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Merge branch 'for-4.12/dax' into libnvdimm-for-next

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This commit is contained in:
Dan Williams
2017-05-04 23:38:43 -07:00
parent d5483feda8 1ef97fe4f8
commit 736163671b
110 changed files with 4762 additions and 2057 deletions
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12
drivers/dax/Kconfig
View File

@@ -1,8 +1,13 @@
menuconfig DEV_DAX
menuconfig DAX
tristate "DAX: direct access to differentiated memory"
default m if NVDIMM_DAX
depends on TRANSPARENT_HUGEPAGE
select SRCU
default m if NVDIMM_DAX
if DAX
config DEV_DAX
tristate "Device DAX: direct access mapping device"
depends on TRANSPARENT_HUGEPAGE
help
Support raw access to differentiated (persistence, bandwidth,
latency...) memory via an mmap(2) capable character
@@ -11,7 +16,6 @@ menuconfig DEV_DAX
baseline memory pool. Mappings of a /dev/daxX.Y device impose
restrictions that make the mapping behavior deterministic.
if DEV_DAX
config DEV_DAX_PMEM
tristate "PMEM DAX: direct access to persistent memory"

5
drivers/dax/Makefile
View File

@@ -1,4 +1,7 @@
obj-$(CONFIG_DEV_DAX) += dax.o
obj-$(CONFIG_DAX) += dax.o
obj-$(CONFIG_DEV_DAX) += device_dax.o
obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o
dax-y := super.o
dax_pmem-y := pmem.o
device_dax-y := device.o

14
drivers/dax/dax-private.h
View File

@@ -38,22 +38,18 @@ struct dax_region {
};
/**
* struct dax_dev - subdivision of a dax region
* struct dev_dax - instance data for a subdivision of a dax region
* @region - parent region
* @inode - inode
* @dev - device backing the character device
* @cdev - core chardev data
* @alive - !alive + srcu grace period == no new mappings can be established
* @dax_dev - core dax functionality
* @dev - device core
* @id - child id in the region
* @num_resources - number of physical address extents in this device
* @res - array of physical address ranges
*/
struct dax_dev {
struct dev_dax {
struct dax_region *region;
struct inode *inode;
struct dax_device *dax_dev;
struct device dev;
struct cdev cdev;
bool alive;
int id;
int num_resources;
struct resource res[0];

15
drivers/dax/dax.h
View File

@@ -1,5 +1,5 @@
/*
* Copyright(c) 2016 Intel Corporation. All rights reserved.
* Copyright(c) 2016 - 2017 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
@@ -12,14 +12,7 @@
*/
#ifndef __DAX_H__
#define __DAX_H__
struct device;
struct dax_dev;
struct resource;
struct dax_region;
void dax_region_put(struct dax_region *dax_region);
struct dax_region *alloc_dax_region(struct device *parent,
int region_id, struct resource *res, unsigned int align,
void *addr, unsigned long flags);
struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
struct resource *res, int count);
struct dax_device;
struct dax_device *inode_dax(struct inode *inode);
struct inode *dax_inode(struct dax_device *dax_dev);
#endif /* __DAX_H__ */

25
drivers/dax/device-dax.h Normal file
View File

@@ -0,0 +1,25 @@
/*
* 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.
*/
#ifndef __DEVICE_DAX_H__
#define __DEVICE_DAX_H__
struct device;
struct dev_dax;
struct resource;
struct dax_region;
void dax_region_put(struct dax_region *dax_region);
struct dax_region *alloc_dax_region(struct device *parent,
int region_id, struct resource *res, unsigned int align,
void *addr, unsigned long flags);
struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
struct resource *res, int count);
#endif /* __DEVICE_DAX_H__ */

