/*
* Copyright 2011 IBM Corporation.
*
* 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 of the License, or (at your option) any later version.
*
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/of.h>
#include <asm/smp.h>
#include <asm/irq.h>
#include <asm/errno.h>
#include <asm/xics.h>
#include <asm/io.h>
#include <asm/hvcall.h>
static inline unsigned int icp_hv_get_xirr(unsigned char cppr)
{
unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
long rc;
unsigned int ret = XICS_IRQ_SPURIOUS;
rc = plpar_hcall(H_XIRR, retbuf, cppr);
if (rc == H_SUCCESS) {
ret = (unsigned int)retbuf[0];
} else {
pr_err("%s: bad return code xirr cppr=0x%x returned %ld\n",
__func__, cppr, rc);
WARN_ON_ONCE(1);
}
return ret;
}
static inline void icp_hv_set_cppr(u8 value)
{
long rc = plpar_hcall_norets(H_CPPR, value);
if (rc != H_SUCCESS) {
pr_err("%s: bad return code cppr cppr=0x%x returned %ld\n",
__func__, value, rc);
WARN_ON_ONCE(1);
}
}
static inline void icp_hv_set_xirr(unsigned int value)
{
long rc = plpar_hcall_norets(H_EOI, value);
if (rc != H_SUCCESS) {
pr_err("%s: bad return code eoi xirr=0x%x returned %ld\n",
__func__, value, rc);
WARN_ON_ONCE(1);
icp_hv_set_cppr(value >> 24);
}
}
static inline void icp_hv_set_qirr(int n_cpu , u8 value)
{
int hw_cpu = get_hard_smp_processor_id(n_cpu);
long rc = plpar_hcall_norets(H_IPI, hw_cpu, value);
if (rc != H_SUCCESS) {
pr_err("%s: bad return code qirr cpu=%d hw_cpu=%d mfrr=0x%x "
"returned %ld\n", __func__, n_cpu, hw_cpu, value, rc);
WARN_ON_ONCE(1);
}
}
static void icp_hv_eoi(struct irq_data *d)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
iosync();
icp_hv_set_xirr((xics_pop_cppr() << 24) | hw_irq);
}
static void icp_hv_teardown_cpu(void)
{
int cpu = smp_processor_id();
/* Clear any pending IPI */
icp_hv_set_qirr(cpu, 0xff);
}
static void icp_hv_flush_ipi(void)
{
/* We take the ipi irq but and never return so we
* need to EOI the IPI, but want to leave our priority 0
*
* should we check all the other interrupts too?
* should we be flagging idle loop instead?
* or creating some task to be scheduled?
*/
icp_hv_set_xirr((0x00 << 24) | XICS_IPI);
}
static unsigned int icp_hv_get_irq(void)
{
unsigned int xirr = icp_hv_get_xirr(xics_cppr_top());
unsigned int vec = xirr & 0x00ffffff;
unsigned int irq;
if (vec == XICS_IRQ_SPURIOUS)
return NO_IRQ;
irq = irq_radix_revmap_lookup(xics_host, vec);
if (likely(irq != NO_IRQ)) {
xics_push_cppr(vec);
return irq;
}
/* We don't have a linux mapping, so have rtas mask it. */
xics_mask_unknown_vec(vec);
/* We might learn about it later, so EOI it */
icp_hv_set_xirr(xirr);
return NO_IRQ;
}
static void icp_hv_set_cpu_priority(unsigned char cppr)
{
xics_set_base_cppr(cppr);
icp_hv_set_cppr(cppr);
iosync();
}
#ifdef CONFIG_SMP
static void icp_hv_cause_ipi(int cpu, unsigned long data)
{
icp_hv_set_qirr(cpu, IPI_PRIORITY);
}
static irqreturn_t icp_hv_ipi_action(int irq, void *dev_id)
{
int cpu = smp_processor_id();
icp_hv_set_qirr(cpu, 0xff);
return smp_ipi_demux();
}
#endif /* CONFIG_SMP */
static const struct icp_ops icp_hv_ops = {
.get_irq = icp_hv_get_irq,
.eoi = icp_hv_eoi,
.set_priority = icp_hv_set_cpu_priority,
.teardown_cpu = icp_hv_teardown_cpu,
.flush_ipi = icp_hv_flush_ipi,
#ifdef CONFIG_SMP
.ipi_action = icp_hv_ipi_action,
.cause_ipi = icp_hv_cause_ipi,
#endif
};
int icp_hv_init(void)
{
struct device_node *np;
np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xicp");
if (!np)
np = of_find_node_by_type(NULL,
"PowerPC-External-Interrupt-Presentation");
if (!np)
return -ENODEV;
icp_ops = &icp_hv_ops;
return 0;
}
