[PATCH v2 20/49] PCI: Skip must+optional if there is no optional addon

Yinghai Lu
2015-07-14T22:49:52Z

If the bridge does not support hotplug or no child with sriov support
we could get out early and don't try must+optional allocation.

Also in the loop that update res with optional add info, skip resource
that add_size is 0.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
drivers/pci/setup-bus.c | 32 +++++++++++++++++++++++++++++---
1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index d1f9e19..64ef516 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -450,6 +450,24 @@ static bool pci_need_to_release(unsigned long mask, struct resource *res)
return false; /* should not get here */
}

+static bool __has_addon(struct list_head *head,
+ struct list_head *realloc_head)
+{
+ int add_count = 0;
+ struct pci_dev_resource *dev_res, *tmp_res;
+
+ /* check if we have add really */
+ list_for_each_entry(dev_res, head, list) {
+ tmp_res = res_to_dev_res(realloc_head, dev_res->res);
+ if (!tmp_res || !tmp_res->add_size)
+ continue;
+
+ add_count++;
+ }
+
+ return add_count != 0;
+}
+
static bool save_resources(struct list_head *head,
struct list_head *save_head)
{
@@ -481,16 +499,24 @@ static bool __assign_resources_must_add_sorted(struct list_head *head,
struct pci_dev_resource *save_res;
struct pci_dev_resource *dev_res, *tmp_res;
unsigned long fail_type;
- resource_size_t add_align;
+ resource_size_t add_align, add_size;
struct resource *res;

+ if (!__has_addon(head, realloc_head))
+ return false;
+
if (!save_resources(head, &save_head))
return false;

/* Update res in head list with add_size in realloc_head list */
list_for_each_entry(dev_res, head, list) {
res = dev_res->res;
- res->end += get_res_add_size(realloc_head, res);
+ add_size = get_res_add_size(realloc_head, res);
+
+ if (!add_size)
+ continue;
+
+ res->end += add_size;

/*
* There are two kinds of additional resources in the list:
@@ -578,7 +604,7 @@ static void __assign_resources_sorted(struct list_head *head,
*/

/* Check must+optional add */
- if (realloc_head && !list_empty(realloc_head) &&
+ if (realloc_head &&
__assign_resources_must_add_sorted(head, realloc_head))
return;

--
1.8.4.5