Loading drivers/dax/Kconfig +5 −0 Original line number Diff line number Diff line Loading @@ -23,4 +23,9 @@ config DEV_DAX_PMEM Say Y if unsure config NR_DEV_DAX int "Maximum number of Device-DAX instances" default 32768 range 256 2147483647 endif drivers/dax/dax.c +350 −227 Original line number Diff line number Diff line Loading @@ -13,15 +13,25 @@ #include <linux/pagemap.h> #include <linux/module.h> #include <linux/device.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 int dax_major; static dev_t dax_devt; 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 Loading @@ -48,7 +58,7 @@ struct dax_region { * struct dax_dev - subdivision of a dax region * @region - parent region * @dev - device backing the character device * @kref - enable this data to be tracked in filp->private_data * @cdev - core chardev data * @alive - !alive + rcu grace period == no new mappings can be established * @id - child id in the region * @num_resources - number of physical address extents in this device Loading @@ -56,50 +66,151 @@ struct dax_region { */ struct dax_dev { struct dax_region *region; struct device *dev; struct kref kref; struct inode *inode; struct device dev; struct cdev cdev; bool alive; int id; int num_resources; struct resource res[0]; }; static void dax_region_free(struct kref *kref) static struct inode *dax_alloc_inode(struct super_block *sb) { struct dax_region *dax_region; return kmem_cache_alloc(dax_cache, GFP_KERNEL); } dax_region = container_of(kref, struct dax_region, kref); kfree(dax_region); 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); } void dax_region_put(struct dax_region *dax_region) static void dax_destroy_inode(struct inode *inode) { kref_put(&dax_region->kref, dax_region_free); call_rcu(&inode->i_rcu, dax_i_callback); } EXPORT_SYMBOL_GPL(dax_region_put); static void dax_dev_free(struct kref *kref) 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) { struct dax_dev *dax_dev; return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC); } dax_dev = container_of(kref, struct dax_dev, kref); dax_region_put(dax_dev->region); kfree(dax_dev); 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_dev_put(struct dax_dev *dax_dev) static void dax_region_free(struct kref *kref) { kref_put(&dax_dev->kref, dax_dev_free); 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); 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; dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); 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; Loading @@ -116,10 +227,15 @@ 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) { return container_of(dev, struct dax_dev, dev); } static ssize_t size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct dax_dev *dax_dev = dev_get_drvdata(dev); struct dax_dev *dax_dev = to_dax_dev(dev); unsigned long long size = 0; int i; Loading @@ -144,180 +260,11 @@ static const struct attribute_group *dax_attribute_groups[] = { NULL, }; static void unregister_dax_dev(void *_dev) { struct device *dev = _dev; struct dax_dev *dax_dev = dev_get_drvdata(dev); struct dax_region *dax_region = dax_dev->region; 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_rcu() has started will abort * upon seeing dax_dev->alive == false. */ dax_dev->alive = false; synchronize_rcu(); get_device(dev); device_unregister(dev); ida_simple_remove(&dax_region->ida, dax_dev->id); ida_simple_remove(&dax_minor_ida, MINOR(dev->devt)); put_device(dev); dax_dev_put(dax_dev); } int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, int count) { struct device *parent = dax_region->dev; struct dax_dev *dax_dev; struct device *dev; int rc, minor; dev_t dev_t; dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL); if (!dax_dev) return -ENOMEM; memcpy(dax_dev->res, res, sizeof(*res) * count); dax_dev->num_resources = count; kref_init(&dax_dev->kref); dax_dev->alive = true; dax_dev->region = dax_region; kref_get(&dax_region->kref); dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL); if (dax_dev->id < 0) { rc = dax_dev->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(dax_major, minor); dev = device_create_with_groups(dax_class, parent, dev_t, dax_dev, dax_attribute_groups, "dax%d.