obj-$(CONFIG_NVM) += lightnvm/
obj-y += base/ block/ misc/ mfd/ nfc/
obj-$(CONFIG_LIBNVDIMM) += nvdimm/
-obj-$(CONFIG_DEV_DAX) += dax/
+obj-$(CONFIG_DAX) += dax/
obj-$(CONFIG_DMA_SHARED_BUFFER) += dma-buf/
obj-$(CONFIG_NUBUS) += nubus/
obj-y += macintosh/
-menuconfig DEV_DAX
+menuconfig DAX
tristate "DAX: direct access to differentiated memory"
+ select SRCU
default m if NVDIMM_DAX
+
+if DAX
+
+config DEV_DAX
+ tristate "Device DAX: direct access mapping device"
depends on TRANSPARENT_HUGEPAGE
- select SRCU
help
Support raw access to differentiated (persistence, bandwidth,
latency...) memory via an mmap(2) capable character
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"
-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
+++ /dev/null
-/*
- * 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.
- */
-#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>
-#include <linux/fs.h>
-#include <linux/mm.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");
-
-/**
- * struct dax_region - mapping infrastructure for dax devices
- * @id: kernel-wide unique region for a memory range
- * @base: linear address corresponding to @res
- * @kref: to pin while other agents have a need to do lookups
- * @dev: parent device backing this region
- * @align: allocation and mapping alignment for child dax devices
- * @res: physical address range of the region
- * @pfn_flags: identify whether the pfns are paged back or not
- */
-struct dax_region {
- int id;
- struct ida ida;
- void *base;
- struct kref kref;
- struct device *dev;
- unsigned int align;
- struct resource res;
- unsigned long pfn_flags;
-};
-
-/**
- * struct dev_dax - instance data for a subdivision of a dax region
- * @region - parent region
- * @dev - device backing the character device
- * @cdev - core chardev data
- * @alive - !alive + srcu grace period == no new mappings can be established
- * @id - child id in the region
- * @num_resources - number of physical address extents in this device
- * @res - array of physical address ranges
- */
-struct dev_dax {
- struct dax_region *region;
- struct inode *inode;
- struct device dev;
- struct cdev cdev;
- bool alive;
- int id;
- int num_resources;
- struct resource res[0];
-};
-
-static ssize_t id_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct dax_region *dax_region;
- ssize_t rc = -ENXIO;
-
- device_lock(dev);
- dax_region = dev_get_drvdata(dev);
- if (dax_region)
- rc = sprintf(buf, "%d\n", dax_region->id);
- device_unlock(dev);
-
- return rc;
-}
-static DEVICE_ATTR_RO(id);
-
-static ssize_t region_size_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct dax_region *dax_region;
- ssize_t rc = -ENXIO;
-
- device_lock(dev);
- dax_region = dev_get_drvdata(dev);
- if (dax_region)
- rc = sprintf(buf, "%llu\n", (unsigned long long)
- resource_size(&dax_region->res));
- device_unlock(dev);
-
- return rc;
-}
-static struct device_attribute dev_attr_region_size = __ATTR(size, 0444,
- region_size_show, NULL);
-
-static ssize_t align_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct dax_region *dax_region;
- ssize_t rc = -ENXIO;
-
- device_lock(dev);
- dax_region = dev_get_drvdata(dev);
- if (dax_region)
- rc = sprintf(buf, "%u\n", dax_region->align);
- device_unlock(dev);
-
- return rc;
-}
-static DEVICE_ATTR_RO(align);
-
-static struct attribute *dax_region_attributes[] = {
- &dev_attr_region_size.attr,
- &dev_attr_align.attr,
- &dev_attr_id.attr,
- NULL,
-};
-
-static const struct attribute_group dax_region_attribute_group = {
- .name = "dax_region",
- .attrs = dax_region_attributes,
-};
-
-static const struct attribute_group *dax_region_attribute_groups[] = {
- &dax_region_attribute_group,
- 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;
-
- dax_region = container_of(kref, struct dax_region, kref);
- kfree(dax_region);
-}
-
-void dax_region_put(struct dax_region *dax_region)
-{
- kref_put(&dax_region->kref, dax_region_free);
-}
-EXPORT_SYMBOL_GPL(dax_region_put);
-
-static void dax_region_unregister(void *region)
-{
- struct dax_region *dax_region = region;
-
- sysfs_remove_groups(&dax_region->dev->kobj,
- dax_region_attribute_groups);
- dax_region_put(dax_region);
-}
-
-struct dax_region *alloc_dax_region(struct device *parent, int region_id,
- struct resource *res, unsigned int align, void *addr,
- unsigned long pfn_flags)
-{
- struct dax_region *dax_region;
-
- /*
- * The DAX core assumes that it can store its private data in
- * parent->driver_data. This WARN is a reminder / safeguard for
- * developers of device-dax drivers.
