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Large amounts of memory managed by the kmem driver may come in via CXL, and it is often desirable to have the memmap for this memory on the new memory itself. Enroll kmem-managed memory for memmap_on_memory semantics if the dax region originates via CXL. For non-CXL dax regions, retain the existing default behavior of hot adding without memmap_on_memory semantics. Link: https://lkml.kernel.org/r/20231107-vv-kmem_memmap-v10-3-1253ec050ed0@intel.com Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Tested-by: Li Zhijian <lizhijian@fujitsu.com> [cxl.kmem and nvdimm.kmem] Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Fan Ni <fan.ni@samsung.com> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
100 lines
2.5 KiB
C
100 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved. */
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#include <linux/memremap.h>
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#include <linux/module.h>
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#include <linux/pfn_t.h>
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#include "../nvdimm/pfn.h"
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#include "../nvdimm/nd.h"
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#include "bus.h"
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static struct dev_dax *__dax_pmem_probe(struct device *dev)
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{
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struct range range;
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int rc, id, region_id;
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resource_size_t offset;
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struct nd_pfn_sb *pfn_sb;
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struct dev_dax_data data;
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struct nd_namespace_io *nsio;
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struct dax_region *dax_region;
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struct dev_pagemap pgmap = { };
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struct nd_namespace_common *ndns;
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struct nd_dax *nd_dax = to_nd_dax(dev);
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struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
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struct nd_region *nd_region = to_nd_region(dev->parent);
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ndns = nvdimm_namespace_common_probe(dev);
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if (IS_ERR(ndns))
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return ERR_CAST(ndns);
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/* parse the 'pfn' info block via ->rw_bytes */
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rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
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if (rc)
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return ERR_PTR(rc);
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rc = nvdimm_setup_pfn(nd_pfn, &pgmap);
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if (rc)
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return ERR_PTR(rc);
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devm_namespace_disable(dev, ndns);
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/* reserve the metadata area, device-dax will reserve the data */
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pfn_sb = nd_pfn->pfn_sb;
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offset = le64_to_cpu(pfn_sb->dataoff);
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nsio = to_nd_namespace_io(&ndns->dev);
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if (!devm_request_mem_region(dev, nsio->res.start, offset,
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dev_name(&ndns->dev))) {
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dev_warn(dev, "could not reserve metadata\n");
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return ERR_PTR(-EBUSY);
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}
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rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", ®ion_id, &id);
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if (rc != 2)
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return ERR_PTR(-EINVAL);
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/* adjust the dax_region range to the start of data */
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range = pgmap.range;
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range.start += offset;
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dax_region = alloc_dax_region(dev, region_id, &range,
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nd_region->target_node, le32_to_cpu(pfn_sb->align),
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IORESOURCE_DAX_STATIC);
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if (!dax_region)
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return ERR_PTR(-ENOMEM);
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data = (struct dev_dax_data) {
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.dax_region = dax_region,
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.id = id,
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.pgmap = &pgmap,
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.size = range_len(&range),
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.memmap_on_memory = false,
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};
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return devm_create_dev_dax(&data);
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}
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static int dax_pmem_probe(struct device *dev)
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{
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return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev));
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}
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static struct nd_device_driver dax_pmem_driver = {
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.probe = dax_pmem_probe,
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.drv = {
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.name = "dax_pmem",
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},
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.type = ND_DRIVER_DAX_PMEM,
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};
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static int __init dax_pmem_init(void)
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{
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return nd_driver_register(&dax_pmem_driver);
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}
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module_init(dax_pmem_init);
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static void __exit dax_pmem_exit(void)
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{
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driver_unregister(&dax_pmem_driver.drv);
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}
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module_exit(dax_pmem_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Intel Corporation");
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MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);
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