%d", dax_region->id, dax_dev->id); if (IS_ERR(dev)) { rc = PTR_ERR(dev); goto err_create; } dax_dev->dev = dev; rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev); if (rc) return rc; return 0; err_create: ida_simple_remove(&dax_minor_ida, minor); err_minor: ida_simple_remove(&dax_region->ida, dax_dev->id); err_id: dax_dev_put(dax_dev); return rc; } EXPORT_SYMBOL_GPL(devm_create_dax_dev); /* return an unmapped area aligned to the dax region specified alignment */ static unsigned long dax_dev_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 dax_dev *dax_dev = filp ? filp->private_data : NULL; struct dax_region *dax_region; if (!dax_dev || addr) goto out; dax_region = dax_dev->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 __match_devt(struct device *dev, const void *data) { const dev_t *devt = data; return dev->devt == *devt; } static struct device *dax_dev_find(dev_t dev_t) { return class_find_device(dax_class, NULL, &dev_t, __match_devt); } static int dax_dev_open(struct inode *inode, struct file *filp) { struct dax_dev *dax_dev = NULL; struct device *dev; dev = dax_dev_find(inode->i_rdev); if (!dev) return -ENXIO; device_lock(dev); dax_dev = dev_get_drvdata(dev); if (dax_dev) { dev_dbg(dev, "%s\n", __func__); filp->private_data = dax_dev; kref_get(&dax_dev->kref); inode->i_flags = S_DAX; } device_unlock(dev); if (!dax_dev) { put_device(dev); return -ENXIO; } return 0; } static int dax_dev_release(struct inode *inode, struct file *filp) { struct dax_dev *dax_dev = filp->private_data; struct device *dev = dax_dev->dev; dev_dbg(dax_dev->dev, "%s\n", __func__); dax_dev_put(dax_dev); put_device(dev); return 0; } static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma, const char *func) { struct dax_region *dax_region = dax_dev->region; struct device *dev = dax_dev->dev; struct device *dev = &dax_dev->dev; unsigned long mask; if (!dax_dev->alive) Loading Loading @@ -382,7 +329,7 @@ static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma, struct vm_fault *vmf) { unsigned long vaddr = (unsigned long) vmf->virtual_address; struct device *dev = dax_dev->dev; struct device *dev = &dax_dev->dev; struct dax_region *dax_region; int rc = VM_FAULT_SIGBUS; phys_addr_t phys; Loading Loading @@ -422,7 +369,7 @@ static int dax_dev_fault(struct vm_area_struct *vma, struct vm_fault *vmf) struct file *filp = vma->vm_file; struct dax_dev *dax_dev = filp->private_data; dev_dbg(dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, current->comm, (vmf->flags & FAULT_FLAG_WRITE) ? "write" : "read", vma->vm_start, vma->vm_end); rcu_read_lock(); Loading @@ -437,7 +384,7 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, unsigned int flags) { unsigned long pmd_addr = addr & PMD_MASK; struct device *dev = dax_dev->dev; struct device *dev = &dax_dev->dev; struct dax_region *dax_region; phys_addr_t phys; pgoff_t pgoff; Loading Loading @@ -479,7 +426,7 @@ static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr, struct file *filp = vma->vm_file; struct dax_dev *dax_dev = filp->private_data; dev_dbg(dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, current->comm, (flags & FAULT_FLAG_WRITE) ? "write" : "read", vma->vm_start, vma->vm_end); Loading @@ -490,81 +437,257 @@ static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr, return rc; } static void dax_dev_vm_open(struct vm_area_struct *vma) { struct file *filp = vma->vm_file; struct dax_dev *dax_dev = filp->private_data; dev_dbg(dax_dev->dev, "%s\n", __func__); kref_get(&dax_dev->kref); } static void dax_dev_vm_close(struct vm_area_struct *vma) { struct file *filp = vma->vm_file; struct dax_dev *dax_dev = filp->private_data; dev_dbg(dax_dev->dev, "%s\n", __func__); dax_dev_put(dax_dev); } static const struct vm_operations_struct dax_dev_vm_ops = { .fault = dax_dev_fault, .pmd_fault = dax_dev_pmd_fault, .open = dax_dev_vm_open, .close = dax_dev_vm_close, }; static int dax_dev_mmap(struct file *filp, struct vm_area_struct *vma) static int dax_mmap(struct file *filp, struct vm_area_struct *vma) { struct dax_dev *dax_dev = filp->private_data; int rc; dev_dbg(dax_dev->dev, "%s\n", __func__); dev_dbg(&dax_dev->dev, "%s\n", __func__); rc = check_vma(dax_dev, vma, __func__); if (rc) return rc; kref_get(&dax_dev->kref); vma->vm_ops = &dax_dev_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 dax_dev *dax_dev = filp ? filp->private_data : NULL; struct dax_region *dax_region; if (!dax_dev || addr) goto out; dax_region = dax_dev->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_dev *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; filp->f_mapping = inode->i_mapping; filp->private_data = dax_dev; inode->i_flags = S_DAX; return 0; } static int dax_release(struct inode *inode, struct file *filp) { struct dax_dev *dax_dev = filp->private_data; dev_dbg(&dax_dev->dev, "%s\n", __func__); return 0; } static const struct file_operations dax_fops = { .llseek = noop_llseek, .owner = THIS_MODULE, .open = dax_dev_open, .release = dax_dev_release, .get_unmapped_area = dax_dev_get_unmapped_area, .mmap = dax_dev_mmap, .open = dax_open, .release = dax_release, .get_unmapped_area = dax_get_unmapped_area, .mmap = dax_mmap, }; static void dax_dev_release(struct device *dev) { struct dax_dev *dax_dev = to_dax_dev(dev); struct dax_region *dax_region = dax_dev->region; ida_simple_remove(&dax_region->ida, dax_dev->id); ida_simple_remove(&dax_minor_ida, MINOR(dev->devt)); dax_region_put(dax_region); iput(dax_dev->inode); kfree(dax_dev); } static void unregister_dax_dev(void *dev) { struct dax_dev *dax_dev = to_dax_dev(dev); struct cdev *cdev = &dax_dev->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_rcu() has started will abort * upon seeing dax_dev->alive == false. */ dax_dev->alive = false; synchronize_rcu(); unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1); cdev_del(cdev); device_unregister(dev); } struct dax_dev *devm_create_dax_dev(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 device *dev; struct cdev *cdev; dev_t dev_t; dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL); if (!dax_dev) 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; } dax_dev->res[i].start = res[i].start; dax_dev->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; 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; /* 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; kref_get(&dax_region->kref); dev->devt = dev_t; 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); if (rc) { put_device(dev); return ERR_PTR(rc); } rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev); if (rc) return ERR_PTR(rc); return dax_dev; 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_id: kfree(dax_dev); return ERR_PTR(rc); } EXPORT_SYMBOL_GPL(devm_create_dax_dev); static int __init dax_init(void) { int rc; rc = register_chrdev(0, "dax", &dax_fops); if (rc < 0) rc = dax_inode_init(); if (rc) return rc; dax_major = 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)) { unregister_chrdev(dax_major, "dax"); return PTR_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(dax_major, "dax"); unregister_chrdev_region(dax_devt, nr_dax); ida_destroy(&dax_minor_ida); dax_inode_exit(); } MODULE_AUTHOR("Intel Corporation"); Loading drivers/dax/dax.h +3 −2 Original line number Diff line number Diff line Loading @@ -13,12 +13,13 @@ #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); int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, int count); struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, int count); #endif /* __DAX_H__ */ drivers/dax/pmem.c +4 −3 Original line number Diff line number Diff line Loading @@ -24,7 +24,7 @@ struct dax_pmem { struct completion cmp; }; struct dax_pmem *to_dax_pmem(struct percpu_ref *ref) static struct dax_pmem *to_dax_pmem(struct percpu_ref *ref) { return container_of(ref, struct dax_pmem, ref); } Loading Loading @@ -61,6 +61,7 @@ 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 dax_pmem *dax_pmem; struct nd_region *nd_region; Loading Loading @@ -126,12 +127,12 @@ static int dax_pmem_probe(struct device *dev) return -ENOMEM; /* TODO: support for subdividing a dax region... */ rc = devm_create_dax_dev(dax_region, &res, 1); dax_dev = devm_create_dax_dev(dax_region, &res, 1); /* child dax_dev instances now own the lifetime of the dax_region */ dax_region_put(dax_region); return rc; return PTR_ERR_OR_ZERO(dax_dev); } static struct nd_device_driver dax_pmem_driver = { Loading drivers/nvdimm/Kconfig +1 −1 Original line number Diff line number Diff line Loading @@ -89,7 +89,7 @@ config NVDIMM_PFN Select Y if unsure config NVDIMM_DAX bool "NVDIMM DAX: Raw access to persistent memory" tristate "NVDIMM DAX: Raw access to persistent memory" default LIBNVDIMM depends on NVDIMM_PFN help Loading Loading
