 0 - 15 to be the i8259
- * interrupts even if the hardware uses a different interrupt numbering.
- */
-struct irq_domain * __init __init_i8259_irqs(struct device_node *node)
-{
-	struct irq_domain *domain;
-
-	insert_resource(&ioport_resource, &pic1_io_resource);
-	insert_resource(&ioport_resource, &pic2_io_resource);
-
-	init_8259A(0);
-
-	domain = irq_domain_add_legacy(node, 16, I8259A_IRQ_BASE, 0,
-				       &i8259A_ops, NULL);
-	if (!domain)
-		panic("Failed to add i8259 IRQ domain");
-
-	setup_irq(I8259A_IRQ_BASE + PIC_CASCADE_IR, &irq2);
-	return domain;
-}
-
-void __init init_i8259_irqs(void)
-{
-	__init_i8259_irqs(NULL);
-}
-
-static void i8259_irq_dispatch(unsigned int irq, struct irq_desc *desc)
-{
-	struct irq_domain *domain = irq_get_handler_data(irq);
-	int hwirq = i8259_irq();
-
-	if (hwirq < 0)
-		return;
-
-	irq = irq_linear_revmap(domain, hwirq);
-	generic_handle_irq(irq);
-}
-
-int __init i8259_of_init(struct device_node *node, struct device_node *parent)
-{
-	struct irq_domain *domain;
-	unsigned int parent_irq;
-
-	parent_irq = irq_of_parse_and_map(node, 0);
-	if (!parent_irq) {
-		pr_err("Failed to map i8259 parent IRQ\n");
-		return -ENODEV;
-	}
-
-	domain = __init_i8259_irqs(node);
-	irq_set_handler_data(parent_irq, domain);
-	irq_set_chained_handler(parent_irq, i8259_irq_dispatch);
-	return 0;
-}
-IRQCHIP_DECLARE(i8259, "intel,i8259", i8259_of_init);
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 120d815..5b85371 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -61,6 +61,10 @@ config ATMEL_AIC5_IRQ
 	select MULTI_IRQ_HANDLER
 	select SPARSE_IRQ
 
