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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-29 10:34:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-29 10:34:42 -0700
commit88793e5c774ec69351ef6b5200bb59f532e41bca (patch)
tree54c4be61777ea53fde892b71e795322c5227d16e /include/linux/nd.h
parent1bc5e157ed2b4f5b206155fc772d860158acd201 (diff)
parent61031952f4c89dba1065f7a5b9419badb112554c (diff)
Merge tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm
Pull libnvdimm subsystem from Dan Williams: "The libnvdimm sub-system introduces, in addition to the libnvdimm-core, 4 drivers / enabling modules: NFIT: Instantiates an "nvdimm bus" with the core and registers memory devices (NVDIMMs) enumerated by the ACPI 6.0 NFIT (NVDIMM Firmware Interface table). After registering NVDIMMs the NFIT driver then registers "region" devices. A libnvdimm-region defines an access mode and the boundaries of persistent memory media. A region may span multiple NVDIMMs that are interleaved by the hardware memory controller. In turn, a libnvdimm-region can be carved into a "namespace" device and bound to the PMEM or BLK driver which will attach a Linux block device (disk) interface to the memory. PMEM: Initially merged in v4.1 this driver for contiguous spans of persistent memory address ranges is re-worked to drive PMEM-namespaces emitted by the libnvdimm-core. In this update the PMEM driver, on x86, gains the ability to assert that writes to persistent memory have been flushed all the way through the caches and buffers in the platform to persistent media. See memcpy_to_pmem() and wmb_pmem(). BLK: This new driver enables access to persistent memory media through "Block Data Windows" as defined by the NFIT. The primary difference of this driver to PMEM is that only a small window of persistent memory is mapped into system address space at any given point in time. Per-NVDIMM windows are reprogrammed at run time, per-I/O, to access different portions of the media. BLK-mode, by definition, does not support DAX. BTT: This is a library, optionally consumed by either PMEM or BLK, that converts a byte-accessible namespace into a disk with atomic sector update semantics (prevents sector tearing on crash or power loss). The sinister aspect of sector tearing is that most applications do not know they have a atomic sector dependency. At least today's disk's rarely ever tear sectors and if they do one almost certainly gets a CRC error on access. NVDIMMs will always tear and always silently. Until an application is audited to be robust in the presence of sector-tearing the usage of BTT is recommended. Thanks to: Ross Zwisler, Jeff Moyer, Vishal Verma, Christoph Hellwig, Ingo Molnar, Neil Brown, Boaz Harrosh, Robert Elliott, Matthew Wilcox, Andy Rudoff, Linda Knippers, Toshi Kani, Nicholas Moulin, Rafael Wysocki, and Bob Moore" * tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm: (33 commits) arch, x86: pmem api for ensuring durability of persistent memory updates libnvdimm: Add sysfs numa_node to NVDIMM devices libnvdimm: Set numa_node to NVDIMM devices acpi: Add acpi_map_pxm_to_online_node() libnvdimm, nfit: handle unarmed dimms, mark namespaces read-only pmem: flag pmem block devices as non-rotational libnvdimm: enable iostat pmem: make_request cleanups libnvdimm, pmem: fix up max_hw_sectors libnvdimm, blk: add support for blk integrity libnvdimm, btt: add support for blk integrity fs/block_dev.c: skip rw_page if bdev has integrity libnvdimm: Non-Volatile Devices tools/testing/nvdimm: libnvdimm unit test infrastructure libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory nd_btt: atomic sector updates libnvdimm: infrastructure for btt devices libnvdimm: write blk label set libnvdimm: write pmem label set libnvdimm: blk labels and namespace instantiation ...
