diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2023-02-10 12:07:19 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2023-02-11 04:33:45 +0300 |
| commit | 09d09e04d2fcf88c4620dd28097e0e2a8f720eac (patch) | |
| tree | 21a7e381b6640bd12821f05fa9aa52f0dfb41cfd /drivers/dax/hmem | |
| parent | e9ee9fe3a9d4ae0e1e935fc2ec1218b66a043cae (diff) | |
| download | linux-09d09e04d2fcf88c4620dd28097e0e2a8f720eac.tar.xz | |
cxl/dax: Create dax devices for CXL RAM regions
While platform firmware takes some responsibility for mapping the RAM
capacity of CXL devices present at boot, the OS is responsible for
mapping the remainder and hot-added devices. Platform firmware is also
responsible for identifying the platform general purpose memory pool,
typically DDR attached DRAM, and arranging for the remainder to be 'Soft
Reserved'. That reservation allows the CXL subsystem to route the memory
to core-mm via memory-hotplug (dax_kmem), or leave it for dedicated
access (device-dax).
The new 'struct cxl_dax_region' object allows for a CXL memory resource
(region) to be published, but also allow for udev and module policy to
act on that event. It also prevents cxl_core.ko from having a module
loading dependency on any drivers/dax/ modules.
Tested-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/167602003896.1924368.10335442077318970468.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dax/hmem')
| -rw-r--r-- | drivers/dax/hmem/hmem.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c index 5ec08f9f8a57..e5fe8b39fb94 100644 --- a/drivers/dax/hmem/hmem.c +++ b/drivers/dax/hmem/hmem.c @@ -72,6 +72,13 @@ static int hmem_register_device(struct device *host, int target_nid, long id; int rc; + if (IS_ENABLED(CONFIG_CXL_REGION) && + region_intersects(res->start, resource_size(res), IORESOURCE_MEM, + IORES_DESC_CXL) != REGION_DISJOINT) { + dev_dbg(host, "deferring range to CXL: %pr\n", res); + return 0; + } + rc = region_intersects(res->start, resource_size(res), IORESOURCE_MEM, IORES_DESC_SOFT_RESERVED); if (rc != REGION_INTERSECTS) @@ -157,6 +164,13 @@ static __exit void dax_hmem_exit(void) module_init(dax_hmem_init); module_exit(dax_hmem_exit); +/* Allow for CXL to define its own dax regions */ +#if IS_ENABLED(CONFIG_CXL_REGION) +#if IS_MODULE(CONFIG_CXL_ACPI) +MODULE_SOFTDEP("pre: cxl_acpi"); +#endif +#endif + MODULE_ALIAS("platform:hmem*"); MODULE_ALIAS("platform:hmem_platform*"); MODULE_LICENSE("GPL v2"); |