+config I8259
+	bool
+	select IRQ_DOMAIN
+
 config BCM7038_L1_IRQ
 	bool
 	select GENERIC_IRQ_CHIP
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b8d4e96..f561b5d 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_ARM_NVIC)			+= irq-nvic.o
 obj-$(CONFIG_ARM_VIC)			+= irq-vic.o
 obj-$(CONFIG_ATMEL_AIC_IRQ)		+= irq-atmel-aic-common.o irq-atmel-aic.o
 obj-$(CONFIG_ATMEL_AIC5_IRQ)	+= irq-atmel-aic-common.o irq-atmel-aic5.o
+obj-$(CONFIG_I8259)			+= irq-i8259.o
 obj-$(CONFIG_IMGPDC_IRQ)		+= irq-imgpdc.o
 obj-$(CONFIG_IRQ_MIPS_CPU)		+= irq-mips-cpu.o
 obj-$(CONFIG_SIRF_IRQ)			+= irq-sirfsoc.o
diff --git a/drivers/irqchip/irq-i8259.c b/drivers/irqchip/irq-i8259.c
new file mode 100644
index 0000000..a29638a
--- /dev/null
+++ b/drivers/irqchip/irq-i8259.c
@@ -0,0 +1,383 @@
+/*
+ * 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.
+ *
+ * Code to handle x86 style IRQs plus some generic interrupt stuff.
+ *
+ * Copyright (C) 1992 Linus Torvalds
+ * Copyright (C) 1994 - 2000 Ralf Baechle
+ */
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/of_irq.h>
+#include <linux/spinlock.h>
+#include <linux/syscore_ops.h>
+#include <linux/irq.h>
+
+#include <asm/i8259.h>
+#include <asm/io.h>
+
+/*
+ * This is the 'legacy' 8259A Programmable Interrupt Controller,
+ * present in the majority of PC/AT boxes.
+ * plus some generic x86 specific things if generic specifics makes
+ * any sense at all.
+ * this file should become arch/i386/kernel/irq.c when the old irq.c
+ * moves to arch independent land
+ */
+
+static int i8259A_auto_eoi = -1;
+DEFINE_RAW_SPINLOCK(i8259A_lock);
+static void disable_8259A_irq(struct irq_data *d);
+static void enable_8259A_irq(struct irq_data *d);
+static void mask_and_ack_8259A(struct irq_data *d);
+static void init_8259A(int auto_eoi);
+
+static struct irq_chip i8259A_chip = {
+	.name			= "XT-PIC",
+	.irq_mask		= disable_8259A_irq,
+	.irq_disable		= disable_8259A_irq,
+	.irq_unmask		= enable_8259A_irq,
+	.irq_mask_ack		= mask_and_ack_8259A,
+};
+
+/*
+ * 8259A PIC functions to handle ISA devices:
+ */
+
+/*
+ * This contains the irq mask for both 8259A irq controllers,
+ */
+static unsigned int cached_irq_mask = 0xffff;
+
+#define cached_master_mask	(cached_irq_mask)
+#define cached_slave_mask	(cached_irq_mask >> 8)
+
+static void disable_8259A_irq(struct irq_data *d)
+{
+	unsigned int mask, irq = d->irq - I8259A_IRQ_BASE;
+	unsigned long flags;
+
+	mask = 1 << irq;
+	raw_spin_lock_irqsave(&i8259A_lock, flags);
+	cached_irq_mask |= mask;
+	if (irq & 8)
+		outb(cached_slave_mask, PIC_SLAVE_IMR);
+	else
+		outb(cached_master_mask, PIC_MASTER_IMR);
+	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
+}
+
+static void enable_8259A_irq(struct irq_data *d)
+{
+	unsigned int mask, irq = d->irq - I8259A_IRQ_BASE;
+	unsigned long flags;
+
+	mask = ~(1 << irq);
+	raw_spin_lock_irqsave(&i8259A_lock, flags);
+	cached_irq_mask &= mask;
+	if (irq & 8)
+		outb(cached_slave_mask, PIC_SLAVE_IMR);
+	else
+		outb(cached_master_mask, PIC_MASTER_IMR);
+	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
+}
+
+int i8259A_irq_pending(unsigned int irq)
+{
+	unsigned int mask;
+	unsigned long flags;
+	int ret;
+
+	irq -= I8259A_IRQ_BASE;
+	mask = 1 << irq;
+	raw_spin_lock_irqsave(&i8259A_lock, flags);
+	if (irq < 8)
+		ret = inb(PIC_MASTER_CMD) & mask;
+	else
+		ret = inb(PIC_SLAVE_CMD) & (mask >> 8);
+	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
+
+	return ret;
+}
+
+void make_8259A_irq(unsigned int irq)
+{
+	disable_irq_nosync(irq);
+	irq_set_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
+	enable_irq(irq);
+}
+
+/*
+ * This function assumes to be called rarely. Switching between
+ * 8259A registers is slow.
+ * This has to be protected by the irq controller spinlock
+ * before being called.
