xref: /openbmc/linux/drivers/scsi/cxlflash/common.h (revision ca55b2fe)
1 /*
2  * CXL Flash Device Driver
3  *
4  * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
5  *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
6  *
7  * Copyright (C) 2015 IBM Corporation
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or (at your option) any later version.
13  */
14 
15 #ifndef _CXLFLASH_COMMON_H
16 #define _CXLFLASH_COMMON_H
17 
18 #include <linux/list.h>
19 #include <linux/types.h>
20 #include <scsi/scsi.h>
21 #include <scsi/scsi_device.h>
22 
23 
24 #define MAX_CONTEXT  CXLFLASH_MAX_CONTEXT       /* num contexts per afu */
25 
26 #define CXLFLASH_BLOCK_SIZE	4096	/* 4K blocks */
27 #define CXLFLASH_MAX_XFER_SIZE	16777216	/* 16MB transfer */
28 #define CXLFLASH_MAX_SECTORS	(CXLFLASH_MAX_XFER_SIZE/512)	/* SCSI wants
29 								   max_sectors
30 								   in units of
31 								   512 byte
32 								   sectors
33 								*/
34 
35 #define NUM_RRQ_ENTRY    16     /* for master issued cmds */
36 #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
37 
38 /* AFU command retry limit */
39 #define MC_RETRY_CNT         5	/* sufficient for SCSI check and
40 				   certain AFU errors */
41 
42 /* Command management definitions */
43 #define CXLFLASH_NUM_CMDS	(2 * CXLFLASH_MAX_CMDS)	/* Must be a pow2 for
44 							   alignment and more
45 							   efficient array
46 							   index derivation
47 							 */
48 
49 #define CXLFLASH_MAX_CMDS               16
50 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
51 
52 
53 static inline void check_sizes(void)
54 {
55 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
56 }
57 
58 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
59 #define CMD_BUFSIZE     SIZE_4K
60 
61 /* flags in IOA status area for host use */
62 #define B_DONE       0x01
63 #define B_ERROR      0x02	/* set with B_DONE */
64 #define B_TIMEOUT    0x04	/* set with B_DONE & B_ERROR */
65 
66 enum cxlflash_lr_state {
67 	LINK_RESET_INVALID,
68 	LINK_RESET_REQUIRED,
69 	LINK_RESET_COMPLETE
70 };
71 
72 enum cxlflash_init_state {
73 	INIT_STATE_NONE,
74 	INIT_STATE_PCI,
75 	INIT_STATE_AFU,
76 	INIT_STATE_SCSI
77 };
78 
79 enum cxlflash_state {
80 	STATE_NORMAL,	/* Normal running state, everything good */
81 	STATE_LIMBO,	/* Limbo running state, trying to reset/recover */
82 	STATE_FAILTERM	/* Failed/terminating state, error out users/threads */
83 };
84 
85 /*
86  * Each context has its own set of resource handles that is visible
87  * only from that context.
88  */
89 
90 struct cxlflash_cfg {
91 	struct afu *afu;
92 	struct cxl_context *mcctx;
93 
94 	struct pci_dev *dev;
95 	struct pci_device_id *dev_id;
96 	struct Scsi_Host *host;
97 
98 	ulong cxlflash_regs_pci;
99 
100 	struct work_struct work_q;
101 	enum cxlflash_init_state init_state;
102 	enum cxlflash_lr_state lr_state;
103 	int lr_port;
104 
105 	struct cxl_afu *cxl_afu;
106 
107 	struct pci_pool *cxlflash_cmd_pool;
108 	struct pci_dev *parent_dev;
109 
110 	atomic_t recovery_threads;
111 	struct mutex ctx_recovery_mutex;
112 	struct mutex ctx_tbl_list_mutex;
113 	struct ctx_info *ctx_tbl[MAX_CONTEXT];
114 	struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
115 	struct file_operations cxl_fops;
116 
117 	atomic_t num_user_contexts;
118 
119 	/* Parameters that are LUN table related */
120 	int last_lun_index[CXLFLASH_NUM_FC_PORTS];
121 	int promote_lun_index;
122 	struct list_head lluns; /* list of llun_info structs */
123 
124 	wait_queue_head_t tmf_waitq;
125 	bool tmf_active;
126 	wait_queue_head_t limbo_waitq;
127 	enum cxlflash_state state;
128 };
129 
130 struct afu_cmd {
131 	struct sisl_ioarcb rcb;	/* IOARCB (cache line aligned) */
132 	struct sisl_ioasa sa;	/* IOASA must follow IOARCB */
133 	spinlock_t slock;
134 	struct completion cevent;
135 	char *buf;		/* per command buffer */
136 	struct afu *parent;
137 	int slot;
138 	atomic_t free;
139 
140 	u8 cmd_tmf:1;
141 
142 	/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
143 	 * However for performance reasons the IOARCB/IOASA should be
144 	 * cache line aligned.
145 	 */
146 } __aligned(cache_line_size());
147 
148 struct afu {
149 	/* Stuff requiring alignment go first. */
150 
151 	u64 rrq_entry[NUM_RRQ_ENTRY];	/* 128B RRQ */
152 	/*
153 	 * Command & data for AFU commands.
154 	 */
155 	struct afu_cmd cmd[CXLFLASH_NUM_CMDS];
156 
157 	/* Beware of alignment till here. Preferably introduce new
158 	 * fields after this point
159 	 */
160 
161 	/* AFU HW */
162 	struct cxl_ioctl_start_work work;
163 	struct cxlflash_afu_map *afu_map;	/* entire MMIO map */
164 	struct sisl_host_map *host_map;		/* MC host map */
165 	struct sisl_ctrl_map *ctrl_map;		/* MC control map */
166 
167 	ctx_hndl_t ctx_hndl;	/* master's context handle */
168 	u64 *hrrq_start;
169 	u64 *hrrq_end;
170 	u64 *hrrq_curr;
171 	bool toggle;
172 	bool read_room;
173 	atomic64_t room;
174 	u64 hb;
175 	u32 cmd_couts;		/* Number of command checkouts */
176 	u32 internal_lun;	/* User-desired LUN mode for this AFU */
177 
178 	char version[8];
179 	u64 interface_version;
180 
181 	struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
182 
183 };
184 
185 static inline u64 lun_to_lunid(u64 lun)
186 {
187 	u64 lun_id;
188 
189 	int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
190 	return swab64(lun_id);
191 }
192 
193 int cxlflash_send_cmd(struct afu *, struct afu_cmd *);
194 void cxlflash_wait_resp(struct afu *, struct afu_cmd *);
195 int cxlflash_afu_reset(struct cxlflash_cfg *);
196 struct afu_cmd *cxlflash_cmd_checkout(struct afu *);
197 void cxlflash_cmd_checkin(struct afu_cmd *);
198 int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
199 void cxlflash_list_init(void);
200 void cxlflash_term_global_luns(void);
201 void cxlflash_free_errpage(void);
202 int cxlflash_ioctl(struct scsi_device *, int, void __user *);
203 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
204 int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
205 void cxlflash_term_local_luns(struct cxlflash_cfg *);
206 void cxlflash_restore_luntable(struct cxlflash_cfg *);
207 
208 #endif /* ifndef _CXLFLASH_COMMON_H */
209