diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/Makefile | 2 | ||||
| -rw-r--r-- | block/blk-iopoll.c | 224 |
2 files changed, 1 insertions, 225 deletions
diff --git a/block/Makefile b/block/Makefile index 00ecc97629db..e8504748c7cb 100644 --- a/block/Makefile +++ b/block/Makefile @@ -5,7 +5,7 @@ obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-tag.o blk-sysfs.o \ blk-flush.o blk-settings.o blk-ioc.o blk-map.o \ blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \ - blk-iopoll.o blk-lib.o blk-mq.o blk-mq-tag.o \ + blk-lib.o blk-mq.o blk-mq-tag.o \ blk-mq-sysfs.o blk-mq-cpu.o blk-mq-cpumap.o ioctl.o \ genhd.o scsi_ioctl.o partition-generic.o ioprio.o \ partitions/ diff --git a/block/blk-iopoll.c b/block/blk-iopoll.c deleted file mode 100644 index 0736729d6494..000000000000 --- a/block/blk-iopoll.c +++ /dev/null @@ -1,224 +0,0 @@ -/* - * Functions related to interrupt-poll handling in the block layer. This - * is similar to NAPI for network devices. - */ -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/init.h> -#include <linux/bio.h> -#include <linux/blkdev.h> -#include <linux/interrupt.h> -#include <linux/cpu.h> -#include <linux/blk-iopoll.h> -#include <linux/delay.h> - -#include "blk.h" - -static unsigned int blk_iopoll_budget __read_mostly = 256; - -static DEFINE_PER_CPU(struct list_head, blk_cpu_iopoll); - -/** - * blk_iopoll_sched - Schedule a run of the iopoll handler - * @iop: The parent iopoll structure - * - * Description: - * Add this blk_iopoll structure to the pending poll list and trigger the - * raise of the blk iopoll softirq. The driver must already have gotten a - * successful return from blk_iopoll_sched_prep() before calling this. - **/ -void blk_iopoll_sched(struct blk_iopoll *iop) -{ - unsigned long flags; - - local_irq_save(flags); - list_add_tail(&iop->list, this_cpu_ptr(&blk_cpu_iopoll)); - __raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ); - local_irq_restore(flags); -} -EXPORT_SYMBOL(blk_iopoll_sched); - -/** - * __blk_iopoll_complete - Mark this @iop as un-polled again - * @iop: The parent iopoll structure - * - * Description: - * See blk_iopoll_complete(). This function must be called with interrupts - * disabled. - **/ -void __blk_iopoll_complete(struct blk_iopoll *iop) -{ - list_del(&iop->list); - smp_mb__before_atomic(); - clear_bit_unlock(IOPOLL_F_SCHED, &iop->state); -} -EXPORT_SYMBOL(__blk_iopoll_complete); - -/** - * blk_iopoll_complete - Mark this @iop as un-polled again - * @iop: The parent iopoll structure - * - * Description: - * If a driver consumes less than the assigned budget in its run of the - * iopoll handler, it'll end the polled mode by calling this function. The - * iopoll handler will not be invoked again before blk_iopoll_sched_prep() - * is called. - **/ -void blk_iopoll_complete(struct blk_iopoll *iop) -{ - unsigned long flags; - - local_irq_save(flags); - __blk_iopoll_complete(iop); - local_irq_restore(flags); -} -EXPORT_SYMBOL(blk_iopoll_complete); - -static void blk_iopoll_softirq(struct softirq_action *h) -{ - struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll); - int rearm = 0, budget = blk_iopoll_budget; - unsigned long start_time = jiffies; - - local_irq_disable(); - - while (!list_empty(list)) { - struct blk_iopoll *iop; - int work, weight; - - /* - * If softirq window is exhausted then punt. - */ - if (budget <= 0 || time_after(jiffies, start_time)) { - rearm = 1; - break; - } - - local_irq_enable(); - - /* Even