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authorYinghai Lu <yhlu.kernel@gmail.com>2008-09-04 21:02:44 +0200
committerIngo Molnar <mingo@elte.hu>2008-09-04 21:02:44 +0200
commit268364a0f48aee2f851f9d1ef8a6cda0f3039ef1 (patch)
tree018d00aa42b74a80baf976258aa9b17abdfb44c6 /kernel
parentd210baf53b699fc61aa891c177b71d7082d3b957 (diff)
IO resources: add reserve_region_with_split()
add reserve_region_with_split() to not lose e820 reserved entries if they overlap with existing IO regions: with test case by extend 0xe0000000 - 0xeffffff to 0xdd800000 - we get: e0000000-efffffff : PCI MMCONFIG 0 e0000000-efffffff : reserved and in /proc/iomem we get: found conflict for reserved [dd800000, efffffff], try to reserve with split __reserve_region_with_split: (PCI Bus #80) [dd000000, ddffffff], res: (reserved) [dd800000, efffffff] __reserve_region_with_split: (PCI Bus #00) [de000000, dfffffff], res: (reserved) [de000000, efffffff] initcall pci_subsys_init+0x0/0x121 returned 0 after 381 msecs in dmesg various fixes and improvements suggested by Linus. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/resource.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index 03d796c1b2e..414d6fc9131 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -516,6 +516,74 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t
return result;
}
+static void __init __reserve_region_with_split(struct resource *root,
+ resource_size_t start, resource_size_t end,
+ const char *name)
+{
+ struct resource *parent = root;
+ struct resource *conflict;
+ struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
+
+ if (!res)
+ return;
+
+ res->name = name;
+ res->start = start;
+ res->end = end;
+ res->flags = IORESOURCE_BUSY;
+
+ for (;;) {
+ conflict = __request_resource(parent, res);
+ if (!conflict)
+ break;
+ if (conflict != parent) {
+ parent = conflict;
+ if (!(conflict->flags & IORESOURCE_BUSY))
+ continue;
+ }
+
+ /* Uhhuh, that didn't work out.. */
+ kfree(res);
+ res = NULL;
+ break;
+ }
+
+ if (!res) {
+ printk(KERN_DEBUG " __reserve_region_with_split: (%s) [%llx, %llx], res: (%s) [%llx, %llx]\n",
+ conflict->name, conflict->start, conflict->end,
+ name, start, end);
+
+ /* failed, split and try again */
+
+ /* conflict coverred whole area */
+ if (conflict->start <= start && conflict->end >= end)
+ return;
+
+ if (conflict->start > start)
+ __reserve_region_with_split(root, start, conflict->start-1, name);
+ if (!(conflict->flags & IORESOURCE_BUSY)) {
+ resource_size_t common_start, common_end;
+
+ common_start = max(conflict->start, start);
+ common_end = min(conflict->end, end);
+ if (common_start < common_end)
+ __reserve_region_with_split(root, common_start, common_end, name);
+ }
+ if (conflict->end < end)
+ __reserve_region_with_split(root, conflict->end+1, end, name);
+ }
+
+}
+
+void reserve_region_with_split(struct resource *root,
+ resource_size_t start, resource_size_t end,
+ const char *name)
+{
+ write_lock(&resource_lock);
+ __reserve_region_with_split(root, start, end, name);
+ write_unlock(&resource_lock);
+}
+
EXPORT_SYMBOL(adjust_resource);
/**