[Skiboot] [PATCH 1/3] pci-dt-slot: Big ol' cleanup
Oliver O'Halloran
oohall at gmail.com
Fri Apr 20 14:40:39 AEST 2018
The underlying data that we get from HDAT can only really describe a
PCIe system. As such we can simplify the devicetree slot lookup code
by only caring about the important cases, namly, root ports and switch
downstream ports.
This also fixes a bug where root port didn't get a Slot label applied
which results in devices under that port not having ibm,loc-code set.
This results in the EEH core being unable to report the location of
EEHed devices under that port.
Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
---
core/pci-dt-slot.c | 154 +++++++++++++++++++++++++----------------------------
1 file changed, 74 insertions(+), 80 deletions(-)
diff --git a/core/pci-dt-slot.c b/core/pci-dt-slot.c
index bee7ba47c445..4f5a0805e005 100644
--- a/core/pci-dt-slot.c
+++ b/core/pci-dt-slot.c
@@ -66,95 +66,33 @@ static struct dt_node *map_phb_to_slot(struct phb *phb)
return NULL;
}
-static struct dt_node *map_downport_to_slot(struct phb *phb,
- struct pci_device *pd)
+static struct dt_node *find_devfn(struct dt_node *bus, uint32_t bdfn)
{
- struct dt_node *bus_node, *child;
- struct pci_device *cursor;
- uint32_t port_dev_id;
+ uint32_t port_dev_id = (bdfn >> 3) & 0x1f;
+ struct dt_node *child;
- /*
- * Downports are a little bit special since we need to figure
- * out which PCI device corresponds to which down port in the
- * slot map.
- *
- * XXX: I'm assuming the ordering of port IDs and probed
- * PCIe switch downstream devices is the same. We should
- * check what we actually get in the HDAT.
- */
-
- list_for_each(&pd->parent->children, cursor, link)
- if (cursor == pd)
- break;
-
- /* the child should always be on the parent's child list */
- assert(cursor);
- port_dev_id = (cursor->bdfn >> 3) & 0x1f;
-
- bus_node = map_pci_dev_to_slot(phb, pd->parent);
- if (!bus_node)
- return NULL;
-
- dt_for_each_child(bus_node, child)
- if (dt_prop_get_u32(child, "reg") == port_dev_id)
+ dt_for_each_child(bus, child)
+ if (dt_prop_get_u32_def(child, "reg", ~0u) == port_dev_id)
return child;
- /* unused downport */
return NULL;
}
-static struct dt_node *__map_pci_dev_to_slot(struct phb *phb,
+/* Looks for a device device under this slot. */
+static struct dt_node *find_dev_under_slot(struct dt_node *slot,
struct pci_device *pd)
{
- struct dt_node *child, *bus_node, *wildcard= NULL;
-
- if (!pd || !pd->parent || pd->dev_type == PCIE_TYPE_ROOT_PORT)
- return map_phb_to_slot(phb);
-
- if (pd->dev_type == PCIE_TYPE_SWITCH_DNPORT)
- return map_downport_to_slot(phb, pd);
-
- /*
- * For matching against devices always use the 0th function.
- * This is necessary since some functions may have a different
- * VDID to the base device. e.g. The DMA engines in PLX switches
- */
- if (pd->bdfn & 0x7) {
- struct pci_device *cursor;
-
- PCIDBG(phb, pd->bdfn, "mapping fn %x to 0th fn (%x)\n",
- pd->bdfn, pd->bdfn & (~0x7));
-
- list_for_each(&pd->parent->children, cursor, link)
- if ((pd->bdfn & ~0x7) == cursor->bdfn)
- return map_pci_dev_to_slot(phb, cursor);
-
- return NULL;
- }
-
- /* No slot information for this device. Might be a firmware bug */
- bus_node = map_pci_dev_to_slot(phb, pd->parent);
- if (!bus_node)
- return NULL;
-
- /*
- * If this PCI device is mounted on a card the parent "bus"
- * may actually be a slot or builtin.
