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authorroot <root@artemis.panaceas.org>2015-12-25 04:40:36 +0000
committerroot <root@artemis.panaceas.org>2015-12-25 04:40:36 +0000
commit849369d6c66d3054688672f97d31fceb8e8230fb (patch)
tree6135abc790ca67dedbe07c39806591e70eda81ce /arch/powerpc/kernel/pci_dn.c
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Diffstat (limited to 'arch/powerpc/kernel/pci_dn.c')
-rw-r--r--arch/powerpc/kernel/pci_dn.c208
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diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
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+/*
+ * pci_dn.c
+ *
+ * Copyright (C) 2001 Todd Inglett, IBM Corporation
+ *
+ * PCI manipulation via device_nodes.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/gfp.h>
+
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/pci-bridge.h>
+#include <asm/ppc-pci.h>
+#include <asm/firmware.h>
+
+/*
+ * Traverse_func that inits the PCI fields of the device node.
+ * NOTE: this *must* be done before read/write config to the device.
+ */
+void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
+{
+ struct pci_controller *phb = data;
+ const int *type =
+ of_get_property(dn, "ibm,pci-config-space-type", NULL);
+ const u32 *regs;
+ struct pci_dn *pdn;
+
+ pdn = zalloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
+ if (pdn == NULL)
+ return NULL;
+ dn->data = pdn;
+ pdn->node = dn;
+ pdn->phb = phb;
+ regs = of_get_property(dn, "reg", NULL);
+ if (regs) {
+ /* First register entry is addr (00BBSS00) */
+ pdn->busno = (regs[0] >> 16) & 0xff;
+ pdn->devfn = (regs[0] >> 8) & 0xff;
+ }
+
+ pdn->pci_ext_config_space = (type && *type == 1);
+ return NULL;
+}
+
+/*
+ * Traverse a device tree stopping each PCI device in the tree.
+ * This is done depth first. As each node is processed, a "pre"
+ * function is called and the children are processed recursively.
+ *
+ * The "pre" func returns a value. If non-zero is returned from
+ * the "pre" func, the traversal stops and this value is returned.
+ * This return value is useful when using traverse as a method of
+ * finding a device.
+ *
+ * NOTE: we do not run the func for devices that do not appear to
+ * be PCI except for the start node which we assume (this is good
+ * because the start node is often a phb which may be missing PCI
+ * properties).
+ * We use the class-code as an indicator. If we run into
+ * one of these nodes we also assume its siblings are non-pci for
+ * performance.
+ */
+void *traverse_pci_devices(struct device_node *start, traverse_func pre,
+ void *data)
+{
+ struct device_node *dn, *nextdn;
+ void *ret;
+
+ /* We started with a phb, iterate all childs */
+ for (dn = start->child; dn; dn = nextdn) {
+ const u32 *classp;
+ u32 class;
+
+ nextdn = NULL;
+ classp = of_get_property(dn, "class-code", NULL);
+ class = classp ? *classp : 0;
+
+ if (pre && ((ret = pre(dn, data)) != NULL))
+ return ret;
+
+ /* If we are a PCI bridge, go down */
+ if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
+ (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
+ /* Depth first...do children */
+ nextdn = dn->child;
+ else if (dn->sibling)
+ /* ok, try next sibling instead. */
+ nextdn = dn->sibling;
+ if (!nextdn) {
+ /* Walk up to next valid sibling. */
+ do {
+ dn = dn->parent;
+ if (dn == start)
+ return NULL;
+ } while (dn->sibling == NULL);
+ nextdn = dn->sibling;
+ }
+ }
+ return NULL;
+}
+
+/**
+ * pci_devs_phb_init_dynamic - setup pci devices under this PHB
+ * phb: pci-to-host bridge (top-level bridge connecting to cpu)
+ *
+ * This routine is called both during boot, (before the memory
+ * subsystem is set up, before kmalloc is valid) and during the
+ * dynamic lpar operation of adding a PHB to a running system.
+ */
+void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
+{
+ struct device_node *dn = phb->dn;
+ struct pci_dn *pdn;
+
+ /* PHB nodes themselves must not match */
+ update_dn_pci_info(dn, phb);
+ pdn = dn->data;
+ if (pdn) {
+ pdn->devfn = pdn->busno = -1;
+ pdn->phb = phb;
+ }
+
+ /* Update dn->phb ptrs for new phb and children devices */
+ traverse_pci_devices(dn, update_dn_pci_info, phb);
+}
+
+/*
+ * Traversal func that looks for a <busno,devfcn> value.
+ * If found, the pci_dn is returned (thus terminating the traversal).
+ */
+static void *is_devfn_node(struct device_node *dn, void *data)
+{
+ int busno = ((unsigned long)data >> 8) & 0xff;
+ int devfn = ((unsigned long)data) & 0xff;
+ struct pci_dn *pci = dn->data;
+
+ if (pci && (devfn == pci->devfn) && (busno == pci->busno))
+ return dn;
+ return NULL;
+}
+
+/*
+ * This is the "slow" path for looking up a device_node from a
+ * pci_dev. It will hunt for the device under its parent's
+ * phb and then update of_node pointer.
+ *
+ * It may also do fixups on the actual device since this happens
+ * on the first read/write.
+ *
+ * Note that it also must deal with devices that don't exist.
+ * In this case it may probe for real hardware ("just in case")
+ * and add a device_node to the device tree if necessary.
+ *
+ * Is this function necessary anymore now that dev->dev.of_node is
+ * used to store the node pointer?
+ *
+ */
+struct device_node *fetch_dev_dn(struct pci_dev *dev)
+{
+ struct pci_controller *phb = dev->sysdata;
+ struct device_node *dn;
+ unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
+
+ if (WARN_ON(!phb))
+ return NULL;
+
+ dn = traverse_pci_devices(phb->dn, is_devfn_node, (void *)searchval);
+ if (dn)
+ dev->dev.of_node = dn;
+ return dn;
+}
+EXPORT_SYMBOL(fetch_dev_dn);
+
+/**
+ * pci_devs_phb_init - Initialize phbs and pci devs under them.
+ *
+ * This routine walks over all phb's (pci-host bridges) on the
+ * system, and sets up assorted pci-related structures
+ * (including pci info in the device node structs) for each
+ * pci device found underneath. This routine runs once,
+ * early in the boot sequence.
+ */
+void __init pci_devs_phb_init(void)
+{
+ struct pci_controller *phb, *tmp;
+
+ /* This must be done first so the device nodes have valid pci info! */
+ list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
+ pci_devs_phb_init_dynamic(phb);
+}