442
drivers/dax/dax.c → drivers/dax/device.c
View File

@@ -1,5 +1,5 @@
/*
* Copyright(c) 2016 Intel Corporation. All rights reserved.
* Copyright(c) 2016 - 2017 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
@@ -13,10 +13,7 @@
#include <linux/pagemap.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/magic.h>
#include <linux/mount.h>
#include <linux/pfn_t.h>
#include <linux/hash.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/dax.h>
@@ -25,16 +22,7 @@
#include "dax-private.h"
#include "dax.h"
static dev_t dax_devt;
DEFINE_STATIC_SRCU(dax_srcu);
static struct class *dax_class;
static DEFINE_IDA(dax_minor_ida);
static int nr_dax = CONFIG_NR_DEV_DAX;
module_param(nr_dax, int, S_IRUGO);
static struct vfsmount *dax_mnt;
static struct kmem_cache *dax_cache __read_mostly;
static struct super_block *dax_superblock __read_mostly;
MODULE_PARM_DESC(nr_dax, "max number of device-dax instances");
/*
* Rely on the fact that drvdata is set before the attributes are
@@ -87,117 +75,6 @@ static const struct attribute_group *dax_region_attribute_groups[] = {
NULL,
};
static struct inode *dax_alloc_inode(struct super_block *sb)
{
return kmem_cache_alloc(dax_cache, GFP_KERNEL);
}
static void dax_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(dax_cache, inode);
}
static void dax_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, dax_i_callback);
}
static const struct super_operations dax_sops = {
.statfs = simple_statfs,
.alloc_inode = dax_alloc_inode,
.destroy_inode = dax_destroy_inode,
.drop_inode = generic_delete_inode,
};
static struct dentry *dax_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC);
}
static struct file_system_type dax_type = {
.name = "dax",
.mount = dax_mount,
.kill_sb = kill_anon_super,
};
static int dax_test(struct inode *inode, void *data)
{
return inode->i_cdev == data;
}
static int dax_set(struct inode *inode, void *data)
{
inode->i_cdev = data;
return 0;
}
static struct inode *dax_inode_get(struct cdev *cdev, dev_t devt)
{
struct inode *inode;
inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31),
dax_test, dax_set, cdev);
if (!inode)
return NULL;
if (inode->i_state & I_NEW) {
inode->i_mode = S_IFCHR;
inode->i_flags = S_DAX;
inode->i_rdev = devt;
mapping_set_gfp_mask(&inode->i_data, GFP_USER);
unlock_new_inode(inode);
}
return inode;
}
static void init_once(void *inode)
{
inode_init_once(inode);
}
static int dax_inode_init(void)
{
int rc;
dax_cache = kmem_cache_create("dax_cache", sizeof(struct inode), 0,
(SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD|SLAB_ACCOUNT),
init_once);
if (!dax_cache)
return -ENOMEM;
rc = register_filesystem(&dax_type);
if (rc)
goto err_register_fs;
dax_mnt = kern_mount(&dax_type);
if (IS_ERR(dax_mnt)) {
rc = PTR_ERR(dax_mnt);
goto err_mount;
}
dax_superblock = dax_mnt->mnt_sb;
return 0;
err_mount:
unregister_filesystem(&dax_type);
err_register_fs:
kmem_cache_destroy(dax_cache);
return rc;
}
static void dax_inode_exit(void)
{
kern_unmount(dax_mnt);
unregister_filesystem(&dax_type);
kmem_cache_destroy(dax_cache);
}
static void dax_region_free(struct kref *kref)
{
struct dax_region *dax_region;
@@ -266,47 +143,47 @@ struct dax_region *alloc_dax_region(struct device *parent, int region_id,
}
EXPORT_SYMBOL_GPL(alloc_dax_region);
static struct dax_dev *to_dax_dev(struct device *dev)
static struct dev_dax *to_dev_dax(struct device *dev)
{
return container_of(dev, struct dax_dev, dev);
return container_of(dev, struct dev_dax, dev);
}
static ssize_t size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct dax_dev *dax_dev = to_dax_dev(dev);
struct dev_dax *dev_dax = to_dev_dax(dev);
unsigned long long size = 0;
int i;
for (i = 0; i < dax_dev->num_resources; i++)
size += resource_size(&dax_dev->res[i]);
for (i = 0; i < dev_dax->num_resources; i++)
size += resource_size(&dev_dax->res[i]);
return sprintf(buf, "%llu\n", size);
}
static DEVICE_ATTR_RO(size);
static struct attribute *dax_device_attributes[] = {
static struct attribute *dev_dax_attributes[] = {
&dev_attr_size.attr,
NULL,
};
static const struct attribute_group dax_device_attribute_group = {
.attrs = dax_device_attributes,
static const struct attribute_group dev_dax_attribute_group = {
.attrs = dev_dax_attributes,
};
static const struct attribute_group *dax_attribute_groups[] = {
&dax_device_attribute_group,
&dev_dax_attribute_group,
NULL,
};
static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma,
static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
const char *func)
{
struct dax_region *dax_region = dax_dev->region;
struct device *dev = &dax_dev->dev;
struct dax_region *dax_region = dev_dax->region;
struct device *dev = &dev_dax->dev;
unsigned long mask;
if (!dax_dev->alive)
if (!dax_alive(dev_dax->dax_dev))
return -ENXIO;