though interrupts have been re-enabled, this - * access is safe because interrupts can only add new - * entries to the tail of this list, and only ->poll() - * calls can remove this head entry from the list. - */ - iop = list_entry(list->next, struct blk_iopoll, list); - - weight = iop->weight; - work = 0; - if (test_bit(IOPOLL_F_SCHED, &iop->state)) - work = iop->poll(iop, weight); - - budget -= work; - - local_irq_disable(); - - /* - * Drivers must not modify the iopoll state, if they - * consume their assigned weight (or more, some drivers can't - * easily just stop processing, they have to complete an - * entire mask of commands).In such cases this code - * still "owns" the iopoll instance and therefore can - * move the instance around on the list at-will. - */ - if (work >= weight) { - if (blk_iopoll_disable_pending(iop)) - __blk_iopoll_complete(iop); - else - list_move_tail(&iop->list, list); - } - } - - if (rearm) - __raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ); - - local_irq_enable(); -} - -/** - * blk_iopoll_disable - Disable iopoll on this @iop - * @iop: The parent iopoll structure - * - * Description: - * Disable io polling and wait for any pending callbacks to have completed. - **/ -void blk_iopoll_disable(struct blk_iopoll *iop) -{ - set_bit(IOPOLL_F_DISABLE, &iop->state); - while (test_and_set_bit(IOPOLL_F_SCHED, &iop->state)) - msleep(1); - clear_bit(IOPOLL_F_DISABLE, &iop->state); -} -EXPORT_SYMBOL(blk_iopoll_disable); - -/** - * blk_iopoll_enable - Enable iopoll on this @iop - * @iop: The parent iopoll structure - * - * Description: - * Enable iopoll on this @iop. Note that the handler run will not be - * scheduled, it will only mark it as active. - **/ -void blk_iopoll_enable(struct blk_iopoll *iop) -{ - BUG_ON(!test_bit(IOPOLL_F_SCHED, &iop->state)); - smp_mb__before_atomic(); - clear_bit_unlock(IOPOLL_F_SCHED, &iop->state); -} -EXPORT_SYMBOL(blk_iopoll_enable); - -/** - * blk_iopoll_init - Initialize this @iop - * @iop: The parent iopoll structure - * @weight: The default weight (or command completion budget) - * @poll_fn: The handler to invoke - * - * Description: - * Initialize this blk_iopoll structure. Before being actively used, the - * driver must call blk_iopoll_enable(). - **/ -void blk_iopoll_init(struct blk_iopoll *iop, int weight, blk_iopoll_fn *poll_fn) -{ - memset(iop, 0, sizeof(*iop)); - INIT_LIST_HEAD(&iop->list); - iop->weight = weight; - iop->poll = poll_fn; - set_bit(IOPOLL_F_SCHED, &iop->state); -} -EXPORT_SYMBOL(blk_iopoll_init); - -static int blk_iopoll_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - /* - * If a CPU goes away, splice its entries to the current CPU - * and trigger a run of the softirq - */ - if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { - int cpu = (unsigned long) hcpu; - - local_irq_disable(); - list_splice_init(&per_cpu(blk_cpu_iopoll, cpu), - this_cpu_ptr(&blk_cpu_iopoll)); - __raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ); - local_irq_enable(); - } - - return NOTIFY_OK; -} - -static struct notifier_block blk_iopoll_cpu_notifier = { - .notifier_call = blk_iopoll_cpu_notify, -}; - -static __init int blk_iopoll_setup(void) -{ - int i; - - for_each_possible_cpu(i) - INIT_LIST_HEAD(&per_cpu(blk_cpu_iopoll, i)); - - open_softirq(BLOCK_IOPOLL_SOFTIRQ, blk_iopoll_softirq); - register_hotcpu_notifier(&blk_iopoll_cpu_notifier); - return 0; -} -subsys_initcall(blk_iopoll_setup); |