- */
- if (dev_get_drvdata(parent)) {
- dev_WARN(parent, "dax core failed to setup private data\n");
- return NULL;
- }
-
- if (!IS_ALIGNED(res->start, align)
- || !IS_ALIGNED(resource_size(res), align))
- return NULL;
-
- dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL);
- if (!dax_region)
- return NULL;
-
- dev_set_drvdata(parent, dax_region);
- memcpy(&dax_region->res, res, sizeof(*res));
- dax_region->pfn_flags = pfn_flags;
- kref_init(&dax_region->kref);
- dax_region->id = region_id;
- ida_init(&dax_region->ida);
- dax_region->align = align;
- dax_region->dev = parent;
- dax_region->base = addr;
- if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) {
- kfree(dax_region);
- return NULL;;
- }
-
- kref_get(&dax_region->kref);
- if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region))
- return NULL;
- return dax_region;
-}
-EXPORT_SYMBOL_GPL(alloc_dax_region);
-
-static struct dev_dax *to_dev_dax(struct device *dev)
-{
- return container_of(dev, struct dev_dax, dev);
-}
-
-static ssize_t size_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct dev_dax *dev_dax = to_dev_dax(dev);
- unsigned long long size = 0;
- int 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 *dev_dax_attributes[] = {
- &dev_attr_size.attr,
- NULL,
-};
-
-static const struct attribute_group dev_dax_attribute_group = {
- .attrs = dev_dax_attributes,
-};
-
-static const struct attribute_group *dax_attribute_groups[] = {
- &dev_dax_attribute_group,
- NULL,
-};
-
-static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
- const char *func)
-{
- struct dax_region *dax_region = dev_dax->region;
- struct device *dev = &dev_dax->dev;
- unsigned long mask;
-
- if (!dev_dax->alive)
- return -ENXIO;
-
- /* prevent private mappings from being established */
- if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) {
- dev_info(dev, "%s: %s: fail, attempted private mapping\n",
- current->comm, func);
- return -EINVAL;
- }
-
- mask = dax_region->align - 1;
- if (vma->vm_start & mask || vma->vm_end & mask) {
- dev_info(dev, "%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n",
- current->comm, func, vma->vm_start, vma->vm_end,
- mask);
- return -EINVAL;
- }
-
- if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV
- && (vma->vm_flags & VM_DONTCOPY) == 0) {
- dev_info(dev, "%s: %s: fail, dax range requires MADV_DONTFORK\n",
- current->comm, func);
- return -EINVAL;
- }
-
- if (!vma_is_dax(vma)) {
- dev_info(dev, "%s: %s: fail, vma is not DAX capable\n",
- current->comm, func);
- return -EINVAL;
- }
-
- return 0;
-}
-
-static phys_addr_t 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 < 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 < dev_dax->num_resources) {
- res = &dev_dax->res[i];
- if (phys + size - 1 <= res->end)
- return phys;
- }
-
- return -1;
-}
-
-static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
-{
- 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(dev_dax, vmf->vma, __func__))
- return VM_FAULT_SIGBUS;
-
- dax_region = dev_dax->region;
- if (dax_region->align > PAGE_SIZE) {
- 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 = 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);
- return VM_FAULT_SIGBUS;
- }
-
- pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
-
- rc = vm_insert_mixed(vmf->vma, vmf->address, pfn);
-
- if (rc == -ENOMEM)
- return VM_FAULT_OOM;
- if (rc < 0 && rc != -EBUSY)
- return VM_FAULT_SIGBUS;
-
- return VM_FAULT_NOPAGE;
-}
-
-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 = &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(dev_dax, vmf->vma, __func__))
- return VM_FAULT_SIGBUS;
-
- dax_region = dev_dax->region;
- if (dax_region->align > PMD_SIZE) {
- 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: region lacks devmap flags\n", __func__);
- return VM_FAULT_SIGBUS;
- }
-
- if (fault_size < dax_region->align)
- return VM_FAULT_SIGBUS;
