Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/resource.c b/kernel/resource.c
index 841737b..817545f 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -382,10 +382,13 @@
if (p) {
/* copy data */
- res->start = max(start, p->start);
- res->end = min(end, p->end);
- res->flags = p->flags;
- res->desc = p->desc;
+ *res = (struct resource) {
+ .start = max(start, p->start),
+ .end = min(end, p->end),
+ .flags = p->flags,
+ .desc = p->desc,
+ .parent = p->parent,
+ };
}
read_unlock(&resource_lock);
@@ -447,7 +450,7 @@
{
unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
- return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
+ return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false,
arg, func);
}
@@ -460,7 +463,7 @@
{
unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
- return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
+ return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, false,
arg, func);
}
@@ -1237,7 +1240,6 @@
#ifdef CONFIG_MEMORY_HOTREMOVE
/**
* release_mem_region_adjustable - release a previously reserved memory region
- * @parent: parent resource descriptor
* @start: resource start address
* @size: resource region size
*
@@ -1255,21 +1257,28 @@
* 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(resource_size_t start, resource_size_t size)
{
+ struct resource *parent = &iomem_resource;
+ 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);
@@ -1295,7 +1304,6 @@
* so if we are dealing with them, let us just back off here.
*/
if (!(res->flags & IORESOURCE_SYSRAM)) {
- ret = 0;
break;
}
@@ -1312,20 +1320,23 @@
/* 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;
@@ -1336,9 +1347,8 @@
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;
@@ -1349,10 +1359,69 @@
write_unlock(&resource_lock);
free_resource(new_res);
- return ret;
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
+#ifdef CONFIG_MEMORY_HOTPLUG
+static bool system_ram_resources_mergeable(struct resource *r1,
+ struct resource *r2)
+{
+ /* We assume either r1 or r2 is IORESOURCE_SYSRAM_MERGEABLE. */
+ return r1->flags == r2->flags && r1->end + 1 == r2->start &&
+ r1->name == r2->name && r1->desc == r2->desc &&
+ !r1->child && !r2->child;
+}
+
+/*
+ * merge_system_ram_resource - mark the System RAM resource mergeable and try to
+ * merge it with adjacent, mergeable resources
+ * @res: resource descriptor
+ *
+ * This interface is intended for memory hotplug, whereby lots of contiguous
+ * system ram resources are added (e.g., via add_memory*()) by a driver, and
+ * the actual resource boundaries are not of interest (e.g., it might be
+ * relevant for DIMMs). Only resources that are marked mergeable, that have the
+ * same parent, and that don't have any children are considered. All mergeable
+ * resources must be immutable during the request.
+ *
+ * Note:
+ * - The caller has to make sure that no pointers to resources that are
+ * marked mergeable are used anymore after this call - the resource might
+ * be freed and the pointer might be stale!
+ * - release_mem_region_adjustable() will split on demand on memory hotunplug
+ */
+void merge_system_ram_resource(struct resource *res)
+{
+ const unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+ struct resource *cur;
+
+ if (WARN_ON_ONCE((res->flags & flags) != flags))
+ return;
+
+ write_lock(&resource_lock);
+ res->flags |= IORESOURCE_SYSRAM_MERGEABLE;
+
+ /* Try to merge with next item in the list. */
+ cur = res->sibling;
+ if (cur && system_ram_resources_mergeable(res, cur)) {
+ res->end = cur->end;
+ res->sibling = cur->sibling;
+ free_resource(cur);
+ }
+
+ /* Try to merge with previous item in the list. */
+ cur = res->parent->child;
+ while (cur && cur->sibling != res)
+ cur = cur->sibling;
+ if (cur && system_ram_resources_mergeable(cur, res)) {
+ cur->end = res->end;
+ cur->sibling = res->sibling;
+ free_resource(res);
+ }
+ write_unlock(&resource_lock);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
/*
* Managed region resource
*/