319 lines
8.5 KiB
C
319 lines
8.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* 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
|
|
*/
|
|
|
|
#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/debugfs.h>
|
|
#include <asm/ppc-pci.h>
|
|
|
|
|
|
/**
|
|
* DOC: Overview
|
|
*
|
|
* 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;
|
|
resource_size_t addr_lo;
|
|
resource_size_t addr_hi;
|
|
struct eeh_dev *edev;
|
|
struct pci_dev *pcidev;
|
|
unsigned long 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
|
|
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. 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_info("PCI: %s addr range %d [%pap-%pap]: %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, resource_size_t alo,
|
|
resource_size_t ahi, unsigned long 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_warn("PIAR: overlapping address range\n");
|
|
}
|
|
return piar;
|
|
}
|
|
}
|
|
piar = kzalloc(sizeof(struct pci_io_addr_range), GFP_ATOMIC);
|
|
if (!piar)
|
|
return NULL;
|
|
|
|
piar->addr_lo = alo;
|
|
piar->addr_hi = ahi;
|
|
piar->edev = pci_dev_to_eeh_dev(dev);
|
|
piar->pcidev = dev;
|
|
piar->flags = flags;
|
|
|
|
pr_debug("PIAR: insert range=[%pap:%pap] dev=%s\n",
|
|
&alo, &ahi, pci_name(dev));
|
|
|
|
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 pci_dn *pdn;
|
|
struct eeh_dev *edev;
|
|
int i;
|
|
|
|
pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
|
|
if (!pdn) {
|
|
pr_warn("PCI: no pci dn found for dev=%s\n",
|
|
pci_name(dev));
|
|
return;
|
|
}
|
|
|
|
edev = pdn_to_eeh_dev(pdn);
|
|
if (!edev) {
|
|
pr_warn("PCI: no EEH dev found for %s\n",
|
|
pci_name(dev));
|
|
return;
|
|
}
|
|
|
|
/* Skip any devices for which EEH is not enabled. */
|
|
if (!edev->pe) {
|
|
dev_dbg(&dev->dev, "EEH: Skip building address cache\n");
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Walk resources on this device, poke the first 7 (6 normal BAR and 1
|
|
* ROM BAR) into the tree.
|
|
*/
|
|
for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
|
|
resource_size_t start = pci_resource_start(dev,i);
|
|
resource_size_t end = pci_resource_end(dev,i);
|
|
unsigned long 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;
|
|
|
|
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) {
|
|
pr_debug("PIAR: remove range=[%pap:%pap] dev=%s\n",
|
|
&piar->addr_lo, &piar->addr_hi, pci_name(dev));
|
|
rb_erase(n, &pci_io_addr_cache_root.rb_root);
|
|
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 pci_dn *pdn;
|
|
struct eeh_dev *edev;
|
|
struct pci_dev *dev = NULL;
|
|
|
|
spin_lock_init(&pci_io_addr_cache_root.piar_lock);
|
|
|
|
for_each_pci_dev(dev) {
|
|
pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
|
|
if (!pdn)
|
|
continue;
|
|
|
|
edev = pdn_to_eeh_dev(pdn);
|
|
if (!edev)
|
|
continue;
|
|
|
|
dev->dev.archdata.edev = edev;
|
|
edev->pdev = dev;
|
|
|
|
eeh_addr_cache_insert_dev(dev);
|
|
eeh_sysfs_add_device(dev);
|
|
}
|
|
}
|
|
|
|
static int eeh_addr_cache_show(struct seq_file *s, void *v)
|
|
{
|
|
struct pci_io_addr_range *piar;
|
|
struct rb_node *n;
|
|
|
|
spin_lock(&pci_io_addr_cache_root.piar_lock);
|
|
for (n = rb_first(&pci_io_addr_cache_root.rb_root); n; n = rb_next(n)) {
|
|
piar = rb_entry(n, struct pci_io_addr_range, rb_node);
|
|
|
|
seq_printf(s, "%s addr range [%pap-%pap]: %s\n",
|
|
(piar->flags & IORESOURCE_IO) ? "i/o" : "mem",
|
|
&piar->addr_lo, &piar->addr_hi, pci_name(piar->pcidev));
|
|
}
|
|
spin_unlock(&pci_io_addr_cache_root.piar_lock);
|
|
|
|
return 0;
|
|
}
|
|
DEFINE_SHOW_ATTRIBUTE(eeh_addr_cache);
|
|
|
|
void eeh_cache_debugfs_init(void)
|
|
{
|
|
debugfs_create_file_unsafe("eeh_address_cache", 0400,
|
|
powerpc_debugfs_root, NULL,
|
|
&eeh_addr_cache_fops);
|
|
}
|