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Diffstat (limited to 'kernel/resource.c')
-rw-r--r--kernel/resource.c194
1 files changed, 113 insertions, 81 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index 627e61b0c124..028a5ab18818 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -64,12 +64,8 @@ static DEFINE_RWLOCK(resource_lock);
static struct resource *bootmem_resource_free;
static DEFINE_SPINLOCK(bootmem_resource_lock);
-static struct resource *next_resource(struct resource *p, bool sibling_only)
+static struct resource *next_resource(struct resource *p)
{
- /* Caller wants to traverse through siblings only */
- if (sibling_only)
- return p->sibling;
-
if (p->child)
return p->child;
while (!p->sibling && p->parent)
@@ -81,7 +77,7 @@ static void *r_next(struct seq_file *m, void *v, loff_t *pos)
{
struct resource *p = v;
(*pos)++;
- return (void *)next_resource(p, false);
+ return (void *)next_resource(p);
}
#ifdef CONFIG_PROC_FS
@@ -330,14 +326,10 @@ EXPORT_SYMBOL(release_resource);
* of the resource that's within [@start..@end]; if none is found, returns
* -ENODEV. Returns -EINVAL for invalid parameters.
*
- * This function walks the whole tree and not just first level children
- * unless @first_lvl is true.
- *
* @start: start address of the resource searched for
* @end: end address of same resource
* @flags: flags which the resource must have
* @desc: descriptor the resource must have
- * @first_lvl: walk only the first level children, if set
* @res: return ptr, if resource found
*
* The caller must specify @start, @end, @flags, and @desc
@@ -345,9 +337,8 @@ EXPORT_SYMBOL(release_resource);
*/
static int find_next_iomem_res(resource_size_t start, resource_size_t end,
unsigned long flags, unsigned long desc,
- bool first_lvl, struct resource *res)
+ struct resource *res)
{
- bool siblings_only = true;
struct resource *p;
if (!res)
@@ -358,7 +349,7 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
read_lock(&resource_lock);
- for (p = iomem_resource.child; p; p = next_resource(p, siblings_only)) {
+ for (p = iomem_resource.child; p; p = next_resource(p)) {
/* If we passed the resource we are looking for, stop */
if (p->start > end) {
p = NULL;
@@ -369,13 +360,6 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
if (p->end < start)
continue;
- /*
- * Now that we found a range that matches what we look for,
- * check the flags and the descriptor. If we were not asked to
- * use only the first level, start looking at children as well.
- */
- siblings_only = first_lvl;
-
if ((p->flags & flags) != flags)
continue;
if ((desc != IORES_DESC_NONE) && (desc != p->desc))
@@ -402,14 +386,14 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
unsigned long flags, unsigned long desc,
- bool first_lvl, void *arg,
+ void *arg,
int (*func)(struct resource *, void *))
{
struct resource res;
int ret = -EINVAL;
while (start < end &&
- !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
+ !find_next_iomem_res(start, end, flags, desc, &res)) {
ret = (*func)(&res, arg);
if (ret)
break;
@@ -431,7 +415,6 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
* @arg: function argument for the callback @func
* @func: callback function that is called for each qualifying resource area
*
- * This walks through whole tree and not just first level children.
* All the memory ranges which overlap start,end and also match flags and
* desc are valid candidates.
*
@@ -441,7 +424,7 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
u64 end, void *arg, int (*func)(struct resource *, void *))
{
- return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func);
+ return __walk_iomem_res_desc(start, end, flags, desc, arg, func);
}
EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
@@ -457,8 +440,8 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
{
unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
- return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
- arg, func);
+ return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
+ func);
}
/*
@@ -470,17 +453,14 @@ int walk_mem_res(u64 start, u64 end, void *arg,
{
unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
- return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
- arg, func);
+ return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, arg,
+ func);
}
/*
* This function calls the @func callback against all memory ranges of type
* System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
* It is to be used only for System RAM.
- *
- * This will find System RAM ranges that are children of top-level resources
- * in addition to top-level System RAM resources.
