kernel-ark/arch/ia64/kernel/irq_ia64.c
Kenji Kaneshige 24eeb568ae [IA64] vector sharing (Large I/O system support)
Current ia64 linux cannot handle greater than 184 interrupt sources
because of the lack of vectors. The following patch enables ia64 linux
to handle greater than 184 interrupt sources by allowing the same
vector number to be shared by multiple IOSAPIC's RTEs. The design of
this patch is besed on "Intel(R) Itanium(R) Processor Family Interrupt
Architecture Guide".

Even if you don't have a large I/O system, you can see the behavior of
vector sharing by changing IOSAPIC_LAST_DEVICE_VECTOR to fewer value.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-04-25 13:26:23 -07:00

289 lines
6.7 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_nopanic (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 -1;
if (test_and_set_bit(pos, ia64_vector_mask))
goto again;
return vector;
}
int
assign_irq_vector (int irq)
{
int vector = assign_irq_vector_nopanic(irq);
if (vector < 0)
panic("assign_irq_vector: out of interrupt vectors!");
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);
}