diff options
Diffstat (limited to 'drivers/dax/pmem.c')
| -rw-r--r-- | drivers/dax/pmem.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c new file mode 100644 index 000000000000..55d510e36cd1 --- /dev/null +++ b/drivers/dax/pmem.c @@ -0,0 +1,158 @@ +/* + * Copyright(c) 2016 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 <linux/percpu-refcount.h> +#include <linux/memremap.h> +#include <linux/module.h> +#include <linux/pfn_t.h> +#include "../nvdimm/pfn.h" +#include "../nvdimm/nd.h" +#include "dax.h" + +struct dax_pmem { + struct device *dev; + struct percpu_ref ref; + struct completion cmp; +}; + +struct dax_pmem *to_dax_pmem(struct percpu_ref *ref) +{ + return container_of(ref, struct dax_pmem, ref); +} + +static void dax_pmem_percpu_release(struct percpu_ref *ref) +{ + struct dax_pmem *dax_pmem = to_dax_pmem(ref); + + dev_dbg(dax_pmem->dev, "%s\n", __func__); + complete(&dax_pmem->cmp); +} + +static void dax_pmem_percpu_exit(void *data) +{ + struct percpu_ref *ref = data; + struct dax_pmem *dax_pmem = to_dax_pmem(ref); + + dev_dbg(dax_pmem->dev, "%s\n", __func__); + percpu_ref_exit(ref); + wait_for_completion(&dax_pmem->cmp); +} + +static void dax_pmem_percpu_kill(void *data) +{ + struct percpu_ref *ref = data; + struct dax_pmem *dax_pmem = to_dax_pmem(ref); + + dev_dbg(dax_pmem->dev, "%s\n", __func__); + percpu_ref_kill(ref); +} + +static int dax_pmem_probe(struct device *dev) +{ + int rc; + void *addr; + struct resource res; + struct nd_pfn_sb *pfn_sb; + struct dax_pmem *dax_pmem; + struct nd_region *nd_region; + struct nd_namespace_io *nsio; + struct dax_region *dax_region; + struct nd_namespace_common *ndns; + struct nd_dax *nd_dax = to_nd_dax(dev); + struct nd_pfn *nd_pfn = &nd_dax->nd_pfn; + struct vmem_altmap __altmap, *altmap = NULL; + + ndns = nvdimm_namespace_common_probe(dev); + if (IS_ERR(ndns)) + return PTR_ERR(ndns); + nsio = to_nd_namespace_io(&ndns->dev); + + /* parse the 'pfn' info block via ->rw_bytes */ + devm_nsio_enable(dev, nsio); + altmap = nvdimm_setup_pfn(nd_pfn, &res, &__altmap); + if (IS_ERR(altmap)) + return PTR_ERR(altmap); + devm_nsio_disable(dev, nsio); + + pfn_sb = nd_pfn->pfn_sb; + + if (!devm_request_mem_region(dev, nsio->res.start, + resource_size(&nsio->res), dev_name(dev))) { + dev_warn(dev, "could not reserve region %pR\n", &nsio->res); + return -EBUSY; + } + + dax_pmem = devm_kzalloc(dev, sizeof(*dax_pmem), GFP_KERNEL); + if (!dax_pmem) + return -ENOMEM; + + dax_pmem->dev = dev; + init_completion(&dax_pmem->cmp); + rc = percpu_ref_init(&dax_pmem->ref, dax_pmem_percpu_release, 0, + GFP_KERNEL); + if (rc) + return rc; + + rc = devm_add_action(dev, dax_pmem_percpu_exit, &dax_pmem->ref); + if (rc) { + dax_pmem_percpu_exit(&dax_pmem->ref); + return rc; + } + + addr = devm_memremap_pages(dev, &res, &dax_pmem->ref, altmap); + if (IS_ERR(addr)) + return PTR_ERR(addr); + + rc = devm_add_action(dev, dax_pmem_percpu_kill, &dax_pmem->ref); + if (rc) { + dax_pmem_percpu_kill(&dax_pmem->ref); + return rc; + } + + nd_region = to_nd_region(dev->parent); + dax_region = alloc_dax_region(dev, nd_region->id, &res, + le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP); + if (!dax_region) + return -ENOMEM; + + /* TODO: support for subdividing a dax region... */ + rc = devm_create_dax_dev(dax_region, &res, 1); + + /* child dax_dev instances now own the lifetime of the dax_region */ + dax_region_put(dax_region); + + return rc; +} + +static struct nd_device_driver dax_pmem_driver = { + .probe = dax_pmem_probe, + .drv = { + .name = "dax_pmem", + }, + .type = ND_DRIVER_DAX_PMEM, +}; + +static int __init dax_pmem_init(void) +{ + return nd_driver_register(&dax_pmem_driver); +} +module_init(dax_pmem_init); + +static void __exit dax_pmem_exit(void) +{ + driver_unregister(&dax_pmem_driver.drv); +} +module_exit(dax_pmem_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Intel Corporation"); +MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM); |