*/
int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
void *arg, int (*func)(unsigned long, unsigned long, void *))
@@ -495,8 +475,7 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
while (start < end &&
- !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
- false, &res)) {
+ !find_next_iomem_res(start, end, flags, IORES_DESC_NONE, &res)) {
pfn = PFN_UP(res.start);
end_pfn = PFN_DOWN(res.end + 1);
if (end_pfn > pfn)
@@ -523,6 +502,34 @@ int __weak page_is_ram(unsigned long pfn)
}
EXPORT_SYMBOL_GPL(page_is_ram);
+static int __region_intersects(resource_size_t start, size_t size,
+ unsigned long flags, unsigned long desc)
+{
+ struct resource res;
+ int type = 0; int other = 0;
+ struct resource *p;
+
+ res.start = start;
+ res.end = start + size - 1;
+
+ for (p = iomem_resource.child; p ; p = p->sibling) {
+ bool is_type = (((p->flags & flags) == flags) &&
+ ((desc == IORES_DESC_NONE) ||
+ (desc == p->desc)));
+
+ if (resource_overlaps(p, &res))
+ is_type ? type++ : other++;
+ }
+
+ if (type == 0)
+ return REGION_DISJOINT;
+
+ if (other == 0)
+ return REGION_INTERSECTS;
+
+ return REGION_MIXED;
+}
+
/**
* region_intersects() - determine intersection of region with known resources
* @start: region start address
@@ -546,31 +553,13 @@ EXPORT_SYMBOL_GPL(page_is_ram);
int region_intersects(resource_size_t start, size_t size, unsigned long flags,
unsigned long desc)
{
- struct resource res;
- int type = 0; int other = 0;
- struct resource *p;
-
- res.start = start;
- res.end = start + size - 1;
+ int ret;
read_lock(&resource_lock);
- for (p = iomem_resource.child; p ; p = p->sibling) {
- bool is_type = (((p->flags & flags) == flags) &&
- ((desc == IORES_DESC_NONE) ||
- (desc == p->desc)));
-
- if (resource_overlaps(p, &res))
- is_type ? type++ : other++;
- }
+ ret = __region_intersects(start, size, flags, desc);
read_unlock(&resource_lock);
- if (type == 0)
- return REGION_DISJOINT;
-
- if (other == 0)
- return REGION_INTERSECTS;
-
- return REGION_MIXED;
+ return ret;
}
EXPORT_SYMBOL_GPL(region_intersects);
@@ -1171,31 +1160,16 @@ struct address_space *iomem_get_mapping(void)
return smp_load_acquire(&iomem_inode)->i_mapping;
}
-/**
- * __request_region - create a new busy resource region
- * @parent: parent resource descriptor
- * @start: resource start address
- * @n: resource region size
- * @name: reserving caller's ID string
- * @flags: IO resource flags
- */
-struct resource * __request_region(struct resource *parent,
+static int __request_region_locked(struct resource *res, struct resource *parent,
resource_size_t start, resource_size_t n,
const char *name, int flags)
{
DECLARE_WAITQUEUE(wait, current);
- struct resource *res = alloc_resource(GFP_KERNEL);
- struct resource *orig_parent = parent;
-
- if (!res)
- return NULL;
res->name = name;
res->start = start;
res->end = start + n - 1;
- write_lock(&resource_lock);
-
for (;;) {
struct resource *conflict;
@@ -1231,13 +1205,40 @@ struct resource * __request_region(struct resource *parent,
continue;
}
/* Uhhuh, that didn't work out.. */
- free_resource(res);
- res = NULL;
- break;
+ return -EBUSY;
}
+
+ return 0;
+}
+
+/**
+ * __request_region - create a new busy resource region
+ * @parent: parent resource descriptor
+ * @start: resource start address
+ * @n: resource region size
+ * @name: reserving caller's ID string
+ * @flags: IO resource flags
+ */
+struct resource *__request_region(struct resource *parent,
+ resource_size_t start, resource_size_t n,
+ const char *name, int flags)
+{
+ struct resource *res = alloc_resource(GFP_KERNEL);
+ int ret;
+
+ if (!res)
+ return NULL;
+
+ write_lock(&resource_lock);
+ ret = __request_region_locked(res, parent, start, n, name, flags);
write_unlock(&resource_lock);
- if (res && orig_parent == &iomem_resource)
+ if (ret) {
+ free_resource(res);
+ return NULL;
+ }
+
+ if (parent == &iomem_resource)
revoke_iomem(res);
return res;
@@ -1779,25 +1780,56 @@ static struct resource *__request_free_mem_region(struct device *dev,
{
resource_size_t end, addr;
struct resource *res;
+ struct region_devres *dr = NULL;
size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
end = min_t(unsigned long, base->end, (1UL << MAX_PHYSMEM_BITS) - 1);
addr = end - size + 1UL;
+ res = alloc_resource(GFP_KERNEL);
+ if (!res)
+ return ERR_PTR(-ENOMEM);
+
+ if (dev) {
+ dr = devres_alloc(devm_region_release,
+ sizeof(struct region_devres), GFP_KERNEL);
+ if (!dr) {
+ free_resource(res);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+
+ write_lock(&resource_lock);
for (; addr > size && addr >= base->start; addr -= size) {
- if (region_intersects(addr, size, 0, IORES_DESC_NONE) !=
+ if (__region_intersects(addr, size, 0, IORES_DESC_NONE) !=
REGION_DISJOINT)
continue;
- if (dev)
- res = devm_request_mem_region(dev, addr, size, name);
- else
- res = request_mem_region(addr, size, name);
- if (!res)
- return ERR_PTR(-ENOMEM);
+ if (!__request_region_locked(res, &iomem_resource, addr, size,
+ name, 0))
+ break;
+
+ if (dev) {
+ dr->parent = &iomem_resource;
+ dr->start = addr;
+ dr->n = size;
+ devres_add(dev, dr);
+ }
+
res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
+ write_unlock(&resource_lock);
+
+ /*
+ * A driver is claiming this region so revoke any mappings.
+ */
+ revoke_iomem(res);
return res;
}
+ write_unlock(&resource_lock);
+
+ free_resource(res);
+ if (dr)
+ devres_free(dr);
return ERR_PTR(-ERANGE);
}