diff options
Diffstat (limited to 'drivers/dax')
| -rw-r--r-- | drivers/dax/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/dax/Makefile | 2 | ||||
| -rw-r--r-- | drivers/dax/cxl.c | 53 | ||||
| -rw-r--r-- | drivers/dax/hmem/hmem.c | 14 |
4 files changed, 82 insertions, 0 deletions
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig index 1163eb62e5f6..bd06e16c7ac8 100644 --- a/drivers/dax/Kconfig +++ b/drivers/dax/Kconfig @@ -45,6 +45,19 @@ config DEV_DAX_HMEM Say M if unsure. +config DEV_DAX_CXL + tristate "CXL DAX: direct access to CXL RAM regions" + depends on CXL_REGION && DEV_DAX + default CXL_REGION && DEV_DAX + help + CXL RAM regions are either mapped by platform-firmware + and published in the initial system-memory map as "System RAM", mapped + by platform-firmware as "Soft Reserved", or dynamically provisioned + after boot by the CXL driver. In the latter two cases a device-dax + instance is created to access that unmapped-by-default address range. + Per usual it can remain as dedicated access via a device interface, or + converted to "System RAM" via the dax_kmem facility. + config DEV_DAX_HMEM_DEVICES depends on DEV_DAX_HMEM && DAX def_bool y diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile index 90a56ca3b345..5ed5c39857c8 100644 --- a/drivers/dax/Makefile +++ b/drivers/dax/Makefile @@ -3,10 +3,12 @@ obj-$(CONFIG_DAX) += dax.o obj-$(CONFIG_DEV_DAX) += device_dax.o obj-$(CONFIG_DEV_DAX_KMEM) += kmem.o obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o +obj-$(CONFIG_DEV_DAX_CXL) += dax_cxl.o dax-y := super.o dax-y += bus.o device_dax-y := device.o dax_pmem-y := pmem.o +dax_cxl-y := cxl.o obj-y += hmem/ diff --git a/drivers/dax/cxl.c b/drivers/dax/cxl.c new file mode 100644 index 000000000000..ccdf8de85bd5 --- /dev/null +++ b/drivers/dax/cxl.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2023 Intel Corporation. All rights reserved. */ +#include <linux/module.h> +#include <linux/dax.h> + +#include "../cxl/cxl.h" +#include "bus.h" + +static int cxl_dax_region_probe(struct device *dev) +{ + struct cxl_dax_region *cxlr_dax = to_cxl_dax_region(dev); + int nid = phys_to_target_node(cxlr_dax->hpa_range.start); + struct cxl_region *cxlr = cxlr_dax->cxlr; + struct dax_region *dax_region; + struct dev_dax_data data; + struct dev_dax *dev_dax; + + if (nid == NUMA_NO_NODE) + nid = memory_add_physaddr_to_nid(cxlr_dax->hpa_range.start); + + dax_region = alloc_dax_region(dev, cxlr->id, &cxlr_dax->hpa_range, nid, + PMD_SIZE, IORESOURCE_DAX_KMEM); + if (!dax_region) + return -ENOMEM; + + data = (struct dev_dax_data) { + .dax_region = dax_region, + .id = -1, + .size = range_len(&cxlr_dax->hpa_range), + }; + dev_dax = devm_create_dev_dax(&data); + if (IS_ERR(dev_dax)) + return PTR_ERR(dev_dax); + + /* child dev_dax instances now own the lifetime of the dax_region */ + dax_region_put(dax_region); + return 0; +} + +static struct cxl_driver cxl_dax_region_driver = { + .name = "cxl_dax_region", + .probe = cxl_dax_region_probe, + .id = CXL_DEVICE_DAX_REGION, + .drv = { + .suppress_bind_attrs = true, + }, +}; + +module_cxl_driver(cxl_dax_region_driver); +MODULE_ALIAS_CXL(CXL_DEVICE_DAX_REGION); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_IMPORT_NS(CXL); 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"); |