/* prevent private mappings from being established */
@@ -341,23 +218,23 @@ static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma,
}
/* see "strong" declaration in tools/testing/nvdimm/dax-dev.c */
__weak phys_addr_t dax_pgoff_to_phys(struct dax_dev *dax_dev, pgoff_t pgoff,
__weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
unsigned long size)
{
struct resource *res;
phys_addr_t phys;
int i;
for (i = 0; i < dax_dev->num_resources; i++) {
res = &dax_dev->res[i];
for (i = 0; i < dev_dax->num_resources; i++) {
res = &dev_dax->res[i];
phys = pgoff * PAGE_SIZE + res->start;
if (phys >= res->start && phys <= res->end)
break;
pgoff -= PHYS_PFN(resource_size(res));
}
if (i < dax_dev->num_resources) {
res = &dax_dev->res[i];
if (i < dev_dax->num_resources) {
res = &dev_dax->res[i];
if (phys + size - 1 <= res->end)
return phys;
}
@@ -365,28 +242,29 @@ __weak phys_addr_t dax_pgoff_to_phys(struct dax_dev *dax_dev, pgoff_t pgoff,
return -1;
}
static int __dax_dev_pte_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
{
struct device *dev = &dax_dev->dev;
struct device *dev = &dev_dax->dev;
struct dax_region *dax_region;
int rc = VM_FAULT_SIGBUS;
phys_addr_t phys;
pfn_t pfn;
unsigned int fault_size = PAGE_SIZE;
if (check_vma(dax_dev, vmf->vma, __func__))
if (check_vma(dev_dax, vmf->vma, __func__))
return VM_FAULT_SIGBUS;
dax_region = dax_dev->region;
dax_region = dev_dax->region;
if (dax_region->align > PAGE_SIZE) {
dev_dbg(dev, "%s: alignment > fault size\n", __func__);
dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
__func__, dax_region->align, fault_size);
return VM_FAULT_SIGBUS;
}
if (fault_size != dax_region->align)
return VM_FAULT_SIGBUS;
phys = dax_pgoff_to_phys(dax_dev, vmf->pgoff, PAGE_SIZE);
phys = dax_pgoff_to_phys(dev_dax, vmf->pgoff, PAGE_SIZE);
if (phys == -1) {
dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
vmf->pgoff);
@@ -405,28 +283,29 @@ static int __dax_dev_pte_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
return VM_FAULT_NOPAGE;
}
static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
static int __dev_dax_pmd_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
{
unsigned long pmd_addr = vmf->address & PMD_MASK;
struct device *dev = &dax_dev->dev;
struct device *dev = &dev_dax->dev;
struct dax_region *dax_region;
phys_addr_t phys;
pgoff_t pgoff;
pfn_t pfn;
unsigned int fault_size = PMD_SIZE;
if (check_vma(dax_dev, vmf->vma, __func__))
if (check_vma(dev_dax, vmf->vma, __func__))
return VM_FAULT_SIGBUS;
dax_region = dax_dev->region;
dax_region = dev_dax->region;
if (dax_region->align > PMD_SIZE) {
dev_dbg(dev, "%s: alignment > fault size\n", __func__);
dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
__func__, dax_region->align, fault_size);
return VM_FAULT_SIGBUS;
}
/* dax pmd mappings require pfn_t_devmap() */
if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
dev_dbg(dev, "%s: alignment > fault size\n", __func__);
dev_dbg(dev, "%s: region lacks devmap flags\n", __func__);
return VM_FAULT_SIGBUS;
}
@@ -441,7 +320,7 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
pgoff = linear_page_index(vmf->vma, pmd_addr);
phys = dax_pgoff_to_phys(dax_dev, pgoff, PMD_SIZE);
phys = dax_pgoff_to_phys(dev_dax, pgoff, PMD_SIZE);
if (phys == -1) {
dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
pgoff);
@@ -455,10 +334,10 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
}
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
{
unsigned long pud_addr = vmf->address & PUD_MASK;
struct device *dev = &dax_dev->dev;
struct device *dev = &dev_dax->dev;
struct dax_region *dax_region;
phys_addr_t phys;
pgoff_t pgoff;
@@ -466,18 +345,19 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
unsigned int fault_size = PUD_SIZE;
if (check_vma(dax_dev, vmf->vma, __func__))
if (check_vma(dev_dax, vmf->vma, __func__))
return VM_FAULT_SIGBUS;
dax_region = dax_dev->region;
dax_region = dev_dax->region;
if (dax_region->align > PUD_SIZE) {
dev_dbg(dev, "%s: alignment > fault size\n", __func__);
dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
__func__, dax_region->align, fault_size);
return VM_FAULT_SIGBUS;
}
/* dax pud mappings require pfn_t_devmap() */
if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
dev_dbg(dev, "%s: alignment > fault size\n", __func__);
dev_dbg(dev, "%s: region lacks devmap flags\n", __func__);
return VM_FAULT_SIGBUS;
}
@@ -492,7 +372,7 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
pgoff = linear_page_index(vmf->vma, pud_addr);
phys = dax_pgoff_to_phys(dax_dev, pgoff, PUD_SIZE);
phys = dax_pgoff_to_phys(dev_dax, pgoff, PUD_SIZE);
if (phys == -1) {
dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
pgoff);
@@ -505,65 +385,71 @@ static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
