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device/pci_device: Do not break tree topology 

Fix regression introduced with commit
   ad7674e device: Introduce pcidev_on_root() and friends

Function pci_scan_bus() breaks bus->children link
in the devicetree topology while scanning a bus.
While the scan is in progress, accessing PCI
devices with number higher than what is being probed
was not possible because new pcidev_on_root() relies
on having proper topology present at any time.

Change-Id: I7bb497f7390628dd2f0310b380f199783a888c4c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/30772
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Tristan Corrick <tristan@corrick.kiwi>
This commit is contained in:
Kyösti Mälkki 2019-01-09 11:31:25 +02:00
parent 82a4e27341
commit 8712aa107f
1 changed files with 42 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
src/device/pci_device.c
View File

@ -989,33 +989,33 @@ bad:
/**
* See if we have already allocated a device structure for a given devfn.
*
* Given a linked list of PCI device structures and a devfn number, find the
* device structure correspond to the devfn, if present. This function also
* removes the device structure from the linked list.
* Given a PCI bus structure and a devfn number, find the device structure
* corresponding to the devfn, if present. Then move the device structure
* as the last child on the bus.
*
* @param list The device structure list.
* @param bus Pointer to the bus structure.
* @param devfn A device/function number.
* @return Pointer to the device structure found or NULL if we have not
* allocated a device for this devfn yet.
*/
static struct device *pci_scan_get_dev(struct device **list, unsigned int devfn)
static struct device *pci_scan_get_dev(struct bus *bus, unsigned int devfn)
{
struct device *dev;
struct device *dev, **prev;
dev = 0;
for (; *list; list = &(*list)->sibling) {
if ((*list)->path.type != DEVICE_PATH_PCI) {
printk(BIOS_ERR, "child %s not a PCI device\n",
dev_path(*list));
continue;
}
if ((*list)->path.pci.devfn == devfn) {
prev = &bus->children;
for (dev = bus->children; dev; dev = dev->sibling) {
if (dev->path.type == DEVICE_PATH_PCI) {
if (dev->path.pci.devfn == devfn) {
/* Unlink from the list. */
dev = *list;
*list = (*list)->sibling;
*prev = dev->sibling;
dev->sibling = NULL;
break;
}
} else {
printk(BIOS_ERR, "child %s not a PCI device\n",
dev_path(dev));
}
prev = &dev->sibling;
}
/*
@ -1027,15 +1027,15 @@ static struct device *pci_scan_get_dev(struct device **list, unsigned int devfn)
if (dev) {
struct device *child;
/* Find the last child of our parent. */
for (child = dev->bus->children; child && child->sibling;)
/* Find the last child on the bus. */
for (child = bus->children; child && child->sibling;)
child = child->sibling;
/* Place the device on the list of children of its parent. */
/* Place the device as last on the bus. */
if (child)
child->sibling = dev;
else
dev->bus->children = dev;
bus->children = dev;
}
return dev;
@ -1180,7 +1180,8 @@ void pci_scan_bus(struct bus *bus, unsigned min_devfn,
unsigned max_devfn)
{
unsigned int devfn;
struct device *old_devices;
struct device *dev, **prev;
int once = 0;
printk(BIOS_DEBUG, "PCI: pci_scan_bus for bus %02x\n", bus->secondary);
@ -1193,9 +1194,6 @@ void pci_scan_bus(struct bus *bus, unsigned min_devfn,
max_devfn=0xff;
}
old_devices = bus->children;
bus->children = NULL;
post_code(0x24);
/*
@ -1203,10 +1201,8 @@ void pci_scan_bus(struct bus *bus, unsigned min_devfn,
* non-existence and single function devices.
*/
for (devfn = min_devfn; devfn <= max_devfn; devfn++) {
struct device *dev;
/* First thing setup the device structure. */
dev = pci_scan_get_dev(&old_devices, devfn);
dev = pci_scan_get_dev(bus, devfn);
/* See if a device is present and setup the device structure. */
dev = pci_probe_dev(dev, bus, devfn);
@ -1228,15 +1224,26 @@ void pci_scan_bus(struct bus *bus, unsigned min_devfn,
* Warn if any leftover static devices are are found.
* There's probably a problem in devicetree.cb.
*/
if (old_devices) {
struct device *left;
printk(BIOS_WARNING, "PCI: Left over static devices:\n");
for (left = old_devices; left; left = left->sibling)
printk(BIOS_WARNING, "%s\n", dev_path(left));
printk(BIOS_WARNING, "PCI: Check your devicetree.cb.\n");
prev = &bus->children;
for (dev = bus->children; dev; dev = dev->sibling) {
/* If we read valid vendor id, it is not leftover device. */
if (dev->vendor != 0) {
prev = &dev->sibling;
continue;
}
/* Unlink it from list. */
*prev = dev->sibling;
if (!once++)
printk(BIOS_WARNING, "PCI: Leftover static devices:\n");
printk(BIOS_WARNING, "%s\n", dev_path(dev));
}
if (once)
printk(BIOS_WARNING, "PCI: Check your devicetree.cb.\n");
/*
* For all children that implement scan_bus() (i.e. bridges)
* scan the bus behind that child.