109 lines
2.9 KiB
C
109 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Copyright(c) 2016-2019 Intel Corporation. All rights reserved. */
|
|
#include <linux/memremap.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/memory.h>
|
|
#include <linux/module.h>
|
|
#include <linux/device.h>
|
|
#include <linux/pfn_t.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/dax.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/mman.h>
|
|
#include "dax-private.h"
|
|
#include "bus.h"
|
|
|
|
int dev_dax_kmem_probe(struct device *dev)
|
|
{
|
|
struct dev_dax *dev_dax = to_dev_dax(dev);
|
|
struct resource *res = &dev_dax->region->res;
|
|
resource_size_t kmem_start;
|
|
resource_size_t kmem_size;
|
|
resource_size_t kmem_end;
|
|
struct resource *new_res;
|
|
int numa_node;
|
|
int rc;
|
|
|
|
/*
|
|
* Ensure good NUMA information for the persistent memory.
|
|
* Without this check, there is a risk that slow memory
|
|
* could be mixed in a node with faster memory, causing
|
|
* unavoidable performance issues.
|
|
*/
|
|
numa_node = dev_dax->target_node;
|
|
if (numa_node < 0) {
|
|
dev_warn(dev, "rejecting DAX region %pR with invalid node: %d\n",
|
|
res, numa_node);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Hotplug starting at the beginning of the next block: */
|
|
kmem_start = ALIGN(res->start, memory_block_size_bytes());
|
|
|
|
kmem_size = resource_size(res);
|
|
/* Adjust the size down to compensate for moving up kmem_start: */
|
|
kmem_size -= kmem_start - res->start;
|
|
/* Align the size down to cover only complete blocks: */
|
|
kmem_size &= ~(memory_block_size_bytes() - 1);
|
|
kmem_end = kmem_start + kmem_size;
|
|
|
|
/* Region is permanently reserved. Hot-remove not yet implemented. */
|
|
new_res = request_mem_region(kmem_start, kmem_size, dev_name(dev));
|
|
if (!new_res) {
|
|
dev_warn(dev, "could not reserve region [%pa-%pa]\n",
|
|
&kmem_start, &kmem_end);
|
|
return -EBUSY;
|
|
}
|
|
|
|
/*
|
|
* Set flags appropriate for System RAM. Leave ..._BUSY clear
|
|
* so that add_memory() can add a child resource. Do not
|
|
* inherit flags from the parent since it may set new flags
|
|
* unknown to us that will break add_memory() below.
|
|
*/
|
|
new_res->flags = IORESOURCE_SYSTEM_RAM;
|
|
new_res->name = dev_name(dev);
|
|
|
|
rc = add_memory(numa_node, new_res->start, resource_size(new_res));
|
|
if (rc)
|
|
return rc;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dev_dax_kmem_remove(struct device *dev)
|
|
{
|
|
/*
|
|
* Purposely leak the request_mem_region() for the device-dax
|
|
* range and return '0' to ->remove() attempts. The removal of
|
|
* the device from the driver always succeeds, but the region
|
|
* is permanently pinned as reserved by the unreleased
|
|
* request_mem_region().
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
static struct dax_device_driver device_dax_kmem_driver = {
|
|
.drv = {
|
|
.probe = dev_dax_kmem_probe,
|
|
.remove = dev_dax_kmem_remove,
|
|
},
|
|
};
|
|
|
|
static int __init dax_kmem_init(void)
|
|
{
|
|
return dax_driver_register(&device_dax_kmem_driver);
|
|
}
|
|
|
|
static void __exit dax_kmem_exit(void)
|
|
{
|
|
dax_driver_unregister(&device_dax_kmem_driver);
|
|
}
|
|
|
|
MODULE_AUTHOR("Intel Corporation");
|
|
MODULE_LICENSE("GPL v2");
|
|
module_init(dax_kmem_init);
|
|
module_exit(dax_kmem_exit);
|
|
MODULE_ALIAS_DAX_DEVICE(0);
|