vmf->flags & FAULT_FLAG_WRITE);
}
#else
static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf)
static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
{
return VM_FAULT_FALLBACK;
}
#endif /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
static int dax_dev_huge_fault(struct vm_fault *vmf,
static int dev_dax_huge_fault(struct vm_fault *vmf,
enum page_entry_size pe_size)
{
int rc, id;
struct file *filp = vmf->vma->vm_file;
struct dax_dev *dax_dev = filp->private_data;
struct dev_dax *dev_dax = filp->private_data;
dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__,
dev_dbg(&dev_dax->dev, "%s: %s: %s (%#lx - %#lx) size = %d\n", __func__,
current->comm, (vmf->flags & FAULT_FLAG_WRITE)
? "write" : "read",
vmf->vma->vm_start, vmf->vma->vm_end);
vmf->vma->vm_start, vmf->vma->vm_end, pe_size);
id = srcu_read_lock(&dax_srcu);
id = dax_read_lock();
switch (pe_size) {
case PE_SIZE_PTE:
rc = __dax_dev_pte_fault(dax_dev, vmf);
rc = __dev_dax_pte_fault(dev_dax, vmf);
break;
case PE_SIZE_PMD:
rc = __dax_dev_pmd_fault(dax_dev, vmf);
rc = __dev_dax_pmd_fault(dev_dax, vmf);
break;
case PE_SIZE_PUD:
rc = __dax_dev_pud_fault(dax_dev, vmf);
rc = __dev_dax_pud_fault(dev_dax, vmf);
break;
default:
return VM_FAULT_FALLBACK;
rc = VM_FAULT_SIGBUS;
}
srcu_read_unlock(&dax_srcu, id);
dax_read_unlock(id);
return rc;
}
static int dax_dev_fault(struct vm_fault *vmf)
static int dev_dax_fault(struct vm_fault *vmf)
{
return dax_dev_huge_fault(vmf, PE_SIZE_PTE);
return dev_dax_huge_fault(vmf, PE_SIZE_PTE);
}
static const struct vm_operations_struct dax_dev_vm_ops = {
.fault = dax_dev_fault,
.huge_fault = dax_dev_huge_fault,
static const struct vm_operations_struct dax_vm_ops = {
.fault = dev_dax_fault,
.huge_fault = dev_dax_huge_fault,
};
static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct dax_dev *dax_dev = filp->private_data;
int rc;
struct dev_dax *dev_dax = filp->private_data;
int rc, id;
dev_dbg(&dax_dev->dev, "%s\n", __func__);
dev_dbg(&dev_dax->dev, "%s\n", __func__);
rc = check_vma(dax_dev, vma, __func__);
/*
* We lock to check dax_dev liveness and will re-check at
* fault time.
*/
id = dax_read_lock();
rc = check_vma(dev_dax, vma, __func__);
dax_read_unlock(id);
if (rc)
return rc;
vma->vm_ops = &dax_dev_vm_ops;
vma->vm_ops = &dax_vm_ops;
vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
return 0;
}
@@ -574,13 +460,13 @@ static unsigned long dax_get_unmapped_area(struct file *filp,
unsigned long flags)
{
unsigned long off, off_end, off_align, len_align, addr_align, align;
struct dax_dev *dax_dev = filp ? filp->private_data : NULL;
struct dev_dax *dev_dax = filp ? filp->private_data : NULL;
struct dax_region *dax_region;
if (!dax_dev || addr)
if (!dev_dax || addr)
goto out;
dax_region = dax_dev->region;
dax_region = dev_dax->region;
align = dax_region->align;
off = pgoff << PAGE_SHIFT;
off_end = off + len;
@@ -605,14 +491,15 @@ static unsigned long dax_get_unmapped_area(struct file *filp,
static int dax_open(struct inode *inode, struct file *filp)
{
struct dax_dev *dax_dev;
struct dax_device *dax_dev = inode_dax(inode);
struct inode *__dax_inode = dax_inode(dax_dev);
struct dev_dax *dev_dax = dax_get_private(dax_dev);
dax_dev = container_of(inode->i_cdev, struct dax_dev, cdev);
dev_dbg(&dax_dev->dev, "%s\n", __func__);
inode->i_mapping = dax_dev->inode->i_mapping;
inode->i_mapping->host = dax_dev->inode;
dev_dbg(&dev_dax->dev, "%s\n", __func__);
inode->i_mapping = __dax_inode->i_mapping;
inode->i_mapping->host = __dax_inode;
filp->f_mapping = inode->i_mapping;
filp->private_data = dax_dev;
filp->private_data = dev_dax;
inode->i_flags = S_DAX;
return 0;
@@ -620,9 +507,9 @@ static int dax_open(struct inode *inode, struct file *filp)
static int dax_release(struct inode *inode, struct file *filp)
{
struct dax_dev *dax_dev = filp->private_data;
struct dev_dax *dev_dax = filp->private_data;
dev_dbg(&dax_dev->dev, "%s\n", __func__);
dev_dbg(&dev_dax->dev, "%s\n", __func__);
return 0;
}
@@ -635,51 +522,54 @@ static const struct file_operations dax_fops = {
.mmap = dax_mmap,
};
static void dax_dev_release(struct device *dev)
static void dev_dax_release(struct device *dev)
{
struct dax_dev *dax_dev = to_dax_dev(dev);
struct dax_region *dax_region = dax_dev->region;
struct dev_dax *dev_dax = to_dev_dax(dev);
struct dax_region *dax_region = dev_dax->region;
struct dax_device *dax_dev = dev_dax->dax_dev;
ida_simple_remove(&dax_region->ida, dax_dev->id);
ida_simple_remove(&dax_minor_ida, MINOR(dev->devt));
ida_simple_remove(&dax_region->ida, dev_dax->id);
dax_region_put(dax_region);
iput(dax_dev->inode);
kfree(dax_dev);
put_dax(dax_dev);
kfree(dev_dax);
}
static void unregister_dax_dev(void *dev)
static void kill_dev_dax(struct dev_dax *dev_dax)
{
struct dax_dev *dax_dev = to_dax_dev(dev);
