From 3d88002e4a7bd40f355550284c6cd140e6fe29dc Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sun, 31 May 2015 15:02:11 -0400 Subject: libnvdimm: support for legacy (non-aliasing) nvdimms The libnvdimm region driver is an intermediary driver that translates non-volatile "region"s into "namespace" sub-devices that are surfaced by persistent memory block-device drivers (PMEM and BLK). ACPI 6 introduces the concept that a given nvdimm may simultaneously offer multiple access modes to its media through direct PMEM load/store access, or windowed BLK mode. Existing nvdimms mostly implement a PMEM interface, some offer a BLK-like mode, but never both as ACPI 6 defines. If an nvdimm is single interfaced, then there is no need for dimm metadata labels. For these devices we can take the region boundaries directly to create a child namespace device (nd_namespace_io). Acked-by: Christoph Hellwig Tested-by: Toshi Kani Signed-off-by: Dan Williams --- drivers/nvdimm/region.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 drivers/nvdimm/region.c (limited to 'drivers/nvdimm/region.c') diff --git a/drivers/nvdimm/region.c b/drivers/nvdimm/region.c new file mode 100644 index 000000000000..ade3dba81afd --- /dev/null +++ b/drivers/nvdimm/region.c @@ -0,0 +1,93 @@ +/* + * Copyright(c) 2013-2015 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +#include +#include +#include +#include "nd.h" + +static int nd_region_probe(struct device *dev) +{ + int err; + struct nd_region_namespaces *num_ns; + struct nd_region *nd_region = to_nd_region(dev); + int rc = nd_region_register_namespaces(nd_region, &err); + + num_ns = devm_kzalloc(dev, sizeof(*num_ns), GFP_KERNEL); + if (!num_ns) + return -ENOMEM; + + if (rc < 0) + return rc; + + num_ns->active = rc; + num_ns->count = rc + err; + dev_set_drvdata(dev, num_ns); + + if (err == 0) + return 0; + + if (rc == err) + return -ENODEV; + + /* + * Given multiple namespaces per region, we do not want to + * disable all the successfully registered peer namespaces upon + * a single registration failure. If userspace is missing a + * namespace that it expects it can disable/re-enable the region + * to retry discovery after correcting the failure. + * /namespaces returns the current + * "/" namespace count. + */ + dev_err(dev, "failed to register %d namespace%s, continuing...\n", + err, err == 1 ? "" : "s"); + return 0; +} + +static int child_unregister(struct device *dev, void *data) +{ + nd_device_unregister(dev, ND_SYNC); + return 0; +} + +static int nd_region_remove(struct device *dev) +{ + /* flush attribute readers and disable */ + nvdimm_bus_lock(dev); + dev_set_drvdata(dev, NULL); + nvdimm_bus_unlock(dev); + + device_for_each_child(dev, NULL, child_unregister); + return 0; +} + +static struct nd_device_driver nd_region_driver = { + .probe = nd_region_probe, + .remove = nd_region_remove, + .drv = { + .name = "nd_region", + }, + .type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM, +}; + +int __init nd_region_init(void) +{ + return nd_driver_register(&nd_region_driver); +} + +void nd_region_exit(void) +{ + driver_unregister(&nd_region_driver.drv); +} + +MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM); +MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK); -- cgit v1.2.3-58-ga151