- else if (fault_size > dax_region->align)
- return VM_FAULT_FALLBACK;
-
- /* if we are outside of the VMA */
- if (pmd_addr < vmf->vma->vm_start ||
- (pmd_addr + PMD_SIZE) > vmf->vma->vm_end)
- return VM_FAULT_SIGBUS;
-
- pgoff = linear_page_index(vmf->vma, pmd_addr);
- phys = pgoff_to_phys(dev_dax, pgoff, PMD_SIZE);
- if (phys == -1) {
- dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
- pgoff);
- return VM_FAULT_SIGBUS;
- }
-
- pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
-
- return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, pfn,
- vmf->flags & FAULT_FLAG_WRITE);
-}
-
-#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-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 = &dev_dax->dev;
- struct dax_region *dax_region;
- phys_addr_t phys;
- pgoff_t pgoff;
- pfn_t pfn;
- unsigned int fault_size = PUD_SIZE;
-
-
- if (check_vma(dev_dax, vmf->vma, __func__))
- return VM_FAULT_SIGBUS;
-
- dax_region = dev_dax->region;
- if (dax_region->align > PUD_SIZE) {
- 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: region lacks devmap flags\n", __func__);
- return VM_FAULT_SIGBUS;
- }
-
- if (fault_size < dax_region->align)
- return VM_FAULT_SIGBUS;
- else if (fault_size > dax_region->align)
- return VM_FAULT_FALLBACK;
-
- /* if we are outside of the VMA */
- if (pud_addr < vmf->vma->vm_start ||
- (pud_addr + PUD_SIZE) > vmf->vma->vm_end)
- return VM_FAULT_SIGBUS;
-
- pgoff = linear_page_index(vmf->vma, pud_addr);
- phys = pgoff_to_phys(dev_dax, pgoff, PUD_SIZE);
- if (phys == -1) {
- dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
- pgoff);
- return VM_FAULT_SIGBUS;
- }
-
- pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
-
- return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, pfn,
- vmf->flags & FAULT_FLAG_WRITE);
-}
-#else
-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 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 dev_dax *dev_dax = filp->private_data;
-
- 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, pe_size);
-
- id = srcu_read_lock(&dax_srcu);
- switch (pe_size) {
- case PE_SIZE_PTE:
- rc = __dev_dax_pte_fault(dev_dax, vmf);
- break;
- case PE_SIZE_PMD:
- rc = __dev_dax_pmd_fault(dev_dax, vmf);
- break;
- case PE_SIZE_PUD:
- rc = __dev_dax_pud_fault(dev_dax, vmf);
- break;
- default:
- rc = VM_FAULT_SIGBUS;
- }
- srcu_read_unlock(&dax_srcu, id);
-
- return rc;
-}
-
-static int dev_dax_fault(struct vm_fault *vmf)
-{
- return dev_dax_huge_fault(vmf, PE_SIZE_PTE);
-}
-
-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 dev_dax *dev_dax = filp->private_data;
- int rc;
-
- dev_dbg(&dev_dax->dev, "%s\n", __func__);
-
- rc = check_vma(dev_dax, vma, __func__);
- if (rc)
- return rc;
-
- vma->vm_ops = &dax_vm_ops;
- vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
- return 0;
-}
-
-/* return an unmapped area aligned to the dax region specified alignment */
-static unsigned long dax_get_unmapped_area(struct file *filp,
- unsigned long addr, unsigned long len, unsigned long pgoff,
- unsigned long flags)
-{
- unsigned long off, off_end, off_align, len_align, addr_align, align;
- struct dev_dax *dev_dax = filp ? filp->private_data : NULL;
- struct dax_region *dax_region;
-
- if (!dev_dax || addr)
- goto out;
-
- dax_region = dev_dax->region;
- align = dax_region->align;
- off = pgoff << PAGE_SHIFT;
- off_end = off + len;
- off_align = round_up(off, align);
-
- if ((off_end <= off_align) || ((off_end - off_align) < align))
- goto out;
-
- len_align = len + align;
- if ((off + len_align) < off)
- goto out;
-
- addr_align = current->mm->get_unmapped_area(filp, addr, len_align,
- pgoff, flags);
- if (!IS_ERR_VALUE(addr_align)) {
- addr_align += (off - addr_align) & (align - 1);
- return addr_align;
- }
- out:
- return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);
-}
-
-static int dax_open(struct inode *inode, struct file *filp)
-{
