/*
* Cell Internal Interrupt Controller
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
*
* Author: Arnd Bergmann <arndb@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/config.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/types.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include "interrupt.h"
#include "cbe_regs.h"
struct iic {
struct cbe_iic_thread_regs __iomem *regs;
u8 target_id;
};
static DEFINE_PER_CPU(struct iic, iic);
void iic_local_enable(void)
{
struct iic *iic = &__get_cpu_var(iic);
u64 tmp;
/*
* There seems to be a bug that is present in DD2.x CPUs
* and still only partially fixed in DD3.1.
* This bug causes a value written to the priority register
* not to make it there, resulting in a system hang unless we
* write it again.
* Masking with 0xf0 is done because the Cell BE does not
* implement the lower four bits of the interrupt priority,
* they always read back as zeroes, although future CPUs
* might implement different bits.
*/
do {
out_be64(&iic->regs->prio, 0xff);
tmp = in_be64(&iic->regs->prio);
} while ((tmp & 0xf0) != 0xf0);
}
void iic_local_disable(void)
{
out_be64(&__get_cpu_var(iic).regs->prio, 0x0);
}
static unsigned int iic_startup(unsigned int irq)
{
return 0;
}
static void iic_enable(unsigned int irq)
{
iic_local_enable();
}
static void iic_disable(unsigned int irq)
{
}
static void iic_end(unsigned int irq)
{
iic_local_enable();
}
static struct hw_interrupt_type iic_pic = {
.typename = " CELL-IIC ",
.startup = iic_startup,
.enable = iic_enable,
.disable = iic_disable,
.end = iic_end,
};
static int iic_external_get_irq(struct cbe_iic_pending_bits pending)
{
int irq;
unsigned char node, unit;
node = pending.source >> 4;
unit = pending.source & 0xf;
irq = -1;
/*
* This mapping is specific to the Cell Broadband
* Engine. We might need to get the numbers
* from the device tree to support future CPUs.
*/
switch (unit) {
case 0x00:
case 0x0b:
/*
* One of these units can be connected
* to an external interrupt controller.
*/
if (pending.class != 2)
break;
irq = IIC_EXT_OFFSET
+ spider_get_irq(node)
+ node * IIC_NODE_STRIDE;
break;
case 0x01 ... 0x04:
case 0x07 ... 0x0a:
/*
* These units are connected to the SPEs
*/
if (pending.class > 2)
break;
irq = IIC_SPE_OFFSET
+ pending.class * IIC_CLASS_STRIDE
+ node * IIC_NODE_STRIDE
+ unit;
break;
}
if (irq == -1)
printk(KERN_WARNING "Unexpected interrupt class %02x, "
"source %02x, prio %02x, cpu %02x\n", pending.class,
pending.source, pending.prio, smp_processor_id());
return irq;
}
/* Get an IRQ number from the pending state register of the IIC */
int iic_get_irq(struct pt_regs *regs)
{
struct iic *iic;
int irq;
struct cbe_iic_pending_bits pending;
iic = &__get_cpu_var(iic);
*(unsigned long *) &pending =
in_be64((unsigned long __iomem *) &iic->regs->pending_destr);
irq = -1;
if (pending.flags & CBE_IIC_IRQ_VALID) {
if (pending.flags & CBE_IIC_IRQ_IPI) {
irq = IIC_IPI_OFFSET + (pending.prio >> 4);
/*
if (irq > 0x80)
printk(KERN_WARNING "Unexpected IPI prio %02x"
"on CPU %02x\n", pending.prio,
smp_processor_id());
*/
} else {
irq = iic_external_get_irq(pending);
}
}
return irq;
}
/* hardcoded part to be compatible with older firmware */
static int setup_iic_hardcoded(void)
{
struct device_node *np;
int nodeid, cpu;
unsigned long regs;
struct iic *iic;
for_each_possible_cpu(cpu) {
iic = &per_cpu(iic, cpu);
nodeid = cpu/2;
for (np = of_find_node_by_type(NULL, "cpu");
np;
np = of_find_node_by_type(np, "cpu")) {
if (nodeid == *(int *)get_property(np, "node-id", NULL))
break;
}
if (!np) {