+ */
+static inline int i8259A_irq_real(unsigned int irq)
+{
+	int value;
+	int irqmask = 1 << irq;
+
+	if (irq < 8) {
+		outb(0x0B, PIC_MASTER_CMD);	/* ISR register */
+		value = inb(PIC_MASTER_CMD) & irqmask;
+		outb(0x0A, PIC_MASTER_CMD);	/* back to the IRR register */
+		return value;
+	}
+	outb(0x0B, PIC_SLAVE_CMD);	/* ISR register */
+	value = inb(PIC_SLAVE_CMD) & (irqmask >> 8);
+	outb(0x0A, PIC_SLAVE_CMD);	/* back to the IRR register */
+	return value;
+}
+
+/*
+ * Careful! The 8259A is a fragile beast, it pretty
+ * much _has_ to be done exactly like this (mask it
+ * first, _then_ send the EOI, and the order of EOI
+ * to the two 8259s is important!
+ */
+static void mask_and_ack_8259A(struct irq_data *d)
+{
+	unsigned int irqmask, irq = d->irq - I8259A_IRQ_BASE;
+	unsigned long flags;
+
+	irqmask = 1 << irq;
+	raw_spin_lock_irqsave(&i8259A_lock, flags);
+	/*
+	 * Lightweight spurious IRQ detection. We do not want
+	 * to overdo spurious IRQ handling - it's usually a sign
+	 * of hardware problems, so we only do the checks we can
+	 * do without slowing down good hardware unnecessarily.
+	 *
+	 * Note that IRQ7 and IRQ15 (the two spurious IRQs
+	 * usually resulting from the 8259A-1|2 PICs) occur
+	 * even if the IRQ is masked in the 8259A. Thus we
+	 * can check spurious 8259A IRQs without doing the
+	 * quite slow i8259A_irq_real() call for every IRQ.
+	 * This does not cover 100% of spurious interrupts,
+	 * but should be enough to warn the user that there
+	 * is something bad going on ...
+	 */
+	if (cached_irq_mask & irqmask)
+		goto spurious_8259A_irq;
+	cached_irq_mask |= irqmask;
+
+handle_real_irq:
+	if (irq & 8) {
+		inb(PIC_SLAVE_IMR);	/* DUMMY - (do we need this?) */
+		outb(cached_slave_mask, PIC_SLAVE_IMR);
+		outb(0x60+(irq&7), PIC_SLAVE_CMD);/* 'Specific EOI' to slave */
+		outb(0x60+PIC_CASCADE_IR, PIC_MASTER_CMD); /* 'Specific EOI' to master-IRQ2 */
+	} else {
+		inb(PIC_MASTER_IMR);	/* DUMMY - (do we need this?) */
+		outb(cached_master_mask, PIC_MASTER_IMR);
+		outb(0x60+irq, PIC_MASTER_CMD); /* 'Specific EOI to master */
+	}
+	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
+	return;
+
+spurious_8259A_irq:
+	/*
+	 * this is the slow path - should happen rarely.
+	 */
+	if (i8259A_irq_real(irq))
+		/*
+		 * oops, the IRQ _is_ in service according to the
+		 * 8259A - not spurious, go handle it.
+		 */
+		goto handle_real_irq;
+
+	{
+		static int spurious_irq_mask;
+		/*
+		 * At this point we can be sure the IRQ is spurious,
+		 * lets ACK and report it. [once per IRQ]
+		 */
+		if (!(spurious_irq_mask & irqmask)) {
+			printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);
+			spurious_irq_mask |= irqmask;
+		}
+		atomic_inc(&irq_err_count);
+		/*
+		 * Theoretically we do not have to handle this IRQ,
+		 * but in Linux this does not cause problems and is
+		 * simpler for us.
+		 */
+		goto handle_real_irq;
+	}
+}
+
+static void i8259A_resume(void)
+{
+	if (i8259A_auto_eoi >= 0)
+		init_8259A(i8259A_auto_eoi);
+}
+
+static void i8259A_shutdown(void)
+{
+	/* Put the i8259A into a quiescent state that
+	 * the kernel initialization code can get it
+	 * out of.
+	 */
+	if (i8259A_auto_eoi >= 0) {
+		outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */
+		outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */
+	}
+}
+
+static struct syscore_ops i8259_syscore_ops = {
+	.resume = i8259A_resume,
+	.shutdown = i8259A_shutdown,
+};
+
+static int __init i8259A_init_sysfs(void)
+{
+	register_syscore_ops(&i8259_syscore_ops);
+	return 0;
+}
+
+device_initcall(i8259A_init_sysfs);
+
+static void init_8259A(int auto_eoi)
+{
+	unsigned long flags;
+
+	i8259A_auto_eoi = auto_eoi;
+
+	raw_spin_lock_irqsave(&i8259A_lock, flags);
+
+	outb(0xff, PIC_MASTER_IMR);	/* mask all of 8259A-1 */