- struct dev_dax *dev_dax;
-
- dev_dax = container_of(inode->i_cdev, struct dev_dax, cdev);
- dev_dbg(&dev_dax->dev, "%s\n", __func__);
- inode->i_mapping = dev_dax->inode->i_mapping;
- inode->i_mapping->host = dev_dax->inode;
- filp->f_mapping = inode->i_mapping;
- filp->private_data = dev_dax;
- inode->i_flags = S_DAX;
-
- return 0;
-}
-
-static int dax_release(struct inode *inode, struct file *filp)
-{
- struct dev_dax *dev_dax = filp->private_data;
-
- dev_dbg(&dev_dax->dev, "%s\n", __func__);
- return 0;
-}
-
-static const struct file_operations dax_fops = {
- .llseek = noop_llseek,
- .owner = THIS_MODULE,
- .open = dax_open,
- .release = dax_release,
- .get_unmapped_area = dax_get_unmapped_area,
- .mmap = dax_mmap,
-};
-
-static void dev_dax_release(struct device *dev)
-{
- struct dev_dax *dev_dax = to_dev_dax(dev);
- struct dax_region *dax_region = dev_dax->region;
-
- ida_simple_remove(&dax_region->ida, dev_dax->id);
- ida_simple_remove(&dax_minor_ida, MINOR(dev->devt));
- dax_region_put(dax_region);
- iput(dev_dax->inode);
- kfree(dev_dax);
-}
-
-static void kill_dev_dax(struct dev_dax *dev_dax)
-{
- /*
- * Note, rcu is not protecting the liveness of dev_dax, rcu is
- * ensuring that any fault handlers that might have seen
- * dev_dax->alive == true, have completed. Any fault handlers
- * that start after synchronize_srcu() has started will abort
- * upon seeing dev_dax->alive == false.
- */
- dev_dax->alive = false;
- synchronize_srcu(&dax_srcu);
- unmap_mapping_range(dev_dax->inode->i_mapping, 0, 0, 1);
-}
-
-static void unregister_dev_dax(void *dev)
-{
- struct dev_dax *dev_dax = to_dev_dax(dev);
-
- dev_dbg(dev, "%s\n", __func__);
-
- kill_dev_dax(dev_dax);
- cdev_device_del(&dev_dax->cdev, dev);
- put_device(dev);
-}
-
-struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
- struct resource *res, int count)
-{
- struct device *parent = dax_region->dev;
- struct dev_dax *dev_dax;
- int rc = 0, minor, i;
- struct device *dev;
- struct cdev *cdev;
- dev_t dev_t;
-
- dev_dax = kzalloc(sizeof(*dev_dax) + sizeof(*res) * count, GFP_KERNEL);
- if (!dev_dax)
- return ERR_PTR(-ENOMEM);
-
- for (i = 0; i < count; i++) {
- if (!IS_ALIGNED(res[i].start, dax_region->align)
- || !IS_ALIGNED(resource_size(&res[i]),
- dax_region->align)) {
- rc = -EINVAL;
- break;
- }
- dev_dax->res[i].start = res[i].start;
- dev_dax->res[i].end = res[i].end;
- }
-
- if (i < count)
- goto err_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 = &dev_dax->dev;
- dev_dax->inode = dax_inode_get(&dev_dax->cdev, dev_t);
- if (!dev_dax->inode) {
- rc = -ENOMEM;
- goto err_inode;
- }
-
- /* from here on we're committed to teardown via dev_dax_release() */
- device_initialize(dev);
-
- cdev = &dev_dax->cdev;
- cdev_init(cdev, &dax_fops);
- cdev->owner = parent->driver->owner;
-
- dev_dax->num_resources = count;
- dev_dax->alive = true;
- dev_dax->region = dax_region;
- kref_get(&dax_region->kref);
-
- dev->devt = dev_t;
- dev->class = dax_class;
- dev->parent = parent;
- dev->groups = dax_attribute_groups;
- 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_dev_dax, dev);
- if (rc)
- return ERR_PTR(rc);
-
- return dev_dax;
-
- err_inode:
- ida_simple_remove(&dax_minor_ida, minor);
- err_minor:
- ida_simple_remove(&dax_region->ida, dev_dax->id);
- err_id:
- kfree(dev_dax);
-
- return ERR_PTR(rc);
-}
-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;
-}
-
-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");
-MODULE_LICENSE("GPL v2");
-subsys_initcall(dax_init);
-module_exit(dax_exit);
/*
- * 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
*/
#ifndef __DAX_H__
#define __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);
+struct dax_device;
+struct dax_device *alloc_dax(void *private);
+void put_dax(struct dax_device *dax_dev);
+bool dax_alive(struct dax_device *dax_dev);
+void kill_dax(struct dax_device *dax_dev);
