From: Arnd Bergmann <arnd.bergmann@de•ibm.com>
To: linuxppc-dev@ozlabs•org
Cc: cbe-oss-dev@ozlabs•org
Subject: [PATCH] powerpc: allow PHBs anywhere in the device tree
Date: Tue, 12 Sep 2006 19:52:04 +0200 [thread overview]
Message-ID: <200609121952.04779.arnd.bergmann@de.ibm.com> (raw)
The rtas_pci code currently restricts pci host bridges to
locations directly under the device tree root. In order to
correctly model a north bridge that has multiple PCI buses,
that restriction needs to be relaxed.
The new definition is a device node of type "pci" whose
parent is of a different type, so we don't treat pci-to-pci
bridges as host bridges.
It also accepts any device type of "pci", "pcie", "ht" and
"pciex" in order to match anything that is currently in use.
I have added a new helper "of_find_phb_node" to prom.c so
that pci implementations of non-rtas platforms can use this
as well.
Signed-off-by: Arnd Bergmann <arnd@arndb•de>
Index: linux-2.6/arch/powerpc/kernel/prom.c
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/prom.c
+++ linux-2.6/arch/powerpc/kernel/prom.c
@@ -1325,6 +1325,72 @@ struct device_node *of_get_next_child(co
EXPORT_SYMBOL(of_get_next_child);
/**
+ * of_node_is_pci - Test if a node a pci host
+ * @node: node to compare
+ *
+ * returns 1 for PCI hosts and 0 for anything else
+ *
+ * This function is meant to be called from
+ * of_find_phb_node as a helper. We compare both
+ * the compatible and the device_type properties
+ * to known strings used to indicate PCI hosts.
+ */
+static int of_node_is_pci(struct device_node *node)
+{
+ if (!node->type)
+ return 0;
+
+ if (strcasecmp(node->type, "pci") == 0 ||
+ strcasecmp(node->type, "ht") == 0 ||
+ strcasecmp(node->type, "pciex") == 0 ||
+ strcasecmp(node->type, "pcie") == 0)
+ return 1;
+
+ if (device_is_compatible(node, "pci") ||
+ device_is_compatible(node, "ht") ||
+ device_is_compatible(node, "pciex") ||
+ device_is_compatible(node, "pcie"))
+ return 1;
+
+ return 0;
+}
+
+/**
+ *
+ * of_find_phb_node - Iterate all PCI host bridge device nodes
+ *
+ * @from: The node to start searching from or NULL, the node
+ * you pass will not be searched, only the next one
+ * will; typically, you pass what the previous call
+ * returned. of_node_put() will be called on it
+ *
+ * Returns a node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ *
+ * since we only want to return host bridges, not pci-pci
+ * bridges, check if the parent is not also a pci host.
+ */
+struct device_node *of_find_phb_node(struct device_node *from)
+{
+ struct device_node *np;
+
+ read_lock(&devtree_lock);
+ np = from ? from->allnext : allnodes;
+ for (; np; np = np->allnext) {
+ if (of_node_is_pci(np) &&
+ np->parent &&
+ !of_node_is_pci(np->parent))
+ break;
+ }
+ if (np)
+ of_node_get(np);
+ if (from)
+ of_node_put(from);
+ read_unlock(&devtree_lock);
+ return np;
+}
+
+/**
* of_node_get - Increment refcount of a node
* @node: Node to inc refcount, NULL is supported to
* simplify writing of callers
Index: linux-2.6/arch/powerpc/kernel/rtas_pci.c
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/rtas_pci.c
+++ linux-2.6/arch/powerpc/kernel/rtas_pci.c
@@ -240,13 +240,6 @@ unsigned long __devinit get_phb_buid (st
if (ibm_read_pci_config == -1) return 0;
- /* PHB's will always be children of the root node,
- * or so it is promised by the current firmware. */
- if (phb->parent == NULL)
- return 0;
- if (phb->parent->parent)
- return 0;
-
buid_vals = (unsigned int *) get_property(phb, "reg", &len);
if (buid_vals == NULL)
return 0;
@@ -297,17 +290,10 @@ unsigned long __init find_and_init_phbs(
struct device_node *node;
struct pci_controller *phb;
unsigned int index;
- struct device_node *root = of_find_node_by_path("/");
+ node = NULL;
index = 0;
- for (node = of_get_next_child(root, NULL);
- node != NULL;
- node = of_get_next_child(root, node)) {
-
- if (node->type == NULL || (strcmp(node->type, "pci") != 0 &&
- strcmp(node->type, "pciex") != 0))
- continue;
-
+ while ((node = of_find_phb_node(node))) {
phb = pcibios_alloc_controller(node);
if (!phb)
continue;
@@ -316,8 +302,6 @@ unsigned long __init find_and_init_phbs(
pci_setup_phb_io(phb, index == 0);
index++;
}
-
- of_node_put(root);
pci_devs_phb_init();
/*
Index: linux-2.6/include/asm-powerpc/prom.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/prom.h
+++ linux-2.6/include/asm-powerpc/prom.h
@@ -131,6 +131,7 @@ extern struct device_node *of_find_compa
extern struct device_node *of_find_node_by_path(const char *path);
extern struct device_node *of_find_node_by_phandle(phandle handle);
extern struct device_node *of_find_all_nodes(struct device_node *prev);
+extern struct device_node *of_find_phb_node(struct device_node *from);
extern struct device_node *of_get_parent(const struct device_node *node);
extern struct device_node *of_get_next_child(const struct device_node *node,
struct device_node *prev);
next reply other threads:[~2006-09-12 17:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-12 17:52 Arnd Bergmann [this message]
2006-09-12 19:54 ` [PATCH] powerpc: allow PHBs anywhere in the device tree Olof Johansson
2006-09-12 21:16 ` [Cbe-oss-dev] " Arnd Bergmann
2006-09-12 21:44 ` Olof Johansson
2006-09-12 22:20 ` Paul Mackerras
2006-09-12 22:39 ` [Cbe-oss-dev] " Arnd Bergmann
2006-09-13 1:46 ` Benjamin Herrenschmidt
2006-09-13 0:23 ` Segher Boessenkool
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