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Commit 48c302dc authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Jon Mason
Browse files

NTB: switchtec: Add link event notifier callback 



In order for the Switchtec NTB code to handle link change events we
create a notifier callback in the switchtec code which gets called
whenever an appropriate event interrupt occurs.

In order to preserve userspace's ability to follow these events,
we compare the event count with a stored copy from last time we
checked.

Signed-off-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarStephen Bates <sbates@raithlin.com>
Reviewed-by: default avatarKurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
parent c082b04c

drivers/pci/switch/switchtec.c

+51 −0
Original line number Diff line number Diff line
@@ -978,6 +978,49 @@ static const struct file_operations switchtec_fops = { 
	.compat_ioctl = switchtec_dev_ioctl,

};



static void link_event_work(struct work_struct *work)

{

	struct switchtec_dev *stdev;



	stdev = container_of(work, struct switchtec_dev, link_event_work);



	if (stdev->link_notifier)

		stdev->link_notifier(stdev);

}



static void check_link_state_events(struct switchtec_dev *stdev)

{

	int idx;

	u32 reg;

	int count;

	int occurred = 0;



	for (idx = 0; idx < stdev->pff_csr_count; idx++) {

		reg = ioread32(&stdev->mmio_pff_csr[idx].link_state_hdr);

		dev_dbg(&stdev->dev, "link_state: %d->%08x\n", idx, reg);

		count = (reg >> 5) & 0xFF;



		if (count != stdev->link_event_count[idx]) {

			occurred = 1;

			stdev->link_event_count[idx] = count;

		}

	}



	if (occurred)

		schedule_work(&stdev->link_event_work);

}



static void enable_link_state_events(struct switchtec_dev *stdev)

{

	int idx;



	for (idx = 0; idx < stdev->pff_csr_count; idx++) {

		iowrite32(SWITCHTEC_EVENT_CLEAR |

			  SWITCHTEC_EVENT_EN_IRQ,

			  &stdev->mmio_pff_csr[idx].link_state_hdr);

	}

}



static void stdev_release(struct device *dev)

{

	struct switchtec_dev *stdev = to_stdev(dev);
@@ -1030,6 +1073,7 @@ static struct switchtec_dev *stdev_create(struct pci_dev *pdev) 
	stdev->mrpc_busy = 0;

	INIT_WORK(&stdev->mrpc_work, mrpc_event_work);

	INIT_DELAYED_WORK(&stdev->mrpc_timeout, mrpc_timeout_work);

	INIT_WORK(&stdev->link_event_work, link_event_work);

	init_waitqueue_head(&stdev->event_wq);

	atomic_set(&stdev->event_cnt, 0);
@@ -1073,6 +1117,9 @@ static int mask_event(struct switchtec_dev *stdev, int eid, int idx) 
	if (!(hdr & SWITCHTEC_EVENT_OCCURRED && hdr & SWITCHTEC_EVENT_EN_IRQ))

		return 0;



	if (eid == SWITCHTEC_IOCTL_EVENT_LINK_STATE)

		return 0;



	dev_dbg(&stdev->dev, "%s: %d %d %x\n", __func__, eid, idx, hdr);

	hdr &= ~(SWITCHTEC_EVENT_EN_IRQ | SWITCHTEC_EVENT_OCCURRED);

	iowrite32(hdr, hdr_reg);
@@ -1092,6 +1139,7 @@ static int mask_all_events(struct switchtec_dev *stdev, int eid) 
		for (idx = 0; idx < stdev->pff_csr_count; idx++) {

			if (!stdev->pff_local[idx])

				continue;



			count += mask_event(stdev, eid, idx);

		}

	} else {
@@ -1116,6 +1164,8 @@ static irqreturn_t switchtec_event_isr(int irq, void *dev) 
		iowrite32(reg, &stdev->mmio_part_cfg->mrpc_comp_hdr);

	}



	check_link_state_events(stdev);



	for (eid = 0; eid < SWITCHTEC_IOCTL_MAX_EVENTS; eid++)

		event_count += mask_all_events(stdev, eid);
@@ -1242,6 +1292,7 @@ static int switchtec_pci_probe(struct pci_dev *pdev, 
	iowrite32(SWITCHTEC_EVENT_CLEAR |

		  SWITCHTEC_EVENT_EN_IRQ,

		  &stdev->mmio_part_cfg->mrpc_comp_hdr);

	enable_link_state_events(stdev);



	rc = cdev_device_add(&stdev->cdev, &stdev->dev);

	if (rc)

include/linux/switchtec.h

+4 −0
Original line number Diff line number Diff line
@@ -353,6 +353,10 @@ struct switchtec_dev { 


	wait_queue_head_t event_wq;

	atomic_t event_cnt;



	struct work_struct link_event_work;

	void (*link_notifier)(struct switchtec_dev *stdev);

	u8 link_event_count[SWITCHTEC_MAX_PFF_CSR];

};



static inline struct switchtec_dev *to_stdev(struct device *dev)