[PATCH] MIPS, IRQCHIP: Move i8259 irqchip driver to drivers/irqchip.
From: Ralf Baechle
Date: Wed Jul 08 2015 - 08:46:28 EST
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);
--
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