+struct dax_device *inode_dax(struct inode *inode);
+struct inode *dax_inode(struct dax_device *dax_dev);
+void *dax_get_private(struct dax_device *dax_dev);
#endif /* __DAX_H__ */
--- /dev/null
+/*
+ * 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__ */
--- /dev/null
+/*
+ * 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
+ * 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/device.h>
+#include <linux/pfn_t.h>
+#include <linux/cdev.h>
+#include <linux/slab.h>
+#include <linux/dax.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include "dax.h"
+
+static struct class *dax_class;
+
+/**
+ * struct dax_region - mapping infrastructure for dax devices
+ * @id: kernel-wide unique region for a memory range
+ * @base: linear address corresponding to @res
+ * @kref: to pin while other agents have a need to do lookups
+ * @dev: parent device backing this region
+ * @align: allocation and mapping alignment for child dax devices
+ * @res: physical address range of the region
+ * @pfn_flags: identify whether the pfns are paged back or not
+ */
+struct dax_region {
+ int id;
+ struct ida ida;
+ void *base;
+ struct kref kref;
+ struct device *dev;
+ unsigned int align;
+ struct resource res;
+ unsigned long pfn_flags;
+};
+
+/**
+ * struct dev_dax - instance data for a subdivision of a dax region
+ * @region - parent region
+ * @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 dev_dax {
+ struct dax_region *region;
+ struct dax_device *dax_dev;
+ struct device dev;
+ int id;
+ int num_resources;
+ struct resource res[0];
+};
+
+static ssize_t id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dax_region *dax_region;
+ ssize_t rc = -ENXIO;
+
+ device_lock(dev);
+ dax_region = dev_get_drvdata(dev);
+ if (dax_region)
+ rc = sprintf(buf, "%d\n", dax_region->id);
+ device_unlock(dev);
+
+ return rc;
+}
+static DEVICE_ATTR_RO(id);
+
+static ssize_t region_size_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dax_region *dax_region;
+ ssize_t rc = -ENXIO;
+
+ device_lock(dev);
+ dax_region = dev_get_drvdata(dev);
+ if (dax_region)
+ rc = sprintf(buf, "%llu\n", (unsigned long long)
+ resource_size(&dax_region->res));
+ device_unlock(dev);
+
+ return rc;
+}
+static struct device_attribute dev_attr_region_size = __ATTR(size, 0444,
+ region_size_show, NULL);
+
+static ssize_t align_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dax_region *dax_region;
+ ssize_t rc = -ENXIO;
+
+ device_lock(dev);
+ dax_region = dev_get_drvdata(dev);
+ if (dax_region)
+ rc = sprintf(buf, "%u\n", dax_region->align);
+ device_unlock(dev);
+
+ return rc;
+}
+static DEVICE_ATTR_RO(align);
+
+static struct attribute *dax_region_attributes[] = {
+ &dev_attr_region_size.attr,
+ &dev_attr_align.attr,
+ &dev_attr_id.attr,
+ NULL,
+};
+
+static const struct attribute_group dax_region_attribute_group = {
+ .name = "dax_region",
+ .attrs = dax_region_attributes,
+};
+
+static const struct attribute_group *dax_region_attribute_groups[] = {
+ &dax_region_attribute_group,
+ NULL,
+};
+
+static void dax_region_free(struct kref *kref)
+{
+ struct dax_region *dax_region;
+
+ dax_region = container_of(kref, struct dax_region, kref);
+ kfree(dax_region);
+}
+
+void dax_region_put(struct dax_region *dax_region)
+{
+ kref_put(&dax_region->kref, dax_region_free);
+}
+EXPORT_SYMBOL_GPL(dax_region_put);
+
+static void dax_region_unregister(void *region)
+{
+ struct dax_region *dax_region = region;
+
+ sysfs_remove_groups(&dax_region->dev->kobj,
+ dax_region_attribute_groups);
+ dax_region_put(dax_region);
+}
+
+struct dax_region *alloc_dax_region(struct device *parent, int region_id,
+ struct resource *res, unsigned int align, void *addr,
+ unsigned long pfn_flags)
+{
+ struct dax_region *dax_region;
+
+ /*
+ * The DAX core assumes that it can store its private data in
+ * parent->driver_data. This WARN is a reminder / safeguard for
+ * developers of device-dax drivers.
