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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2011 IBM Corporation.
*/
#include <linux/types.h>
#include <linux/threads.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/debugfs.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/irq.h>
#include <asm/errno.h>
#include <asm/rtas.h>
#include <asm/xics.h>
#include <asm/firmware.h>
/* Globals common to all ICP/ICS implementations */
const struct icp_ops *icp_ops;
unsigned int xics_default_server = 0xff;
unsigned int xics_default_distrib_server = 0;
unsigned int xics_interrupt_server_size = 8;
DEFINE_PER_CPU(struct xics_cppr, xics_cppr);
struct irq_domain *xics_host;
static struct ics *xics_ics;
void xics_update_irq_servers(void)
{
int i, j;
struct device_node *np;
u32 ilen;
const __be32 *ireg;
u32 hcpuid;
/* Find the server numbers for the boot cpu. */
np = of_get_cpu_node(boot_cpuid, NULL);
BUG_ON(!np);
hcpuid = get_hard_smp_processor_id(boot_cpuid);
xics_default_server = xics_default_distrib_server = hcpuid;
pr_devel("xics: xics_default_server = 0x%x\n", xics_default_server);
ireg = of_get_property(np, "ibm,ppc-interrupt-gserver#s", &ilen);
if (!ireg) {
of_node_put(np);
return;
}
i = ilen / sizeof(int);
/* Global interrupt distribution server is specified in the last
* entry of "ibm,ppc-interrupt-gserver#s" property. Get the last
* entry fom this property for current boot cpu id and use it as
* default distribution server
*/
for (j = 0; j < i; j += 2) {
if (be32_to_cpu(ireg[j]) == hcpuid) {
xics_default_distrib_server = be32_to_cpu(ireg[j+1]);
break;
}
}
pr_devel("xics: xics_default_distrib_server = 0x%x\n",
xics_default_distrib_server);
of_node_put(np);
}
/* GIQ stuff, currently only supported on RTAS setups, will have
* to be sorted properly for bare metal
*/
void xics_set_cpu_giq(unsigned int gserver, unsigned int join)
{
#ifdef CONFIG_PPC_RTAS
int index;
int status;
if (!rtas_indicator_present(GLOBAL_INTERRUPT_QUEUE, NULL))
return;
index = (1UL << xics_interrupt_server_size) - 1 - gserver;
status = rtas_set_indicator_fast(GLOBAL_INTERRUPT_QUEUE, index, join);
WARN(status < 0, "set-indicator(%d, %d, %u) returned %d\n",
GLOBAL_INTERRUPT_QUEUE, index, join, status);
#endif
}
void xics_setup_cpu(void)
{
icp_ops->set_priority(LOWEST_PRIORITY);
xics_set_cpu_giq(xics_default_distrib_server, 1);
}
void xics_mask_unknown_vec(unsigned int vec)
{
pr_err("Interrupt 0x%x (real) is invalid, disabling it.\n", vec);
if (WARN_ON(!xics_ics))
return;
xics_ics->mask_unknown(xics_ics, vec);
}
#ifdef CONFIG_SMP
static void __init xics_request_ipi(void)
{
unsigned int ipi;
ipi = irq_create_mapping(xics_host, XICS_IPI);
BUG_ON(!ipi);
/*
* IPIs are marked IRQF_PERCPU. The handler was set in map.
*/
BUG_ON(request_irq(ipi, icp_ops->ipi_action,
IRQF_NO_DEBUG | IRQF_PERCPU | IRQF_NO_THREAD, "IPI", NULL));
}
void __init xics_smp_probe(void)
{
/* Register all the IPIs */
xics_request_ipi();
/* Setup cause_ipi callback based on which ICP is used */
smp_ops->cause_ipi = icp_ops->cause_ipi;
}
#endif /* CONFIG_SMP */
noinstr void xics_teardown_cpu(void)
{
struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
/*
* we have to reset the cppr index to 0 because we're
* not going to return from the IPI
*/
os_cppr->index = 0;
icp_ops->set_priority(0);
icp_ops->teardown_cpu();
}
noinstr void xics_kexec_teardown_cpu(int secondary)
{
xics_teardown_cpu();
icp_ops->flush_ipi();
/*
* Some machines need to have at least one cpu in the GIQ,
* so leave the master cpu in the group.
