[PATCH 1/9] move blk_iopoll to limit and make it generally available

Christoph Hellwig
2015-11-13T13:51:26Z

The new name is irq_poll as iopoll is already taken. Better suggestions
welcome.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
Documentation/kernel-per-CPU-kthreads.txt | 2 +-
block/Makefile | 2 +-
block/blk-iopoll.c | 224 ------------------------------
drivers/scsi/Kconfig | 1 +
drivers/scsi/be2iscsi/Kconfig | 1 +
drivers/scsi/be2iscsi/be.h | 4 +-
drivers/scsi/be2iscsi/be_iscsi.c | 4 +-
drivers/scsi/be2iscsi/be_main.c | 24 ++--
drivers/scsi/ipr.c | 28 ++--
drivers/scsi/ipr.h | 4 +-
include/linux/blk-iopoll.h | 46 ------
include/linux/interrupt.h | 2 +-
include/linux/irq_poll.h | 46 ++++++
include/trace/events/irq.h | 2 +-
lib/Kconfig | 5 +
lib/Makefile | 1 +
lib/irq_poll.c | 221 +++++++++++++++++++++++++++++
tools/lib/traceevent/event-parse.c | 2 +-
tools/perf/util/trace-event-parse.c | 2 +-
19 files changed, 313 insertions(+), 308 deletions(-)
delete mode 100644 block/blk-iopoll.c
delete mode 100644 include/linux/blk-iopoll.h
create mode 100644 include/linux/irq_poll.h
create mode 100644 lib/irq_poll.c

diff --git a/Documentation/kernel-per-CPU-kthreads.txt b/Documentation/kernel-per-CPU-kthreads.txt
index f4cbfe0..edec3a3 100644
--- a/Documentation/kernel-per-CPU-kthreads.txt
+++ b/Documentation/kernel-per-CPU-kthreads.txt
@@ -90,7 +90,7 @@ BLOCK_SOFTIRQ: Do all of the following:
from being initiated from tasks that might run on the CPU to
be de-jittered. (It is OK to force this CPU offline and then
bring it back online before you start your application.)
-BLOCK_IOPOLL_SOFTIRQ: Do all of the following:
+IRQ_POLL_SOFTIRQ: Do all of the following:
1. Force block-device interrupts onto some other CPU.
2. Initiate any block I/O and block-I/O polling on other CPUs.
3. Once your application has started, prevent CPU-hotplug operations
diff --git a/block/Makefile b/block/Makefile
index 00ecc97..e850474 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 0736729..0000000
--- 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);
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index d2f480b..cea683e 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -1103,6 +1103,7 @@ config SCSI_IPR
tristate "IBM Power Linux RAID adapter support"
depends on PCI && SCSI && ATA
select FW_LOADER
+ select IRQ_POLL
---help---
This driver supports the IBM Power Linux family RAID adapters.
This includes IBM pSeries 5712, 5703, 5709, and 570A, as well
diff --git a/drivers/scsi/be2iscsi/Kconfig b/drivers/scsi/be2iscsi/Kconfig
index 4e7cad2..bad5f32 100644
--- a/drivers/scsi/be2iscsi/Kconfig
+++ b/drivers/scsi/be2iscsi/Kconfig
@@ -3,6 +3,7 @@ config BE2ISCSI
depends on PCI && SCSI && NET
select SCSI_ISCSI_ATTRS
select ISCSI_BOOT_SYSFS
+ select IRQ_POLL

help
This driver implements the iSCSI functionality for Emulex
diff --git a/drivers/scsi/be2iscsi/be.h b/drivers/scsi/be2iscsi/be.h
index 77f992e..a41c643 100644
--- a/drivers/scsi/be2iscsi/be.h
+++ b/drivers/scsi/be2iscsi/be.h
@@ -20,7 +20,7 @@

