Messages in this thread Patch in this message | | | Subject | [PATCH 4/5] resource: Report parent to walk_iomem_res_desc() callback | From | Dan Williams <> | Date | Mon, 02 Mar 2020 14:20:20 -0800 |
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In support of detecting whether a resource might have been been claimed, report the parent to the walk_iomem_res_desc() callback. For example, the ACPI HMAT parser publishes "hmem" platform devices per target range. However, if the HMAT is disabled / missing a fallback driver can attach devices to the raw memory ranges as a fallback if it sees unclaimed / orphan "Soft Reserved" resources in the resource tree.
Otherwise, find_next_iomem_res() returns a resource with garbage data from the stack allocation in __walk_iomem_res_desc() for the res->parent field.
Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- kernel/resource.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/kernel/resource.c b/kernel/resource.c index 76036a41143b..6e22e312fd55 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -386,6 +386,7 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end, res->end = min(end, p->end); res->flags = p->flags; res->desc = p->desc; + res->parent = p->parent; } read_unlock(&resource_lock);
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