LIBNVDIMM supports the creation of regions for both persistent and volatile memory ranges. The cxl_region driver is capable of handling the CXL side of region creation but will reuse LIBVDIMM for interfacing with the rest of the kernel.
TODO: CXL regions can go away. As a result the nd_region must also be torn down. TODO2: Handle mappings. LIBNVDIMM is capable of being informed about which parts of devices contribute to a region and validating whether or not the region is configured properly. To do this properly requires tracking allocations per device. Reported-by: kernel test robot <[email protected]> (v2) Signed-off-by: Ben Widawsky <[email protected]> --- Changes since v2: - Check nvb is non-null - Give a dev_dbg for non-existent nvdimm_bus --- drivers/cxl/Kconfig | 3 ++- drivers/cxl/core/pmem.c | 16 ++++++++++++ drivers/cxl/cxl.h | 1 + drivers/cxl/region.c | 58 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 77 insertions(+), 1 deletion(-) diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 742847503c16..054dc78d6f7d 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -99,7 +99,8 @@ config CXL_PORT tristate config CXL_REGION - default CXL_PORT + depends on CXL_PMEM + default CXL_BUS tristate endif diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c index 7e431667ade1..58dc6fba3130 100644 --- a/drivers/cxl/core/pmem.c +++ b/drivers/cxl/core/pmem.c @@ -220,6 +220,22 @@ struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev) } EXPORT_SYMBOL_NS_GPL(to_cxl_nvdimm, CXL); +static int match_cxl_nvdimm(struct device *dev, void *data) +{ + return is_cxl_nvdimm(dev); +} + +struct cxl_nvdimm *cxl_find_nvdimm(struct cxl_memdev *cxlmd) +{ + struct device *dev; + + dev = device_find_child(&cxlmd->dev, NULL, match_cxl_nvdimm); + if (!dev) + return NULL; + return to_cxl_nvdimm(dev); +} +EXPORT_SYMBOL_NS_GPL(cxl_find_nvdimm, CXL); + static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd) { struct cxl_nvdimm *cxl_nvd; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 062654204eca..7eb8f36af30b 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -480,6 +480,7 @@ bool is_cxl_nvdimm(struct device *dev); bool is_cxl_nvdimm_bridge(struct device *dev); int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd); struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct device *dev); +struct cxl_nvdimm *cxl_find_nvdimm(struct cxl_memdev *cxlmd); /* * Unit test builds overrides this to __weak, find the 'strong' version diff --git a/drivers/cxl/region.c b/drivers/cxl/region.c index ac290677534d..be472560fc6a 100644 --- a/drivers/cxl/region.c +++ b/drivers/cxl/region.c @@ -708,6 +708,58 @@ static int bind_region(struct cxl_region *cxlr) return rc; } +static int connect_to_libnvdimm(struct cxl_region *region) +{ + struct nd_region_desc ndr_desc; + struct cxl_nvdimm_bridge *nvb; + struct nd_region *ndr; + int rc = 0; + + nvb = cxl_find_nvdimm_bridge(®ion->config.targets[0]->dev); + if (!nvb) { + dev_dbg(®ion->dev, "Couldn't find nvdimm bridge\n"); + return -ENODEV; + } + + device_lock(&nvb->dev); + if (!nvb->nvdimm_bus) { + dev_dbg(&nvb->dev, "Couldn't find nvdimm bridge's bus\n"); + rc = -ENXIO; + goto out; + } + + memset(&ndr_desc, 0, sizeof(ndr_desc)); + + ndr_desc.res = region->res; + + ndr_desc.numa_node = memory_add_physaddr_to_nid(region->res->start); + ndr_desc.target_node = phys_to_target_node(region->res->start); + if (ndr_desc.numa_node == NUMA_NO_NODE) { + ndr_desc.numa_node = + memory_add_physaddr_to_nid(region->res->start); + dev_info(®ion->dev, + "changing numa node from %d to %d for CXL region %pR", + NUMA_NO_NODE, ndr_desc.numa_node, region->res); + } + if (ndr_desc.target_node == NUMA_NO_NODE) { + ndr_desc.target_node = ndr_desc.numa_node; + dev_info(®ion->dev, + "changing target node from %d to %d for CXL region %pR", + NUMA_NO_NODE, ndr_desc.target_node, region->res); + } + + ndr = nvdimm_pmem_region_create(nvb->nvdimm_bus, &ndr_desc); + if (IS_ERR(ndr)) + rc = PTR_ERR(ndr); + else + dev_set_drvdata(®ion->dev, ndr); + +out: + device_unlock(&nvb->dev); + put_device(&nvb->dev); + return rc; +} + static void region_unregister(void *dev) { struct cxl_region *region = to_cxl_region(dev); @@ -791,6 +843,12 @@ static int cxl_region_probe(struct device *dev) return ret; } + ret = connect_to_libnvdimm(cxlr); + if (ret) { + region_unregister(dev); + return ret; + } + cxlr->active = true; dev_info(dev, "Bound"); return devm_add_action_or_reset(dev, region_unregister, dev); -- 2.35.0