#include <linux/pci.h>
#include <linux/if_vlan.h>
-#include <linux/blk-iopoll.h>
+#include <linux/irq_poll.h>
#define FW_VER_LEN 32
#define MCC_Q_LEN 128
#define MCC_CQ_LEN 256
@@ -101,7 +101,7 @@ struct be_eq_obj {
struct beiscsi_hba *phba;
struct be_queue_info *cq;
struct work_struct work_cqs; /* Work Item */
- struct blk_iopoll iopoll;
+ struct irq_poll iopoll;
};

struct be_mcc_obj {
diff --git a/drivers/scsi/be2iscsi/be_iscsi.c b/drivers/scsi/be2iscsi/be_iscsi.c
index b7087ba..022e87b 100644
--- a/drivers/scsi/be2iscsi/be_iscsi.c
+++ b/drivers/scsi/be2iscsi/be_iscsi.c
@@ -1292,9 +1292,9 @@ static void beiscsi_flush_cq(struct beiscsi_hba *phba)

for (i = 0; i < phba->num_cpus; i++) {
pbe_eq = &phwi_context->be_eq[i];
- blk_iopoll_disable(&pbe_eq->iopoll);
+ irq_poll_disable(&pbe_eq->iopoll);
beiscsi_process_cq(pbe_eq);
- blk_iopoll_enable(&pbe_eq->iopoll);
+ irq_poll_enable(&pbe_eq->iopoll);
}
}

diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
index 2e6abe7..7f0fdbe 100644
--- a/drivers/scsi/be2iscsi/be_main.c
+++ b/drivers/scsi/be2iscsi/be_main.c
@@ -910,8 +910,8 @@ static irqreturn_t be_isr_msix(int irq, void *dev_id)
num_eq_processed = 0;
while (eqe->dw[offsetof(struct amap_eq_entry, valid) / 32]
& EQE_VALID_MASK) {
- if (!blk_iopoll_sched_prep(&pbe_eq->iopoll))
- blk_iopoll_sched(&pbe_eq->iopoll);
+ if (!irq_poll_sched_prep(&pbe_eq->iopoll))
+ irq_poll_sched(&pbe_eq->iopoll);

AMAP_SET_BITS(struct amap_eq_entry, valid, eqe, 0);
queue_tail_inc(eq);
@@ -972,8 +972,8 @@ static irqreturn_t be_isr(int irq, void *dev_id)
spin_unlock_irqrestore(&phba->isr_lock, flags);
num_mcceq_processed++;
} else {
- if (!blk_iopoll_sched_prep(&pbe_eq->iopoll))
- blk_iopoll_sched(&pbe_eq->iopoll);
+ if (!irq_poll_sched_prep(&pbe_eq->iopoll))
+ irq_poll_sched(&pbe_eq->iopoll);
num_ioeq_processed++;
}
AMAP_SET_BITS(struct amap_eq_entry, valid, eqe, 0);
@@ -2293,7 +2293,7 @@ void beiscsi_process_all_cqs(struct work_struct *work)
hwi_ring_eq_db(phba, pbe_eq->q.id, 0, 0, 1, 1);
}

-static int be_iopoll(struct blk_iopoll *iop, int budget)
+static int be_iopoll(struct irq_poll *iop, int budget)
{
unsigned int ret;
struct beiscsi_hba *phba;
@@ -2304,7 +2304,7 @@ static int be_iopoll(struct blk_iopoll *iop, int budget)
pbe_eq->cq_count += ret;
if (ret < budget) {
phba = pbe_eq->phba;
- blk_iopoll_complete(iop);
+ irq_poll_complete(iop);
beiscsi_log(phba, KERN_INFO,
BEISCSI_LOG_CONFIG | BEISCSI_LOG_IO,
"BM_%d : rearm pbe_eq->q.id =%d\n",
@@ -5261,7 +5261,7 @@ static void beiscsi_quiesce(struct beiscsi_hba *phba,