struct cdev *cdev = &dax_dev->cdev;
struct dax_device *dax_dev = dev_dax->dax_dev;
struct inode *inode = dax_inode(dax_dev);
kill_dax(dax_dev);
unmap_mapping_range(inode->i_mapping, 0, 0, 1);
}
static void unregister_dev_dax(void *dev)
{
struct dev_dax *dev_dax = to_dev_dax(dev);
struct dax_device *dax_dev = dev_dax->dax_dev;
struct inode *inode = dax_inode(dax_dev);
struct cdev *cdev = inode->i_cdev;
dev_dbg(dev, "%s\n", __func__);
/*
* Note, rcu is not protecting the liveness of dax_dev, rcu is
* ensuring that any fault handlers that might have seen
* dax_dev->alive == true, have completed. Any fault handlers
* that start after synchronize_srcu() has started will abort
* upon seeing dax_dev->alive == false.
*/
dax_dev->alive = false;
synchronize_srcu(&dax_srcu);
unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1);
cdev_del(cdev);
device_unregister(dev);
kill_dev_dax(dev_dax);
cdev_device_del(cdev, dev);
put_device(dev);
}
struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
struct resource *res, int count)
{
struct device *parent = dax_region->dev;
struct dax_dev *dax_dev;
int rc = 0, minor, i;
struct dax_device *dax_dev;
struct dev_dax *dev_dax;
struct inode *inode;
struct device *dev;
struct cdev *cdev;
dev_t dev_t;
int rc = 0, i;
dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL);
if (!dax_dev)
dev_dax = kzalloc(sizeof(*dev_dax) + sizeof(*res) * count, GFP_KERNEL);
if (!dev_dax)
return ERR_PTR(-ENOMEM);
for (i = 0; i < count; i++) {
@@ -689,115 +579,79 @@ struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region,
rc = -EINVAL;
break;
}
dax_dev->res[i].start = res[i].start;
dax_dev->res[i].end = res[i].end;
dev_dax->res[i].start = res[i].start;
dev_dax->res[i].end = res[i].end;
}
if (i < count)
goto err_id;
dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
if (dax_dev->id < 0) {
rc = dax_dev->id;
dev_dax->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL);
if (dev_dax->id < 0) {
rc = dev_dax->id;
goto err_id;
}
minor = ida_simple_get(&dax_minor_ida, 0, 0, GFP_KERNEL);
if (minor < 0) {
rc = minor;
goto err_minor;
}
dev_t = MKDEV(MAJOR(dax_devt), minor);
dev = &dax_dev->dev;
dax_dev->inode = dax_inode_get(&dax_dev->cdev, dev_t);
if (!dax_dev->inode) {
rc = -ENOMEM;
goto err_inode;
}
/* device_initialize() so cdev can reference kobj parent */
device_initialize(dev);
cdev = &dax_dev->cdev;
cdev_init(cdev, &dax_fops);
cdev->owner = parent->driver->owner;
cdev->kobj.parent = &dev->kobj;
rc = cdev_add(&dax_dev->cdev, dev_t, 1);
if (rc)
goto err_cdev;
/*
* No 'host' or dax_operations since there is no access to this
* device outside of mmap of the resulting character device.
*/
dax_dev = alloc_dax(dev_dax, NULL, NULL);
if (!dax_dev)
goto err_dax;
/* from here on we're committed to teardown via dax_dev_release() */
dax_dev->num_resources = count;
dax_dev->alive = true;
dax_dev->region = dax_region;
dev = &dev_dax->dev;
device_initialize(dev);
inode = dax_inode(dax_dev);
cdev = inode->i_cdev;
cdev_init(cdev, &dax_fops);
cdev->owner = parent->driver->owner;
dev_dax->num_resources = count;
dev_dax->dax_dev = dax_dev;
dev_dax->region = dax_region;
kref_get(&dax_region->kref);
dev->devt = dev_t;
dev->devt = inode->i_rdev;
dev->class = dax_class;
dev->parent = parent;
dev->groups = dax_attribute_groups;
dev->release = dax_dev_release;
dev_set_name(dev, "dax%d.%d", dax_region->id, dax_dev->id);
rc = device_add(dev);
dev->release = dev_dax_release;
dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
rc = cdev_device_add(cdev, dev);
if (rc) {
kill_dev_dax(dev_dax);
put_device(dev);
return ERR_PTR(rc);
}
rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev);
rc = devm_add_action_or_reset(dax_region->dev, unregister_dev_dax, dev);
if (rc)
return ERR_PTR(rc);
return dax_dev;
return dev_dax;
err_cdev:
iput(dax_dev->inode);
err_inode:
ida_simple_remove(&dax_minor_ida, minor);
err_minor:
ida_simple_remove(&dax_region->ida, dax_dev->id);
err_dax:
ida_simple_remove(&dax_region->ida, dev_dax->id);
err_id:
kfree(dax_dev);
kfree(dev_dax);
return ERR_PTR(rc);
}
EXPORT_SYMBOL_GPL(devm_create_dax_dev);
EXPORT_SYMBOL_GPL(devm_create_dev_dax);
static int __init dax_init(void)
{
int rc;
rc = dax_inode_init();
if (rc)
return rc;
nr_dax = max(nr_dax, 256);
rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax");
if (rc)
goto err_chrdev;
dax_class = class_create(THIS_MODULE, "dax");
if (IS_ERR(dax_class)) {
rc = PTR_ERR(dax_class);
goto err_class;
}
return 0;
err_class:
unregister_chrdev_region(dax_devt, nr_dax);
err_chrdev:
dax_inode_exit();
return rc;
return PTR_ERR_OR_ZERO(dax_class);
}
static void __exit dax_exit(void)
{
class_destroy(dax_class);
unregister_chrdev_region(dax_devt, nr_dax);
ida_destroy(&dax_minor_ida);
dax_inode_exit();
}
MODULE_AUTHOR("Intel Corporation");

