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authorOliver O'Halloran <oohall@gmail.com>2019-09-03 20:15:59 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2019-09-05 14:22:39 +1000
commit7fd1fe4e4811f52b854647b8ff324745135224a5 (patch)
tree5e6cebc1c8d834bdacdfc650331189f89e22ae91 /drivers/pci/hotplug
parentpowernv/eeh: Use generic code to handle hot resets (diff)
downloadwireguard-linux-7fd1fe4e4811f52b854647b8ff324745135224a5.tar.xz
wireguard-linux-7fd1fe4e4811f52b854647b8ff324745135224a5.zip
pci-hotplug/pnv_php: Add a reset_slot() callback
When performing EEH recovery of devices in a hotplug slot we need to use the slot driver's ->reset_slot() callback to prevent spurious hotplug events due to spurious DLActive and PresDet change interrupts. Add a reset_slot() callback to pnv_php so we can handle recovery of devices in pnv_php managed slots. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190903101605.2890-9-oohall@gmail.com
Diffstat (limited to 'drivers/pci/hotplug')
-rw-r--r--drivers/pci/hotplug/pnv_php.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index 6758fd7c382e..b0e243dabf77 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -511,6 +511,37 @@ scan:
return 0;
}
+static int pnv_php_reset_slot(struct hotplug_slot *slot, int probe)
+{
+ struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
+ struct pci_dev *bridge = php_slot->pdev;
+ uint16_t sts;
+
+ /*
+ * The CAPI folks want pnv_php to drive OpenCAPI slots
+ * which don't have a bridge. Only claim to support
+ * reset_slot() if we have a bridge device (for now...)
+ */
+ if (probe)
+ return !bridge;
+
+ /* mask our interrupt while resetting the bridge */
+ if (php_slot->irq > 0)
+ disable_irq(php_slot->irq);
+
+ pci_bridge_secondary_bus_reset(bridge);
+
+ /* clear any state changes that happened due to the reset */
+ pcie_capability_read_word(php_slot->pdev, PCI_EXP_SLTSTA, &sts);
+ sts &= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
+ pcie_capability_write_word(php_slot->pdev, PCI_EXP_SLTSTA, sts);
+
+ if (php_slot->irq > 0)
+ enable_irq(php_slot->irq);
+
+ return 0;
+}
+
static int pnv_php_enable_slot(struct hotplug_slot *slot)
{
struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
@@ -548,6 +579,7 @@ static const struct hotplug_slot_ops php_slot_ops = {
.set_attention_status = pnv_php_set_attention_state,
.enable_slot = pnv_php_enable_slot,
.disable_slot = pnv_php_disable_slot,
+ .reset_slot = pnv_php_reset_slot,
};
static void pnv_php_release(struct pnv_php_slot *php_slot)
@@ -721,6 +753,12 @@ static irqreturn_t pnv_php_interrupt(int irq, void *data)
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts);
sts &= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts);
+
+ pci_dbg(pdev, "PCI slot [%s]: HP int! DLAct: %d, PresDet: %d\n",
+ php_slot->name,
+ !!(sts & PCI_EXP_SLTSTA_DLLSC),
+ !!(sts & PCI_EXP_SLTSTA_PDC));
+
if (sts & PCI_EXP_SLTSTA_DLLSC) {
pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lsts);
added = !!(lsts & PCI_EXP_LNKSTA_DLLLA);
@@ -735,6 +773,7 @@ static irqreturn_t pnv_php_interrupt(int irq, void *data)
added = !!(presence == OPAL_PCI_SLOT_PRESENT);
} else {
+ pci_dbg(pdev, "PCI slot [%s]: Spurious IRQ?\n", php_slot->name);
return IRQ_NONE;
}