for (i = 0; i < phba->num_cpus; i++) {
pbe_eq = &phwi_context->be_eq[i];
- blk_iopoll_disable(&pbe_eq->iopoll);
+ irq_poll_disable(&pbe_eq->iopoll);
}

if (unload_state == BEISCSI_CLEAN_UNLOAD) {
@@ -5547,9 +5547,9 @@ static void beiscsi_eeh_resume(struct pci_dev *pdev)

for (i = 0; i < phba->num_cpus; i++) {
pbe_eq = &phwi_context->be_eq[i];
- blk_iopoll_init(&pbe_eq->iopoll, be_iopoll_budget,
+ irq_poll_init(&pbe_eq->iopoll, be_iopoll_budget,
be_iopoll);
- blk_iopoll_enable(&pbe_eq->iopoll);
+ irq_poll_enable(&pbe_eq->iopoll);
}

i = (phba->msix_enabled) ? i : 0;
@@ -5720,9 +5720,9 @@ static int beiscsi_dev_probe(struct pci_dev *pcidev,

for (i = 0; i < phba->num_cpus; i++) {
pbe_eq = &phwi_context->be_eq[i];
- blk_iopoll_init(&pbe_eq->iopoll, be_iopoll_budget,
+ irq_poll_init(&pbe_eq->iopoll, be_iopoll_budget,
be_iopoll);
- blk_iopoll_enable(&pbe_eq->iopoll);
+ irq_poll_enable(&pbe_eq->iopoll);
}

i = (phba->msix_enabled) ? i : 0;
@@ -5763,7 +5763,7 @@ free_blkenbld:
destroy_workqueue(phba->wq);
for (i = 0; i < phba->num_cpus; i++) {
pbe_eq = &phwi_context->be_eq[i];
- blk_iopoll_disable(&pbe_eq->iopoll);
+ irq_poll_disable(&pbe_eq->iopoll);
}
free_twq:
beiscsi_clean_port(phba);
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index b62836d..6b98e75 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -3638,7 +3638,7 @@ static struct device_attribute ipr_ioa_reset_attr = {
.store = ipr_store_reset_adapter
};

-static int ipr_iopoll(struct blk_iopoll *iop, int budget);
+static int ipr_iopoll(struct irq_poll *iop, int budget);
/**
* ipr_show_iopoll_weight - Show ipr polling mode
* @dev: class device struct
@@ -3681,34 +3681,34 @@ static ssize_t ipr_store_iopoll_weight(struct device *dev,
int i;

if (!ioa_cfg->sis64) {
- dev_info(&ioa_cfg->pdev->dev, "blk-iopoll not supported on this adapter\n");
+ dev_info(&ioa_cfg->pdev->dev, "irq_poll not supported on this adapter\n");
return -EINVAL;
}
if (kstrtoul(buf, 10, &user_iopoll_weight))
return -EINVAL;

if (user_iopoll_weight > 256) {
- dev_info(&ioa_cfg->pdev->dev, "Invalid blk-iopoll weight. It must be less than 256\n");
+ dev_info(&ioa_cfg->pdev->dev, "Invalid irq_poll weight. It must be less than 256\n");
return -EINVAL;
}

if (user_iopoll_weight == ioa_cfg->iopoll_weight) {
- dev_info(&ioa_cfg->pdev->dev, "Current blk-iopoll weight has the same weight\n");
+ dev_info(&ioa_cfg->pdev->dev, "Current irq_poll weight has the same weight\n");
return strlen(buf);
}

if (ioa_cfg->iopoll_weight && ioa_cfg->sis64 && ioa_cfg->nvectors > 1) {
for (i = 1; i < ioa_cfg->hrrq_num; i++)
- blk_iopoll_disable(&ioa_cfg->hrrq[i].iopoll);
+ irq_poll_disable(&ioa_cfg->hrrq[i].iopoll);
}

