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Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/platforms/pseries/io_event_irq.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/io_event_irq.c b/arch/powerpc/platforms/pseries/io_event_irq.c new file mode 100644 index 000000000000..c829e6067d54 --- /dev/null +++ b/arch/powerpc/platforms/pseries/io_event_irq.c @@ -0,0 +1,231 @@ +/* + * Copyright 2010 2011 Mark Nelson and Tseng-Hui (Frank) Lin, 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/errno.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/of.h> +#include <linux/list.h> +#include <linux/notifier.h> + +#include <asm/machdep.h> +#include <asm/rtas.h> +#include <asm/irq.h> +#include <asm/io_event_irq.h> + +#include "pseries.h" + +/* + * IO event interrupt is a mechanism provided by RTAS to return + * information about hardware error and non-error events. Device + * drivers can register their event handlers to receive events. + * Device drivers are expected to use atomic_notifier_chain_register() + * and atomic_notifier_chain_unregister() to register and unregister + * their event handlers. Since multiple IO event types and scopes + * share an IO event interrupt, the event handlers are called one + * by one until the IO event is claimed by one of the handlers. + * The event handlers are expected to return NOTIFY_OK if the + * event is handled by the event handler or NOTIFY_DONE if the + * event does not belong to the handler. + * + * Usage: + * + * Notifier function: + * #include <asm/io_event_irq.h> + * int event_handler(struct notifier_block *nb, unsigned long val, void *data) { + * p = (struct pseries_io_event_sect_data *) data; + * if (! is_my_event(p->scope, p->event_type)) return NOTIFY_DONE; + * : + * : + * return NOTIFY_OK; + * } + * struct notifier_block event_nb = { + * .notifier_call = event_handler, + * } + * + * Registration: + * atomic_notifier_chain_register(&pseries_ioei_notifier_list, &event_nb); + * + * Unregistration: + * atomic_notifier_chain_unregister(&pseries_ioei_notifier_list, &event_nb); + */ + +ATOMIC_NOTIFIER_HEAD(pseries_ioei_notifier_list); +EXPORT_SYMBOL_GPL(pseries_ioei_notifier_list); + +static int ioei_check_exception_token; + +/* pSeries event log format */ + +/* Two bytes ASCII section IDs */ +#define PSERIES_ELOG_SECT_ID_PRIV_HDR (('P' << 8) | 'H') +#define PSERIES_ELOG_SECT_ID_USER_HDR (('U' << 8) | 'H') +#define PSERIES_ELOG_SECT_ID_PRIMARY_SRC (('P' << 8) | 'S') +#define PSERIES_ELOG_SECT_ID_EXTENDED_UH (('E' << 8) | 'H') +#define PSERIES_ELOG_SECT_ID_FAILING_MTMS (('M' << 8) | 'T') +#define PSERIES_ELOG_SECT_ID_SECONDARY_SRC (('S' << 8) | 'S') +#define PSERIES_ELOG_SECT_ID_DUMP_LOCATOR (('D' << 8) | 'H') +#define PSERIES_ELOG_SECT_ID_FW_ERROR (('S' << 8) | 'W') +#define PSERIES_ELOG_SECT_ID_IMPACT_PART_ID (('L' << 8) | 'P') +#define PSERIES_ELOG_SECT_ID_LOGIC_RESOURCE_ID (('L' << 8) | 'R') +#define PSERIES_ELOG_SECT_ID_HMC_ID (('H' << 8) | 'M') +#define PSERIES_ELOG_SECT_ID_EPOW (('E' << 8) | 'P') +#define PSERIES_ELOG_SECT_ID_IO_EVENT (('I' << 8) | 'E') +#define PSERIES_ELOG_SECT_ID_MANUFACT_INFO (('M' << 8) | 'I') +#define PSERIES_ELOG_SECT_ID_CALL_HOME (('C' << 8) | 'H') +#define PSERIES_ELOG_SECT_ID_USER_DEF (('U' << 8) | 'D') + +/* Vendor specific Platform Event Log Format, Version 6, section header */ +struct pseries_elog_section { + uint16_t id; /* 0x00 2-byte ASCII section ID */ + uint16_t length; /* 0x02 Section length in bytes */ + uint8_t version; /* 0x04 Section version */ + uint8_t subtype; /* 0x05 Section subtype */ + uint16_t creator_component; /* 0x06 Creator component ID */ + uint8_t data[]; /* 0x08 Start of section data */ +}; + +static char ioei_rtas_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned; + +/** + * Find data portion of a specific section in RTAS extended event log. + * @elog: RTAS error/event log. + * @sect_id: secsion ID. + * + * Return: + * pointer to the section data