LXR linux/drivers/dax/pmem/core.c

   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
   3#include <linux/memremap.h>
   4#include <linux/module.h>
   5#include <linux/pfn_t.h>
   6#include "../../nvdimm/pfn.h"
   7#include "../../nvdimm/nd.h"
   8#include "../bus.h"
   9
  10struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
  11{
  12        struct resource res;
  13        int rc, id, region_id;
  14        resource_size_t offset;
  15        struct nd_pfn_sb *pfn_sb;
  16        struct dev_dax *dev_dax;
  17        struct nd_namespace_io *nsio;
  18        struct dax_region *dax_region;
  19        struct dev_pagemap pgmap = { };
  20        struct nd_namespace_common *ndns;
  21        struct nd_dax *nd_dax = to_nd_dax(dev);
  22        struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
  23        struct nd_region *nd_region = to_nd_region(dev->parent);
  24
  25        ndns = nvdimm_namespace_common_probe(dev);
  26        if (IS_ERR(ndns))
  27                return ERR_CAST(ndns);
  28        nsio = to_nd_namespace_io(&ndns->dev);
  29
  30        /* parse the 'pfn' info block via ->rw_bytes */
  31        rc = devm_nsio_enable(dev, nsio);
  32        if (rc)
  33                return ERR_PTR(rc);
  34        rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
  35        if (rc)
  36                return ERR_PTR(rc);
  37        devm_nsio_disable(dev, nsio);
  38
  39        /* reserve the metadata area, device-dax will reserve the data */
  40        pfn_sb = nd_pfn->pfn_sb;
  41        offset = le64_to_cpu(pfn_sb->dataoff);
  42        if (!devm_request_mem_region(dev, nsio->res.start, offset,
  43                                dev_name(&ndns->dev))) {
  44                dev_warn(dev, "could not reserve metadata\n");
  45                return ERR_PTR(-EBUSY);
  46        }
  47
  48        rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);
  49        if (rc != 2)
  50                return ERR_PTR(-EINVAL);
  51
  52        /* adjust the dax_region resource to the start of data */
  53        memcpy(&res, &pgmap.res, sizeof(res));
  54        res.start += offset;
  55        dax_region = alloc_dax_region(dev, region_id, &res,
  56                        nd_region->target_node, le32_to_cpu(pfn_sb->align),
  57                        PFN_DEV|PFN_MAP);
  58        if (!dax_region)
  59                return ERR_PTR(-ENOMEM);
  60
  61        dev_dax = __devm_create_dev_dax(dax_region, id, &pgmap, subsys);
  62
  63        /* child dev_dax instances now own the lifetime of the dax_region */
  64        dax_region_put(dax_region);
  65
  66        return dev_dax;
  67}
  68EXPORT_SYMBOL_GPL(__dax_pmem_probe);
  69
  70MODULE_LICENSE("GPL v2");
  71MODULE_AUTHOR("Intel Corporation");
  72