From e5fd91f1ef340da553f7a79da9540c3db711c937 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Tue, 8 Sep 2015 01:01:14 -0300 Subject: Linux-libre 4.2-gnu --- arch/powerpc/platforms/powernv/opal-irqchip.c | 253 ++++++++++++++++++++++++++ 1 file changed, 253 insertions(+) create mode 100644 arch/powerpc/platforms/powernv/opal-irqchip.c (limited to 'arch/powerpc/platforms/powernv/opal-irqchip.c') diff --git a/arch/powerpc/platforms/powernv/opal-irqchip.c b/arch/powerpc/platforms/powernv/opal-irqchip.c new file mode 100644 index 000000000..e2e7d75f5 --- /dev/null +++ b/arch/powerpc/platforms/powernv/opal-irqchip.c @@ -0,0 +1,253 @@ +/* + * This file implements an irqchip for OPAL events. Whenever there is + * an interrupt that is handled by OPAL we get passed a list of events + * that Linux needs to do something about. These basically look like + * interrupts to Linux so we implement an irqchip to handle them. + * + * Copyright Alistair Popple, IBM Corporation 2014. + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "powernv.h" + +/* Maximum number of events supported by OPAL firmware */ +#define MAX_NUM_EVENTS 64 + +struct opal_event_irqchip { + struct irq_chip irqchip; + struct irq_domain *domain; + unsigned long mask; +}; +static struct opal_event_irqchip opal_event_irqchip; + +static unsigned int opal_irq_count; +static unsigned int *opal_irqs; + +static void opal_handle_irq_work(struct irq_work *work); +static __be64 last_outstanding_events; +static struct irq_work opal_event_irq_work = { + .func = opal_handle_irq_work, +}; + +static void opal_event_mask(struct irq_data *d) +{ + clear_bit(d->hwirq, &opal_event_irqchip.mask); +} + +static void opal_event_unmask(struct irq_data *d) +{ + set_bit(d->hwirq, &opal_event_irqchip.mask); + + opal_poll_events(&last_outstanding_events); + if (last_outstanding_events & opal_event_irqchip.mask) + /* Need to retrigger the interrupt */ + irq_work_queue(&opal_event_irq_work); +} + +static int opal_event_set_type(struct irq_data *d, unsigned int flow_type) +{ + /* + * For now we only support level triggered events. The irq + * handler will be called continuously until the event has + * been cleared in OPAL. + */ + if (flow_type != IRQ_TYPE_LEVEL_HIGH) + return -EINVAL; + + return 0; +} + +static struct opal_event_irqchip opal_event_irqchip = { + .irqchip = { + .name = "OPAL EVT", + .irq_mask = opal_event_mask, + .irq_unmask = opal_event_unmask, + .irq_set_type = opal_event_set_type, + }, + .mask = 0, +}; + +static int opal_event_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hwirq) +{ + irq_set_chip_data(irq, &opal_event_irqchip); + irq_set_chip_and_handler(irq, &opal_event_irqchip.irqchip, + handle_level_irq); + + return 0; +} + +void opal_handle_events(uint64_t events) +{ + int virq, hwirq = 0; + u64 mask = opal_event_irqchip.mask; + + if (!in_irq() && (events & mask)) { + last_outstanding_events = events; + irq_work_queue(&opal_event_irq_work); + return; + } + + while (events & mask) { + hwirq = fls64(events) - 1; + if (BIT_ULL(hwirq) & mask) { + virq = irq_find_mapping(opal_event_irqchip.domain, + hwirq); + if (virq) + generic_handle_irq(virq); + } + events &= ~BIT_ULL(hwirq); + } +} + +static irqreturn_t opal_interrupt(int irq, void *data) +{ + __be64 events; + + opal_handle_interrupt(virq_to_hw(irq), &events); + opal_handle_events(be64_to_cpu(events)); + + return IRQ_HANDLED; +} + +static void opal_handle_irq_work(struct irq_work *work) +{ + opal_handle_events(be64_to_cpu(last_outstanding_events)); +} + +static int opal_event_match(struct irq_domain *h, struct device_node *node) +{ + return h->of_node == node; +} + +static int opal_event_xlate(struct irq_domain *h, struct device_node *np, + const u32 *intspec, unsigned int intsize, + irq_hw_number_t *out_hwirq, unsigned int *out_flags) +{ + *out_hwirq = intspec[0]; + *out_flags = IRQ_TYPE_LEVEL_HIGH; + + return 0; +} + +static const struct irq_domain_ops opal_event_domain_ops = { + .match = opal_event_match, + .map = opal_event_map, + .xlate = opal_event_xlate, +}; + +void opal_event_shutdown(void) +{ + unsigned int i; + + /* First free interrupts, which will also mask them */ + for (i = 0; i < opal_irq_count; i++) { + if (opal_irqs[i]) + free_irq(opal_irqs[i], NULL); + opal_irqs[i] = 0; + } +} + +int __init opal_event_init(void) +{ + struct device_node *dn, *opal_node; + const __be32 *irqs; + int i, irqlen, rc = 0; + + opal_node = of_find_node_by_path("/ibm,opal"); + if (!opal_node) { + pr_warn("opal: Node not found\n"); + return -ENODEV; + } + + /* If dn is NULL it means the domain won't be linked to a DT + * node so therefore irq_of_parse_and_map(...) wont work. But + * that shouldn't be problem because if we're running a + * version of skiboot that doesn't have the dn then the + * devices won't have the correct properties and will have to + * fall back to the legacy method (opal_event_request(...)) + * anyway. */ + dn = of_find_compatible_node(NULL, NULL, "ibm,opal-event"); + opal_event_irqchip.domain = irq_domain_add_linear(dn, MAX_NUM_EVENTS, + &opal_event_domain_ops, &opal_event_irqchip); + of_node_put(dn); + if (!opal_event_irqchip.domain) { + pr_warn("opal: Unable to create irq domain\n"); + rc = -ENOMEM; + goto out; + } + + /* Get interrupt property */ + irqs = of_get_property(opal_node, "opal-interrupts", &irqlen); + opal_irq_count = irqs ? (irqlen / 4) : 0; + pr_debug("Found %d interrupts reserved for OPAL\n", opal_irq_count); + + /* Install interrupt handlers */ + opal_irqs = kcalloc(opal_irq_count, sizeof(*opal_irqs), GFP_KERNEL); + for (i = 0; irqs && i < opal_irq_count; i++, irqs++) { + unsigned int irq, virq; + + /* Get hardware and virtual IRQ */ + irq = be32_to_cpup(irqs); + virq = irq_create_mapping(NULL, irq); + if (virq == NO_IRQ) { + pr_warn("Failed to map irq 0x%x\n", irq); + continue; + } + + /* Install interrupt handler */ + rc = request_irq(virq, opal_interrupt, 0, "opal", NULL); + if (rc) { + irq_dispose_mapping(virq); + pr_warn("Error %d requesting irq %d (0x%x)\n", + rc, virq, irq); + continue; + } + + /* Cache IRQ */ + opal_irqs[i] = virq; + } + +out: + of_node_put(opal_node); + return rc; +} +machine_arch_initcall(powernv, opal_event_init); + +/** + * opal_event_request(unsigned int opal_event_nr) - Request an event + * @opal_event_nr: the opal event number to request + * + * This routine can be used to find the linux virq number which can + * then be passed to request_irq to assign a handler for a particular + * opal event. This should only be used by legacy devices which don't + * have proper device tree bindings. Most devices should use + * irq_of_parse_and_map() instead. + */ +int opal_event_request(unsigned int opal_event_nr) +{ + if (WARN_ON_ONCE(!opal_event_irqchip.domain)) + return NO_IRQ; + + return irq_create_mapping(opal_event_irqchip.domain, opal_event_nr); +} +EXPORT_SYMBOL(opal_event_request); -- cgit v1.2.3