diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2025-11-20 03:19:17 +0000 |
|---|---|---|
| committer | Dave Jiang <dave.jiang@intel.com> | 2026-01-16 09:02:36 -0700 |
| commit | bc62f5b308cbdedf29132fe96e9d591e526527e1 (patch) | |
| tree | 56c7ebfbe7d47906e747b4cc601cb17b3f7feb38 /include | |
| parent | 29317f8dc6ed601ec54575689c2cd55cc470bcce (diff) | |
dax/hmem, e820, resource: Defer Soft Reserved insertion until hmem is ready
Insert Soft Reserved memory into a dedicated soft_reserve_resource tree
instead of the iomem_resource tree at boot. Delay publishing these ranges
into the iomem hierarchy until ownership is resolved and the HMEM path
is ready to consume them.
Publishing Soft Reserved ranges into iomem too early conflicts with CXL
hotplug and prevents region assembly when those ranges overlap CXL
windows.
Follow up patches will reinsert Soft Reserved ranges into iomem after CXL
window publication is complete and HMEM is ready to claim the memory. This
provides a cleaner handoff between EFI-defined memory ranges and CXL
resource management without trimming or deleting resources later.
In the meantime "Soft Reserved" resources will no longer appear in
/proc/iomem, only their results. I.e. with "memmap=4G%4G+0xefffffff"
Before:
100000000-1ffffffff : Soft Reserved
100000000-1ffffffff : dax1.0
100000000-1ffffffff : System RAM (kmem)
After:
100000000-1ffffffff : dax1.0
100000000-1ffffffff : System RAM (kmem)
The expectation is that this does not lead to a user visible regression
because the dax1.0 device is created in both instances.
Co-developed-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
[Smita: incorporate feedback from x86 maintainer review]
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Link: https://patch.msgid.link/20251120031925.87762-2-Smita.KoralahalliChannabasappa@amd.com
[djbw: cleanups and clarifications]
Link: https://lore.kernel.org/69443f707b025_1cee10022@dwillia2-mobl4.notmuch
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/ioport.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 9afa30f9346f..95662b2fb458 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -232,6 +232,7 @@ struct resource_constraint { /* PC/ISA/whatever - the normal PC address spaces: IO and memory */ extern struct resource ioport_resource; extern struct resource iomem_resource; +extern struct resource soft_reserve_resource; extern struct resource *request_resource_conflict(struct resource *root, struct resource *new); extern int request_resource(struct resource *root, struct resource *new); @@ -418,6 +419,10 @@ walk_system_ram_res_rev(u64 start, u64 end, void *arg, extern int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)); +extern int walk_soft_reserve_res(u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)); +extern int +region_intersects_soft_reserve(resource_size_t start, size_t size); struct resource *devm_request_free_mem_region(struct device *dev, struct resource *base, unsigned long size); |