cxl/region: Drop redundant pmem region release handling

Now that a cxl_nvdimm object can only experience ->remove() via an
unregistration event (because the cxl_nvdimm bind attributes are
suppressed), additional cleanups are possible.

It is already the case that the removal of a cxl_memdev object triggers
->remove() on any associated region. With that mechanism in place there
is no need for the cxl_nvdimm removal to trigger the same. Just rely on
cxl_region_detach() to tear down the whole cxl_pmem_region.

Tested-by: Robert Richter <rrichter@amd.com>
Link: https://lore.kernel.org/r/166993041215.1882361.6321535567798911286.stgit@dwillia2-xfh.jf.intel.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c
index 36aa5070d90241e530c35c7ed3faeeb8df162594..1d12a8206444ef759a14e143f9c3eb7c084b4930 100644 (file)
--- a/drivers/cxl/core/pmem.c
+++ b/drivers/cxl/core/pmem.c
@@ -188,7 +188,6 @@ static void cxl_nvdimm_release(struct device *dev)
 {
        struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev);
 
-       xa_destroy(&cxl_nvd->pmem_regions);
        kfree(cxl_nvd);
 }
 
@@ -231,7 +230,6 @@ static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd)
 
        dev = &cxl_nvd->dev;
        cxl_nvd->cxlmd = cxlmd;
-       xa_init(&cxl_nvd->pmem_regions);
        device_initialize(dev);
        lockdep_set_class(&dev->mutex, &cxl_nvdimm_key);
        device_set_pm_not_required(dev);

diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 7d07127eade3c1490d0a477266f82507845db81b..4ac7938eaf6ca470d726c257c59f57c7ee7af87d 100644 (file)
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -424,7 +424,6 @@ struct cxl_nvdimm {
        struct device dev;
        struct cxl_memdev *cxlmd;
        struct cxl_nvdimm_bridge *bridge;
-       struct xarray pmem_regions;
 };
 
 struct cxl_pmem_region_mapping {

diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
index 946e171e7d4a9fa303a1aff60d91f50cae315345..652f00fc68cac7860ddabbb8e94bb0196c67f5e1 100644 (file)
--- a/drivers/cxl/pmem.c
+++ b/drivers/cxl/pmem.c
@@ -27,26 +27,7 @@ static void clear_exclusive(void *cxlds)
 
 static void unregister_nvdimm(void *nvdimm)
 {
-       struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
-       struct cxl_nvdimm_bridge *cxl_nvb = cxl_nvd->bridge;
-       struct cxl_pmem_region *cxlr_pmem;
-       unsigned long index;
-
-       device_lock(&cxl_nvb->dev);
-       dev_set_drvdata(&cxl_nvd->dev, NULL);
-       xa_for_each(&cxl_nvd->pmem_regions, index, cxlr_pmem) {
-               get_device(&cxlr_pmem->dev);
-               device_unlock(&cxl_nvb->dev);
-
-               device_release_driver(&cxlr_pmem->dev);
-               put_device(&cxlr_pmem->dev);
-
-               device_lock(&cxl_nvb->dev);
-       }
-       device_unlock(&cxl_nvb->dev);
-
        nvdimm_delete(nvdimm);
-       cxl_nvd->bridge = NULL;
 }
 
 static int cxl_nvdimm_probe(struct device *dev)
@@ -243,21 +224,6 @@ static int cxl_nvdimm_release_driver(struct device *dev, void *cxl_nvb)
        return 0;
 }
 
-static int cxl_pmem_region_release_driver(struct device *dev, void *cxl_nvb)
-{
-       struct cxl_pmem_region *cxlr_pmem;
-
-       if (!is_cxl_pmem_region(dev))
-               return 0;
-
-       cxlr_pmem = to_cxl_pmem_region(dev);
-       if (cxlr_pmem->bridge != cxl_nvb)
-               return 0;
-
-       device_release_driver(dev);
-       return 0;
-}
-
 static void offline_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb,
                               struct nvdimm_bus *nvdimm_bus)
 {
@@ -269,8 +235,6 @@ static void offline_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb,
         * nvdimm_bus_unregister() rips the nvdimm objects out from
         * underneath them.
         */
-       bus_for_each_dev(&cxl_bus_type, NULL, cxl_nvb,
-                        cxl_pmem_region_release_driver);
        bus_for_each_dev(&cxl_bus_type, NULL, cxl_nvb,
                         cxl_nvdimm_release_driver);
        nvdimm_bus_unregister(nvdimm_bus);
@@ -378,48 +342,6 @@ static void unregister_nvdimm_region(void *nd_region)
        nvdimm_region_delete(nd_region);
 }
 
-static int cxl_nvdimm_add_region(struct cxl_nvdimm *cxl_nvd,
-                                struct cxl_pmem_region *cxlr_pmem)
-{
-       int rc;
-
-       rc = xa_insert(&cxl_nvd->pmem_regions, (unsigned long)cxlr_pmem,
-                      cxlr_pmem, GFP_KERNEL);
-       if (rc)
-               return rc;
-
-       get_device(&cxlr_pmem->dev);
-       return 0;
-}
-
-static void cxl_nvdimm_del_region(struct cxl_nvdimm *cxl_nvd,
-                                 struct cxl_pmem_region *cxlr_pmem)
-{
-       /*
-        * It is possible this is called without a corresponding
-        * cxl_nvdimm_add_region for @cxlr_pmem
-        */
-       cxlr_pmem = xa_erase(&cxl_nvd->pmem_regions, (unsigned long)cxlr_pmem);
-       if (cxlr_pmem)
-               put_device(&cxlr_pmem->dev);
-}
-
-static void release_mappings(void *data)
-{
-       int i;
-       struct cxl_pmem_region *cxlr_pmem = data;
-       struct cxl_nvdimm_bridge *cxl_nvb = cxlr_pmem->bridge;
-
-       device_lock(&cxl_nvb->dev);
-       for (i = 0; i < cxlr_pmem->nr_mappings; i++) {
-               struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i];
-               struct cxl_nvdimm *cxl_nvd = m->cxl_nvd;
-
-               cxl_nvdimm_del_region(cxl_nvd, cxlr_pmem);
-       }
-       device_unlock(&cxl_nvb->dev);
-}
-
 static void cxlr_pmem_remove_resource(void *res)
 {
        remove_resource(res);
@@ -508,10 +430,6 @@ static int cxl_pmem_region_probe(struct device *dev)
                goto out_nvb;
        }
 
-       rc = devm_add_action_or_reset(dev, release_mappings, cxlr_pmem);
-       if (rc)
-               goto out_nvd;
-
        for (i = 0; i < cxlr_pmem->nr_mappings; i++) {
                struct cxl_pmem_region_mapping *m = &cxlr_pmem->mapping[i];
                struct cxl_memdev *cxlmd = m->cxlmd;
@@ -538,14 +456,6 @@ static int cxl_pmem_region_probe(struct device *dev)
                        goto out_nvd;
                }
 
-               /*
-                * Pin the region per nvdimm device as those may be released
-                * out-of-order with respect to the region, and a single nvdimm
-                * maybe associated with multiple regions
-                */
-               rc = cxl_nvdimm_add_region(cxl_nvd, cxlr_pmem);
-               if (rc)
-                       goto out_nvd;
                m->cxl_nvd = cxl_nvd;
                mappings[i] = (struct nd_mapping_desc) {
                        .nvdimm = nvdimm,