cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pmem.c (2689B)

      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
     10static struct dev_dax *__dax_pmem_probe(struct device *dev)
     11{
     12	struct range range;
     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 dev_dax_data data;
     18	struct nd_namespace_io *nsio;
     19	struct dax_region *dax_region;
     20	struct dev_pagemap pgmap = { };
     21	struct nd_namespace_common *ndns;
     22	struct nd_dax *nd_dax = to_nd_dax(dev);
     23	struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
     24	struct nd_region *nd_region = to_nd_region(dev->parent);
     25
     26	ndns = nvdimm_namespace_common_probe(dev);
     27	if (IS_ERR(ndns))
     28		return ERR_CAST(ndns);
     29
     30	/* parse the 'pfn' info block via ->rw_bytes */
     31	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
     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_namespace_disable(dev, ndns);
     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	nsio = to_nd_namespace_io(&ndns->dev);
     43	if (!devm_request_mem_region(dev, nsio->res.start, offset,
     44				dev_name(&ndns->dev))) {
     45		dev_warn(dev, "could not reserve metadata\n");
     46		return ERR_PTR(-EBUSY);
     47	}
     48
     49	rc = sscanf(dev_name(&ndns->dev), "namespace%d.%d", &region_id, &id);
     50	if (rc != 2)
     51		return ERR_PTR(-EINVAL);
     52
     53	/* adjust the dax_region range to the start of data */
     54	range = pgmap.range;
     55	range.start += offset;
     56	dax_region = alloc_dax_region(dev, region_id, &range,
     57			nd_region->target_node, le32_to_cpu(pfn_sb->align),
     58			IORESOURCE_DAX_STATIC);
     59	if (!dax_region)
     60		return ERR_PTR(-ENOMEM);
     61
     62	data = (struct dev_dax_data) {
     63		.dax_region = dax_region,
     64		.id = id,
     65		.pgmap = &pgmap,
     66		.size = range_len(&range),
     67	};
     68	dev_dax = devm_create_dev_dax(&data);
     69
     70	/* child dev_dax instances now own the lifetime of the dax_region */
     71	dax_region_put(dax_region);
     72
     73	return dev_dax;
     74}
     75
     76static int dax_pmem_probe(struct device *dev)
     77{
     78	return PTR_ERR_OR_ZERO(__dax_pmem_probe(dev));
     79}
     80
     81static struct nd_device_driver dax_pmem_driver = {
     82	.probe = dax_pmem_probe,
     83	.drv = {
     84		.name = "dax_pmem",
     85	},
     86	.type = ND_DRIVER_DAX_PMEM,
     87};
     88
     89static int __init dax_pmem_init(void)
     90{
     91	return nd_driver_register(&dax_pmem_driver);
     92}
     93module_init(dax_pmem_init);
     94
     95static void __exit dax_pmem_exit(void)
     96{
     97	driver_unregister(&dax_pmem_driver.drv);
     98}
     99module_exit(dax_pmem_exit);
    100
    101MODULE_LICENSE("GPL v2");
    102MODULE_AUTHOR("Intel Corporation");
    103MODULE_ALIAS_ND_DEVICE(ND_DEVICE_DAX_PMEM);