From bef69ea0dcce574a425feb0a5aa4c63dd108b9a6 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 29 Aug 2008 20:18:31 -0700 Subject: Resource handling: add 'insert_resource_expand_to_fit()' function Not used anywhere yet, but this complements the existing plain 'insert_resource()' functionality with a version that can expand the resource we are adding in order to fix up any conflicts it has with existing resources. Signed-off-by: Linus Torvalds --- kernel/resource.c | 88 +++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 63 insertions(+), 25 deletions(-) (limited to 'kernel/resource.c') diff --git a/kernel/resource.c b/kernel/resource.c index f5b518eabef..cf0a178c751 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -362,35 +362,21 @@ int allocate_resource(struct resource *root, struct resource *new, EXPORT_SYMBOL(allocate_resource); -/** - * 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. - * - * 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. +/* + * Insert a resource into the resource tree. If successful, return NULL, + * otherwise return the conflicting resource (compare to __request_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 *first, *next; - write_lock(&resource_lock); - for (;; parent = first) { - result = 0; first = __request_resource(parent, new); if (!first) - goto out; + return first; - result = -EBUSY; if (first == parent) - goto out; + return first; if ((first->start > new->start) || (first->end < new->end)) break; @@ -401,15 +387,13 @@ int insert_resource(struct resource *parent, struct resource *new) for (next = first; ; next = next->sibling) { /* Partial overlap? Bad, and unfixable */ if (next->start < new->start || next->end > new->end) - goto out; + return next; if (!next->sibling) break; if (next->sibling->start > new->end) break; } - result = 0; - new->parent = parent; new->sibling = next->sibling; new->child = first; @@ -426,10 +410,64 @@ int insert_resource(struct resource *parent, struct resource *new) next = next->sibling; next->sibling = new; } + return NULL; +} - out: +/** + * 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. + * + * 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) +{ + struct resource *conflict; + + write_lock(&resource_lock); + conflict = __insert_resource(parent, new); + write_unlock(&resource_lock); + return conflict ? -EBUSY : 0; +} + +/** + * insert_resource_expand_to_fit - Insert a resource into the resource tree + * @parent: parent of the new resource + * @new: new resource to insert + * + * Insert a resource into the resource tree, possibly expanding it in order + * to make it encompass any conflicting resources. + */ +void insert_resource_expand_to_fit(struct resource *root, struct resource *new) +{ + if (new->parent) + return; + + write_lock(&resource_lock); + for (;;) { + struct resource *conflict; + + conflict = __insert_resource(root, new); + if (!conflict) + break; + if (conflict == root) + break; + + /* Ok, expand resource to cover the conflict, then try again .. */ + if (conflict->start < new->start) + new->start = conflict->start; + if (conflict->end > new->end) + new->end = conflict->end; + + printk("Expanded resource %s due to conflict with %s\n", new->name, conflict->name); + } write_unlock(&resource_lock); - return result; } /** -- cgit v1.2.3-70-g09d2 From 6781f4ae30bbb8ebf31187b3c9304be16966f5a0 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Sun, 31 Aug 2008 20:31:55 -0700 Subject: kernel/resource.c: fix new kernel-doc warning Fix kernel-doc warning for new function: Warning(linux-2.6.27-rc5-git2//kernel/resource.c:448): No description found for parameter 'root' Signed-off-by: Randy Dunlap Signed-off-by: Linus Torvalds --- kernel/resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/resource.c') diff --git a/kernel/resource.c b/kernel/resource.c index cf0a178c751..03d796c1b2e 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -438,7 +438,7 @@ int insert_resource(struct resource *parent, struct resource *new) /** * insert_resource_expand_to_fit - Insert a resource into the resource tree - * @parent: parent of the new resource + * @root: root resource descriptor * @new: new resource to insert * * Insert a resource into the resource tree, possibly expanding it in order -- cgit v1.2.3-70-g09d2 From 268364a0f48aee2f851f9d1ef8a6cda0f3039ef1 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 4 Sep 2008 21:02:44 +0200 Subject: 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 Signed-off-by: Ingo Molnar --- include/linux/ioport.h | 3 +++ kernel/resource.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 71 insertions(+) (limited to 'kernel/resource.c') diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 8d3b7a9afd1..fded376b94e 100644 --- a/include/linux/ioport.h +++ b/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, + const char *name); extern int insert_resource(struct resource *parent, struct resource *new); extern void insert_resource_expand_to_fit(struct resource *root, struct resource *new); extern int allocate_resource(struct resource *root, struct resource *new, 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); /** -- cgit v1.2.3-70-g09d2