spin_lock_irqsave(shost->host_lock, lock_flags);
ioa_cfg->iopoll_weight = user_iopoll_weight;
if (ioa_cfg->iopoll_weight && ioa_cfg->sis64 && ioa_cfg->nvectors > 1) {
for (i = 1; i < ioa_cfg->hrrq_num; i++) {
- blk_iopoll_init(&ioa_cfg->hrrq[i].iopoll,
+ irq_poll_init(&ioa_cfg->hrrq[i].iopoll,
ioa_cfg->iopoll_weight, ipr_iopoll);
- blk_iopoll_enable(&ioa_cfg->hrrq[i].iopoll);
+ irq_poll_enable(&ioa_cfg->hrrq[i].iopoll);
}
}
spin_unlock_irqrestore(shost->host_lock, lock_flags);
@@ -5569,7 +5569,7 @@ static int ipr_process_hrrq(struct ipr_hrr_queue *hrr_queue, int budget,
return num_hrrq;
}

-static int ipr_iopoll(struct blk_iopoll *iop, int budget)
+static int ipr_iopoll(struct irq_poll *iop, int budget)
{
struct ipr_ioa_cfg *ioa_cfg;
struct ipr_hrr_queue *hrrq;
@@ -5585,7 +5585,7 @@ static int ipr_iopoll(struct blk_iopoll *iop, int budget)
completed_ops = ipr_process_hrrq(hrrq, budget, &doneq);

if (completed_ops < budget)
- blk_iopoll_complete(iop);
+ irq_poll_complete(iop);
spin_unlock_irqrestore(hrrq->lock, hrrq_flags);

list_for_each_entry_safe(ipr_cmd, temp, &doneq, queue) {
@@ -5693,8 +5693,8 @@ static irqreturn_t ipr_isr_mhrrq(int irq, void *devp)
if (ioa_cfg->iopoll_weight && ioa_cfg->sis64 && ioa_cfg->nvectors > 1) {
if ((be32_to_cpu(*hrrq->hrrq_curr) & IPR_HRRQ_TOGGLE_BIT) ==
hrrq->toggle_bit) {
- if (!blk_iopoll_sched_prep(&hrrq->iopoll))
- blk_iopoll_sched(&hrrq->iopoll);
+ if (!irq_poll_sched_prep(&hrrq->iopoll))
+ irq_poll_sched(&hrrq->iopoll);
spin_unlock_irqrestore(hrrq->lock, hrrq_flags);
return IRQ_HANDLED;
}
@@ -10285,9 +10285,9 @@ static int ipr_probe(struct pci_dev *pdev, const struct pci_device_id *dev_id)

if (ioa_cfg->iopoll_weight && ioa_cfg->sis64 && ioa_cfg->nvectors > 1) {
for (i = 1; i < ioa_cfg->hrrq_num; i++) {
- blk_iopoll_init(&ioa_cfg->hrrq[i].iopoll,
+ irq_poll_init(&ioa_cfg->hrrq[i].iopoll,
ioa_cfg->iopoll_weight, ipr_iopoll);
- blk_iopoll_enable(&ioa_cfg->hrrq[i].iopoll);
+ irq_poll_enable(&ioa_cfg->hrrq[i].iopoll);
}
}

@@ -10316,7 +10316,7 @@ static void ipr_shutdown(struct pci_dev *pdev)
if (ioa_cfg->iopoll_weight && ioa_cfg->sis64 && ioa_cfg->nvectors > 1) {
ioa_cfg->iopoll_weight = 0;
for (i = 1; i < ioa_cfg->hrrq_num; i++)
- blk_iopoll_disable(&ioa_cfg->hrrq[i].iopoll);
+ irq_poll_disable(&ioa_cfg->hrrq[i].iopoll);
}

while (ioa_cfg->in_reset_reload) {
diff --git a/drivers/scsi/ipr.h b/drivers/scsi/ipr.h
index e4fb17a..022fc3c 100644
--- a/drivers/scsi/ipr.h
+++ b/drivers/scsi/ipr.h
@@ -32,7 +32,7 @@
#include <linux/libata.h>
#include <linux/list.h>
#include <linux/kref.h>
-#include <linux/blk-iopoll.h>
+#include <linux/irq_poll.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>

