arch/mips/jazz/irq.c
Source file repositories/reference/linux-study-clean/arch/mips/jazz/irq.c
File Facts
- System
- Linux kernel
- Corpus path
arch/mips/jazz/irq.c- Extension
.c- Size
- 4042 bytes
- Lines
- 150
- Domain
- Architecture Layer
- Bucket
- arch/mips
- Inferred role
- Architecture Layer: implementation source
- Status
- source implementation candidate
Why This File Exists
CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/clockchips.hlinux/i8253.hlinux/init.hlinux/interrupt.hlinux/kernel.hlinux/smp.hlinux/spinlock.hlinux/irq.hlinux/pgtable.hasm/irq_cpu.hasm/i8259.hasm/io.hasm/jazz.hasm/tlbmisc.h
Detected Declarations
function enable_r4030_irqfunction disable_r4030_irqfunction init_r4030_intsfunction arch_init_irqfunction plat_irq_dispatchfunction r4030_timer_interruptfunction plat_time_init
Annotated Snippet
#include <linux/clockchips.h>
#include <linux/i8253.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <linux/pgtable.h>
#include <asm/irq_cpu.h>
#include <asm/i8259.h>
#include <asm/io.h>
#include <asm/jazz.h>
#include <asm/tlbmisc.h>
static DEFINE_RAW_SPINLOCK(r4030_lock);
static void enable_r4030_irq(struct irq_data *d)
{
unsigned int mask = 1 << (d->irq - JAZZ_IRQ_START);
unsigned long flags;
raw_spin_lock_irqsave(&r4030_lock, flags);
mask |= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
raw_spin_unlock_irqrestore(&r4030_lock, flags);
}
void disable_r4030_irq(struct irq_data *d)
{
unsigned int mask = ~(1 << (d->irq - JAZZ_IRQ_START));
unsigned long flags;
raw_spin_lock_irqsave(&r4030_lock, flags);
mask &= r4030_read_reg16(JAZZ_IO_IRQ_ENABLE);
r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, mask);
raw_spin_unlock_irqrestore(&r4030_lock, flags);
}
static struct irq_chip r4030_irq_type = {
.name = "R4030",
.irq_mask = disable_r4030_irq,
.irq_unmask = enable_r4030_irq,
};
void __init init_r4030_ints(void)
{
int i;
for (i = JAZZ_IRQ_START; i <= JAZZ_IRQ_END; i++)
irq_set_chip_and_handler(i, &r4030_irq_type, handle_level_irq);
r4030_write_reg16(JAZZ_IO_IRQ_ENABLE, 0);
r4030_read_reg16(JAZZ_IO_IRQ_SOURCE); /* clear pending IRQs */
r4030_read_reg32(JAZZ_R4030_INVAL_ADDR); /* clear error bits */
}
/*
* 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.
*/
void __init arch_init_irq(void)
{
/*
* this is a hack to get back the still needed wired mapping
* killed by init_mm()
*/
/* Map 0xe0000000 -> 0x0:800005C0, 0xe0010000 -> 0x1:30000580 */
add_wired_entry(0x02000017, 0x03c00017, 0xe0000000, PM_64K);
/* Map 0xe2000000 -> 0x0:900005C0, 0xe3010000 -> 0x0:910005C0 */
add_wired_entry(0x02400017, 0x02440017, 0xe2000000, PM_16M);
/* Map 0xe4000000 -> 0x0:600005C0, 0xe4100000 -> 400005C0 */
add_wired_entry(0x01800017, 0x01000017, 0xe4000000, PM_4M);
init_i8259_irqs(); /* Integrated i8259 */
mips_cpu_irq_init();
init_r4030_ints();
change_c0_status(ST0_IM, IE_IRQ2 | IE_IRQ1);
}
asmlinkage void plat_irq_dispatch(void)
{
unsigned int pending = read_c0_cause() & read_c0_status();
unsigned int irq;
if (pending & IE_IRQ4) {
Annotation
- Immediate include surface: `linux/clockchips.h`, `linux/i8253.h`, `linux/init.h`, `linux/interrupt.h`, `linux/kernel.h`, `linux/smp.h`, `linux/spinlock.h`, `linux/irq.h`.
- Detected declarations: `function enable_r4030_irq`, `function disable_r4030_irq`, `function init_r4030_ints`, `function arch_init_irq`, `function plat_irq_dispatch`, `function r4030_timer_interrupt`, `function plat_time_init`.
- Atlas domain: Architecture Layer / arch/mips.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.