+ */
+ if (dev_get_drvdata(parent)) {
+ dev_WARN(parent, "dax core failed to setup private data\n");
+ return NULL;
+ }
+
+ if (!IS_ALIGNED(res->start, align)
+ || !IS_ALIGNED(resource_size(res), align))
+ return NULL;
+
+ dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL);
+ if (!dax_region)
+ return NULL;
+
+ dev_set_drvdata(parent, dax_region);
+ memcpy(&dax_region->res, res, sizeof(*res));
+ dax_region->pfn_flags = pfn_flags;
+ kref_init(&dax_region->kref);
+ dax_region->id = region_id;
+ ida_init(&dax_region->ida);
+ dax_region->align = align;
+ dax_region->dev = parent;
+ dax_region->base = addr;
+ if (sysfs_create_groups(&parent->kobj, dax_region_attribute_groups)) {
+ kfree(dax_region);
+ return NULL;;
+ }
+
+ kref_get(&dax_region->kref);
+ if (devm_add_action_or_reset(parent, dax_region_unregister, dax_region))
+ return NULL;
+ return dax_region;
+}
+EXPORT_SYMBOL_GPL(alloc_dax_region);
+
+static struct dev_dax *to_dev_dax(struct device *dev)
+{
+ return container_of(dev, struct dev_dax, dev);
+}
+
+static ssize_t size_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dev_dax *dev_dax = to_dev_dax(dev);
+ unsigned long long size = 0;
+ int 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 *dev_dax_attributes[] = {
+ &dev_attr_size.attr,
+ NULL,
+};
+
+static const struct attribute_group dev_dax_attribute_group = {
+ .attrs = dev_dax_attributes,
+};
+
+static const struct attribute_group *dax_attribute_groups[] = {
+ &dev_dax_attribute_group,
+ NULL,
+};
+
+static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
+ const char *func)
+{
+ struct dax_region *dax_region = dev_dax->region;
+ struct device *dev = &dev_dax->dev;
+ unsigned long mask;
+
+ if (!dax_alive(dev_dax->dax_dev))
+ return -ENXIO;
+
+ /* prevent private mappings from being established */
+ if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) {
+ dev_info(dev, "%s: %s: fail, attempted private mapping\n",
+ current->comm, func);
+ return -EINVAL;
+ }
+
+ mask = dax_region->align - 1;
+ if (vma->vm_start & mask || vma->vm_end & mask) {
+ dev_info(dev, "%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n",
+ current->comm, func, vma->vm_start, vma->vm_end,
+ mask);
+ return -EINVAL;
+ }
+
+ if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV
+ && (vma->vm_flags & VM_DONTCOPY) == 0) {
+ dev_info(dev, "%s: %s: fail, dax range requires MADV_DONTFORK\n",
+ current->comm, func);
+ return -EINVAL;
+ }
+
+ if (!vma_is_dax(vma)) {
+ dev_info(dev, "%s: %s: fail, vma is not DAX capable\n",
+ current->comm, func);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static phys_addr_t 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 < 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 < dev_dax->num_resources) {
+ res = &dev_dax->res[i];
+ if (phys + size - 1 <= res->end)
+ return phys;
+ }
+
+ return -1;
+}
+
+static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
+{
+ 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(dev_dax, vmf->vma, __func__))
+ return VM_FAULT_SIGBUS;
+
+ dax_region = dev_dax->region;
+ if (dax_region->align > PAGE_SIZE) {
+ 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 = 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);
+ return VM_FAULT_SIGBUS;
+ }
+
+ pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+
+ rc = vm_insert_mixed(vmf->vma, vmf->address, pfn);
+
+ if (rc == -ENOMEM)
+ return VM_FAULT_OOM;
+ if (rc < 0 && rc != -EBUSY)
+ return VM_FAULT_SIGBUS;
+
+ return VM_FAULT_NOPAGE;
+}
+
+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 = &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(dev_dax, vmf->vma, __func__))
+ return VM_FAULT_SIGBUS;
+
+ dax_region = dev_dax->region;
+ if (dax_region->align > PMD_SIZE) {
+ 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: region lacks devmap flags\n", __func__);
+ return VM_FAULT_SIGBUS;
+ }
+
+ if (fault_size < dax_region->align)
+ return VM_FAULT_SIGBUS;
+ else if (fault_size > dax_region->align)
+ return VM_FAULT_FALLBACK;
+
+ /* if we are outside of the VMA */
+ if (pmd_addr < vmf->vma->vm_start ||
+ (pmd_addr + PMD_SIZE) > vmf->vma->vm_end)
+ return VM_FAULT_SIGBUS;
+
