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Message-Id: <1220083122-4058-4-git-send-email-yhlu.kernel@gmail.com>
Date: Sat, 30 Aug 2008 00:58:42 -0700
From: Yinghai Lu <yhlu.kernel@...il.com>
To: Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Jesse Barnes <jbarnes@...tuousgeek.org>,
Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, Yinghai Lu <yhlu.kernel@...il.com>
Subject: [PATCH] x86: split e820 reserved entries record to late v4 - fix v3
try to insert_resource second time, by expand the resource...
for case: e820 reserved entry is partially overlapped with bar res...
hope it will never happen
v2: according to Linus, add insert_resource_expand_to_fit, and change
__insert_resource to static without lock
v3: use reserve_region_with_split() instead to hand overlapping
with test case by extend 0xe0000000 - 0xeffffff to 0xdd800000 -
get
e0000000-efffffff : PCI MMCONFIG 0
e0000000-efffffff : reserved
in /proc/iomem
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
Signed-off-by: Yinghai Lu <yhlu.kernel@...il.com>
---
arch/x86/kernel/e820.c | 8 +++-
include/linux/ioport.h | 3 +
kernel/resource.c | 95 ++++++++++++++++++++++++++++++++++++++++++-------
3 files changed, 92 insertions(+), 14 deletions(-)
Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -1319,8 +1319,12 @@ void __init e820_reserve_resources_late(
res = e820_res;
for (i = 0; i < e820.nr_map; i++) {
- if (!res->parent && res->end)
- insert_resource(&iomem_resource, res);
+ if (!res->parent && res->end && insert_resource(&iomem_resource, res)) {
+ printk(KERN_WARNING "found conflict for %s [%08llx, %08llx], try to reserve with split\n",
+ res->name, res->start, res->end);
+
+ reserve_region_with_split(&iomem_resource, res->start, res->end, res->name);
+ }
res++;
}
}
Index: linux-2.6/include/linux/ioport.h
===================================================================
--- linux-2.6.orig/include/linux/ioport.h
+++ linux-2.6/include/linux/ioport.h
@@ -108,6 +108,9 @@ extern struct resource iomem_resource;
extern int request_resource(struct resource *root, struct resource *new);
extern int release_resource(struct resource *new);
+extern void reserve_region_with_split(struct resource *root,
+ resource_size_t start, resource_size_t end,
+ char *name);
extern int insert_resource(struct resource *parent, struct resource *new);
extern int allocate_resource(struct resource *root, struct resource *new,
resource_size_t size, resource_size_t min,
Index: linux-2.6/kernel/resource.c
===================================================================
--- linux-2.6.orig/kernel/resource.c
+++ linux-2.6/kernel/resource.c
@@ -363,32 +363,30 @@ int allocate_resource(struct resource *r
EXPORT_SYMBOL(allocate_resource);
/**
- * insert_resource - Inserts a resource in the resource tree
+ * __insert_resource - Inserts a resource in the resource tree
* @parent: parent of the new resource
* @new: new resource to insert
*
- * Returns 0 on success, -EBUSY if the resource can't be inserted.
+ * Returns NULL on success, or first conflict resource.
*
- * This function is equivalent to request_resource when no conflict
+ * This function is equivalent to __request_resource when no conflict
* happens. If a conflict happens, and the conflicting resources
* entirely fit within the range of the new resource, then the new
* resource is inserted and the conflicting resources become children of
* the new resource.
*/
-int insert_resource(struct resource *parent, struct resource *new)
+static struct resource *__insert_resource(struct resource *parent, struct resource *new)
{
- int result;
+ struct resource *ret_res;
struct resource *first, *next;
- write_lock(&resource_lock);
-
for (;; parent = first) {
- result = 0;
+ ret_res = NULL;
first = __request_resource(parent, new);
if (!first)
goto out;
- result = -EBUSY;
+ ret_res = first;
if (first == parent)
goto out;
@@ -400,15 +398,17 @@ int insert_resource(struct resource *par
for (next = first; ; next = next->sibling) {
/* Partial overlap? Bad, and unfixable */
- if (next->start < new->start || next->end > new->end)
+ if (next->start < new->start || next->end > new->end) {
+ ret_res = next;
goto out;
+ }
if (!next->sibling)
break;
if (next->sibling->start > new->end)
break;
}
- result = 0;
+ ret_res = NULL;
new->parent = parent;
new->sibling = next->sibling;
@@ -428,8 +428,79 @@ int insert_resource(struct resource *par
}
out:
+ return ret_res;
+}
+
+/**
+ * insert_resource - Inserts a resource in the resource tree
+ * @parent: parent of the new resource
+ * @new: new resource to insert
+ *
+ * Returns 0 on success, -EBUSY if the resource can't be inserted.
+ */
+int insert_resource(struct resource *parent, struct resource *new)
+{
+ struct resource *res_conflict;
+
+ write_lock(&resource_lock);
+ res_conflict = __insert_resource(parent, new);
+ write_unlock(&resource_lock);
+
+ return res_conflict ? -EBUSY : 0;
+}
+
+static void __init __reserve_region_with_split(struct resource *root,
+ resource_size_t start, resource_size_t end,
+ 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 */
+ if (conflict->start > start)
+ __reserve_region_with_split(root, start, conflict->start, 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,
+ char *name)
+{
+ write_lock(&resource_lock);
+ __reserve_region_with_split(root, start, end, name);
write_unlock(&resource_lock);
- return result;
}
/**
--
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