linux/arch/ia64/kernel/irq_ia64.c
Kenji Kaneshige 3b5cc09033 [IA64] assign_irq_vector() should not panic
Current assign_irq_vector() will panic if interrupt vectors is running
out. But I think how to handle the case of lack of interrupt vectors
should be handled by the caller of this function. For example, some
PCI devices can raise the interrupt signal via both MSI and I/O
APIC. So even if the driver for these device fails to allocate a
vector for MSI, the driver still has a chance to use I/O APIC based
interrupt. But currently there is no chance for these driver to use
I/O APIC based interrupt because kernel will panic when
assign_irq_vector() fails to allocate interrupt vector.

The following patch changes assign_irq_vector() for ia64 to return
-ENOSPC on error instead of panic (as i386 and x86_64 versions do).

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-07-11 10:30:07 -07:00

278 lines
6.5 KiB
C

/*
* linux/arch/ia64/kernel/irq.c
*
* Copyright (C) 1998-2001 Hewlett-Packard Co
* Stephane Eranian <eranian@hpl.hp.com>
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 6/10/99: Updated to bring in sync with x86 version to facilitate
* support for SMP and different interrupt controllers.
*
* 09/15/00 Goutham Rao <goutham.rao@intel.com> Implemented pci_irq_to_vector
* PCI to vector allocation routine.
* 04/14/2004 Ashok Raj <ashok.raj@intel.com>
* Added CPU Hotplug handling for IPF.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel_stat.h>
#include <linux/slab.h>
#include <linux/ptrace.h>
#include <linux/random.h> /* for rand_initialize_irq() */
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/threads.h>
#include <linux/bitops.h>
#include <asm/delay.h>
#include <asm/intrinsics.h>
#include <asm/io.h>
#include <asm/hw_irq.h>
#include <asm/machvec.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#ifdef CONFIG_PERFMON
# include <asm/perfmon.h>
#endif
#define IRQ_DEBUG 0
/* default base addr of IPI table */
void __iomem *ipi_base_addr = ((void __iomem *)
(__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));
/*
* Legacy IRQ to IA-64 vector translation table.
*/
__u8 isa_irq_to_vector_map[16] = {
/* 8259 IRQ translation, first 16 entries */
0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
};
EXPORT_SYMBOL(isa_irq_to_vector_map);
static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_NUM_DEVICE_VECTORS)];
int
assign_irq_vector (int irq)
{
int pos, vector;
again:
pos = find_first_zero_bit(ia64_vector_mask, IA64_NUM_DEVICE_VECTORS);
vector = IA64_FIRST_DEVICE_VECTOR + pos;
if (vector > IA64_LAST_DEVICE_VECTOR)
return -ENOSPC;
if (test_and_set_bit(pos, ia64_vector_mask))
goto again;
return vector;
}
void
free_irq_vector (int vector)
{
int pos;
if (vector < IA64_FIRST_DEVICE_VECTOR || vector > IA64_LAST_DEVICE_VECTOR)
return;
pos = vector - IA64_FIRST_DEVICE_VECTOR;
if (!test_and_clear_bit(pos, ia64_vector_mask))
printk(KERN_WARNING "%s: double free!\n", __FUNCTION__);
}
#ifdef CONFIG_SMP
# define IS_RESCHEDULE(vec) (vec == IA64_IPI_RESCHEDULE)
#else
# define IS_RESCHEDULE(vec) (0)
#endif
/*
* That's where the IVT branches when we get an external
* interrupt. This branches to the correct hardware IRQ handler via
* function ptr.
*/
void
ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
{
unsigned long saved_tpr;
#if IRQ_DEBUG
{
unsigned long bsp, sp;
/*
* Note: if the interrupt happened while executing in
* the context switch routine (ia64_switch_to), we may
* get a spurious stack overflow here. This is
