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Date: Sat, 21 Jan 2012 02:24:07 -0800
From: Yinghai Lu <yinghai@...nel.org>
To: Jesse Barnes <jbarnes@...tuousgeek.org>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
Yinghai Lu <yinghai@...nel.org>
Subject: [RFC PATCH 2/3] PCI: Allocate bus range instead of use max blindly
every bus have extra busn_res, and linked them toghter to iobusn_resource.
when need to find usabled bus number range, try allocate from
iobusn_resource tree.
-v3: support extend buses top.
Signed-off-by: Yinghai Lu <yinghai@...nel.org>
---
drivers/pci/probe.c | 220 ++++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 184 insertions(+), 36 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 3e08207..e20fe45 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -624,6 +624,124 @@ static void pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
}
}
+static void __devinit pci_bus_extend_top(struct pci_bus *parent,
+ resource_size_t needed_size, struct resource *parent_res)
+{
+ while (parent) {
+ if (&parent->busn_res == parent_res)
+ break;
+ parent->busn_res.end += needed_size;
+ parent->subordinate += needed_size;
+ pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS,
+ parent->subordinate);
+ dev_printk(KERN_DEBUG, &parent->dev, "busn_res: %06llx-%06llx extended\n", (unsigned long long)parent->busn_res.start, (unsigned long long)parent->busn_res.end);
+ parent = parent->parent;
+ }
+}
+
+static void __devinit pci_bus_shrink_top(struct pci_bus *parent,
+ resource_size_t needed_size, struct resource *parent_res)
+{
+ while (parent) {
+ if (&parent->busn_res == parent_res)
+ break;
+ parent->busn_res.end -= needed_size;
+ parent->subordinate -= needed_size;
+ pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS,
+ parent->subordinate);
+ dev_printk(KERN_DEBUG, &parent->dev, "busn_res: %06llx-%06llx shrinked\n", (unsigned long long)parent->busn_res.start, (unsigned long long)parent->busn_res.end);
+ parent = parent->parent;
+ }
+}
+
+static int __devinit pci_bridge_probe_busn_res(struct pci_bus *bus, struct pci_dev *dev, struct resource *busn_res, resource_size_t needed_size, struct resource **p)
+{
+ int ret = -ENOMEM;
+ resource_size_t n_size;
+ struct pci_bus *parent;
+ struct resource *parent_res;
+ resource_size_t tmp = bus->busn_res.end + 1;
+
+ parent_res = NULL;
+
+again:
+ /* find bigest range in bus->busn_res that we can use in the middle */
+ n_size = resource_size(&bus->busn_res) - 1;
+ memset(busn_res, 0, sizeof(struct resource));
+ dev_printk(KERN_DEBUG, &dev->dev, "find free busn in busn_res: %06llx-%06llx\n", (unsigned long long)bus->busn_res.start, (unsigned long long)bus->busn_res.end);
+ while (n_size >= needed_size) {
+ ret = allocate_resource(&bus->busn_res, busn_res, n_size,
+ bus->busn_res.start + 1, bus->busn_res.end,
+ 1, NULL, NULL);
+ if (ret == 0) {
+ /* release busn_res */
+ release_resource(busn_res);
+
+ return ret;
+ }
+ n_size--;
+ }
+
+ /*
+ * try extend the top of parent buss
+ * find out number below bus->busn_res, that we can use at first
+ */
+ ret = -ENOMEM;
+ n_size = resource_size(&bus->busn_res) - 1;
+ memset(busn_res, 0, sizeof(struct resource));
+ dev_printk(KERN_DEBUG, &dev->dev, "find free busn in busn_res: %06llx-%06llx near top \n", (unsigned long long)bus->busn_res.start, (unsigned long long)bus->busn_res.end);
+ while (n_size > 0) {
+ ret = allocate_resource(&bus->busn_res, busn_res, n_size,
+ bus->busn_res.end - n_size + 1, bus->busn_res.end,
+ 1, NULL, NULL);
+ if (ret == 0) {
+ /* release busn_res */
+ release_resource(busn_res);
+ break;
+ }
+ n_size--;
+ }
+
+ /* check if extend could cross domain boundary */
+ ret = -ENOMEM;
+ if ((bus->busn_res.end & 0xff) == 0xff)
+ goto reduce_needed_size;
+ if ((0x100 - (tmp & 0xff)) < (needed_size - n_size))
+ goto reduce_needed_size;
+
+ /* find exteded range */
+ memset(busn_res, 0, sizeof(struct resource));
+ parent = bus->parent;
+ while (parent) {
+ ret = allocate_resource(&parent->busn_res, busn_res,
+ needed_size - n_size, tmp, tmp + needed_size - n_size,
+ 1, NULL, NULL);
+ if (ret == 0)
+ break;
+ parent = parent->parent;
+ }
+
+reduce_needed_size:
+ if (ret != 0) {
+ needed_size--;
+ if (!needed_size)
+ return ret;
+
+ goto again;
+ }
+
+ parent_res = busn_res->parent;
+ /* release busn_res */
+ release_resource(busn_res);
+ busn_res->start -= n_size;
+
+ /* extend */
+ pci_bus_extend_top(bus, needed_size - n_size, parent_res);
+
+ *p = parent_res;
+ return ret;
+}
+
/*
* If it's a bridge, configure it and scan the bus behind it.
