irq_poll: make blk-iopoll available outside the block layer

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

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>

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

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/

drivers/scsi/Kconfig

@@ -1102,6 +1102,7 @@ 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

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

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 {

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);
 	}
 }
 

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);
@@ -2295,7 +2295,7 @@ 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;
@@ -2306,7 +2306,7 @@ 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",
@@ -5293,7 +5293,7 @@ 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) {
@@ -5579,9 +5579,9 @@ 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;
@@ -5752,9 +5752,9 @@ 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;
@@ -5795,7 +5795,7 @@ static int beiscsi_dev_probe(struct pci_dev *pcidev,
 	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);

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;
 		}
@@ -10405,9 +10405,9 @@ 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);
 		}
 	}
 
@@ -10436,7 +10436,7 @@ 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) {

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>
 
@@ -517,7 +517,7 @@ struct ipr_hrr_queue {
 	u8 allow_cmds:1;
 	u8 removing_ioa:1;
 
-	struct blk_iopoll iopoll;
+	struct irq_poll iopoll;
 };
 
 /* Command packet structure */

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

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

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)		\

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

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