@@ -510,7 +510,7 @@ struct ipr_hrr_queue {
u8 allow_cmds:1;
u8 removing_ioa:1;

- struct blk_iopoll iopoll;
+ struct irq_poll iopoll;
};

/* Command packet structure */
diff --git a/include/linux/blk-iopoll.h b/include/linux/blk-iopoll.h
deleted file mode 100644
index 77ae77c..0000000
--- a/include/linux/blk-iopoll.h
+++ /dev/null
@@ -1,46 +0,0 @@
-#ifndef BLK_IOPOLL_H
-#define BLK_IOPOLL_H
-
-struct blk_iopoll;
-typedef int (blk_iopoll_fn)(struct blk_iopoll *, int);
-
-struct blk_iopoll {
- struct list_head list;
- unsigned long state;
- unsigned long data;
- int weight;
- int max;
- blk_iopoll_fn *poll;
-};
-
-enum {
- IOPOLL_F_SCHED = 0,
- IOPOLL_F_DISABLE = 1,
-};
-
-/*
- * Returns 0 if we successfully set the IOPOLL_F_SCHED bit, indicating
- * that we were the first to acquire this iop for scheduling. If this iop
- * is currently disabled, return "failure".
- */
-static inline int blk_iopoll_sched_prep(struct blk_iopoll *iop)
-{
- if (!test_bit(IOPOLL_F_DISABLE, &iop->state))
- return test_and_set_bit(IOPOLL_F_SCHED, &iop->state);
-
- return 1;
-}
-
-static inline int blk_iopoll_disable_pending(struct blk_iopoll *iop)
-{
- return test_bit(IOPOLL_F_DISABLE, &iop->state);
-}
-
-extern void blk_iopoll_sched(struct blk_iopoll *);
-extern void blk_iopoll_init(struct blk_iopoll *, int, blk_iopoll_fn *);
-extern void blk_iopoll_complete(struct blk_iopoll *);
-extern void __blk_iopoll_complete(struct blk_iopoll *);
-extern void blk_iopoll_enable(struct blk_iopoll *);
-extern void blk_iopoll_disable(struct blk_iopoll *);
-
-#endif
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index ad16809..7ff98c2 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -412,7 +412,7 @@ enum
NET_TX_SOFTIRQ,
NET_RX_SOFTIRQ,
BLOCK_SOFTIRQ,
- BLOCK_IOPOLL_SOFTIRQ,
+ IRQ_POLL_SOFTIRQ,
TASKLET_SOFTIRQ,
SCHED_SOFTIRQ,
HRTIMER_SOFTIRQ, /* Unused, but kept as tools rely on the
diff --git a/include/linux/irq_poll.h b/include/linux/irq_poll.h
new file mode 100644
index 0000000..0cf7c26
--- /dev/null
+++ b/include/linux/irq_poll.h
@@ -0,0 +1,46 @@
+#ifndef IRQ_POLL_H
+#define IRQ_POLL_H
+
+struct irq_poll;
+typedef int (irq_poll_fn)(struct irq_poll *, int);
+
+struct irq_poll {
+ struct list_head list;
+ unsigned long state;
+ unsigned long data;
+ int weight;
+ int max;
+ irq_poll_fn *poll;
+};
+
+enum {
+ IRQ_POLL_F_SCHED = 0,
+ IRQ_POLL_F_DISABLE = 1,
+};
+
+/*
+ * Returns 0 if we successfully set the IRQ_POLL_F_SCHED bit, indicating
+ * that we were the first to acquire this iop for scheduling. If this iop
+ * is currently disabled, return "failure".
+ */
+static inline int irq_poll_sched_prep(struct irq_poll *iop)
+{
+ if (!test_bit(IRQ_POLL_F_DISABLE, &iop->state))
+ return test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state);
+
+ return 1;
+}
+
+static inline int irq_poll_disable_pending(struct irq_poll *iop)
+{
+ return test_bit(IRQ_POLL_F_DISABLE, &iop->state);
+}
+
+extern void irq_poll_sched(struct irq_poll *);
+extern void irq_poll_init(struct irq_poll *, int, irq_poll_fn *);
+extern void irq_poll_complete(struct irq_poll *);
+extern void __irq_poll_complete(struct irq_poll *);
+extern void irq_poll_enable(struct irq_poll *);
+extern void irq_poll_disable(struct irq_poll *);
+
+#endif
diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h
index ff8f6c0..f95f25e 100644
--- a/include/trace/events/irq.h
+++ b/include/trace/events/irq.h
@@ -15,7 +15,7 @@ struct softirq_action;
softirq_name(NET_TX) \
softirq_name(NET_RX) \
softirq_name(BLOCK) \
- softirq_name(BLOCK_IOPOLL) \
+ softirq_name(IRQ_POLL) \
softirq_name(TASKLET) \
softirq_name(SCHED) \
softirq_name(HRTIMER) \
diff --git a/lib/Kconfig b/lib/Kconfig
index f0df318..e00e196 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -475,6 +475,11 @@ config DDR
information. This data is useful for drivers handling
DDR SDRAM controllers.

