diff options
author | 2016-04-11 10:41:07 +0300 | |
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committer | 2016-04-13 08:17:18 +0300 | |
commit | e09b41010ba33a20a87472ee821fa407a5b8da36 (patch) | |
tree | d10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/arch/powerpc/platforms/powernv/opal-irqchip.c | |
parent | f93b97fd65072de626c074dbe099a1fff05ce060 (diff) |
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page.
During the rebasing, the following patch collided:
Force tick interrupt and get rid of softirq magic(I70131fb85).
Collisions have been removed because its logic was found on the
source already.
Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/arch/powerpc/platforms/powernv/opal-irqchip.c')
-rw-r--r-- | kernel/arch/powerpc/platforms/powernv/opal-irqchip.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/platforms/powernv/opal-irqchip.c b/kernel/arch/powerpc/platforms/powernv/opal-irqchip.c new file mode 100644 index 000000000..e505223b4 --- /dev/null +++ b/kernel/arch/powerpc/platforms/powernv/opal-irqchip.c @@ -0,0 +1,266 @@ +/* + * 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 <linux/bitops.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqdomain.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/kthread.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/irq_work.h> + +#include <asm/machdep.h> +#include <asm/opal.h> + +#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 u64 last_outstanding_events; +static struct irq_work opal_event_irq_work = { + .func = opal_handle_irq_work, +}; + +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 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) +{ + __be64 events; + + set_bit(d->hwirq, &opal_event_irqchip.mask); + + opal_poll_events(&events); + last_outstanding_events = be64_to_cpu(events); + + /* + * We can't just handle the events now with opal_handle_events(). + * If we did we would deadlock when opal_event_unmask() is called from + * handle_level_irq() with the irq descriptor lock held, because + * calling opal_handle_events() would call generic_handle_irq() and + * then handle_level_irq() which would try to take the descriptor lock + * again. Instead queue the events for later. + */ + 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; +} + +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(last_outstanding_events); +} + +static int opal_event_match(struct irq_domain *h, struct device_node *node, + enum irq_domain_bus_token bus_token) +{ + return irq_domain_get_of_node(h) == 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); |