xref: /linux/drivers/scsi/cxlflash/common.h (revision cd41e18daf1a21fea5a195a5a74c97c6b183c15a)
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/irq_poll.h>
19 #include <linux/list.h>
20 #include <linux/rwsem.h>
21 #include <linux/types.h>
22 #include <scsi/scsi.h>
23 #include <scsi/scsi_cmnd.h>
24 #include <scsi/scsi_device.h>
25 
26 extern const struct file_operations cxlflash_cxl_fops;
27 
28 #define MAX_CONTEXT	CXLFLASH_MAX_CONTEXT	/* num contexts per afu */
29 #define MAX_FC_PORTS	CXLFLASH_MAX_FC_PORTS	/* max ports per AFU */
30 #define LEGACY_FC_PORTS	2			/* legacy ports per AFU */
31 
32 #define CHAN2PORTBANK(_x)	((_x) >> ilog2(CXLFLASH_NUM_FC_PORTS_PER_BANK))
33 #define CHAN2BANKPORT(_x)	((_x) & (CXLFLASH_NUM_FC_PORTS_PER_BANK - 1))
34 
35 #define CHAN2PORTMASK(_x)	(1 << (_x))	/* channel to port mask */
36 #define PORTMASK2CHAN(_x)	(ilog2((_x)))	/* port mask to channel */
37 #define PORTNUM2CHAN(_x)	((_x) - 1)	/* port number to channel */
38 
39 #define CXLFLASH_BLOCK_SIZE	4096	/* 4K blocks */
40 #define CXLFLASH_MAX_XFER_SIZE	16777216	/* 16MB transfer */
41 #define CXLFLASH_MAX_SECTORS	(CXLFLASH_MAX_XFER_SIZE/512)	/* SCSI wants
42 								   max_sectors
43 								   in units of
44 								   512 byte
45 								   sectors
46 								*/
47 
48 #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
49 
50 /* AFU command retry limit */
51 #define MC_RETRY_CNT         5	/* sufficient for SCSI check and
52 				   certain AFU errors */
53 
54 /* Command management definitions */
55 #define CXLFLASH_MAX_CMDS               256
56 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
57 
58 /* RRQ for master issued cmds */
59 #define NUM_RRQ_ENTRY                   CXLFLASH_MAX_CMDS
60 
61 /* SQ for master issued cmds */
62 #define NUM_SQ_ENTRY			CXLFLASH_MAX_CMDS
63 
64 
65 static inline void check_sizes(void)
66 {
67 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_FC_PORTS_PER_BANK);
68 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_MAX_CMDS);
69 }
70 
71 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
72 #define CMD_BUFSIZE     SIZE_4K
73 
74 enum cxlflash_lr_state {
75 	LINK_RESET_INVALID,
76 	LINK_RESET_REQUIRED,
77 	LINK_RESET_COMPLETE
78 };
79 
80 enum cxlflash_init_state {
81 	INIT_STATE_NONE,
82 	INIT_STATE_PCI,
83 	INIT_STATE_AFU,
84 	INIT_STATE_SCSI
85 };
86 
87 enum cxlflash_state {
88 	STATE_PROBING,	/* Initial state during probe */
89 	STATE_PROBED,	/* Temporary state, probe completed but EEH occurred */
90 	STATE_NORMAL,	/* Normal running state, everything good */
91 	STATE_RESET,	/* Reset state, trying to reset/recover */
92 	STATE_FAILTERM	/* Failed/terminating state, error out users/threads */
93 };
94 
95 /*
96  * Each context has its own set of resource handles that is visible
97  * only from that context.
98  */
99 
100 struct cxlflash_cfg {
101 	struct afu *afu;
102 	struct cxl_context *mcctx;
103 
104 	struct pci_dev *dev;
105 	struct pci_device_id *dev_id;
106 	struct Scsi_Host *host;
107 	int num_fc_ports;
108 
109 	ulong cxlflash_regs_pci;
110 
111 	struct work_struct work_q;
112 	enum cxlflash_init_state init_state;
113 	enum cxlflash_lr_state lr_state;
114 	int lr_port;
115 	atomic_t scan_host_needed;
116 
117 	struct cxl_afu *cxl_afu;
118 
119 	atomic_t recovery_threads;
120 	struct mutex ctx_recovery_mutex;
121 	struct mutex ctx_tbl_list_mutex;
122 	struct rw_semaphore ioctl_rwsem;
123 	struct ctx_info *ctx_tbl[MAX_CONTEXT];
124 	struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
125 	struct file_operations cxl_fops;
126 
127 	/* Parameters that are LUN table related */
128 	int last_lun_index[MAX_FC_PORTS];
129 	int promote_lun_index;
130 	struct list_head lluns; /* list of llun_info structs */
131 
132 	wait_queue_head_t tmf_waitq;
133 	spinlock_t tmf_slock;
134 	bool tmf_active;
135 	wait_queue_head_t reset_waitq;
136 	enum cxlflash_state state;
137 };
138 
139 struct afu_cmd {
140 	struct sisl_ioarcb rcb;	/* IOARCB (cache line aligned) */
141 	struct sisl_ioasa sa;	/* IOASA must follow IOARCB */
142 	struct afu *parent;
143 	struct scsi_cmnd *scp;
144 	struct completion cevent;
145 	struct list_head queue;
146 
147 	u8 cmd_tmf:1;
148 
149 	/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
150 	 * However for performance reasons the IOARCB/IOASA should be
151 	 * cache line aligned.