* For CardBus bridges, we don't scan behind as the devices will
@@ -638,10 +756,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
{
struct pci_bus *child;
int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
- u32 buses, i, j = 0;
+ u32 buses;
u16 bctl;
u8 primary, secondary, subordinate;
int broken = 0;
+ struct resource *parent_res = NULL;
pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
primary = buses & 0xFF;
@@ -653,11 +772,30 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
/* Check if setup is sensible at all */
if (!pass &&
- (primary != bus->number || secondary <= bus->number)) {
- dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n");
+ (primary != bus->number || secondary <= bus->number))
broken = 1;
+
+ /* more strict checking */
+ if (!pass && !broken) {
+ struct resource busn_res;
+ int ret;
+
+ memset(&busn_res, 0, sizeof(struct resource));
+ dev_printk(KERN_DEBUG, &dev->dev, "try to check if busn %02x-%02x is in busn_res: %06llx-%06llx \n", secondary, subordinate, (unsigned long long)bus->busn_res.start, (unsigned long long)bus->busn_res.end);
+ ret = allocate_resource(&bus->busn_res, &busn_res,
+ (subordinate - secondary + 1),
+ (pci_domain_nr(bus)<<8) | secondary,
+ (pci_domain_nr(bus)<<8) | subordinate,
+ 1, NULL, NULL);
+ if (ret)
+ broken = 1;
+ else
+ release_resource(&busn_res);
}
+ if (broken)
+ dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n");
+
/* Disable MasterAbortMode during probing to avoid reporting
of bus errors (in some architectures) */
pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl);
@@ -689,6 +827,12 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
child->primary = primary;
child->subordinate = subordinate;
child->bridge_ctl = bctl;
+
+ child->busn_res.start = (pci_domain_nr(bus) << 8) | secondary;
+ child->busn_res.end = (pci_domain_nr(bus) << 8) | subordinate;
+ child->busn_res.flags = IORESOURCE_BUS | IORESOURCE_BUSY;
+ dev_printk(KERN_DEBUG, &child->dev, "busn_res: %06llx-%06llx inserted\n", (unsigned long long)child->busn_res.start, (unsigned long long)child->busn_res.end);
+ insert_resource(&bus->busn_res, &child->busn_res);
}
cmax = pci_scan_child_bus(child);
@@ -701,6 +845,11 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
* We need to assign a number to this bus which we always
* do in the second pass.
*/
+ resource_size_t shrink_size;
+ struct resource busn_res;
+ int ret = -ENOMEM;
+ int old_max = max;
+
if (!pass) {
if (pcibios_assign_all_busses() || broken)
/* Temporarily disable forwarding of the
@@ -717,20 +866,31 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
/* Clear errors */
pci_write_config_word(dev, PCI_STATUS, 0xffff);
- /* Prevent assigning a bus number that already exists.
- * This can happen when a bridge is hot-plugged, so in
- * this case we only re-scan this bus. */
- child = pci_find_bus(pci_domain_nr(bus), max+1);
- if (!child) {
- child = pci_add_new_bus(bus, dev, ++max);
- if (!child)
- goto out;
- }
+ ret = pci_bridge_probe_busn_res(bus, dev, &busn_res,
+ is_cardbus ? (CARDBUS_RESERVE_BUSNR + 1) : 8,
+ &parent_res);
+
+ if (ret != 0)
+ goto out;
+
+ child = pci_add_new_bus(bus, dev, busn_res.start & 0xff);
+ if (!child)
+ goto out;
+
+ child->subordinate = busn_res.end & 0xff;
+ child->busn_res.start = busn_res.start;
+ child->busn_res.end = busn_res.end;
+ child->busn_res.flags = IORESOURCE_BUS | IORESOURCE_BUSY;
+ dev_printk(KERN_DEBUG, &child->dev, "busn_res: %06llx-%06llx inserted\n", child->busn_res.start, child->busn_res.end);
+ insert_resource(&bus->busn_res, &child->busn_res);
+
buses = (buses & 0xff000000)
| ((unsigned int)(child->primary) << 0)
| ((unsigned int)(child->secondary) << 8)
| ((unsigned int)(child->subordinate) << 16);
+ max = child->subordinate;
+
/*
* yenta.c forces a secondary latency timer of 176.
* Copy that behaviour here.
@@ -761,43 +921,31 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
* the real value of max.
*/
pci_fixup_parent_subordinate_busnr(child, max);
+
} else {
/*
* For CardBus bridges, we leave 4 bus numbers
* as cards with a PCI-to-PCI bridge can be
* inserted later.
*/
- for (i=0; i<CARDBUS_RESERVE_BUSNR; i++) {
- struct pci_bus *parent = bus;
- if (pci_find_bus(pci_domain_nr(bus),
- max+i+1))
- break;
- while (parent->parent) {
- if ((!pcibios_assign_all_busses()) &&
- (parent->subordinate > max) &&
- (parent->subordinate <= max+i)) {
- j = 1;
- }
- parent = parent->parent;
- }
- if (j) {
- /*
- * Often, there are two cardbus bridges
- * -- try to leave one valid bus number
- * for each one.
- */
- i /= 2;
- break;
- }
- }
- max += i;
pci_fixup_parent_subordinate_busnr(child, max);
}
/*
* Set the subordinate bus number to its real value.
*/
+ shrink_size = child->subordinate - max;
child->subordinate = max;
pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
+ child->busn_res.end &= ~0xff;
+ child->busn_res.end |= max;
+ dev_printk(KERN_DEBUG, &child->dev, "busn_res: %06llx-%06llx adjusted\n", (unsigned long long)child->busn_res.start, (unsigned long long)child->busn_res.end);
+
+ /* shrink some back, if we extend top before */
+ if (!is_cardbus && (shrink_size > 0) && parent_res)
+ pci_bus_shrink_top(bus, shrink_size, parent_res);
+
+ if (old_max > max)
+ max = old_max;
}
sprintf(child->name,
--
1.7.7
--
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