+	outb(0xff, PIC_SLAVE_IMR);	/* mask all of 8259A-2 */
+
+	/*
+	 * outb_p - this has to work on a wide range of PC hardware.
+	 */
+	outb_p(0x11, PIC_MASTER_CMD);	/* ICW1: select 8259A-1 init */
+	outb_p(I8259A_IRQ_BASE + 0, PIC_MASTER_IMR);	/* ICW2: 8259A-1 IR0 mapped to I8259A_IRQ_BASE + 0x00 */
+	outb_p(1U << PIC_CASCADE_IR, PIC_MASTER_IMR);	/* 8259A-1 (the master) has a slave on IR2 */
+	if (auto_eoi)	/* master does Auto EOI */
+		outb_p(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR);
+	else		/* master expects normal EOI */
+		outb_p(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR);
+
+	outb_p(0x11, PIC_SLAVE_CMD);	/* ICW1: select 8259A-2 init */
+	outb_p(I8259A_IRQ_BASE + 8, PIC_SLAVE_IMR);	/* ICW2: 8259A-2 IR0 mapped to I8259A_IRQ_BASE + 0x08 */
+	outb_p(PIC_CASCADE_IR, PIC_SLAVE_IMR);	/* 8259A-2 is a slave on master's IR2 */
+	outb_p(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR); /* (slave's support for AEOI in flat mode is to be investigated) */
+	if (auto_eoi)
+		/*
+		 * In AEOI mode we just have to mask the interrupt
+		 * when acking.
+		 */
+		i8259A_chip.irq_mask_ack = disable_8259A_irq;
+	else
+		i8259A_chip.irq_mask_ack = mask_and_ack_8259A;
+
+	udelay(100);		/* wait for 8259A to initialize */
+
+	outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */
+	outb(cached_slave_mask, PIC_SLAVE_IMR);	  /* restore slave IRQ mask */
+
+	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
+}
+
+/*
+ * IRQ2 is cascade interrupt to second interrupt controller
+ */
+static struct irqaction irq2 = {
+	.handler = no_action,
+	.name = "cascade",
+	.flags = IRQF_NO_THREAD,
+};
+
+static struct resource pic1_io_resource = {
+	.name = "pic1",
+	.start = PIC_MASTER_CMD,
+	.end = PIC_MASTER_IMR,
+	.flags = IORESOURCE_BUSY
+};
+
+static struct resource pic2_io_resource = {
+	.name = "pic2",
+	.start = PIC_SLAVE_CMD,
+	.end = PIC_SLAVE_IMR,
+	.flags = IORESOURCE_BUSY
+};
+
+static int i8259A_irq_domain_map(struct irq_domain *d, unsigned int virq,
+				 irq_hw_number_t hw)
+{
+	irq_set_chip_and_handler(virq, &i8259A_chip, handle_level_irq);
+	irq_set_probe(virq);
+	return 0;
+}
+
+static struct irq_domain_ops i8259A_ops = {
+	.map = i8259A_irq_domain_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+/*
+ * On systems with i8259-style interrupt controllers we assume for
+ * driver compatibility reasons interrupts 0 - 15 to be the i8259
+ * interrupts even if the hardware uses a different interrupt numbering.
+ */
+struct irq_domain * __init __init_i8259_irqs(struct device_node *node)
+{
+	struct irq_domain *domain;
+
+	insert_resource(&ioport_resource, &pic1_io_resource);
+	insert_resource(&ioport_resource, &pic2_io_resource);
+
+	init_8259A(0);
+
+	domain = irq_domain_add_legacy(node, 16, I8259A_IRQ_BASE, 0,
+				       &i8259A_ops, NULL);
+	if (!domain)
+		panic("Failed to add i8259 IRQ domain");
+
+	setup_irq(I8259A_IRQ_BASE + PIC_CASCADE_IR, &irq2);
+	return domain;
+}
+
+void __init init_i8259_irqs(void)
+{
+	__init_i8259_irqs(NULL);
+}
+
+static void i8259_irq_dispatch(unsigned int irq, struct irq_desc *desc)
+{
+	struct irq_domain *domain = irq_get_handler_data(irq);
+	int hwirq = i8259_irq();
+
+	if (hwirq < 0)
+		return;
+
+	irq = irq_linear_revmap(domain, hwirq);
+	generic_handle_irq(irq);
+}
+
+int __init i8259_of_init(struct device_node *node, struct device_node *parent)
+{
+	struct irq_domain *domain;
+	unsigned int parent_irq;
+
+	parent_irq = irq_of_parse_and_map(node, 0);
+	if (!parent_irq) {
+		pr_err("Failed to map i8259 parent IRQ\n");
+		return -ENODEV;
+	}
+
+	domain = __init_i8259_irqs(node);
+	irq_set_handler_data(parent_irq, domain);
+	irq_set_chained_handler(parent_irq, i8259_irq_dispatch);
+	return 0;
+}
+IRQCHIP_DECLARE(i8259, "intel,i8259", i8259_of_init);

