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authorLogan Gunthorpe <logang@deltatee.com>2017-08-03 21:19:43 +0300
committerJon Mason <jdmason@kudzu.us>2017-11-19 04:37:11 +0300
commit48c302dc8f3acc1b0ef56a28569bc6a35b9b0e60 (patch)
tree5fd88d18529d648ca29527592fa1e51004f17cc0 /drivers/pci
parentc082b04c9d40f69dacd93a151db114299f5de6eb (diff)
downloadlinux-48c302dc8f3acc1b0ef56a28569bc6a35b9b0e60.tar.xz
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>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/switch/switchtec.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
index 39c9218d733f..807569e62bee 100644
--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -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)