*/
if (secondary)
xics_set_cpu_giq(xics_default_distrib_server, 0);
}
#ifdef CONFIG_HOTPLUG_CPU
/* Interrupts are disabled. */
void xics_migrate_irqs_away(void)
{
int cpu = smp_processor_id(), hw_cpu = hard_smp_processor_id();
unsigned int irq, virq;
struct irq_desc *desc;
pr_debug("%s: CPU %u\n", __func__, cpu);
/* If we used to be the default server, move to the new "boot_cpuid" */
if (hw_cpu == xics_default_server)
xics_update_irq_servers();
/* Reject any interrupt that was queued to us... */
icp_ops->set_priority(0);
/* Remove ourselves from the global interrupt queue */
xics_set_cpu_giq(xics_default_distrib_server, 0);
for_each_irq_desc(virq, desc) {
struct irq_chip *chip;
long server;
unsigned long flags;
struct irq_data *irqd;
/* We can't set affinity on ISA interrupts */
if (virq < NR_IRQS_LEGACY)
continue;
/* We only need to migrate enabled IRQS */
if (!desc->action)
continue;
/* We need a mapping in the XICS IRQ domain */
irqd = irq_domain_get_irq_data(xics_host, virq);
if (!irqd)
continue;
irq = irqd_to_hwirq(irqd);
/* We need to get IPIs still. */
if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
continue;
chip = irq_desc_get_chip(desc);
if (!chip || !chip->irq_set_affinity)
continue;
raw_spin_lock_irqsave(&desc->lock, flags);
/* Locate interrupt server */
server = xics_ics->get_server(xics_ics, irq);
if (server < 0) {
pr_err("%s: Can't find server for irq %d/%x\n",
__func__, virq, irq);
goto unlock;
}
/* We only support delivery to all cpus or to one cpu.
* The irq has to be migrated only in the single cpu
* case.
*/
if (server != hw_cpu)
goto unlock;
/* This is expected during cpu offline. */
if (cpu_online(cpu))
pr_warn("IRQ %u affinity broken off cpu %u\n",
virq, cpu);
/* Reset affinity to all cpus */
raw_spin_unlock_irqrestore(&desc->lock, flags);
irq_set_affinity(virq, cpu_all_mask);
continue;
unlock:
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
/* Allow "sufficient" time to drop any inflight IRQ's */
mdelay(5);
/*
* Allow IPIs again. This is done at the very end, after migrating all
* interrupts, the expectation is that we'll only get woken up by an IPI
* interrupt beyond this point, but leave externals masked just to be
* safe. If we're using icp-opal this may actually allow all
* interrupts anyway, but that should be OK.
*/
icp_ops->set_priority(DEFAULT_PRIORITY);
}
#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_SMP
/*
* For the moment we only implement delivery to all cpus or one cpu.
*
* If the requested affinity is cpu_all_mask, we set global affinity.
* If not we set it to the first cpu in the mask, even if multiple cpus
* are set. This is so things like irqbalance (which set core and package
* wide affinities) do the right thing.
*
* We need to fix this to implement support for the links
*/
int xics_get_irq_server(unsigned int virq, const struct cpumask *cpumask,
unsigned int strict_check)
{
if (!distribute_irqs)
return xics_default_server;
if (!cpumask_subset(cpu_possible_mask, cpumask)) {
int server = cpumask_first_and(cpu_online_mask, cpumask);
if (server < nr_cpu_ids)
return get_hard_smp_processor_id(server);
if (strict_check)
return -1;
}
/*
* Workaround issue with some versions of JS20 firmware that
* deliver interrupts to cpus which haven't been started. This
* happens when using the maxcpus= boot option.
*/
if (cpumask_equal(cpu_online_mask, cpu_present_mask))
return xics_default_distrib_server;
return xics_default_server;
}
#endif /* CONFIG_SMP */
static int xics_host_match(struct irq_domain *h, struct device_node *node,
enum irq_domain_bus_token bus_token)
{
if (WARN_ON(!xics_ics))
return 0;
return xics_ics->host_match(xics_ics, node) ? 1 : 0;
}
/* Dummies */
static void xics_ipi_unmask(struct irq_data *d) { }
static void xics_ipi_mask(struct irq_data *d) { }
static struct irq_chip xics_ipi_chip = {
.name = "XICS",
.irq_eoi = NULL, /* Patched at init time */
.irq_mask = xics_ipi_mask,
.irq_unmask = xics_ipi_unmask,
};
static int xics_host_map(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hwirq)
{
pr_devel("xics: map virq %d, hwirq 0x%lx\n", virq, hwirq);
/*
* Mark interrupts as edge sensitive by default so that resend
* actually works. The device-tree parsing will turn the LSIs
* back to level.
*/
irq_clear_status_flags(virq, IRQ_LEVEL);
/* Don't call into ICS for IPIs */
if (hwirq == XICS_IPI) {
irq_set_chip_and_handler(virq, &xics_ipi_chip,
handle_percpu_irq);
return 0;
}
if (WARN_ON(!xics_ics))
return -EINVAL;
if (xics_ics->check(xics_ics, hwirq))
return -EINVAL;
/* Let the ICS be the chip data for the XICS domain. For ICS native */
irq_domain_set_info(domain, virq, hwirq, xics_ics->chip,
xics_ics, handle_fasteoi_irq, NULL, NULL);
return 0;
}
static int xics_host_xlate(struct irq_domain *h, struct device_node *ct,
const u32 *intspec, unsigned int intsize,
irq_hw_number_t *out_hwirq, unsigned int *out_flags)
{
*out_hwirq = intspec[0];
/*
* If intsize is at least 2, we look for the type in the second cell,
* we assume the LSB indicates a level interrupt.