+ pgoff = linear_page_index(vmf->vma, pmd_addr);
+ phys = pgoff_to_phys(dev_dax, pgoff, PMD_SIZE);
+ if (phys == -1) {
+ dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
+ pgoff);
+ return VM_FAULT_SIGBUS;
+ }
+
+ pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+
+ return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, pfn,
+ vmf->flags & FAULT_FLAG_WRITE);
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+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 = &dev_dax->dev;
+ struct dax_region *dax_region;
+ phys_addr_t phys;
+ pgoff_t pgoff;
+ pfn_t pfn;
+ unsigned int fault_size = PUD_SIZE;
+
+
+ if (check_vma(dev_dax, vmf->vma, __func__))
+ return VM_FAULT_SIGBUS;
+
+ dax_region = dev_dax->region;
+ if (dax_region->align > PUD_SIZE) {
+ 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: region lacks devmap flags\n", __func__);
+ return VM_FAULT_SIGBUS;
+ }
+
+ if (fault_size < dax_region->align)
+ return VM_FAULT_SIGBUS;
+ else if (fault_size > dax_region->align)
+ return VM_FAULT_FALLBACK;
+
+ /* if we are outside of the VMA */
+ if (pud_addr < vmf->vma->vm_start ||
+ (pud_addr + PUD_SIZE) > vmf->vma->vm_end)
+ return VM_FAULT_SIGBUS;
+
+ pgoff = linear_page_index(vmf->vma, pud_addr);
+ phys = pgoff_to_phys(dev_dax, pgoff, PUD_SIZE);
+ if (phys == -1) {
+ dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
+ pgoff);
+ return VM_FAULT_SIGBUS;
+ }
+
+ pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
+
+ return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, pfn,
+ vmf->flags & FAULT_FLAG_WRITE);
+}
+#else
+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 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 dev_dax *dev_dax = filp->private_data;
+
+ 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, pe_size);
+
+ id = dax_read_lock();
+ switch (pe_size) {
+ case PE_SIZE_PTE:
+ rc = __dev_dax_pte_fault(dev_dax, vmf);
+ break;
+ case PE_SIZE_PMD:
+ rc = __dev_dax_pmd_fault(dev_dax, vmf);
+ break;
+ case PE_SIZE_PUD:
+ rc = __dev_dax_pud_fault(dev_dax, vmf);
+ break;
+ default:
+ rc = VM_FAULT_SIGBUS;
+ }
+ dax_read_unlock(id);
+
+ return rc;
+}
+
+static int dev_dax_fault(struct vm_fault *vmf)
+{
+ return dev_dax_huge_fault(vmf, PE_SIZE_PTE);
+}
+
+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 dev_dax *dev_dax = filp->private_data;
+ int rc, id;
+
+ dev_dbg(&dev_dax->dev, "%s\n", __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_vm_ops;
+ vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
+ return 0;
+}
+
+/* return an unmapped area aligned to the dax region specified alignment */
+static unsigned long dax_get_unmapped_area(struct file *filp,
+ unsigned long addr, unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ unsigned long off, off_end, off_align, len_align, addr_align, align;
+ struct dev_dax *dev_dax = filp ? filp->private_data : NULL;
+ struct dax_region *dax_region;
+
+ if (!dev_dax || addr)
+ goto out;
+
+ dax_region = dev_dax->region;
+ align = dax_region->align;
+ off = pgoff << PAGE_SHIFT;
+ off_end = off + len;
+ off_align = round_up(off, align);
+
+ if ((off_end <= off_align) || ((off_end - off_align) < align))
+ goto out;
+
+ len_align = len + align;
+ if ((off + len_align) < off)
+ goto out;
+
+ addr_align = current->mm->get_unmapped_area(filp, addr, len_align,
+ pgoff, flags);
+ if (!IS_ERR_VALUE(addr_align)) {
+ addr_align += (off - addr_align) & (align - 1);
+ return addr_align;
+ }
+ out:
+ return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);
+}
+
+static int dax_open(struct inode *inode, struct file *filp)
+{
+ 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);
+
+ 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 = dev_dax;
+ inode->i_flags = S_DAX;
+
+ return 0;
+}
+
+static int dax_release(struct inode *inode, struct file *filp)
+{
+ struct dev_dax *dev_dax = filp->private_data;
+
+ dev_dbg(&dev_dax->dev, "%s\n", __func__);
+ return 0;
+}
+
+static const struct file_operations dax_fops = {
+ .llseek = noop_llseek,
+ .owner = THIS_MODULE,
+ .open = dax_open,
+ .release = dax_release,
+ .get_unmapped_area = dax_get_unmapped_area,
+ .mmap = dax_mmap,
+};
+