Re: [PATCH] MIPS, IRQCHIP: Move i8259 irqchip driver to drivers/irqchip.

[Thomas Gleixner]

On Wed, 8 Jul 2015, Ralf Baechle wrote:

>  arch/mips/Kconfig           |   4 -
>  arch/mips/kernel/Makefile   |   1 -
>  arch/mips/kernel/i8259.c    | 384 --------------------------------------------
>  drivers/irqchip/Kconfig     |   4 +
>  drivers/irqchip/Makefile    |   1 +
>  drivers/irqchip/irq-i8259.c | 383 +++++++++++++++++++++++++++++++++++++++++++
>  6 files changed, 388 insertions(+), 389 deletions(-)

Should I carry it, or want you merge it via the mips tree?

In the latter case: Acked-by-me.
 

Re: [PATCH] MIPS, IRQCHIP: Move i8259 irqchip driver to drivers/irqchip.

[Ralf Baechle]

On Wed, Jul 08, 2015 at 02:57:38PM +0200, Thomas Gleixner wrote:

> >  arch/mips/Kconfig           |   4 -
> >  arch/mips/kernel/Makefile   |   1 -
> >  arch/mips/kernel/i8259.c    | 384 --------------------------------------------
> >  drivers/irqchip/Kconfig     |   4 +
> >  drivers/irqchip/Makefile    |   1 +
> >  drivers/irqchip/irq-i8259.c | 383 +++++++++++++++++++++++++++++++++++++++++++
> >  6 files changed, 388 insertions(+), 389 deletions(-)
> 
> Should I carry it, or want you merge it via the mips tree?
> 
> In the latter case: Acked-by-me.

I guess the conflict potencial will be lower if you carry it - and if
somebody wants to merge it with one of the other i8259.c littered through
the tree it probably also is better if you carry it.

Thanks!

  Ralf

Re: [PATCH] MIPS, IRQCHIP: Move i8259 irqchip driver to drivers/irqchip.

[Thomas Gleixner]

On Wed, 8 Jul 2015, Ralf Baechle wrote:
> On Wed, Jul 08, 2015 at 02:57:38PM +0200, Thomas Gleixner wrote:
> 
> > >  arch/mips/Kconfig           |   4 -
> > >  arch/mips/kernel/Makefile   |   1 -
> > >  arch/mips/kernel/i8259.c    | 384 --------------------------------------------
> > >  drivers/irqchip/Kconfig     |   4 +
> > >  drivers/irqchip/Makefile    |   1 +
> > >  drivers/irqchip/irq-i8259.c | 383 +++++++++++++++++++++++++++++++++++++++++++
> > >  6 files changed, 388 insertions(+), 389 deletions(-)
> > 
> > Should I carry it, or want you merge it via the mips tree?
> > 
> > In the latter case: Acked-by-me.
> 
> I guess the conflict potencial will be lower if you carry it - and if
> somebody wants to merge it with one of the other i8259.c littered through
> the tree it probably also is better if you carry it.

Good point. That move might be just the trigger for me to sit down and
do it :)

Thanks,

	tglx

Re: [PATCH] MIPS, IRQCHIP: Move i8259 irqchip driver to drivers/irqchip.

[Sergei Shtylyov]

Hello.

On 7/8/2015 3:46 PM, Ralf Baechle wrote:

>   arch/mips/Kconfig           |   4 -
>   arch/mips/kernel/Makefile   |   1 -
>   arch/mips/kernel/i8259.c    | 384 --------------------------------------------
>   drivers/irqchip/Kconfig     |   4 +
>   drivers/irqchip/Makefile    |   1 +
>   drivers/irqchip/irq-i8259.c | 383 +++++++++++++++++++++++++++++++++++++++++++
>   6 files changed, 388 insertions(+), 389 deletions(-)

[...]