152 	 */
153 } __aligned(cache_line_size());
154 
155 static inline struct afu_cmd *sc_to_afuc(struct scsi_cmnd *sc)
156 {
157 	return PTR_ALIGN(scsi_cmd_priv(sc), __alignof__(struct afu_cmd));
158 }
159 
160 static inline struct afu_cmd *sc_to_afucz(struct scsi_cmnd *sc)
161 {
162 	struct afu_cmd *afuc = sc_to_afuc(sc);
163 
164 	memset(afuc, 0, sizeof(*afuc));
165 	return afuc;
166 }
167 
168 struct afu {
169 	/* Stuff requiring alignment go first. */
170 	struct sisl_ioarcb sq[NUM_SQ_ENTRY];		/* 16K SQ */
171 	u64 rrq_entry[NUM_RRQ_ENTRY];			/* 2K RRQ */
172 
173 	/* Beware of alignment till here. Preferably introduce new
174 	 * fields after this point
175 	 */
176 
177 	int (*send_cmd)(struct afu *, struct afu_cmd *);
178 	void (*context_reset)(struct afu_cmd *);
179 
180 	/* AFU HW */
181 	struct cxl_ioctl_start_work work;
182 	struct cxlflash_afu_map __iomem *afu_map;	/* entire MMIO map */
183 	struct sisl_host_map __iomem *host_map;		/* MC host map */
184 	struct sisl_ctrl_map __iomem *ctrl_map;		/* MC control map */
185 
186 	ctx_hndl_t ctx_hndl;	/* master's context handle */
187 
188 	atomic_t hsq_credits;
189 	spinlock_t hsq_slock;
190 	struct sisl_ioarcb *hsq_start;
191 	struct sisl_ioarcb *hsq_end;
192 	struct sisl_ioarcb *hsq_curr;
193 	spinlock_t hrrq_slock;
194 	u64 *hrrq_start;
195 	u64 *hrrq_end;
196 	u64 *hrrq_curr;
197 	bool toggle;
198 	atomic_t cmds_active;	/* Number of currently active AFU commands */
199 	s64 room;
200 	spinlock_t rrin_slock; /* Lock to rrin queuing and cmd_room updates */
201 	u64 hb;
202 	u32 internal_lun;	/* User-desired LUN mode for this AFU */
203 
204 	char version[16];
205 	u64 interface_version;
206 
207 	u32 irqpoll_weight;
208 	struct irq_poll irqpoll;
209 	struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
210 
211 };
212 
213 static inline bool afu_is_irqpoll_enabled(struct afu *afu)
214 {
215 	return !!afu->irqpoll_weight;
216 }
217 
218 static inline bool afu_is_cmd_mode(struct afu *afu, u64 cmd_mode)
219 {
220 	u64 afu_cap = afu->interface_version >> SISL_INTVER_CAP_SHIFT;
221 
222 	return afu_cap & cmd_mode;
223 }
224 
225 static inline bool afu_is_sq_cmd_mode(struct afu *afu)
226 {
227 	return afu_is_cmd_mode(afu, SISL_INTVER_CAP_SQ_CMD_MODE);
228 }
229 
230 static inline bool afu_is_ioarrin_cmd_mode(struct afu *afu)
231 {
232 	return afu_is_cmd_mode(afu, SISL_INTVER_CAP_IOARRIN_CMD_MODE);
233 }
234 
235 static inline u64 lun_to_lunid(u64 lun)
236 {
237 	__be64 lun_id;
238 
239 	int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
240 	return be64_to_cpu(lun_id);
241 }
242 
243 static inline struct fc_port_bank __iomem *get_fc_port_bank(
244 					    struct cxlflash_cfg *cfg, int i)
245 {
246 	struct afu *afu = cfg->afu;
247 
248 	return &afu->afu_map->global.bank[CHAN2PORTBANK(i)];
249 }
250 
251 static inline __be64 __iomem *get_fc_port_regs(struct cxlflash_cfg *cfg, int i)
252 {
253 	struct fc_port_bank __iomem *fcpb = get_fc_port_bank(cfg, i);
254 
255 	return &fcpb->fc_port_regs[CHAN2BANKPORT(i)][0];
256 }
257 
258 static inline __be64 __iomem *get_fc_port_luns(struct cxlflash_cfg *cfg, int i)
259 {
260 	struct fc_port_bank __iomem *fcpb = get_fc_port_bank(cfg, i);
261 
262 	return &fcpb->fc_port_luns[CHAN2BANKPORT(i)][0];
263 }
264 
265 int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
266 void cxlflash_list_init(void);
267 void cxlflash_term_global_luns(void);
268 void cxlflash_free_errpage(void);
269 int cxlflash_ioctl(struct scsi_device *, int, void __user *);
270 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
271 int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
272 void cxlflash_term_local_luns(struct cxlflash_cfg *);
273 void cxlflash_restore_luntable(struct cxlflash_cfg *);
274 
275 #endif /* ifndef _CXLFLASH_COMMON_H */
276