+config IRQ_POLL
+ bool "IRQ polling library"
+ help
+ Helper library to poll interrupt mitigation using polling.
+
config MPILIB
tristate
select CLZ_TAB
diff --git a/lib/Makefile b/lib/Makefile
index 7f1de26..1478ae2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -164,6 +164,7 @@ obj-$(CONFIG_GENERIC_NET_UTILS) += net_utils.o

obj-$(CONFIG_SG_SPLIT) += sg_split.o
obj-$(CONFIG_STMP_DEVICE) += stmp_device.o
+obj-$(CONFIG_IRQ_POLL) += irq_poll.o

libfdt_files = fdt.o fdt_ro.o fdt_wip.o fdt_rw.o fdt_sw.o fdt_strerror.o \
fdt_empty_tree.o
diff --git a/lib/irq_poll.c b/lib/irq_poll.c
new file mode 100644
index 0000000..e6fd1dc
--- /dev/null
+++ b/lib/irq_poll.c
@@ -0,0 +1,221 @@
+/*
+ * 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/interrupt.h>
+#include <linux/cpu.h>
+#include <linux/irq_poll.h>
+#include <linux/delay.h>
+
+static unsigned int irq_poll_budget __read_mostly = 256;
+
+static DEFINE_PER_CPU(struct list_head, blk_cpu_iopoll);
+
+/**
+ * irq_poll_sched - Schedule a run of the iopoll handler
+ * @iop: The parent iopoll structure
+ *
+ * Description:
+ * Add this irq_poll 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 irq_poll_sched_prep() before calling this.
+ **/
+void irq_poll_sched(struct irq_poll *iop)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ list_add_tail(&iop->list, this_cpu_ptr(&blk_cpu_iopoll));
+ __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(irq_poll_sched);
+
+/**
+ * __irq_poll_complete - Mark this @iop as un-polled again
+ * @iop: The parent iopoll structure
+ *
+ * Description:
+ * See irq_poll_complete(). This function must be called with interrupts
+ * disabled.
+ **/
+void __irq_poll_complete(struct irq_poll *iop)
+{
+ list_del(&iop->list);
+ smp_mb__before_atomic();
+ clear_bit_unlock(IRQ_POLL_F_SCHED, &iop->state);
+}
+EXPORT_SYMBOL(__irq_poll_complete);
+
+/**
+ * irq_poll_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 irq_poll_sched_prep()
+ * is called.
+ **/
+void irq_poll_complete(struct irq_poll *iop)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __irq_poll_complete(iop);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(irq_poll_complete);
+
+static void irq_poll_softirq(struct softirq_action *h)
+{
+ struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll);
+ int rearm = 0, budget = irq_poll_budget;
+ unsigned long start_time = jiffies;
+
+ local_irq_disable();
+
+ while (!list_empty(list)) {
+ struct irq_poll *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 irq_poll, list);
+
+ weight = iop->weight;
+ work = 0;