drivers/dax/Kconfig +5 −0 Original line number Diff line number Diff line Loading @@ -23,4 +23,9 @@ config DEV_DAX_PMEM Say Y if unsure config NR_DEV_DAX int "Maximum number of Device-DAX instances" default 32768 range 256 2147483647 endif
drivers/dax/dax.c +350 −227 Original line number Diff line number Diff line Loading @@ -13,15 +13,25 @@ #include <linux/pagemap.h> #include <linux/module.h> #include <linux/device.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 int dax_major; static dev_t dax_devt; 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 Loading @@ -48,7 +58,7 @@ struct dax_region { * struct dax_dev - subdivision of a dax region * @region - parent region * @dev - device backing the character device * @kref - enable this data to be tracked in filp->private_data * @cdev - core chardev data * @alive - !alive + rcu grace period == no new mappings can be established * @id - child id in the region * @num_resources - number of physical address extents in this device Loading @@ -56,50 +66,151 @@ struct dax_region { */ struct dax_dev { struct dax_region *region; struct device *dev; struct kref kref; struct inode *inode; struct device dev; struct cdev cdev; bool alive; int id; int num_resources; struct resource res[0]; }; static void dax_region_free(struct kref *kref) static struct inode *dax_alloc_inode(struct super_block *sb) { struct dax_region *dax_region; return kmem_cache_alloc(dax_cache, GFP_KERNEL); } dax_region = container_of(kref, struct dax_region, kref); kfree(dax_region); 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); } void dax_region_put(struct dax_region *dax_region) static void dax_destroy_inode(struct inode *inode) { kref_put(&dax_region->kref, dax_region_free); call_rcu(&inode->i_rcu, dax_i_callback); } EXPORT_SYMBOL_GPL(dax_region_put); static void dax_dev_free(struct kref *kref) 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) { struct dax_dev *dax_dev; return mount_pseudo(fs_type, "dax:", &dax_sops, NULL, DAXFS_MAGIC); } dax_dev = container_of(kref, struct dax_dev, kref); dax_region_put(dax_dev->region); kfree(dax_dev); 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_dev_put(struct dax_dev *dax_dev) static void dax_region_free(struct kref *kref) { kref_put(&dax_dev->kref, dax_dev_free); 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); 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; dax_region = kzalloc(sizeof(*dax_region), GFP_KERNEL); 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; Loading @@ -116,10 +227,15 @@ 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) { return container_of(dev, struct dax_dev, dev); } static ssize_t size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct dax_dev *dax_dev = dev_get_drvdata(dev); struct dax_dev *dax_dev = to_dax_dev(dev); unsigned long long size = 0; int i; Loading @@ -144,180 +260,11 @@ static const struct attribute_group *dax_attribute_groups[] = { NULL, }; static void unregister_dax_dev(void *_dev) { struct device *dev = _dev; struct dax_dev *dax_dev = dev_get_drvdata(dev); struct dax_region *dax_region = dax_dev->region; 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_rcu() has started will abort * upon seeing dax_dev->alive == false. */ dax_dev->alive = false; synchronize_rcu(); get_device(dev); device_unregister(dev); ida_simple_remove(&dax_region->ida, dax_dev->id); ida_simple_remove(&dax_minor_ida, MINOR(dev->devt)); put_device(dev); dax_dev_put(dax_dev); } int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, int count) { struct device *parent = dax_region->dev; struct dax_dev *dax_dev; struct device *dev; int rc, minor; dev_t dev_t; dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL); if (!dax_dev) return -ENOMEM; memcpy(dax_dev->res, res, sizeof(*res) * count); dax_dev->num_resources = count; kref_init(&dax_dev->kref); dax_dev->alive = true; dax_dev->region = dax_region; kref_get(&dax_region->kref); dax_dev->id = ida_simple_get(&dax_region->ida, 0, 0, GFP_KERNEL); if (dax_dev->id < 0) { rc = dax_dev->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(dax_major, minor); dev = device_create_with_groups(dax_class, parent, dev_t, dax_dev, dax_attribute_groups, "dax%d.