> diff --git a/drivers/irqchip/irq-i8259.c b/drivers/irqchip/irq-i8259.c
> new file mode 100644
> index 0000000..a29638a
> --- /dev/null
> +++ b/drivers/irqchip/irq-i8259.c
> @@ -0,0 +1,383 @@
> +/*
> + * 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.
> + *
> + * Code to handle x86 style IRQs plus some generic interrupt stuff.
> + *
> + * Copyright (C) 1992 Linus Torvalds
> + * Copyright (C) 1994 - 2000 Ralf Baechle
> + */
> +#include <linux/delay.h>
> +#include <linux/init.h>
> +#include <linux/ioport.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/of_irq.h>
> +#include <linux/spinlock.h>
> +#include <linux/syscore_ops.h>
> +#include <linux/irq.h>
> +
> +#include <asm/i8259.h>
> +#include <asm/io.h>
> +
> +/*
> + * This is the 'legacy' 8259A Programmable Interrupt Controller,
> + * present in the majority of PC/AT boxes.
> + * plus some generic x86 specific things if generic specifics makes
> + * any sense at all.
> + * this file should become arch/i386/kernel/irq.c when the old irq.c
> + * moves to arch independent land

    This comment doesn't make sense anymore, does it?

> +static struct irq_chip i8259A_chip = {
> +	.name			= "XT-PIC",

    This name is wrong, wrong, wrong. XT only had single 8259 (and is not 
supported by Linux anyway) while jhere we drive the AT specific two cascaded 
8259s (which is just wrong in my opinion as well).

> +	.irq_mask		= disable_8259A_irq,
> +	.irq_disable		= disable_8259A_irq,
> +	.irq_unmask		= enable_8259A_irq,
> +	.irq_mask_ack		= mask_and_ack_8259A,

    I have always thought 8259 was the "fast-EOI" class interrupt chip, I've 
never quite understood all this mask-and-ACK type handling for 8259...

[...]
> +/*
> + * Careful! The 8259A is a fragile beast, it pretty
> + * much _has_ to be done exactly like this (mask it
> + * first, _then_ send the EOI, and the order of EOI
> + * to the two 8259s is important!
> + */
> +static void mask_and_ack_8259A(struct irq_data *d)
> +{
[...]
> +handle_real_irq:
> +	if (irq & 8) {
> +		inb(PIC_SLAVE_IMR);	/* DUMMY - (do we need this?) */

    Hardly.

> +		outb(cached_slave_mask, PIC_SLAVE_IMR);
> +		outb(0x60+(irq&7), PIC_SLAVE_CMD);/* 'Specific EOI' to slave */

   Need spaces around ops.

> +		outb(0x60+PIC_CASCADE_IR, PIC_MASTER_CMD); /* 'Specific EOI' to master-IRQ2 */
> +	} else {
> +		inb(PIC_MASTER_IMR);	/* DUMMY - (do we need this?) */
> +		outb(cached_master_mask, PIC_MASTER_IMR);
> +		outb(0x60+irq, PIC_MASTER_CMD); /* 'Specific EOI to master */

    Same here...

> +	}
> +	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
> +	return;

> +	{
> +		static int spurious_irq_mask;
> +		/*
> +		 * At this point we can be sure the IRQ is spurious,
> +		 * lets ACK and report it. [once per IRQ]

    There's no point in ACKing spurious interrupt, if my memory serves. The 
in-srvice register doesn't have the bit set, so no need to clear it.

> +		 */
> +		if (!(spurious_irq_mask & irqmask)) {
> +			printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);
> +			spurious_irq_mask |= irqmask;
> +		}
> +		atomic_inc(&irq_err_count);
> +		/*
> +		 * Theoretically we do not have to handle this IRQ,
> +		 * but in Linux this does not cause problems and is
> +		 * simpler for us.
> +		 */
> +		goto handle_real_irq;

    Hum... only because it doesn't cause issues?

WBR, Sergei

Re: [PATCH] MIPS, IRQCHIP: Move i8259 irqchip driver to drivers/irqchip.

[Sergei Shtylyov]

On 07/08/2015 03:46 PM, Ralf Baechle wrote:

    I don't see any signoffs.

>   arch/mips/Kconfig           |   4 -
>   arch/mips/kernel/Makefile   |   1 -
>   arch/mips/kernel/i8259.c    | 384 --------------------------------------------
>   drivers/irqchip/Kconfig     |   4 +
>   drivers/irqchip/Makefile    |   1 +
>   drivers/irqchip/irq-i8259.c | 383 +++++++++++++++++++++++++++++++++++++++++++

    Please use the -M switch with 'git format-patch'.

>   6 files changed, 388 insertions(+), 389 deletions(-)

WBR, Sergei