+ if (test_bit(IRQ_POLL_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 (irq_poll_disable_pending(iop))
+ __irq_poll_complete(iop);
+ else
+ list_move_tail(&iop->list, list);
+ }
+ }
+
+ if (rearm)
+ __raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
+
+ local_irq_enable();
+}
+
+/**
+ * irq_poll_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 irq_poll_disable(struct irq_poll *iop)
+{
+ set_bit(IRQ_POLL_F_DISABLE, &iop->state);
+ while (test_and_set_bit(IRQ_POLL_F_SCHED, &iop->state))
+ msleep(1);
+ clear_bit(IRQ_POLL_F_DISABLE, &iop->state);
+}
+EXPORT_SYMBOL(irq_poll_disable);
+
+/**
+ * irq_poll_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 irq_poll_enable(struct irq_poll *iop)
+{
+ BUG_ON(!test_bit(IRQ_POLL_F_SCHED, &iop->state));
+ smp_mb__before_atomic();
+ clear_bit_unlock(IRQ_POLL_F_SCHED, &iop->state);
+}
+EXPORT_SYMBOL(irq_poll_enable);
+
+/**
+ * irq_poll_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 irq_poll structure. Before being actively used, the
+ * driver must call irq_poll_enable().
+ **/
+void irq_poll_init(struct irq_poll *iop, int weight, irq_poll_fn *poll_fn)
+{
+ memset(iop, 0, sizeof(*iop));
+ INIT_LIST_HEAD(&iop->list);
+ iop->weight = weight;
+ iop->poll = poll_fn;
+ set_bit(IRQ_POLL_F_SCHED, &iop->state);
+}
+EXPORT_SYMBOL(irq_poll_init);
+
+static int irq_poll_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(IRQ_POLL_SOFTIRQ);
+ local_irq_enable();
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block irq_poll_cpu_notifier = {
+ .notifier_call = irq_poll_cpu_notify,
+};
+
+static __init int irq_poll_setup(void)
+{
+ int i;
+
+ for_each_possible_cpu(i)
+ INIT_LIST_HEAD(&per_cpu(blk_cpu_iopoll, i));
+
+ open_softirq(IRQ_POLL_SOFTIRQ, irq_poll_softirq);
+ register_hotcpu_notifier(&irq_poll_cpu_notifier);
+ return 0;
+}
+subsys_initcall(irq_poll_setup);
diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 2a912df..af5a316 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -3746,7 +3746,7 @@ static const struct flag flags[] = {
{ "NET_TX_SOFTIRQ", 2 },
{ "NET_RX_SOFTIRQ", 3 },
{ "BLOCK_SOFTIRQ", 4 },
- { "BLOCK_IOPOLL_SOFTIRQ", 5 },
+ { "IRQ_POLL_SOFTIRQ", 5 },
{ "TASKLET_SOFTIRQ", 6 },
{ "SCHED_SOFTIRQ", 7 },
{ "HRTIMER_SOFTIRQ", 8 },
diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 8ff7d62..33b52ea 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -209,7 +209,7 @@ static const struct flag flags[] = {
{ "NET_TX_SOFTIRQ", 2 },
{ "NET_RX_SOFTIRQ", 3 },
{ "BLOCK_SOFTIRQ", 4 },
- { "BLOCK_IOPOLL_SOFTIRQ", 5 },
+ { "IRQ_POLL_SOFTIRQ", 5 },
{ "TASKLET_SOFTIRQ", 6 },
{ "SCHED_SOFTIRQ", 7 },
{ "HRTIMER_SOFTIRQ", 8 },
--
1.9.1