Messages in this thread Patch in this message | | | From | Toshi Kani <> | Subject | [PATCH v3 1/4] resource: Change __request_region to inherit from immediate parent | Date | Wed, 9 Mar 2016 12:47:03 -0700 |
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__request_region() sets 'flags' of a new resource from @parent as it inherits the parent's attribute. When a target resource has a conflict, this function inserts the new resource entry under the conflicted entry by updating @parent. In this case, the new resource entry needs to inherit attribute from the updated parent. This conflict is a typical case since __request_region() is used to allocate a new resource from a specific resource range.
For instance, request_mem_region() calls __request_region() with @parent set to &iomem_resource, which is the root entry of the whole iomem range. When this request results in inserting a new entry "DEV-A" under "BUS-1", "DEV-A" needs to inherit from the immediate parent "BUS-1" as it holds specific attribute for the range.
root (&iomem_resource) : + "BUS-1" + "DEV-A"
Change __request_region() to set 'flags' and 'desc' of a new entry from the immediate parent.
Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> --- kernel/resource.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/resource.c b/kernel/resource.c index 4d46605..5a56e8f 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1085,15 +1085,16 @@ struct resource * __request_region(struct resource *parent, res->name = name; res->start = start; res->end = start + n - 1; - res->flags = resource_type(parent) | resource_ext_type(parent); - res->flags |= IORESOURCE_BUSY | flags; - res->desc = IORES_DESC_NONE; write_lock(&resource_lock); for (;;) { struct resource *conflict; + res->flags = resource_type(parent) | resource_ext_type(parent); + res->flags |= IORESOURCE_BUSY | flags; + res->desc = parent->desc; + conflict = __request_resource(parent, res); if (!conflict) break;
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