%d", dax_region->id, dax_dev->id); if (IS_ERR(dev)) { rc = PTR_ERR(dev); goto err_create; } dax_dev->dev = dev; rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev); if (rc) return rc; return 0; err_create: ida_simple_remove(&dax_minor_ida, minor); err_minor: ida_simple_remove(&dax_region->ida, dax_dev->id); err_id: dax_dev_put(dax_dev); return rc; } EXPORT_SYMBOL_GPL(devm_create_dax_dev); /* return an unmapped area aligned to the dax region specified alignment */ static unsigned long dax_dev_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 dax_dev *dax_dev = filp ? filp->private_data : NULL; struct dax_region *dax_region; if (!dax_dev || addr) goto out; dax_region = dax_dev->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 __match_devt(struct device *dev, const void *data) { const dev_t *devt = data; return dev->devt == *devt; } static struct device *dax_dev_find(dev_t dev_t) { return class_find_device(dax_class, NULL, &dev_t, __match_devt); } static int dax_dev_open(struct inode *inode, struct file *filp) { struct dax_dev *dax_dev = NULL; struct device *dev; dev = dax_dev_find(inode->i_rdev); if (!dev) return -ENXIO; device_lock(dev); dax_dev = dev_get_drvdata(dev); if (dax_dev) { dev_dbg(dev, "%s\n", __func__); filp->private_data = dax_dev; kref_get(&dax_dev->kref); inode->i_flags = S_DAX; } device_unlock(dev); if (!dax_dev) { put_device(dev); return -ENXIO; } return 0; } static int dax_dev_release(struct inode *inode, struct file *filp) { struct dax_dev *dax_dev = filp->private_data; struct device *dev = dax_dev->dev; dev_dbg(dax_dev->dev, "%s\n", __func__); dax_dev_put(dax_dev); put_device(dev); return 0; } static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma, const char *func) { struct dax_region *dax_region = dax_dev->region; struct device *dev = dax_dev->dev; struct device *dev = &dax_dev->dev; unsigned long mask; if (!dax_dev->alive) Loading Loading @@ -382,7 +329,7 @@ static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma, struct vm_fault *vmf) { unsigned long vaddr = (unsigned long) vmf->virtual_address; struct device *dev = dax_dev->dev; struct device *dev = &dax_dev->dev; struct dax_region *dax_region; int rc = VM_FAULT_SIGBUS; phys_addr_t phys; Loading Loading @@ -422,7 +369,7 @@ static int dax_dev_fault(struct vm_area_struct *vma, struct vm_fault *vmf) struct file *filp = vma->vm_file; struct dax_dev *dax_dev = filp->private_data; dev_dbg(dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, current->comm, (vmf->flags & FAULT_FLAG_WRITE) ? "write" : "read", vma->vm_start, vma->vm_end); rcu_read_lock(); Loading @@ -437,7 +384,7 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, unsigned int flags) { unsigned long pmd_addr = addr & PMD_MASK; struct device *dev = dax_dev->dev; struct device *dev = &dax_dev->dev; struct dax_region *dax_region; phys_addr_t phys; pgoff_t pgoff; Loading Loading @@ -479,7 +426,7 @@ static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr, struct file *filp = vma->vm_file; struct dax_dev *dax_dev = filp->private_data; dev_dbg(dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, dev_dbg(&dax_dev->dev, "%s: %s: %s (%#lx - %#lx)\n", __func__, current->comm, (flags & FAULT_FLAG_WRITE) ? "write" : "read", vma->vm_start, vma->vm_end); Loading @@ -490,81 +437,257 @@ static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr, return rc; } static void dax_dev_vm_open(struct vm_area_struct *vma) { struct file *filp = vma->vm_file; struct dax_dev *dax_dev = filp->private_data; dev_dbg(dax_dev->dev, "%s\n", __func__); kref_get(&dax_dev->kref); } static void dax_dev_vm_close(struct vm_area_struct *vma) { struct file *filp = vma->vm_file; struct dax_dev *dax_dev = filp->private_data; dev_dbg(dax_dev->dev, "%s\n", __func__); dax_dev_put(dax_dev); } static const struct vm_operations_struct dax_dev_vm_ops = { .fault = dax_dev_fault, .pmd_fault = dax_dev_pmd_fault, .open = dax_dev_vm_open, .close = dax_dev_vm_close, }; static int dax_dev_mmap(struct file *filp, struct vm_area_struct *vma) static int dax_mmap(struct file *filp, struct vm_area_struct *vma) { struct dax_dev *dax_dev = filp->private_data; int rc; dev_dbg(dax_dev->dev, "%s\n", __func__); dev_dbg(&dax_dev->dev, "%s\n", __func__); rc = check_vma(dax_dev, vma, __func__); if (rc) return rc; kref_get(&dax_dev->kref); vma->vm_ops = &dax_dev_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 dax_dev *dax_dev = filp ? filp->private_data : NULL; struct dax_region *dax_region; if (!dax_dev || addr) goto out; dax_region = dax_dev->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_dev *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; filp->f_mapping = inode->i_mapping; filp->private_data = dax_dev; inode->i_flags = S_DAX; return 0; } static int dax_release(struct inode *inode, struct file *filp) { struct dax_dev *dax_dev = filp->private_data; dev_dbg(&dax_dev->dev, "%s\n", __func__); return 0; } static const struct file_operations dax_fops = { .llseek = noop_llseek, .owner = THIS_MODULE, .open = dax_dev_open, .release = dax_dev_release, .get_unmapped_area = dax_dev_get_unmapped_area, .mmap = dax_dev_mmap, .open = dax_open, .release = dax_release, .get_unmapped_area = dax_get_unmapped_area, .mmap = dax_mmap, }; static void dax_dev_release(struct device *dev) { struct dax_dev *dax_dev = to_dax_dev(dev); struct dax_region *dax_region = dax_dev->region; ida_simple_remove(&dax_region->ida, dax_dev->id); ida_simple_remove(&dax_minor_ida, MINOR(dev->devt)); dax_region_put(dax_region); iput(dax_dev->inode); kfree(dax_dev); } static void unregister_dax_dev(void *dev) { struct dax_dev *dax_dev = to_dax_dev(dev); struct cdev *cdev = &dax_dev->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_rcu() has started will abort * upon seeing dax_dev->alive == false. */ dax_dev->alive = false; synchronize_rcu(); unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1); cdev_del(cdev); device_unregister(dev); } struct dax_dev *devm_create_dax_dev(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 device *dev; struct cdev *cdev; dev_t dev_t; dax_dev = kzalloc(sizeof(*dax_dev) + sizeof(*res) * count, GFP_KERNEL); if (!dax_dev) 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; } dax_dev->res[i].start = res[i].start; dax_dev->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; 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; /* 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; kref_get(&dax_region->kref); dev->devt = dev_t; 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); if (rc) { put_device(dev); return ERR_PTR(rc); } rc = devm_add_action_or_reset(dax_region->dev, unregister_dax_dev, dev); if (rc) return ERR_PTR(rc); return dax_dev; 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_id: kfree(dax_dev); return ERR_PTR(rc); } EXPORT_SYMBOL_GPL(devm_create_dax_dev); static int __init dax_init(void) { int rc; rc = register_chrdev(0, "dax", &dax_fops); if (rc < 0) rc = dax_inode_init(); if (rc) return rc; dax_major = 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)) { unregister_chrdev(dax_major, "dax"); return PTR_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(dax_major, "dax"); unregister_chrdev_region(dax_devt, nr_dax); ida_destroy(&dax_minor_ida); dax_inode_exit(); } MODULE_AUTHOR("Intel Corporation"); Loading
drivers/dax/dax.h +3 −2 Original line number Diff line number Diff line Loading @@ -13,12 +13,13 @@ #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); int devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, int count); struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region, struct resource *res, int count); #endif /* __DAX_H__ */
drivers/dax/pmem.c +4 −3 Original line number Diff line number Diff line Loading @@ -24,7 +24,7 @@ struct dax_pmem { struct completion cmp; }; struct dax_pmem *to_dax_pmem(struct percpu_ref *ref) static struct dax_pmem *to_dax_pmem(struct percpu_ref *ref) { return container_of(ref, struct dax_pmem, ref); } Loading Loading @@ -61,6 +61,7 @@ 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 dax_pmem *dax_pmem; struct nd_region *nd_region; Loading Loading @@ -126,12 +127,12 @@ static int dax_pmem_probe(struct device *dev) return -ENOMEM; /* TODO: support for subdividing a dax region... */ rc = devm_create_dax_dev(dax_region, &res, 1); dax_dev = devm_create_dax_dev(dax_region, &res, 1); /* child dax_dev instances now own the lifetime of the dax_region */ dax_region_put(dax_region); return rc; return PTR_ERR_OR_ZERO(dax_dev); } static struct nd_device_driver dax_pmem_driver = { Loading
drivers/nvdimm/Kconfig +1 −1 Original line number Diff line number Diff line Loading @@ -89,7 +89,7 @@ config NVDIMM_PFN Select Y if unsure config NVDIMM_DAX bool "NVDIMM DAX: Raw access to persistent memory" tristate "NVDIMM DAX: Raw access to persistent memory" default LIBNVDIMM depends on NVDIMM_PFN help Loading