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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ICS backend for OPAL managed interrupts.
*
* Copyright 2011 IBM Corp.
*/
#undef DEBUG
#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 <linux/spinlock.h>
#include <linux/msi.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/irq.h>
#include <asm/errno.h>
#include <asm/xics.h>
#include <asm/opal.h>
#include <asm/firmware.h>
static int ics_opal_mangle_server(int server)
{
/* No link for now */
return server << 2;
}
static int ics_opal_unmangle_server(int server)
{
/* No link for now */
return server >> 2;
}
static void ics_opal_unmask_irq(struct irq_data *d)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
int64_t rc;
int server;
pr_devel("ics-hal: unmask virq %d [hw 0x%x]\n", d->irq, hw_irq);
if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
return;
server = xics_get_irq_server(d->irq, irq_data_get_affinity_mask(d), 0);
server = ics_opal_mangle_server(server);
rc = opal_set_xive(hw_irq, server, DEFAULT_PRIORITY);
if (rc != OPAL_SUCCESS)
pr_err("%s: opal_set_xive(irq=%d [hw 0x%x] server=%x)"
" error %lld\n",
__func__, d->irq, hw_irq, server, rc);
}
static unsigned int ics_opal_startup(struct irq_data *d)
{
ics_opal_unmask_irq(d);
return 0;
}
static void ics_opal_mask_real_irq(unsigned int hw_irq)
{
int server = ics_opal_mangle_server(xics_default_server);
int64_t rc;
if (hw_irq == XICS_IPI)
return;
/* Have to set XIVE to 0xff to be able to remove a slot */
rc = opal_set_xive(hw_irq, server, 0xff);
if (rc != OPAL_SUCCESS)
pr_err("%s: opal_set_xive(0xff) irq=%u returned %lld\n",
__func__, hw_irq, rc);
}
static void ics_opal_mask_irq(struct irq_data *d)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
pr_devel("ics-hal: mask virq %d [hw 0x%x]\n", d->irq, hw_irq);
if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
return;
ics_opal_mask_real_irq(hw_irq);
}
static int ics_opal_set_affinity(struct irq_data *d,
const struct cpumask *cpumask,
bool force)
{
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
__be16 oserver;
int16_t server;
int8_t priority;
int64_t rc;
int wanted_server;
if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
return -1;
rc = opal_get_xive(hw_irq, &oserver, &priority);
if (rc != OPAL_SUCCESS) {
pr_err("%s: opal_get_xive(irq=%d [hw 0x%x]) error %lld\n",
__func__, d->irq, hw_irq, rc);
return -1;
}
server = be16_to_cpu(oserver);
wanted_server = xics_get_irq_server(d->irq, cpumask, 1);
if (wanted_server < 0) {
pr_warn("%s: No online cpus in the mask %*pb for irq %d\n",
__func__, cpumask_pr_args(cpumask), d->irq);
return -1;
}
server = ics_opal_mangle_server(wanted_server);
pr_debug("ics-hal: set-affinity irq %d [hw 0x%x] server: 0x%x/0x%x\n",
d->irq, hw_irq, wanted_server, server);
rc = opal_set_xive(hw_irq, server, priority);
if (rc != OPAL_SUCCESS) {
pr_err("%s: opal_set_xive(irq=%d [hw 0x%x] server=%x)"
" error %lld\n",
__func__, d->irq, hw_irq, server, rc);
return -1;
}
return IRQ_SET_MASK_OK;
}
static struct irq_chip ics_opal_irq_chip = {
.name = "OPAL ICS",
.irq_startup = ics_opal_startup,
.irq_mask = ics_opal_mask_irq,
.irq_unmask = ics_opal_unmask_irq,
.irq_eoi = NULL, /* Patched at init time */
.irq_set_affinity = ics_opal_set_affinity,
.irq_set_type = xics_set_irq_type,
.irq_retrigger = xics_retrigger,
};
static int ics_opal_host_match(struct ics *ics, struct device_node *node)
{
return 1;
}
static int ics_opal_check(struct ics *ics, unsigned int hw_irq)
{
int64_t rc;
__be16 server;
int8_t priority;
if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS))
return -EINVAL;
/* Check if HAL knows about this interrupt */
rc = opal_get_xive(hw_irq, &server, &priority);
if (rc != OPAL_SUCCESS)
return -ENXIO;
return 0;
}
static void ics_opal_mask_unknown(struct ics *ics, unsigned long vec)
{
int64_t rc;
__be16 server;
int8_t priority;
/* Check if HAL knows about this interrupt */
rc = opal_get_xive(vec, &server, &priority);
if (rc != OPAL_SUCCESS)
return;
ics_opal_mask_real_irq(vec);
}
static long ics_opal_get_server(struct ics *ics, unsigned long vec)
{
int64_t rc;
__be16 server;
int8_t priority;
/* Check if HAL knows about this interrupt */
rc = opal_get_xive(vec, &server, &priority);
if (rc != OPAL_SUCCESS)
return -1;
return ics_opal_unmangle_server(be16_to_cpu(server));
}
/* Only one global & state struct ics */
static struct ics ics_hal = {
.check = ics_opal_check,
.mask_unknown = ics_opal_mask_unknown,
.get_server = ics_opal_get_server,
.host_match = ics_opal_host_match,
.chip = &ics_opal_irq_chip,
};
int __init ics_opal_init(void)
{
if (!firmware_has_feature(FW_FEATURE_OPAL))
return -ENODEV;
/* We need to patch our irq chip's EOI to point to the
* right ICP
*/
ics_opal_irq_chip.irq_eoi = icp_ops->eoi;
/* Register ourselves */
xics_register_ics(&ics_hal);
pr_info("ICS OPAL backend registered\n");
return 0;
}