of the specified section + * NULL if not found + */ +static struct pseries_elog_section *find_xelog_section(struct rtas_error_log *elog, + uint16_t sect_id) +{ + struct rtas_ext_event_log_v6 *xelog = + (struct rtas_ext_event_log_v6 *) elog->buffer; + struct pseries_elog_section *sect; + unsigned char *p, *log_end; + + /* Check that we understand the format */ + if (elog->extended_log_length < sizeof(struct rtas_ext_event_log_v6) || + xelog->log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG || + xelog->company_id != RTAS_V6EXT_COMPANY_ID_IBM) + return NULL; + + log_end = elog->buffer + elog->extended_log_length; + p = xelog->vendor_log; + while (p < log_end) { + sect = (struct pseries_elog_section *)p; + if (sect->id == sect_id) + return sect; + p += sect->length; + } + return NULL; +} + +/** + * Find the data portion of an IO Event section from event log. + * @elog: RTAS error/event log. + * + * Return: + * pointer to a valid IO event section data. NULL if not found. + */ +static struct pseries_io_event * ioei_find_event(struct rtas_error_log *elog) +{ + struct pseries_elog_section *sect; + + /* We should only ever get called for io-event interrupts, but if + * we do get called for another type then something went wrong so + * make some noise about it. + * RTAS_TYPE_IO only exists in extended event log version 6 or later. + * No need to check event log version. + */ + if (unlikely(elog->type != RTAS_TYPE_IO)) { + printk_once(KERN_WARNING "io_event_irq: Unexpected event type %d", + elog->type); + return NULL; + } + + sect = find_xelog_section(elog, PSERIES_ELOG_SECT_ID_IO_EVENT); + if (unlikely(!sect)) { + printk_once(KERN_WARNING "io_event_irq: RTAS extended event " + "log does not contain an IO Event section. " + "Could be a bug in system firmware!\n"); + return NULL; + } + return (struct pseries_io_event *) §->data; +} + +/* + * PAPR: + * - check-exception returns the first found error or event and clear that + * error or event so it is reported once. + * - Each interrupt returns one event. If a plateform chooses to report + * multiple events through a single interrupt, it must ensure that the + * interrupt remains asserted until check-exception has been used to + * process all out-standing events for that interrupt. + * + * Implementation notes: + * - Events must be processed in the order they are returned. Hence, + * sequential in nature. + * - The owner of an event is determined by combinations of scope, + * event type, and sub-type. There is no easy way to pre-sort clients + * by scope or event type alone. For example, Torrent ISR route change + * event is reported with scope 0x00 (Not Applicatable) rather than + * 0x3B (Torrent-hub). It is better to let the clients to identify + * who owns the the event. + */ + +static irqreturn_t ioei_interrupt(int irq, void *dev_id) +{ + struct pseries_io_event *event; + int rtas_rc; + + for (;;) { + rtas_rc = rtas_call(ioei_check_exception_token, 6, 1, NULL, + RTAS_VECTOR_EXTERNAL_INTERRUPT, + virq_to_hw(irq), + RTAS_IO_EVENTS, 1 /* Time Critical */, + __pa(ioei_rtas_buf), + RTAS_DATA_BUF_SIZE); + if (rtas_rc != 0) + break; + + event = ioei_find_event((struct rtas_error_log *)ioei_rtas_buf); + if (!event) + continue; + + atomic_notifier_call_chain(&pseries_ioei_notifier_list, + 0, event); + } + return IRQ_HANDLED; +} + +static int __init ioei_init(void) +{ + struct device_node *np; + + ioei_check_exception_token = rtas_token("check-exception"); + if (ioei_check_exception_token == RTAS_UNKNOWN_SERVICE) { + pr_warning("IO Event IRQ not supported on this system !\n"); + return -ENODEV; + } + np = of_find_node_by_path("/event-sources/ibm,io-events"); + if (np) { + request_event_sources_irqs(np, ioei_interrupt, "IO_EVENT"); + of_node_put(np); + } else { + pr_err("io_event_irq: No ibm,io-events on system! " + "IO Event interrupt disabled.\n"); + return -ENODEV; + } + return 0; +} +machine_subsys_initcall(pseries, ioei_init); + |