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 /drivers | |
| 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 'drivers')
| -rw-r--r-- | drivers/dax/hmem/device.c | 3 | ||||
| -rw-r--r-- | drivers/dax/hmem/hmem.c | 5 |
2 files changed, 4 insertions, 4 deletions
diff --git a/drivers/dax/hmem/device.c b/drivers/dax/hmem/device.c index f9e1a76a04a9..56e3cbd181b5 100644 --- a/drivers/dax/hmem/device.c +++ b/drivers/dax/hmem/device.c @@ -83,8 +83,7 @@ static __init int hmem_register_one(struct resource *res, void *data) static __init int hmem_init(void) { - walk_iomem_res_desc(IORES_DESC_SOFT_RESERVED, - IORESOURCE_MEM, 0, -1, NULL, hmem_register_one); + walk_soft_reserve_res(0, -1, NULL, hmem_register_one); return 0; } diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c index c18451a37e4f..1cf7c2a0ee1c 100644 --- a/drivers/dax/hmem/hmem.c +++ b/drivers/dax/hmem/hmem.c @@ -73,11 +73,12 @@ static int hmem_register_device(struct device *host, int target_nid, return 0; } - rc = region_intersects(res->start, resource_size(res), IORESOURCE_MEM, - IORES_DESC_SOFT_RESERVED); + rc = region_intersects_soft_reserve(res->start, resource_size(res)); if (rc != REGION_INTERSECTS) return 0; + /* TODO: Add Soft-Reserved memory back to iomem */ + id = memregion_alloc(GFP_KERNEL); if (id < 0) { dev_err(host, "memregion allocation failure for %pr\n", res); |