printk(KERN_WARNING "IIC: CPU %d not found\n", cpu);
iic->regs = NULL;
iic->target_id = 0xff;
return -ENODEV;
}
regs = *(long *)get_property(np, "iic", NULL);
/* hack until we have decided on the devtree info */
regs += 0x400;
if (cpu & 1)
regs += 0x20;
printk(KERN_INFO "IIC for CPU %d at %lx\n", cpu, regs);
iic->regs = ioremap(regs, sizeof(struct cbe_iic_thread_regs));
iic->target_id = (nodeid << 4) + ((cpu & 1) ? 0xf : 0xe);
}
return 0;
}
static int setup_iic(void)
{
struct device_node *dn;
unsigned long *regs;
char *compatible;
unsigned *np, found = 0;
struct iic *iic = NULL;
for (dn = NULL; (dn = of_find_node_by_name(dn, "interrupt-controller"));) {
compatible = (char *)get_property(dn, "compatible", NULL);
if (!compatible) {
printk(KERN_WARNING "no compatible property found !\n");
continue;
}
if (strstr(compatible, "IBM,CBEA-Internal-Interrupt-Controller"))
regs = (unsigned long *)get_property(dn,"reg", NULL);
else
continue;
if (!regs)
printk(KERN_WARNING "IIC: no reg property\n");
np = (unsigned int *)get_property(dn, "ibm,interrupt-server-ranges", NULL);
if (!np) {
printk(KERN_WARNING "IIC: CPU association not found\n");
iic->regs = NULL;
iic->target_id = 0xff;
return -ENODEV;
}
iic = &per_cpu(iic, np[0]);
iic->regs = ioremap(regs[0], sizeof(struct cbe_iic_thread_regs));
iic->target_id = ((np[0] & 2) << 3) + ((np[0] & 1) ? 0xf : 0xe);
printk("IIC for CPU %d at %lx mapped to %p\n", np[0], regs[0], iic->regs);
iic = &per_cpu(iic, np[1]);
iic->regs = ioremap(regs[2], sizeof(struct cbe_iic_thread_regs));
iic->target_id = ((np[1] & 2) << 3) + ((np[1] & 1) ? 0xf : 0xe);
printk("IIC for CPU %d at %lx mapped to %p\n", np[1], regs[2], iic->regs);
found++;
}
if (found)
return 0;
else
return -ENODEV;
}
#ifdef CONFIG_SMP
/* Use the highest interrupt priorities for IPI */
static inline int iic_ipi_to_irq(int ipi)
{
return IIC_IPI_OFFSET + IIC_NUM_IPIS - 1 - ipi;
}
static inline int iic_irq_to_ipi(int irq)
{
return IIC_NUM_IPIS - 1 - (irq - IIC_IPI_OFFSET);
}
void iic_setup_cpu(void)
{
out_be64(&__get_cpu_var(iic).regs->prio, 0xff);
}
void iic_cause_IPI(int cpu, int mesg)
{
out_be64(&per_cpu(iic, cpu).regs->generate, (IIC_NUM_IPIS - 1 - mesg) << 4);
}
u8 iic_get_target_id(int cpu)
{
return per_cpu(iic, cpu).target_id;
}
EXPORT_SYMBOL_GPL(iic_get_target_id);
static irqreturn_t iic_ipi_action(int irq, void *dev_id, struct pt_regs *regs)
{
smp_message_recv(iic_irq_to_ipi(irq), regs);
return IRQ_HANDLED;
}
static void iic_request_ipi(int ipi, const char *name)
{
int irq;
irq = iic_ipi_to_irq(ipi);
/* IPIs are marked SA_INTERRUPT as they must run with irqs
* disabled */
get_irq_desc(irq)->handler = &iic_pic;
get_irq_desc(irq)->status |= IRQ_PER_CPU;
request_irq(irq, iic_ipi_action, SA_INTERRUPT, name, NULL);
}
void iic_request_IPIs(void)
{
iic_request_ipi(PPC_MSG_CALL_FUNCTION, "IPI-call");
iic_request_ipi(PPC_MSG_RESCHEDULE, "IPI-resched");
#ifdef CONFIG_DEBUGGER
iic_request_ipi(PPC_MSG_DEBUGGER_BREAK, "IPI-debug");
#endif /* CONFIG_DEBUGGER */
}
#endif /* CONFIG_SMP */
static void iic_setup_spe_handlers(void)
{
int be, isrc;
/* Assume two threads per BE are present */
for (be=0; be < num_present_cpus() / 2; be++) {
for (isrc = 0; isrc < IIC_CLASS_STRIDE * 3; isrc++) {
int irq = IIC_NODE_STRIDE * be + IIC_SPE_OFFSET + isrc;
get_irq_desc(irq)->handler = &iic_pic;
}
}
}
void iic_init_IRQ(void)
{
int cpu, irq_offset;
struct iic *iic;
if (setup_iic() < 0)
setup_iic_hardcoded();
irq_offset = 0;
for_each_possible_cpu(cpu) {
iic = &per_cpu(iic, cpu);
if (iic->regs)
out_be64(&iic->regs->prio, 0xff);
}
iic_setup_spe_handlers();
}