Diffstat (limited to 'include/linux/nd.h')
-rw-r--r--include/linux/nd.h151
1 files changed, 151 insertions, 0 deletions
diff --git a/include/linux/nd.h b/include/linux/nd.h
new file mode 100644
index 000000000000..507e47c86737
--- /dev/null
+++ b/include/linux/nd.h
@@ -0,0 +1,151 @@
+/*
+ * Copyright(c) 2013-2015 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 __LINUX_ND_H__
+#define __LINUX_ND_H__
+#include <linux/fs.h>
+#include <linux/ndctl.h>
+#include <linux/device.h>
+
+struct nd_device_driver {
+ struct device_driver drv;
+ unsigned long type;
+ int (*probe)(struct device *dev);
+ int (*remove)(struct device *dev);
+};
+
+static inline struct nd_device_driver *to_nd_device_driver(
+ struct device_driver *drv)
+{
+ return container_of(drv, struct nd_device_driver, drv);
+};
+
+/**
+ * struct nd_namespace_common - core infrastructure of a namespace
+ * @force_raw: ignore other personalities for the namespace (e.g. btt)
+ * @dev: device model node
+ * @claim: when set a another personality has taken ownership of the namespace
+ * @rw_bytes: access the raw namespace capacity with byte-aligned transfers
+ */
+struct nd_namespace_common {
+ int force_raw;
+ struct device dev;
+ struct device *claim;
+ int (*rw_bytes)(struct nd_namespace_common *, resource_size_t offset,
+ void *buf, size_t size, int rw);
+};
+
+static inline struct nd_namespace_common *to_ndns(struct device *dev)
+{
+ return container_of(dev, struct nd_namespace_common, dev);
+}
+
+/**
+ * struct nd_namespace_io - infrastructure for loading an nd_pmem instance
+ * @dev: namespace device created by the nd region driver
+ * @res: struct resource conversion of a NFIT SPA table
+ */
+struct nd_namespace_io {
+ struct nd_namespace_common common;
+ struct resource res;
+};
+
+/**
+ * struct nd_namespace_pmem - namespace device for dimm-backed interleaved memory
+ * @nsio: device and system physical address range to drive
+ * @alt_name: namespace name supplied in the dimm label
+ * @uuid: namespace name supplied in the dimm label
+ */
+struct nd_namespace_pmem {
+ struct nd_namespace_io nsio;
+ char *alt_name;
+ u8 *uuid;
+};
+
+/**
+ * struct nd_namespace_blk - namespace for dimm-bounded persistent memory
+ * @alt_name: namespace name supplied in the dimm label
+ * @uuid: namespace name supplied in the dimm label
+ * @id: ida allocated id
+ * @lbasize: blk namespaces have a native sector size when btt not present
+ * @num_resources: number of dpa extents to claim
+ * @res: discontiguous dpa extents for given dimm
+ */
+struct nd_namespace_blk {
+ struct nd_namespace_common common;
+ char *alt_name;
+ u8 *uuid;
+ int id;
+ unsigned long lbasize;
+ int num_resources;
+ struct resource **res;
+};
+
+static inline struct nd_namespace_io *to_nd_namespace_io(struct device *dev)
+{
+ return container_of(dev, struct nd_namespace_io, common.dev);
+}
+
+static inline struct nd_namespace_pmem *to_nd_namespace_pmem(struct device *dev)
+{
+ struct nd_namespace_io *nsio = to_nd_namespace_io(dev);
+
+ return container_of(nsio, struct nd_namespace_pmem, nsio);
+}
+
+static inline struct nd_namespace_blk *to_nd_namespace_blk(struct device *dev)
+{
+ return container_of(dev, struct nd_namespace_blk, common.dev);
+}
+
+/**
+ * nvdimm_read_bytes() - synchronously read bytes from an nvdimm namespace
+ * @ndns: device to read
+ * @offset: namespace-relative starting offset
+ * @buf: buffer to fill
+ * @size: transfer length
+ *
+ * @buf is up-to-date upon return from this routine.
+ */
+static inline int nvdimm_read_bytes(struct nd_namespace_common *ndns,
+ resource_size_t offset, void *buf, size_t size)
+{
+ return ndns->rw_bytes(ndns, offset, buf, size, READ);
+}
+
+/**
+ * nvdimm_write_bytes() - synchronously write bytes to an nvdimm namespace
+ * @ndns: device to read
+ * @offset: namespace-relative starting offset
+ * @buf: buffer to drain
+ * @size: transfer length
+ *
+ * NVDIMM Namepaces disks do not implement sectors internally. Depending on
+ * the @ndns, the contents of @buf may be in cpu cache, platform buffers,
+ * or on backing memory media upon return from this routine. Flushing
+ * to media is handled internal to the @ndns driver, if at all.
+ */
+static inline int nvdimm_write_bytes(struct nd_namespace_common *ndns,
+ resource_size_t offset, void *buf, size_t size)
+{
+ return ndns->rw_bytes(ndns, offset, buf, size, WRITE);
+}
+
+#define MODULE_ALIAS_ND_DEVICE(type) \
+ MODULE_ALIAS("nd:t" __stringify(type) "*")
+#define ND_DEVICE_MODALIAS_FMT "nd:t%d"
+
+int __must_check __nd_driver_register(struct nd_device_driver *nd_drv,
+ struct module *module, const char *mod_name);
+#define nd_driver_register(driver) \
+ __nd_driver_register(driver, THIS_MODULE, KBUILD_MODNAME)
+#endif /* __LINUX_ND_H__ */