--- /dev/null
- eeh_addr_cache_insert_dev(dev);
-
+/*
+ * PCI address cache; allows the lookup of PCI devices based on I/O address
+ *
+ * Copyright IBM Corporation 2004
+ * Copyright Linas Vepstas <linas@austin.ibm.com> 2004
+ *
+ * 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/list.h>
+#include <linux/pci.h>
+#include <linux/rbtree.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/atomic.h>
+#include <asm/pci-bridge.h>
+#include <asm/ppc-pci.h>
+
+
+/**
+ * The pci address cache subsystem. This subsystem places
+ * PCI device address resources into a red-black tree, sorted
+ * according to the address range, so that given only an i/o
+ * address, the corresponding PCI device can be **quickly**
+ * found. It is safe to perform an address lookup in an interrupt
+ * context; this ability is an important feature.
+ *
+ * Currently, the only customer of this code is the EEH subsystem;
+ * thus, this code has been somewhat tailored to suit EEH better.
+ * In particular, the cache does *not* hold the addresses of devices
+ * for which EEH is not enabled.
+ *
+ * (Implementation Note: The RB tree seems to be better/faster
+ * than any hash algo I could think of for this problem, even
+ * with the penalty of slow pointer chases for d-cache misses).
+ */
+struct pci_io_addr_range {
+ struct rb_node rb_node;
+ unsigned long addr_lo;
+ unsigned long addr_hi;
+ struct eeh_dev *edev;
+ struct pci_dev *pcidev;
+ unsigned int flags;
+};
+
+static struct pci_io_addr_cache {
+ struct rb_root rb_root;
+ spinlock_t piar_lock;
+} pci_io_addr_cache_root;
+
+static inline struct eeh_dev *__eeh_addr_cache_get_device(unsigned long addr)
+{
+ struct rb_node *n = pci_io_addr_cache_root.rb_root.rb_node;
+
+ while (n) {
+ struct pci_io_addr_range *piar;
+ piar = rb_entry(n, struct pci_io_addr_range, rb_node);
+
+ if (addr < piar->addr_lo) {
+ n = n->rb_left;
+ } else {
+ if (addr > piar->addr_hi) {
+ n = n->rb_right;
+ } else {
+ pci_dev_get(piar->pcidev);
+ return piar->edev;
+ }
+ }
+ }
+
+ return NULL;
+}
+
+/**
+ * eeh_addr_cache_get_dev - Get device, given only address
+ * @addr: mmio (PIO) phys address or i/o port number
+ *
+ * Given an mmio phys address, or a port number, find a pci device
+ * that implements this address. Be sure to pci_dev_put the device
+ * when finished. I/O port numbers are assumed to be offset
+ * from zero (that is, they do *not* have pci_io_addr added in).
+ * It is safe to call this function within an interrupt.
+ */
+struct eeh_dev *eeh_addr_cache_get_dev(unsigned long addr)
+{
+ struct eeh_dev *edev;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags);
+ edev = __eeh_addr_cache_get_device(addr);
+ spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
+ return edev;
+}
+
+#ifdef DEBUG
+/*
+ * Handy-dandy debug print routine, does nothing more
+ * than print out the contents of our addr cache.
+ */
+static void eeh_addr_cache_print(struct pci_io_addr_cache *cache)
+{
+ struct rb_node *n;
+ int cnt = 0;
+
+ n = rb_first(&cache->rb_root);
+ while (n) {
+ struct pci_io_addr_range *piar;
+ piar = rb_entry(n, struct pci_io_addr_range, rb_node);
+ pr_debug("PCI: %s addr range %d [%lx-%lx]: %s\n",
+ (piar->flags & IORESOURCE_IO) ? "i/o" : "mem", cnt,
+ piar->addr_lo, piar->addr_hi, pci_name(piar->pcidev));
+ cnt++;
+ n = rb_next(n);
+ }
+}
+#endif
+
+/* Insert address range into the rb tree. */
+static struct pci_io_addr_range *
+eeh_addr_cache_insert(struct pci_dev *dev, unsigned long alo,
+ unsigned long ahi, unsigned int flags)
+{
+ struct rb_node **p = &pci_io_addr_cache_root.rb_root.rb_node;
+ struct rb_node *parent = NULL;
+ struct pci_io_addr_range *piar;
+
+ /* Walk tree, find a place to insert into tree */
+ while (*p) {
+ parent = *p;
+ piar = rb_entry(parent, struct pci_io_addr_range, rb_node);
+ if (ahi < piar->addr_lo) {
+ p = &parent->rb_left;
+ } else if (alo > piar->addr_hi) {
+ p = &parent->rb_right;
+ } else {
+ if (dev != piar->pcidev ||
+ alo != piar->addr_lo || ahi != piar->addr_hi) {
+ pr_warning("PIAR: overlapping address range\n");
+ }
+ return piar;
+ }
+ }
+ piar = kzalloc(sizeof(struct pci_io_addr_range), GFP_ATOMIC);
+ if (!piar)
+ return NULL;
+
+ pci_dev_get(dev);
+ piar->addr_lo = alo;
+ piar->addr_hi = ahi;
