From: Dan Williams Date: Thu, 13 Nov 2025 02:14:41 +0000 (-0800) Subject: resource: Introduce resource_assigned() for discerning active resources X-Git-Tag: v6.19-rc1~79^2~11 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c16af019d9d6d23f211c82b5561f2ecd2a7dff54;p=thirdparty%2Fkernel%2Flinux.git resource: Introduce resource_assigned() for discerning active resources A PCI bridge resource lifecycle involves both a "request" and "assign" phase. At any point in time that resource may not yet be assigned, or may have failed to assign (because it does not fit). There are multiple conventions to determine when assignment has not completed: IORESOURCE_UNSET, IORESOURCE_DISABLED, and checking whether the resource is parented. In code paths that are known to not be racing assignment, e.g. post subsys_initcall(), the most reliable method to judge that a bridge resource is assigned is to check the resource is parented [1]. Introduce a resource_assigned() helper for this purpose. Link: http://lore.kernel.org/2b9f7f7b-d6a4-be59-14d4-7b4ffccfe373@linux.intel.com [1] Suggested-by: Ilpo Järvinen Cc: Bjorn Helgaas Reviewed-by: Jonathan Cameron Link: https://patch.msgid.link/20251113021446.436830-4-dan.j.williams@intel.com Signed-off-by: Dan Williams --- diff --git a/include/linux/ioport.h b/include/linux/ioport.h index e8b2d6aa40135..9afa30f9346fc 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -334,6 +334,15 @@ static inline bool resource_union(const struct resource *r1, const struct resour return true; } +/* + * Check if this resource is added to a resource tree or detached. Caller is + * responsible for not racing assignment. + */ +static inline bool resource_assigned(struct resource *res) +{ + return res->parent; +} + int find_resource_space(struct resource *root, struct resource *new, resource_size_t size, struct resource_constraint *constraint);