diff options
Diffstat (limited to 'drivers/dax/kmem.c')
| -rw-r--r-- | drivers/dax/kmem.c | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 3d0a7e702c94..275aa5f87399 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -14,6 +14,11 @@ #include "dax-private.h" #include "bus.h" +/* Memory resource name used for add_memory_driver_managed(). */ +static const char *kmem_name; +/* Set if any memory will remain added when the driver will be unloaded. */ +static bool any_hotremove_failed; + int dev_dax_kmem_probe(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); @@ -22,6 +27,7 @@ int dev_dax_kmem_probe(struct device *dev) resource_size_t kmem_size; resource_size_t kmem_end; struct resource *new_res; + const char *new_res_name; int numa_node; int rc; @@ -48,11 +54,16 @@ int dev_dax_kmem_probe(struct device *dev) kmem_size &= ~(memory_block_size_bytes() - 1); kmem_end = kmem_start + kmem_size; - /* Region is permanently reserved. Hot-remove not yet implemented. */ - new_res = request_mem_region(kmem_start, kmem_size, dev_name(dev)); + new_res_name = kstrdup(dev_name(dev), GFP_KERNEL); + if (!new_res_name) + return -ENOMEM; + + /* Region is permanently reserved if hotremove fails. */ + new_res = request_mem_region(kmem_start, kmem_size, new_res_name); if (!new_res) { dev_warn(dev, "could not reserve region [%pa-%pa]\n", &kmem_start, &kmem_end); + kfree(new_res_name); return -EBUSY; } @@ -63,12 +74,17 @@ int dev_dax_kmem_probe(struct device *dev) * unknown to us that will break add_memory() below. */ new_res->flags = IORESOURCE_SYSTEM_RAM; - new_res->name = dev_name(dev); - rc = add_memory(numa_node, new_res->start, resource_size(new_res)); + /* + * Ensure that future kexec'd kernels will not treat this as RAM + * automatically. + */ + rc = add_memory_driver_managed(numa_node, new_res->start, + resource_size(new_res), kmem_name); if (rc) { release_resource(new_res); kfree(new_res); + kfree(new_res_name); return rc; } dev_dax->dax_kmem_res = new_res; @@ -83,6 +99,7 @@ static int dev_dax_kmem_remove(struct device *dev) struct resource *res = dev_dax->dax_kmem_res; resource_size_t kmem_start = res->start; resource_size_t kmem_size = resource_size(res); + const char *res_name = res->name; int rc; /* @@ -93,6 +110,7 @@ static int dev_dax_kmem_remove(struct device *dev) */ rc = remove_memory(dev_dax->target_node, kmem_start, kmem_size); if (rc) { + any_hotremove_failed = true; dev_err(dev, "DAX region %pR cannot be hotremoved until the next reboot\n", res); @@ -102,6 +120,7 @@ static int dev_dax_kmem_remove(struct device *dev) /* Release and free dax resources */ release_resource(res); kfree(res); + kfree(res_name); dev_dax->dax_kmem_res = NULL; return 0; @@ -116,6 +135,7 @@ static int dev_dax_kmem_remove(struct device *dev) * permanently pinned as reserved by the unreleased * request_mem_region(). */ + any_hotremove_failed = true; return 0; } #endif /* CONFIG_MEMORY_HOTREMOVE */ @@ -129,12 +149,24 @@ static struct dax_device_driver device_dax_kmem_driver = { static int __init dax_kmem_init(void) { - return dax_driver_register(&device_dax_kmem_driver); + int rc; + + /* Resource name is permanently allocated if any hotremove fails. */ + kmem_name = kstrdup_const("System RAM (kmem)", GFP_KERNEL); + if (!kmem_name) + return -ENOMEM; + + rc = dax_driver_register(&device_dax_kmem_driver); + if (rc) + kfree_const(kmem_name); + return rc; } static void __exit dax_kmem_exit(void) { dax_driver_unregister(&device_dax_kmem_driver); + if (!any_hotremove_failed) + kfree_const(kmem_name); } MODULE_AUTHOR("Intel Corporation"); |