+ piar->edev = pci_dev_to_eeh_dev(dev);
+ piar->pcidev = dev;
+ piar->flags = flags;
+
+#ifdef DEBUG
+ pr_debug("PIAR: insert range=[%lx:%lx] dev=%s\n",
+ alo, ahi, pci_name(dev));
+#endif
+
+ rb_link_node(&piar->rb_node, parent, p);
+ rb_insert_color(&piar->rb_node, &pci_io_addr_cache_root.rb_root);
+
+ return piar;
+}
+
+static void __eeh_addr_cache_insert_dev(struct pci_dev *dev)
+{
+ struct device_node *dn;
+ struct eeh_dev *edev;
+ int i;
+
+ dn = pci_device_to_OF_node(dev);
+ if (!dn) {
+ pr_warning("PCI: no pci dn found for dev=%s\n", pci_name(dev));
+ return;
+ }
+
+ edev = of_node_to_eeh_dev(dn);
+ if (!edev) {
+ pr_warning("PCI: no EEH dev found for dn=%s\n",
+ dn->full_name);
+ return;
+ }
+
+ /* Skip any devices for which EEH is not enabled. */
+ if (!eeh_probe_mode_dev() && !edev->pe) {
+#ifdef DEBUG
+ pr_info("PCI: skip building address cache for=%s - %s\n",
+ pci_name(dev), dn->full_name);
+#endif
+ return;
+ }
+
+ /* Walk resources on this device, poke them into the tree */
+ for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+ unsigned long start = pci_resource_start(dev,i);
+ unsigned long end = pci_resource_end(dev,i);
+ unsigned int flags = pci_resource_flags(dev,i);
+
+ /* We are interested only bus addresses, not dma or other stuff */
+ if (0 == (flags & (IORESOURCE_IO | IORESOURCE_MEM)))
+ continue;
+ if (start == 0 || ~start == 0 || end == 0 || ~end == 0)
+ continue;
+ eeh_addr_cache_insert(dev, start, end, flags);
+ }
+}
+
+/**
+ * eeh_addr_cache_insert_dev - Add a device to the address cache
+ * @dev: PCI device whose I/O addresses we are interested in.
+ *
+ * In order to support the fast lookup of devices based on addresses,
+ * we maintain a cache of devices that can be quickly searched.
+ * This routine adds a device to that cache.
+ */
+void eeh_addr_cache_insert_dev(struct pci_dev *dev)
+{
+ unsigned long flags;
+
+ /* Ignore PCI bridges */
+ if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE)
+ return;
+
+ spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags);
+ __eeh_addr_cache_insert_dev(dev);
+ spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
+}
+
+static inline void __eeh_addr_cache_rmv_dev(struct pci_dev *dev)
+{
+ struct rb_node *n;
+
+restart:
+ n = rb_first(&pci_io_addr_cache_root.rb_root);
+ while (n) {
+ struct pci_io_addr_range *piar;
+ piar = rb_entry(n, struct pci_io_addr_range, rb_node);
+
+ if (piar->pcidev == dev) {
+ rb_erase(n, &pci_io_addr_cache_root.rb_root);
+ pci_dev_put(piar->pcidev);
+ kfree(piar);
+ goto restart;
+ }
+ n = rb_next(n);
+ }
+}
+
+/**
+ * eeh_addr_cache_rmv_dev - remove pci device from addr cache
+ * @dev: device to remove
+ *
+ * Remove a device from the addr-cache tree.
+ * This is potentially expensive, since it will walk
+ * the tree multiple times (once per resource).
+ * But so what; device removal doesn't need to be that fast.
+ */
+void eeh_addr_cache_rmv_dev(struct pci_dev *dev)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&pci_io_addr_cache_root.piar_lock, flags);
+ __eeh_addr_cache_rmv_dev(dev);
+ spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
+}
+
+/**
+ * eeh_addr_cache_build - Build a cache of I/O addresses
+ *
+ * Build a cache of pci i/o addresses. This cache will be used to
+ * find the pci device that corresponds to a given address.
+ * This routine scans all pci busses to build the cache.
+ * Must be run late in boot process, after the pci controllers
+ * have been scanned for devices (after all device resources are known).
+ */
+void eeh_addr_cache_build(void)
+{
+ struct device_node *dn;
+ struct eeh_dev *edev;
+ struct pci_dev *dev = NULL;
+
+ spin_lock_init(&pci_io_addr_cache_root.piar_lock);
+
+ for_each_pci_dev(dev) {
+ dn = pci_device_to_OF_node(dev);
+ if (!dn)
+ continue;
+
+ edev = of_node_to_eeh_dev(dn);
+ if (!edev)
+ continue;
+
+ pci_dev_get(dev); /* matching put is in eeh_remove_device() */
+ dev->dev.archdata.edev = edev;
+ edev->pdev = dev;
+
++ eeh_addr_cache_insert_dev(dev);
++
+ eeh_sysfs_add_device(dev);
+ }
+
+#ifdef DEBUG
+ /* Verify tree built up above, echo back the list of addrs. */
+ eeh_addr_cache_print(&pci_io_addr_cache_root);
+#endif
+}
projects / cascardo / linux.git / commitdiff