[PATCH v7 41/50] powerpc/powernv: Use firmware PCI slot reset infrastructure

Gavin Shan
2015-11-04T13:13:55Z

The skiboot firmware might provide the PCI slot reset capability
which is identified by property "ibm,reset-by-firmware" on the
PCI slot associated device node.

This checks the property. If it exists, the reset request is routed
to firmware. Otherwise, the reset is done by kernel as before.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/eeh-powernv.c | 41 +++++++++++++++++++++++++++-
1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index e533535..086d153 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
@@ -801,7 +801,7 @@ static int pnv_eeh_root_reset(struct pci_controller *hose, int option)
return ret;
}

-static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option)
+static int __pnv_eeh_bridge_reset(struct pci_dev *dev, int option)
{
struct pci_dn *pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
@@ -852,6 +852,45 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option)
return 0;
}

+static int pnv_eeh_bridge_reset(struct pci_dev *pdev, int option)
+{
+ struct pci_controller *hose;
+ struct pnv_phb *phb;
+ struct device_node *dn = pdev ? pci_device_to_OF_node(pdev) : NULL;
+ uint64_t id = (0x1ul << 60);
+ uint8_t scope;
+ int64_t rc;
+
+ /*
+ * If the firmware can't handle it, we will issue hot reset
+ * on the secondary bus despite the requested reset type.
+ */
+ if (!dn || !of_get_property(dn, "ibm,reset-by-firmware", NULL))
+ return __pnv_eeh_bridge_reset(pdev, option);
+
+ /* The firmware can handle the request */
+ switch (option) {
+ case EEH_RESET_HOT:
+ scope = OPAL_RESET_PCI_HOT;
+ break;
+ case EEH_RESET_FUNDAMENTAL:
+ scope = OPAL_RESET_PCI_FUNDAMENTAL;
+ break;
+ case EEH_RESET_DEACTIVATE:
+ return 0;
+ default:
+ dev_warn(&pdev->dev, "%s: Unsupported reset %d\n",
+ __func__, option);
+ return -EINVAL;
+ }
+
+ hose = pci_bus_to_host(pdev->bus);
+ phb = hose->private_data;
+ id |= (pdev->bus->number << 24) | (pdev->devfn << 16) | phb->opal_id;
+ rc = opal_pci_reset(id, scope, OPAL_ASSERT_RESET);
+ return pnv_pci_poll(id, rc, NULL);
+}
+
static int pnv_pci_dev_reset_type(struct pci_dev *pdev, void *data)
{
int *freset = data;
--
2.1.0