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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: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
This commit is contained in:
Logan Gunthorpe 2017-08-03 12:19:43 -06:00 committed by Jon Mason
parent c082b04c9d
commit 48c302dc8f
2 changed files with 55 additions and 0 deletions
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51
drivers/pci/switch/switchtec.c
View File

@ -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)

4
include/linux/switchtec.h
View File

@ -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)