[PATCH v6 18/53] PCI: Reorder resources list for required/optional resources

From: Yinghai Lu
Date: Thu Oct 01 2015 - 01:59:30 EST


We try to allocate required+optional before allocate required only and
expand with optional.

At first we update size and alignment for required+optional resource.
And after that we reorder them with new alignment, but current we only
do that STARTALIGN ones.

For SIZEALIGN type resource, after add back add_size, the alignment
get changed, so need to do sorting like STARTALIGN type resources.

Also we need to reorder the sorting back after we restore
resource to required only when required+optional fail to allocate for all.

So move out the reordering code from the loop to separated function,
and call it two times accordingly.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/setup-bus.c | 62 +++++++++++++++++++++++++++++--------------------
1 file changed, 37 insertions(+), 25 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 6fda7ad..92677c5 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -286,6 +286,31 @@ static inline void reset_resource(struct resource *res)
res->flags = 0;
}

+static void sort_resources(struct list_head *head)
+{
+ struct pci_dev_resource *res1, *tmp_res, *res2;
+
+ list_for_each_entry_safe(res1, tmp_res, head, list) {
+ resource_size_t align1, size1, align2, size2;
+
+ align1 = pci_resource_alignment(res1->dev, res1->res);
+ size1 = resource_size(res1->res);
+
+ /* reorder it */
+ list_for_each_entry(res2, head, list) {
+ if (res2 == res1)
+ break;
+
+ align2 = pci_resource_alignment(res2->dev, res2->res);
+ size2 = resource_size(res2->res);
+ if (is_before(align1, size1, align2, size2)) {
+ list_move_tail(&res1->list, &res2->list);
+ break;
+ }
+ }
+ }
+}
+
/**
* reassign_resources_sorted() - satisfy any additional resource requests
*
@@ -454,9 +479,9 @@ static void __assign_resources_sorted(struct list_head *head,
LIST_HEAD(save_head);
LIST_HEAD(local_fail_head);
struct pci_dev_resource *save_res;
- struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
+ struct pci_dev_resource *dev_res, *tmp_res;
unsigned long fail_type;
- resource_size_t add_align, align;
+ resource_size_t add_align;

/* Check if optional add_size is there */
if (!realloc_head || list_empty(realloc_head))
@@ -471,47 +496,32 @@ static void __assign_resources_sorted(struct list_head *head,
}

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

/*
* There are two kinds of additional resources in the list:
- * 1. bridge resource -- IORESOURCE_STARTALIGN
- * 2. SR-IOV resource -- IORESOURCE_SIZEALIGN
- * Here just fix the additional alignment for bridge
+ * 1. bridge resource with IORESOURCE_STARTALIGN
+ * need to update start to change alignment
+ * 2. resource with IORESOURCE_SIZEALIGN
+ * update size above already change alignment.
*/
if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
continue;

add_align = get_res_add_align(realloc_head, dev_res->res);

- /*
- * The "head" list is sorted by the alignment to make sure
- * resources with bigger alignment will be assigned first.
- * After we change the alignment of a dev_res in "head" list,
- * we need to reorder the list by alignment to make it
- * consistent.
- */
- if (add_align > dev_res->res->start) {
+ if (add_align) {
resource_size_t r_size = resource_size(dev_res->res);

dev_res->res->start = add_align;
dev_res->res->end = add_align + r_size - 1;
-
- list_for_each_entry(dev_res2, head, list) {
- align = pci_resource_alignment(dev_res2->dev,
- dev_res2->res);
- if (add_align > align) {
- list_move_tail(&dev_res->list,
- &dev_res2->list);
- break;
- }
- }
}
-
}

+ sort_resources(head);
+
/* Try updated head list with add_size added */
assign_requested_resources_sorted(head, &local_fail_head);

@@ -553,6 +563,8 @@ static void __assign_resources_sorted(struct list_head *head,
}
free_list(&save_head);

+ sort_resources(head);
+
requested_and_reassign:
/* Satisfy the must-have resource requests */
assign_requested_resources_sorted(head, fail_head);
--
1.8.4.5

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