*/
if (intsize > 1) {
if (intspec[1] & 1)
*out_flags = IRQ_TYPE_LEVEL_LOW;
else
*out_flags = IRQ_TYPE_EDGE_RISING;
} else
*out_flags = IRQ_TYPE_LEVEL_LOW;
return 0;
}
int xics_set_irq_type(struct irq_data *d, unsigned int flow_type)
{
/*
* We only support these. This has really no effect other than setting
* the corresponding descriptor bits mind you but those will in turn
* affect the resend function when re-enabling an edge interrupt.
*
* Set set the default to edge as explained in map().
*/
if (flow_type == IRQ_TYPE_DEFAULT || flow_type == IRQ_TYPE_NONE)
flow_type = IRQ_TYPE_EDGE_RISING;
if (flow_type != IRQ_TYPE_EDGE_RISING &&
flow_type != IRQ_TYPE_LEVEL_LOW)
return -EINVAL;
irqd_set_trigger_type(d, flow_type);
return IRQ_SET_MASK_OK_NOCOPY;
}
int xics_retrigger(struct irq_data *data)
{
/*
* We need to push a dummy CPPR when retriggering, since the subsequent
* EOI will try to pop it. Passing 0 works, as the function hard codes
* the priority value anyway.
*/
xics_push_cppr(0);
/* Tell the core to do a soft retrigger */
return 0;
}
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
static int xics_host_domain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
unsigned long *hwirq, unsigned int *type)
{
return xics_host_xlate(d, to_of_node(fwspec->fwnode), fwspec->param,
fwspec->param_count, hwirq, type);
}
static int xics_host_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
struct irq_fwspec *fwspec = arg;
irq_hw_number_t hwirq;
unsigned int type = IRQ_TYPE_NONE;
int i, rc;
rc = xics_host_domain_translate(domain, fwspec, &hwirq, &type);
if (rc)
return rc;
pr_debug("%s %d/%lx #%d\n", __func__, virq, hwirq, nr_irqs);
for (i = 0; i < nr_irqs; i++)
irq_domain_set_info(domain, virq + i, hwirq + i, xics_ics->chip,
xics_ics, handle_fasteoi_irq, NULL, NULL);
return 0;
}
static void xics_host_domain_free(struct irq_domain *domain,
unsigned int virq, unsigned int nr_irqs)
{
pr_debug("%s %d #%d\n", __func__, virq, nr_irqs);
}
#endif
static const struct irq_domain_ops xics_host_ops = {
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
.alloc = xics_host_domain_alloc,
.free = xics_host_domain_free,
.translate = xics_host_domain_translate,
#endif
.match = xics_host_match,
.map = xics_host_map,
.xlate = xics_host_xlate,
};
static int __init xics_allocate_domain(void)
{
struct fwnode_handle *fn;
fn = irq_domain_alloc_named_fwnode("XICS");
if (!fn)
return -ENOMEM;
xics_host = irq_domain_create_tree(fn, &xics_host_ops, NULL);
if (!xics_host) {
irq_domain_free_fwnode(fn);
return -ENOMEM;
}
irq_set_default_host(xics_host);
return 0;
}
void __init xics_register_ics(struct ics *ics)
{
if (WARN_ONCE(xics_ics, "XICS: Source Controller is already defined !"))
return;
xics_ics = ics;
}
static void __init xics_get_server_size(void)
{
struct device_node *np;
const __be32 *isize;
/* We fetch the interrupt server size from the first ICS node
* we find if any
*/
np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xics");
if (!np)
return;
isize = of_get_property(np, "ibm,interrupt-server#-size", NULL);
if (isize)
xics_interrupt_server_size = be32_to_cpu(*isize);
of_node_put(np);
}
void __init xics_init(void)
{
int rc = -1;
/* Fist locate ICP */
if (firmware_has_feature(FW_FEATURE_LPAR))
rc = icp_hv_init();
if (rc < 0) {
rc = icp_native_init();
if (rc == -ENODEV)
rc = icp_opal_init();
}
if (rc < 0) {
pr_warn("XICS: Cannot find a Presentation Controller !\n");
return;
}
/* Copy get_irq callback over to ppc_md */
ppc_md.get_irq = icp_ops->get_irq;
/* Patch up IPI chip EOI */
xics_ipi_chip.irq_eoi = icp_ops->eoi;
/* Now locate ICS */
rc = ics_rtas_init();
if (rc < 0)
rc = ics_opal_init();
if (rc < 0)
rc = ics_native_init();
if (rc < 0)
pr_warn("XICS: Cannot find a Source Controller !\n");
/* Initialize common bits */
xics_get_server_size();
xics_update_irq_servers();
rc = xics_allocate_domain();
if (rc < 0)
pr_err("XICS: Failed to create IRQ domain");
xics_setup_cpu();
}