10
drivers/dax/pmem.c
View File

@@ -16,7 +16,7 @@
#include <linux/pfn_t.h>
#include "../nvdimm/pfn.h"
#include "../nvdimm/nd.h"
#include "dax.h"
#include "device-dax.h"
struct dax_pmem {
struct device *dev;
@@ -61,8 +61,8 @@ static int dax_pmem_probe(struct device *dev)
int rc;
void *addr;
struct resource res;
struct dax_dev *dax_dev;
struct nd_pfn_sb *pfn_sb;
struct dev_dax *dev_dax;
struct dax_pmem *dax_pmem;
struct nd_region *nd_region;
struct nd_namespace_io *nsio;
@@ -130,12 +130,12 @@ static int dax_pmem_probe(struct device *dev)
return -ENOMEM;
/* TODO: support for subdividing a dax region... */
dax_dev = devm_create_dax_dev(dax_region, &res, 1);
dev_dax = devm_create_dev_dax(dax_region, &res, 1);
/* child dax_dev instances now own the lifetime of the dax_region */
/* child dev_dax instances now own the lifetime of the dax_region */
dax_region_put(dax_region);
return PTR_ERR_OR_ZERO(dax_dev);
return PTR_ERR_OR_ZERO(dev_dax);
}
static struct nd_device_driver dax_pmem_driver = {