* because the register and the memory stack are not
* switched atomically.
*/
bsp = ia64_getreg(_IA64_REG_AR_BSP);
sp = ia64_getreg(_IA64_REG_SP);
if ((sp - bsp) < 1024) {
static unsigned char count;
static long last_time;
if (jiffies - last_time > 5*HZ)
count = 0;
if (++count < 5) {
last_time = jiffies;
printk("ia64_handle_irq: DANGER: less than "
"1KB of free stack space!!\n"
"(bsp=0x%lx, sp=%lx)\n", bsp, sp);
}
}
}
#endif /* IRQ_DEBUG */
/*
* Always set TPR to limit maximum interrupt nesting depth to
* 16 (without this, it would be ~240, which could easily lead
* to kernel stack overflows).
*/
irq_enter();
saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
ia64_srlz_d();
while (vector != IA64_SPURIOUS_INT_VECTOR) {
if (!IS_RESCHEDULE(vector)) {
ia64_setreg(_IA64_REG_CR_TPR, vector);
ia64_srlz_d();
__do_IRQ(local_vector_to_irq(vector), regs);
/*
* Disable interrupts and send EOI:
*/
local_irq_disable();
ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
}
ia64_eoi();
vector = ia64_get_ivr();
}
/*
* This must be done *after* the ia64_eoi(). For example, the keyboard softirq
* handler needs to be able to wait for further keyboard interrupts, which can't
* come through until ia64_eoi() has been done.
*/
irq_exit();
}
#ifdef CONFIG_HOTPLUG_CPU
/*
* This function emulates a interrupt processing when a cpu is about to be
* brought down.
*/
void ia64_process_pending_intr(void)
{
ia64_vector vector;
unsigned long saved_tpr;
extern unsigned int vectors_in_migration[NR_IRQS];
vector = ia64_get_ivr();
irq_enter();
saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
ia64_srlz_d();
/*
* Perform normal interrupt style processing
*/
while (vector != IA64_SPURIOUS_INT_VECTOR) {
if (!IS_RESCHEDULE(vector)) {
ia64_setreg(_IA64_REG_CR_TPR, vector);
ia64_srlz_d();
/*
* Now try calling normal ia64_handle_irq as it would have got called
* from a real intr handler. Try passing null for pt_regs, hopefully
* it will work. I hope it works!.
* Probably could shared code.
*/
vectors_in_migration[local_vector_to_irq(vector)]=0;
__do_IRQ(local_vector_to_irq(vector), NULL);
/*
* Disable interrupts and send EOI
*/
local_irq_disable();
ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
}
ia64_eoi();
vector = ia64_get_ivr();
}
irq_exit();
}
#endif
#ifdef CONFIG_SMP
extern irqreturn_t handle_IPI (int irq, void *dev_id, struct pt_regs *regs);
static struct irqaction ipi_irqaction = {
.handler = handle_IPI,
.flags = SA_INTERRUPT,
.name = "IPI"
};
#endif
void
register_percpu_irq (ia64_vector vec, struct irqaction *action)
{
irq_desc_t *desc;
unsigned int irq;
for (irq = 0; irq < NR_IRQS; ++irq)
if (irq_to_vector(irq) == vec) {
desc = irq_descp(irq);
desc->status |= IRQ_PER_CPU;
desc->handler = &irq_type_ia64_lsapic;
if (action)
setup_irq(irq, action);
}
}
void __init
init_IRQ (void)
{
register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
#ifdef CONFIG_SMP
register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
#endif
#ifdef CONFIG_PERFMON
pfm_init_percpu();
#endif
platform_irq_init();
}
void
ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
{
void __iomem *ipi_addr;
unsigned long ipi_data;
unsigned long phys_cpu_id;
#ifdef CONFIG_SMP
phys_cpu_id = cpu_physical_id(cpu);
#else
phys_cpu_id = (ia64_getreg(_IA64_REG_CR_LID) >> 16) & 0xffff;
#endif
/*
* cpu number is in 8bit ID and 8bit EID
*/
ipi_data = (delivery_mode << 8) | (vector & 0xff);
ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
writeq(ipi_data, ipi_addr);
}