diff options
Diffstat (limited to 'drivers/dax')
| -rw-r--r-- | drivers/dax/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/dax/Makefile | 5 | ||||
| -rw-r--r-- | drivers/dax/dax-private.h | 57 | ||||
| -rw-r--r-- | drivers/dax/dax.h | 15 | ||||
| -rw-r--r-- | drivers/dax/device-dax.h | 25 | ||||
| -rw-r--r-- | drivers/dax/device.c (renamed from drivers/dax/dax.c) | 501 | ||||
| -rw-r--r-- | drivers/dax/pmem.c | 10 | ||||
| -rw-r--r-- | drivers/dax/super.c | 425 |
8 files changed, 677 insertions, 371 deletions
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig index 9e95bf94eb13..b7053eafd88e 100644 --- a/drivers/dax/Kconfig +++ b/drivers/dax/Kconfig @@ -1,8 +1,13 @@ -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 @@ -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" diff --git a/drivers/dax/Makefile b/drivers/dax/Makefile index 27c54e38478a..dc7422530462 100644 --- a/drivers/dax/Makefile +++ b/drivers/dax/Makefile @@ -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 diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h new file mode 100644 index 000000000000..b6fc4f04636d --- /dev/null +++ b/drivers/dax/dax-private.h @@ -0,0 +1,57 @@ +/* + * 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 __DAX_PRIVATE_H__ +#define __DAX_PRIVATE_H__ + +#include <linux/device.h> +#include <linux/cdev.h> + +/** + * 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]; +}; +#endif diff --git a/drivers/dax/dax.h b/drivers/dax/dax.h index ddd829ab58c0..f9e5feea742c 100644 --- a/drivers/dax/dax.h +++ b/drivers/dax/dax.h @@ -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__ */ diff --git a/drivers/dax/device-dax.h b/drivers/dax/device-dax.h new file mode 100644 index 000000000000..fdcd9769ffde --- /dev/null +++ b/drivers/dax/device-dax.h @@ -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__ */ diff --git a/drivers/dax/dax.c b/drivers/dax/device.c index 19795eb35579..006e657dfcb9 100644 --- a/drivers/dax/dax.c +++ b/drivers/dax/device.c @@ -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 @@ -13,100 +13,38 @@ #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-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"); - -/** - * 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 dax_dev - 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 +/* + * Rely on the fact that drvdata is set before the attributes are + * registered, and that the attributes are unregistered before drvdata + * is cleared to assume that drvdata is always valid. */ -struct dax_dev { - 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); + struct dax_region *dax_region = dev_get_drvdata(dev); - return rc; + return sprintf(buf, "%d\n", dax_region->id); } 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); + struct dax_region *dax_region = dev_get_drvdata(dev); - return rc; + return sprintf(buf, "%llu\n", (unsigned long long) + resource_size(&dax_region->res)); } static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, region_size_show, NULL); @@ -114,16 +52,9 @@ static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, 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); + struct dax_region *dax_region = dev_get_drvdata(dev); - return rc; + return sprintf(buf, "%u\n", dax_region->align); } static DEVICE_ATTR_RO(align); @@ -144,117 +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; @@ -323,47 +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 */ @@ -397,23 +217,24 @@ static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma, return 0; } -static phys_addr_t pgoff_to_phys(struct dax_dev *dax_dev, pgoff_t pgoff, +/* see "strong" declaration in tools/testing/nvdimm/dax-dev.c */ +__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; } @@ -421,28 +242,29 @@ static phys_addr_t 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 = 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); @@ -461,28 +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; } @@ -497,7 +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 = 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); @@ -511,10 +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; @@ -522,18 +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; } @@ -548,7 +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 = 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); @@ -561,65 +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; } @@ -630,13 +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; @@ -661,14 +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; @@ -676,9 +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; } @@ -691,55 +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 kill_dax_dev(struct dax_dev *dax_dev) +static void kill_dev_dax(struct dev_dax *dev_dax) { - /* - * 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); + 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_dax_dev(void *dev) +static void unregister_dev_dax(void *dev) { - struct dax_dev *dax_dev = to_dax_dev(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_dax_dev(dax_dev); - cdev_device_del(&dax_dev->cdev, 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++) { @@ -749,110 +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; - } + /* + * 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() */ + dev = &dev_dax->dev; device_initialize(dev); - cdev = &dax_dev->cdev; + inode = dax_inode(dax_dev); + cdev = inode->i_cdev; cdev_init(cdev, &dax_fops); cdev->owner = parent->driver->owner; - dax_dev->num_resources = count; - dax_dev->alive = true; - dax_dev->region = dax_region; + 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); + 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_dax_dev(dax_dev); + 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_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"); diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index cb0d742fa23f..9f2a0b4fd801 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -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 = { diff --git a/drivers/dax/super.c b/drivers/dax/super.c new file mode 100644 index 000000000000..465dcd7317d5 --- /dev/null +++ b/drivers/dax/super.c @@ -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); |