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Subject[PATCH] PCI: Don't let mmio fallback to must-only, if ioport fails with must+optional
Date
BenH reported that there is some assign unassigned resource problem
in powerpc.

It turns out after
| commit 0c5be0cb0edfe3b5c4b62eac68aa2aa15ec681af
| Date: Thu Feb 23 19:23:29 2012 -0800
|
| PCI: Retry on IORESOURCE_IO type allocations

even the root bus does not have io port range, it will keep retrying
to realloc with mmio.

Current retry logic is : try with must+optional at first, and if
it fails with any ioport or mmio, it will try must then try to extend
must with optional.
That will fail as mmio-non-pref and mmio-pref for bridge will
be next to each other. So we have no chance to extend mmio-non-pref.

We can check fail type and only fall back for io port only, that will
keep mmio type still have must+optional.

This will be become more often when we have x86 8 sockets or 32 sockets
system, and those system will have one root bus per socket.
They will have some root buses do not have ioport range.

-v2: need to remove assigned entries from optional list too.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
drivers/pci/setup-bus.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -317,6 +317,10 @@ static void __assign_resources_sorted(st
LIST_HEAD(local_fail_head);
struct pci_dev_resource *save_res;
struct pci_dev_resource *dev_res;
+ unsigned long fail_type = 0;
+ struct pci_dev_resource *fail_res;
+ unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+ IORESOURCE_PREFETCH;

/* Check if optional add_size is there */
if (!realloc_head || list_empty(realloc_head))
@@ -348,6 +352,25 @@ static void __assign_resources_sorted(st
return;
}

+ /* check failed type */
+ list_for_each_entry(fail_res, &local_fail_head, list)
+ fail_type |= fail_res->flags & type_mask;
+ /* only io port fails */
+ if ((fail_type & type_mask) == IORESOURCE_IO) {
+ struct pci_dev_resource *tmp_res;
+
+ /* remove assigned non ioport from head list etc */
+ list_for_each_entry_safe(dev_res, tmp_res, head, list)
+ if (dev_res->res->parent &&
+ !(dev_res->res->flags & IORESOURCE_IO)) {
+ /* remove it from realloc_head list */
+ remove_from_list(realloc_head, dev_res->res);
+ remove_from_list(&save_head, dev_res->res);
+ list_del(&dev_res->list);
+ kfree(dev_res);
+ }
+ }
+
free_list(&local_fail_head);
/* Release assigned resource */
list_for_each_entry(dev_res, head, list)

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