- */
- if (list_empty(&bus_node->children))
- return bus_node;
+ struct dt_node *child, *wildcard = NULL;
/* find the device in the parent bus node */
- dt_for_each_child(bus_node, child) {
+ dt_for_each_child(slot, child) {
u32 vdid;
/* "pluggable" and "builtin" without unit addrs are wildcards */
if (!dt_has_node_property(child, "reg", NULL)) {
- if (wildcard) {
+ if (wildcard)
prerror("Duplicate wildcard entry! Already have %s, found %s",
wildcard->name, child->name);
- assert(0);
- }
wildcard = child;
continue;
@@ -169,30 +107,86 @@ static struct dt_node *__map_pci_dev_to_slot(struct phb *phb,
}
if (!wildcard)
- PCIDBG(phb, pd->bdfn,
+ PCIDBG(pd->phb, pd->bdfn,
"Unable to find a slot for device %.4x:%.4x\n",
(pd->vdid & 0xffff0000) >> 16, pd->vdid & 0xffff);
return wildcard;
}
+/*
+ * If the `pd` is a bridge this returns a node with a compatible of
+ * ibm,pcie-port to indicate it's a "slot node".
+ */
+static struct dt_node *find_node_for_dev(struct phb *phb,
+ struct pci_device *pd)
+{
+ struct dt_node *sw_slot, *sw_up;
+
+ assert(pd);
+
+ if (pd->slot && pd->slot->data)
+ return pd->slot->data;
+
+ /*
+ * Example DT:
+ * /root-complex at 8,5/switch-up at 10b5,8725/down-port at 4
+ */
+ switch (pd->dev_type) {
+ case PCIE_TYPE_ROOT_PORT: // find the root-complex@<chip>,<phb> node
+ return map_phb_to_slot(phb);
+
+ case PCIE_TYPE_SWITCH_DNPORT: // grab the down-port@<devfn>
+ /*
+ * Walk up the topology to find the slot that contains
+ * the switch upstream port is connected to. In the example
+ * this would be the root-complex at 8,5 node.
+ */
+ sw_slot = find_node_for_dev(phb, pd->parent->parent);
+ if (!sw_slot)
+ return NULL;
+
+ /* find the per-device node for this switch */
+ sw_up = find_dev_under_slot(sw_slot, pd->parent);
+ if (!sw_up)
+ return NULL;
+
+ /* find this down port */
+ return find_devfn(sw_up, pd->bdfn & 0x1f);
+
+ default:
+ PCIDBG(phb, pd->bdfn,
+ "Trying to find a slot for non-pcie bridge type %d\n",
+ pd->dev_type);
+ assert(0);
+ }
+
+ return NULL;
+}
+
struct dt_node *map_pci_dev_to_slot(struct phb *phb, struct pci_device *pd)
{
- uint32_t bdfn = pd ? pd->bdfn : 0;
struct dt_node *n;
char *path;
- if (pd && pd->slot && pd->slot->data)
- return pd->slot->data;
+ assert(pd);
+
+ /*
+ * Having a slot only makes sense for root and switch downstream ports.
+ * We don't care about PCI-X.
+ */
+ if (pd->dev_type != PCIE_TYPE_SWITCH_DNPORT &&
+ pd->dev_type != PCIE_TYPE_ROOT_PORT)
+ return NULL;
- PCIDBG(phb, bdfn, "Finding slot\n");
+ PCIDBG(phb, pd->bdfn, "Finding slot\n");
- n = __map_pci_dev_to_slot(phb, pd);
+ n = find_node_for_dev(phb, pd);
if (!n) {
- PCIDBG(phb, bdfn, "No slot found!\n");
+ PCIDBG(phb, pd->bdfn, "No slot found!\n");
} else {
path = dt_get_path(n);
- PCIDBG(phb, bdfn, "Slot found %s\n", path);
+ PCIDBG(phb, pd->bdfn, "Slot found %s\n", path);
free(path);
}
--
2.9.5
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