NVMe: avoid kmalloc/kfree for smaller IO
[linux-block.git] / include / linux / nvme.h
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1/*
2 * Definitions for the NVM Express interface
8757ad65 3 * Copyright (c) 2011-2014, Intel Corporation.
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4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
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13 */
14
15#ifndef _LINUX_NVME_H
16#define _LINUX_NVME_H
17
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18#include <uapi/linux/nvme.h>
19#include <linux/pci.h>
20#include <linux/miscdevice.h>
21#include <linux/kref.h>
a4aea562 22#include <linux/blk-mq.h>
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23
24struct nvme_bar {
25 __u64 cap; /* Controller Capabilities */
26 __u32 vs; /* Version */
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27 __u32 intms; /* Interrupt Mask Set */
28 __u32 intmc; /* Interrupt Mask Clear */
b60503ba 29 __u32 cc; /* Controller Configuration */
897cfe1c 30 __u32 rsvd1; /* Reserved */
b60503ba 31 __u32 csts; /* Controller Status */
897cfe1c 32 __u32 rsvd2; /* Reserved */
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33 __u32 aqa; /* Admin Queue Attributes */
34 __u64 asq; /* Admin SQ Base Address */
35 __u64 acq; /* Admin CQ Base Address */
36};
37
a0cadb85 38#define NVME_CAP_MQES(cap) ((cap) & 0xffff)
22605f96 39#define NVME_CAP_TIMEOUT(cap) (((cap) >> 24) & 0xff)
f1938f6e 40#define NVME_CAP_STRIDE(cap) (((cap) >> 32) & 0xf)
8fc23e03 41#define NVME_CAP_MPSMIN(cap) (((cap) >> 48) & 0xf)
1d090624 42#define NVME_CAP_MPSMAX(cap) (((cap) >> 52) & 0xf)
22605f96 43
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44enum {
45 NVME_CC_ENABLE = 1 << 0,
46 NVME_CC_CSS_NVM = 0 << 4,
47 NVME_CC_MPS_SHIFT = 7,
48 NVME_CC_ARB_RR = 0 << 11,
49 NVME_CC_ARB_WRRU = 1 << 11,
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50 NVME_CC_ARB_VS = 7 << 11,
51 NVME_CC_SHN_NONE = 0 << 14,
52 NVME_CC_SHN_NORMAL = 1 << 14,
53 NVME_CC_SHN_ABRUPT = 2 << 14,
1894d8f1 54 NVME_CC_SHN_MASK = 3 << 14,
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55 NVME_CC_IOSQES = 6 << 16,
56 NVME_CC_IOCQES = 4 << 20,
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57 NVME_CSTS_RDY = 1 << 0,
58 NVME_CSTS_CFS = 1 << 1,
59 NVME_CSTS_SHST_NORMAL = 0 << 2,
60 NVME_CSTS_SHST_OCCUR = 1 << 2,
61 NVME_CSTS_SHST_CMPLT = 2 << 2,
1894d8f1 62 NVME_CSTS_SHST_MASK = 3 << 2,
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63};
64
65#define NVME_VS(major, minor) (major << 16 | minor)
66
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67extern unsigned char nvme_io_timeout;
68#define NVME_IO_TIMEOUT (nvme_io_timeout * HZ)
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69
70/*
71 * Represents an NVM Express device. Each nvme_dev is a PCI function.
72 */
73struct nvme_dev {
74 struct list_head node;
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75 struct nvme_queue **queues;
76 struct request_queue *admin_q;
77 struct blk_mq_tag_set tagset;
78 struct blk_mq_tag_set admin_tagset;
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79 u32 __iomem *dbs;
80 struct pci_dev *pci_dev;
81 struct dma_pool *prp_page_pool;
82 struct dma_pool *prp_small_pool;
83 int instance;
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84 unsigned queue_count;
85 unsigned online_queues;
86 unsigned max_qid;
87 int q_depth;
b80d5ccc 88 u32 db_stride;
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89 u32 ctrl_config;
90 struct msix_entry *entry;
91 struct nvme_bar __iomem *bar;
92 struct list_head namespaces;
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93 struct kref kref;
94 struct miscdevice miscdev;
9ca97374 95 work_func_t reset_workfn;
9a6b9458 96 struct work_struct reset_work;
5e82e952 97 char name[12];
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98 char serial[20];
99 char model[40];
100 char firmware_rev[8];
101 u32 max_hw_sectors;
159b67d7 102 u32 stripe_size;
1d090624 103 u32 page_size;
13c3b0fc 104 u16 oncs;
c30341dc 105 u16 abort_limit;
6fccf938 106 u8 event_limit;
a7d2ce28 107 u8 vwc;
d4b4ff8e 108 u8 initialized;
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109};
110
111/*
112 * An NVM Express namespace is equivalent to a SCSI LUN
113 */
114struct nvme_ns {
115 struct list_head list;
116
117 struct nvme_dev *dev;
118 struct request_queue *queue;
119 struct gendisk *disk;
120
c3bfe717 121 unsigned ns_id;
13c3b0fc 122 int lba_shift;
f410c680 123 int ms;
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124 u64 mode_select_num_blocks;
125 u32 mode_select_block_len;
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126};
127
128/*
129 * The nvme_iod describes the data in an I/O, including the list of PRP
130 * entries. You can't see it in this data structure because C doesn't let
131 * me express that. Use nvme_alloc_iod to ensure there's enough space
132 * allocated to store the PRP list.
133 */
134struct nvme_iod {
ac3dd5bd 135 unsigned long private; /* For the use of the submitter of the I/O */
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136 int npages; /* In the PRP list. 0 means small pool in use */
137 int offset; /* Of PRP list */
138 int nents; /* Used in scatterlist */
139 int length; /* Of data, in bytes */
140 dma_addr_t first_dma;
141 struct scatterlist sg[0];
142};
5d0f6131 143
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144static inline u64 nvme_block_nr(struct nvme_ns *ns, sector_t sector)
145{
146 return (sector >> (ns->lba_shift - 9));
147}
148
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149/**
150 * nvme_free_iod - frees an nvme_iod
151 * @dev: The device that the I/O was submitted to
152 * @iod: The memory to free
153 */
154void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod);
155
a4aea562 156int nvme_setup_prps(struct nvme_dev *, struct nvme_iod *, int, gfp_t);
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157struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write,
158 unsigned long addr, unsigned length);
159void nvme_unmap_user_pages(struct nvme_dev *dev, int write,
160 struct nvme_iod *iod);
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161int nvme_submit_io_cmd(struct nvme_dev *, struct nvme_ns *,
162 struct nvme_command *, u32 *);
163int nvme_submit_flush_data(struct nvme_queue *nvmeq, struct nvme_ns *ns);
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164int nvme_submit_admin_cmd(struct nvme_dev *, struct nvme_command *,
165 u32 *result);
166int nvme_identify(struct nvme_dev *, unsigned nsid, unsigned cns,
167 dma_addr_t dma_addr);
168int nvme_get_features(struct nvme_dev *dev, unsigned fid, unsigned nsid,
169 dma_addr_t dma_addr, u32 *result);
170int nvme_set_features(struct nvme_dev *dev, unsigned fid, unsigned dword11,
171 dma_addr_t dma_addr, u32 *result);
172
173struct sg_io_hdr;
174
175int nvme_sg_io(struct nvme_ns *ns, struct sg_io_hdr __user *u_hdr);
320a3827 176int nvme_sg_io32(struct nvme_ns *ns, unsigned long arg);
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177int nvme_sg_get_version_num(int __user *ip);
178
b60503ba 179#endif /* _LINUX_NVME_H */