diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2016-09-14 20:53:26 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2016-09-14 20:53:26 +0200 |
commit | 16217dc79dbc599b110dda26d0421df47904bba4 (patch) | |
tree | 98df3c18b14284b8a6f8b04de12e0b7dde5a55fa /Documentation/nvdimm/btt.txt | |
parent | ecb3f394c5dba897d215a5422f1b363e93e2ce4e (diff) | |
parent | 723344dd0b2aa10ef9d28fe7f35d594d3e64f0f9 (diff) |
Merge tag 'irqchip-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Merge the first drop of irqchip updates for 4.9 from Marc Zyngier:
- ACPI IORT core code
- IORT support for the GICv3 ITS
- A few of GIC cleanups
Diffstat (limited to 'Documentation/nvdimm/btt.txt')
-rw-r--r-- | Documentation/nvdimm/btt.txt | 28 |
1 files changed, 9 insertions, 19 deletions
diff --git a/Documentation/nvdimm/btt.txt b/Documentation/nvdimm/btt.txt index b91443f577dc..e293fb664924 100644 --- a/Documentation/nvdimm/btt.txt +++ b/Documentation/nvdimm/btt.txt @@ -256,28 +256,18 @@ If any of these error conditions are encountered, the arena is put into a read only state using a flag in the info block. -5. In-kernel usage -================== +5. Usage +======== -Any block driver that supports byte granularity IO to the storage may register -with the BTT. It will have to provide the rw_bytes interface in its -block_device_operations struct: +The BTT can be set up on any disk (namespace) exposed by the libnvdimm subsystem +(pmem, or blk mode). The easiest way to set up such a namespace is using the +'ndctl' utility [1]: - int (*rw_bytes)(struct gendisk *, void *, size_t, off_t, int rw); +For example, the ndctl command line to setup a btt with a 4k sector size is: -It may register with the BTT after it adds its own gendisk, using btt_init: + ndctl create-namespace -f -e namespace0.0 -m sector -l 4k - struct btt *btt_init(struct gendisk *disk, unsigned long long rawsize, - u32 lbasize, u8 uuid[], int maxlane); +See ndctl create-namespace --help for more options. -note that maxlane is the maximum amount of concurrency the driver wishes to -allow the BTT to use. - -The BTT 'disk' appears as a stacked block device that grabs the underlying block -device in the O_EXCL mode. - -When the driver wishes to remove the backing disk, it should similarly call -btt_fini using the same struct btt* handle that was provided to it by btt_init. - - void btt_fini(struct btt *btt); +[1]: https://github.com/pmem/ndctl |