diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/resource.c | 49 |
1 files changed, 28 insertions, 21 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index f1175ce93a1d..4c1c487abbfb 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1258,21 +1258,28 @@ EXPORT_SYMBOL(__release_region); * assumes that all children remain in the lower address entry for * simplicity. Enhance this logic when necessary. */ -int release_mem_region_adjustable(struct resource *parent, - resource_size_t start, resource_size_t size) +void release_mem_region_adjustable(struct resource *parent, + resource_size_t start, resource_size_t size) { + struct resource *new_res = NULL; + bool alloc_nofail = false; struct resource **p; struct resource *res; - struct resource *new_res; resource_size_t end; - int ret = -EINVAL; end = start + size - 1; - if ((start < parent->start) || (end > parent->end)) - return ret; + if (WARN_ON_ONCE((start < parent->start) || (end > parent->end))) + return; - /* The alloc_resource() result gets checked later */ - new_res = alloc_resource(GFP_KERNEL); + /* + * We free up quite a lot of memory on memory hotunplug (esp., memap), + * just before releasing the region. This is highly unlikely to + * fail - let's play save and make it never fail as the caller cannot + * perform any error handling (e.g., trying to re-add memory will fail + * similarly). + */ +retry: + new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0)); p = &parent->child; write_lock(&resource_lock); @@ -1298,7 +1305,6 @@ int release_mem_region_adjustable(struct resource *parent, * so if we are dealing with them, let us just back off here. */ if (!(res->flags & IORESOURCE_SYSRAM)) { - ret = 0; break; } @@ -1315,20 +1321,23 @@ int release_mem_region_adjustable(struct resource *parent, /* free the whole entry */ *p = res->sibling; free_resource(res); - ret = 0; } else if (res->start == start && res->end != end) { /* adjust the start */ - ret = __adjust_resource(res, end + 1, - res->end - end); + WARN_ON_ONCE(__adjust_resource(res, end + 1, + res->end - end)); } else if (res->start != start && res->end == end) { /* adjust the end */ - ret = __adjust_resource(res, res->start, - start - res->start); + WARN_ON_ONCE(__adjust_resource(res, res->start, + start - res->start)); } else { - /* split into two entries */ + /* split into two entries - we need a new resource */ if (!new_res) { - ret = -ENOMEM; - break; + new_res = alloc_resource(GFP_ATOMIC); + if (!new_res) { + alloc_nofail = true; + write_unlock(&resource_lock); + goto retry; + } } new_res->name = res->name; new_res->start = end + 1; @@ -1339,9 +1348,8 @@ int release_mem_region_adjustable(struct resource *parent, new_res->sibling = res->sibling; new_res->child = NULL; - ret = __adjust_resource(res, res->start, - start - res->start); - if (ret) + if (WARN_ON_ONCE(__adjust_resource(res, res->start, + start - res->start))) break; res->sibling = new_res; new_res = NULL; @@ -1352,7 +1360,6 @@ int release_mem_region_adjustable(struct resource *parent, write_unlock(&resource_lock); free_resource(new_res); - return ret; } #endif /* CONFIG_MEMORY_HOTREMOVE */ |