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authorYinghai Lu <yinghai@kernel.org>2013-07-25 06:31:38 -0700
committerBjorn Helgaas <bhelgaas@google.com>2013-07-26 07:32:20 -0600
commitaa914f5ec25e4371ba18b312971314be1b9b1076 (patch)
tree318090c34fc438e39c59780bf98e705ce8c50d9e /drivers
parentc10cc483bf3f1d0e8f9f077ca36ecc053de9bbbc (diff)
PCI: Retry allocation of only the resource type that failed
Ben Herrenschmidt reported the following problem: - The bus has space for all desired MMIO resources, including optional space for SR-IOV devices - We attempt to allocate I/O port space, but it fails because the bus has no I/O space - Because of the I/O allocation failure, we retry MMIO allocation, requesting only the required space, without the optional SR-IOV space This means we don't allocate the optional SR-IOV space, even though we could. This is related to 0c5be0cb0e ("PCI: Retry on IORESOURCE_IO type allocations"). This patch changes how we handle allocation failures. We will now retry allocation of only the resource type that failed. If MMIO allocation fails, we'll retry only MMIO allocation. If I/O port allocation fails, we'll retry only I/O port allocation. [bhelgaas: changelog] Reference: https://lkml.kernel.org/r/1367712653.11982.19.camel@pasglop 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> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v3.10+
Diffstat (limited to 'drivers')
-rw-r--r--drivers/pci/setup-bus.c69
1 files changed, 68 insertions, 1 deletions
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index d254e2379533..64a7de22d9af 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -300,6 +300,47 @@ static void assign_requested_resources_sorted(struct list_head *head,
}
}
+static unsigned long pci_fail_res_type_mask(struct list_head *fail_head)
+{
+ struct pci_dev_resource *fail_res;
+ unsigned long mask = 0;
+
+ /* check failed type */
+ list_for_each_entry(fail_res, fail_head, list)
+ mask |= fail_res->flags;
+
+ /*
+ * one pref failed resource will set IORESOURCE_MEM,
+ * as we can allocate pref in non-pref range.
+ * Will release all assigned non-pref sibling resources
+ * according to that bit.
+ */
+ return mask & (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH);
+}
+
+static bool pci_need_to_release(unsigned long mask, struct resource *res)
+{
+ if (res->flags & IORESOURCE_IO)
+ return !!(mask & IORESOURCE_IO);
+
+ /* check pref at first */
+ if (res->flags & IORESOURCE_PREFETCH) {
+ if (mask & IORESOURCE_PREFETCH)
+ return true;
+ /* count pref if its parent is non-pref */
+ else if ((mask & IORESOURCE_MEM) &&
+ !(res->parent->flags & IORESOURCE_PREFETCH))
+ return true;
+ else
+ return false;
+ }
+
+ if (res->flags & IORESOURCE_MEM)
+ return !!(mask & IORESOURCE_MEM);
+
+ return false; /* should not get here */
+}
+
static void __assign_resources_sorted(struct list_head *head,
struct list_head *realloc_head,
struct list_head *fail_head)
@@ -312,11 +353,24 @@ static void __assign_resources_sorted(struct list_head *head,
* if could do that, could get out early.
* if could not do that, we still try to assign requested at first,
* then try to reassign add_size for some resources.
+ *
+ * Separate three resource type checking if we need to release
+ * assigned resource after requested + add_size try.
+ * 1. if there is io port assign fail, will release assigned
+ * io port.
+ * 2. if there is pref mmio assign fail, release assigned
+ * pref mmio.
+ * if assigned pref mmio's parent is non-pref mmio and there
+ * is non-pref mmio assign fail, will release that assigned
+ * pref mmio.
+ * 3. if there is non-pref mmio assign fail or pref mmio
+ * assigned fail, will release assigned non-pref mmio.
*/
LIST_HEAD(save_head);
LIST_HEAD(local_fail_head);
struct pci_dev_resource *save_res;
- struct pci_dev_resource *dev_res;
+ struct pci_dev_resource *dev_res, *tmp_res;
+ unsigned long fail_type;
/* Check if optional add_size is there */
if (!realloc_head || list_empty(realloc_head))
@@ -348,6 +402,19 @@ static void __assign_resources_sorted(struct list_head *head,
return;
}
+ /* check failed type */
+ fail_type = pci_fail_res_type_mask(&local_fail_head);
+ /* remove not need to be released assigned res from head list etc */
+ list_for_each_entry_safe(dev_res, tmp_res, head, list)
+ if (dev_res->res->parent &&
+ !pci_need_to_release(fail_type, dev_res->res)) {
+ /* 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)