Commit 7fd1fe4e authored by Oliver O'Halloran's avatar Oliver O'Halloran Committed by Michael Ellerman
Browse files

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: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903101605.2890-9-oohall@gmail.com
parent 98fd32cd

drivers/pci/hotplug/pnv_php.c

+39 −0
Original line number Diff line number Diff line
@@ -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;

	}

CRA Git | Maintained and supported by SUSTech CRA and CCSE