+static void dev_dax_release(struct device *dev)
+{
+ 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, dev_dax->id);
+ dax_region_put(dax_region);
+ put_dax(dax_dev);
+ kfree(dev_dax);
+}
+
+static void kill_dev_dax(struct dev_dax *dev_dax)
+{
+ 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__);
+
+ kill_dev_dax(dev_dax);
+ cdev_device_del(cdev, dev);
+ put_device(dev);
+}
+
+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_device *dax_dev;
+ struct dev_dax *dev_dax;
+ struct inode *inode;
+ struct device *dev;
+ struct cdev *cdev;
+ int rc = 0, i;
+
+ dev_dax = kzalloc(sizeof(*dev_dax) + sizeof(*res) * count, GFP_KERNEL);
+ if (!dev_dax)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < count; i++) {
+ if (!IS_ALIGNED(res[i].start, dax_region->align)
+ || !IS_ALIGNED(resource_size(&res[i]),
+ dax_region->align)) {
+ rc = -EINVAL;
+ break;
+ }
+ dev_dax->res[i].start = res[i].start;
+ dev_dax->res[i].end = res[i].end;
+ }
+
+ if (i < count)
+ goto err_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;
+ }
+
+ dax_dev = alloc_dax(dev_dax);
+ if (!dax_dev)
+ goto err_dax;
+
+ /* from here on we're committed to teardown via dax_dev_release() */
+ 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 = inode->i_rdev;
+ dev->class = dax_class;
+ dev->parent = parent;
+ dev->groups = dax_attribute_groups;
+ 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_dev_dax, dev);
+ if (rc)
+ return ERR_PTR(rc);
+
+ return dev_dax;
+
+ err_dax:
+ ida_simple_remove(&dax_region->ida, dev_dax->id);
+ err_id:
+ kfree(dev_dax);
+
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(devm_create_dev_dax);
+
+static int __init dax_init(void)
+{
+ dax_class = class_create(THIS_MODULE, "dax");
+ return PTR_ERR_OR_ZERO(dax_class);
+}
+
+static void __exit dax_exit(void)
+{
+ class_destroy(dax_class);
+}
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+subsys_initcall(dax_init);
+module_exit(dax_exit);
#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;
--- /dev/null
+/*
+ * 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/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;
+
+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"
+ * @private: dax driver private data
+ * @alive: !alive + rcu grace period == no new operations / mappings
+ */
+struct dax_device {
+ struct inode inode;
+ struct cdev cdev;
+ void *private;
+ bool alive;
+};
+
+bool dax_alive(struct dax_device *dax_dev)
+{
+ lockdep_assert_held(&dax_srcu);
+ return dax_dev->alive;
+}
+EXPORT_SYMBOL_GPL(dax_alive);
+
+/*
+ * 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);
+ 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);
+
+ 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;
+}
+
+struct dax_device *alloc_dax(void *private)
+{
+ struct dax_device *dax_dev;
+ dev_t devt;
+ int minor;
+
+ minor = ida_simple_get(&dax_minor_ida, 0, nr_dax, GFP_KERNEL);
+ if (minor < 0)
+ return NULL;
+
+ devt = MKDEV(MAJOR(dax_devt), minor);
+ dax_dev = dax_dev_get(devt);
+ if (!dax_dev)
+ goto err_inode;
+
+ dax_dev->private = private;
+ return dax_dev;
+
+ err_inode:
+ ida_simple_remove(&dax_minor_ida, minor);
+ 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);
+
+/**
+ * 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);
struct iomap_ops;
+int dax_read_lock(void);
+void dax_read_unlock(int id);
+
/*
* We use lowest available bit in exceptional entry for locking, one bit for
* the entry size (PMD) and two more to tell us if the entry is a huge zero
obj-$(CONFIG_ND_BLK) += nd_blk.o
obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
obj-$(CONFIG_ACPI_NFIT) += nfit.o
-obj-$(CONFIG_DEV_DAX) += dax.o
+ifeq ($(CONFIG_DAX),m)
+obj-$(CONFIG_DAX) += dax.o
+endif
+obj-$(CONFIG_DEV_DAX) += device_dax.o
obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o
nfit-y := $(ACPI_SRC)/core.o
nd_e820-y := $(NVDIMM_SRC)/e820.o
nd_e820-y += config_check.o
-dax-y := $(DAX_SRC)/dax.o
+dax-y := $(DAX_SRC)/super.o
dax-y += config_check.o
+device_dax-y := $(DAX_SRC)/device.o
+device_dax-y += config_check.o
+
dax_pmem-y := $(DAX_SRC)/pmem.o
dax_pmem-y += config_check.o
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff