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-rw-r--r--kernel/resource.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index e81b17b53fa5..92190f62ebc5 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -382,7 +382,7 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
int (*func)(struct resource *, void *))
{
struct resource res;
- int ret = -1;
+ int ret = -EINVAL;
while (start < end &&
!find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
@@ -452,6 +452,9 @@ int walk_mem_res(u64 start, u64 end, void *arg,
* 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 *))
@@ -460,14 +463,14 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
unsigned long flags;
struct resource res;
unsigned long pfn, end_pfn;
- int ret = -1;
+ int ret = -EINVAL;
start = (u64) start_pfn << PAGE_SHIFT;
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,
- true, &res)) {
+ false, &res)) {
pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
end_pfn = (res.end + 1) >> PAGE_SHIFT;
if (end_pfn > pfn)
@@ -1128,6 +1131,15 @@ struct resource * __request_region(struct resource *parent,
conflict = __request_resource(parent, res);
if (!conflict)
break;
+ /*
+ * mm/hmm.c reserves physical addresses which then
+ * become unavailable to other users. Conflicts are
+ * not expected. Warn to aid debugging if encountered.
+ */
+ if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
+ pr_warn("Unaddressable device %s %pR conflicts with %pR",
+ conflict->name, conflict, res);
+ }
if (conflict != parent) {
if (!(conflict->flags & IORESOURCE_BUSY)) {
parent = conflict;