425
drivers/dax/super.c Normal file
View File

@@ -0,0 +1,425 @@
/*
* Copyright(c) 2017 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/pagemap.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/magic.h>
#include <linux/cdev.h>
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/dax.h>
#include <linux/fs.h>
static int nr_dax = CONFIG_NR_DEV_DAX;
module_param(nr_dax, int, S_IRUGO);
MODULE_PARM_DESC(nr_dax, "max number of dax device instances");
static dev_t dax_devt;
DEFINE_STATIC_SRCU(dax_srcu);
static struct vfsmount *dax_mnt;
static DEFINE_IDA(dax_minor_ida);
static struct kmem_cache *dax_cache __read_mostly;
static struct super_block *dax_superblock __read_mostly;
#define DAX_HASH_SIZE (PAGE_SIZE / sizeof(struct hlist_head))
static struct hlist_head dax_host_list[DAX_HASH_SIZE];
static DEFINE_SPINLOCK(dax_host_lock);
int dax_read_lock(void)
{
return srcu_read_lock(&dax_srcu);
}
EXPORT_SYMBOL_GPL(dax_read_lock);
void dax_read_unlock(int id)
{
srcu_read_unlock(&dax_srcu, id);
}
EXPORT_SYMBOL_GPL(dax_read_unlock);
/**
* struct dax_device - anchor object for dax services
* @inode: core vfs
* @cdev: optional character interface for "device dax"
* @host: optional name for lookups where the device path is not available
* @private: dax driver private data
* @alive: !alive + rcu grace period == no new operations / mappings
*/
struct dax_device {
struct hlist_node list;
struct inode inode;
struct cdev cdev;
const char *host;
void *private;
bool alive;
const struct dax_operations *ops;
};
/**
* dax_direct_access() - translate a device pgoff to an absolute pfn
* @dax_dev: a dax_device instance representing the logical memory range
* @pgoff: offset in pages from the start of the device to translate
* @nr_pages: number of consecutive pages caller can handle relative to @pfn
* @kaddr: output parameter that returns a virtual address mapping of pfn
* @pfn: output parameter that returns an absolute pfn translation of @pgoff
*
* Return: negative errno if an error occurs, otherwise the number of
* pages accessible at the device relative @pgoff.
*/
long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
void **kaddr, pfn_t *pfn)
{
long avail;
/*
* The device driver is allowed to sleep, in order to make the
* memory directly accessible.
*/
might_sleep();
if (!dax_dev)
return -EOPNOTSUPP;
if (!dax_alive(dax_dev))
return -ENXIO;
if (nr_pages < 0)
return nr_pages;
avail = dax_dev->ops->direct_access(dax_dev, pgoff, nr_pages,
kaddr, pfn);
if (!avail)
return -ERANGE;
return min(avail, nr_pages);
}
EXPORT_SYMBOL_GPL(dax_direct_access);
bool dax_alive(struct dax_device *dax_dev)
{
lockdep_assert_held(&dax_srcu);
return dax_dev->alive;
}
EXPORT_SYMBOL_GPL(dax_alive);
static int dax_host_hash(const char *host)
{
return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE;
}
/*
* Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring
* that any fault handlers or operations that might have seen
* dax_alive(), have completed. Any operations that start after
* synchronize_srcu() has run will abort upon seeing !dax_alive().
*/
void kill_dax(struct dax_device *dax_dev)
{
if (!dax_dev)
return;
dax_dev->alive = false;
synchronize_srcu(&dax_srcu);
spin_lock(&dax_host_lock);
hlist_del_init(&dax_dev->list);
spin_unlock(&dax_host_lock);
dax_dev->private = NULL;
}
EXPORT_SYMBOL_GPL(kill_dax);
static struct inode *dax_alloc_inode(struct super_block *sb)
{
struct dax_device *dax_dev;
dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL);
return &dax_dev->inode;
}
static struct dax_device *to_dax_dev(struct inode *inode)
{
return container_of(inode, struct dax_device, inode);
}
static void dax_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
struct dax_device *dax_dev = to_dax_dev(inode);
kfree(dax_dev->host);
dax_dev->host = NULL;
ida_simple_remove(&dax_minor_ida, MINOR(inode->i_rdev));
kmem_cache_free(dax_cache, dax_dev);
}
static void dax_destroy_inode(struct inode *inode)
{
struct dax_device *dax_dev = to_dax_dev(inode);
WARN_ONCE(dax_dev->alive,
"kill_dax() must be called before final iput()\n");
call_rcu(&inode->i_rcu, dax_i_callback);
}
static const struct super_operations dax_sops = {
.statfs = simple_statfs,
.alloc_inode = dax_alloc_inode,
.destroy_inode = dax_destroy_inode,
.drop_inode = generic_delete_inode,
};
static struct dentry *dax_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC);
}
static struct file_system_type dax_fs_type = {
.name = "dax",
.mount = dax_mount,
.kill_sb = kill_anon_super,
};
static int dax_test(struct inode *inode, void *data)
{
dev_t devt = *(dev_t *) data;
return inode->i_rdev == devt;
}
static int dax_set(struct inode *inode, void *data)
{
dev_t devt = *(dev_t *) data;
inode->i_rdev = devt;
return 0;
}
static struct dax_device *dax_dev_get(dev_t devt)
{
struct dax_device *dax_dev;
struct inode *inode;
inode = iget5_locked(dax_superblock, hash_32(devt + DAXFS_MAGIC, 31),
dax_test, dax_set, &devt);
if (!inode)
return NULL;
dax_dev = to_dax_dev(inode);
if (inode->i_state & I_NEW) {
dax_dev->alive = true;
inode->i_cdev = &dax_dev->cdev;
inode->i_mode = S_IFCHR;
inode->i_flags = S_DAX;
mapping_set_gfp_mask(&inode->i_data, GFP_USER);
unlock_new_inode(inode);
}
return dax_dev;
}
static void dax_add_host(struct dax_device *dax_dev, const char *host)
{
int hash;
/*
* Unconditionally init dax_dev since it's coming from a
* non-zeroed slab cache
*/
INIT_HLIST_NODE(&dax_dev->list);
dax_dev->host = host;
if (!host)
return;
hash = dax_host_hash(host);
spin_lock(&dax_host_lock);
hlist_add_head(&dax_dev->list, &dax_host_list[hash]);
spin_unlock(&dax_host_lock);
}
struct dax_device *alloc_dax(void *private, const char *__host,
const struct dax_operations *ops)
{
struct dax_device *dax_dev;
const char *host;
dev_t devt;
int minor;
host = kstrdup(__host, GFP_KERNEL);
if (__host && !host)
return NULL;
minor = ida_simple_get(&dax_minor_ida, 0, nr_dax, GFP_KERNEL);
if (minor < 0)
goto err_minor;
devt = MKDEV(MAJOR(dax_devt), minor);
dax_dev = dax_dev_get(devt);
if (!dax_dev)
goto err_dev;
dax_add_host(dax_dev, host);
dax_dev->ops = ops;
dax_dev->private = private;
return dax_dev;
err_dev:
ida_simple_remove(&dax_minor_ida, minor);
err_minor:
kfree(host);
return NULL;
}
EXPORT_SYMBOL_GPL(alloc_dax);
void put_dax(struct dax_device *dax_dev)
{
if (!dax_dev)
return;
iput(&dax_dev->inode);
}
EXPORT_SYMBOL_GPL(put_dax);
/**
* dax_get_by_host() - temporary lookup mechanism for filesystem-dax
* @host: alternate name for the device registered by a dax driver
*/
struct dax_device *dax_get_by_host(const char *host)
{
struct dax_device *dax_dev, *found = NULL;
int hash, id;
if (!host)
return NULL;
hash = dax_host_hash(host);
id = dax_read_lock();
spin_lock(&dax_host_lock);
hlist_for_each_entry(dax_dev, &dax_host_list[hash], list) {
if (!dax_alive(dax_dev)
|| strcmp(host, dax_dev->host) != 0)
continue;
if (igrab(&dax_dev->inode))
found = dax_dev;
break;
}
spin_unlock(&dax_host_lock);
dax_read_unlock(id);
return found;
}
EXPORT_SYMBOL_GPL(dax_get_by_host);
/**
* inode_dax: convert a public inode into its dax_dev
* @inode: An inode with i_cdev pointing to a dax_dev
*
* Note this is not equivalent to to_dax_dev() which is for private
* internal use where we know the inode filesystem type == dax_fs_type.
*/
struct dax_device *inode_dax(struct inode *inode)
{
struct cdev *cdev = inode->i_cdev;
return container_of(cdev, struct dax_device, cdev);
}
EXPORT_SYMBOL_GPL(inode_dax);
struct inode *dax_inode(struct dax_device *dax_dev)
{
return &dax_dev->inode;
}
EXPORT_SYMBOL_GPL(dax_inode);
void *dax_get_private(struct dax_device *dax_dev)
{
return dax_dev->private;
}
EXPORT_SYMBOL_GPL(dax_get_private);
static void init_once(void *_dax_dev)
{
struct dax_device *dax_dev = _dax_dev;
struct inode *inode = &dax_dev->inode;
inode_init_once(inode);
}
static int __dax_fs_init(void)
{
int rc;
dax_cache = kmem_cache_create("dax_cache", sizeof(struct dax_device), 0,
(SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD|SLAB_ACCOUNT),
init_once);
if (!dax_cache)
return -ENOMEM;
rc = register_filesystem(&dax_fs_type);
if (rc)
goto err_register_fs;
dax_mnt = kern_mount(&dax_fs_type);
if (IS_ERR(dax_mnt)) {
rc = PTR_ERR(dax_mnt);
goto err_mount;
}
dax_superblock = dax_mnt->mnt_sb;
return 0;
err_mount:
unregister_filesystem(&dax_fs_type);
err_register_fs:
kmem_cache_destroy(dax_cache);
return rc;
}
static void __dax_fs_exit(void)
{
kern_unmount(dax_mnt);
unregister_filesystem(&dax_fs_type);
kmem_cache_destroy(dax_cache);
}
static int __init dax_fs_init(void)
{
int rc;
rc = __dax_fs_init();
if (rc)
return rc;
nr_dax = max(nr_dax, 256);
rc = alloc_chrdev_region(&dax_devt, 0, nr_dax, "dax");
if (rc)
__dax_fs_exit();
return rc;
}
static void __exit dax_fs_exit(void)
{
unregister_chrdev_region(dax_devt, nr_dax);
ida_destroy(&dax_minor_ida);
__dax_fs_exit();
}
MODULE_AUTHOR("Intel Corporation");
MODULE_LICENSE("GPL v2");
subsys_initcall(dax_fs_init);
module_exit(dax_fs_exit);