xref: /linux/drivers/scsi/cxlflash/common.h (revision fcc87e74a987dc9c0c85f53546df944ede76486a)
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 and certain AFU errors */
52 
53 /* Command management definitions */
54 #define CXLFLASH_MAX_CMDS               256
55 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
56 
57 /* RRQ for master issued cmds */
58 #define NUM_RRQ_ENTRY                   CXLFLASH_MAX_CMDS
59 
60 /* SQ for master issued cmds */
61 #define NUM_SQ_ENTRY			CXLFLASH_MAX_CMDS
62 
63 
64 static inline void check_sizes(void)
65 {
66 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_FC_PORTS_PER_BANK);
67 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_MAX_CMDS);
68 }
69 
70 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
71 #define CMD_BUFSIZE     SIZE_4K
72 
73 enum cxlflash_lr_state {
74 	LINK_RESET_INVALID,
75 	LINK_RESET_REQUIRED,
76 	LINK_RESET_COMPLETE
77 };
78 
79 enum cxlflash_init_state {
80 	INIT_STATE_NONE,
81 	INIT_STATE_PCI,
82 	INIT_STATE_AFU,
83 	INIT_STATE_SCSI
84 };
85 
86 enum cxlflash_state {
87 	STATE_PROBING,	/* Initial state during probe */
88 	STATE_PROBED,	/* Temporary state, probe completed but EEH occurred */
89 	STATE_NORMAL,	/* Normal running state, everything good */
90 	STATE_RESET,	/* Reset state, trying to reset/recover */
91 	STATE_FAILTERM	/* Failed/terminating state, error out users/threads */
92 };
93 
94 /*
95  * Each context has its own set of resource handles that is visible
96  * only from that context.
97  */
98 
99 struct cxlflash_cfg {
100 	struct afu *afu;
101 	struct cxl_context *mcctx;
102 
103 	struct pci_dev *dev;
104 	struct pci_device_id *dev_id;
105 	struct Scsi_Host *host;
106 	int num_fc_ports;
107 
108 	ulong cxlflash_regs_pci;
109 
110 	struct work_struct work_q;
111 	enum cxlflash_init_state init_state;
112 	enum cxlflash_lr_state lr_state;
113 	int lr_port;
114 	atomic_t scan_host_needed;
115 
116 	struct cxl_afu *cxl_afu;
117 
118 	atomic_t recovery_threads;
119 	struct mutex ctx_recovery_mutex;
120 	struct mutex ctx_tbl_list_mutex;
121 	struct rw_semaphore ioctl_rwsem;
122 	struct ctx_info *ctx_tbl[MAX_CONTEXT];
123 	struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
124 	struct file_operations cxl_fops;
125 
126 	/* Parameters that are LUN table related */
127 	int last_lun_index[MAX_FC_PORTS];
128 	int promote_lun_index;
129 	struct list_head lluns; /* list of llun_info structs */
130 
131 	wait_queue_head_t tmf_waitq;
132 	spinlock_t tmf_slock;
133 	bool tmf_active;
134 	wait_queue_head_t reset_waitq;
135 	enum cxlflash_state state;
136 };
137 
138 struct afu_cmd {
139 	struct sisl_ioarcb rcb;	/* IOARCB (cache line aligned) */
140 	struct sisl_ioasa sa;	/* IOASA must follow IOARCB */
141 	struct afu *parent;
142 	struct scsi_cmnd *scp;
143 	struct completion cevent;
144 	struct list_head queue;
145 
146 	u8 cmd_tmf:1;
147 
148 	/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
149 	 * However for performance reasons the IOARCB/IOASA should be
150 	 * cache line aligned.
151 	 */
152 } __aligned(cache_line_size());
153 
154 static inline struct afu_cmd *sc_to_afuc(struct scsi_cmnd *sc)
155 {
156 	return PTR_ALIGN(scsi_cmd_priv(sc), __alignof__(struct afu_cmd));
157 }
158 
159 static inline struct afu_cmd *sc_to_afucz(struct scsi_cmnd *sc)
160 {
161 	struct afu_cmd *afuc = sc_to_afuc(sc);
162 
163 	memset(afuc, 0, sizeof(*afuc));
164 	return afuc;
165 }
166 
167 struct afu {
168 	/* Stuff requiring alignment go first. */
169 	struct sisl_ioarcb sq[NUM_SQ_ENTRY];		/* 16K SQ */
170 	u64 rrq_entry[NUM_RRQ_ENTRY];			/* 2K RRQ */
171 
172 	/* Beware of alignment till here. Preferably introduce new
173 	 * fields after this point
174 	 */
175 
176 	int (*send_cmd)(struct afu *, struct afu_cmd *);
177 	void (*context_reset)(struct afu_cmd *);
178 
179 	/* AFU HW */
180 	struct cxl_ioctl_start_work work;
181 	struct cxlflash_afu_map __iomem *afu_map;	/* entire MMIO map */
182 	struct sisl_host_map __iomem *host_map;		/* MC host map */
183 	struct sisl_ctrl_map __iomem *ctrl_map;		/* MC control map */
184 
185 	ctx_hndl_t ctx_hndl;	/* master's context handle */
186 
187 	atomic_t hsq_credits;
188 	spinlock_t hsq_slock;
189 	struct sisl_ioarcb *hsq_start;
190 	struct sisl_ioarcb *hsq_end;
191 	struct sisl_ioarcb *hsq_curr;
192 	spinlock_t hrrq_slock;
193 	u64 *hrrq_start;
194 	u64 *hrrq_end;
195 	u64 *hrrq_curr;
196 	bool toggle;
197 	atomic_t cmds_active;	/* Number of currently active AFU commands */
198 	s64 room;
199 	spinlock_t rrin_slock; /* Lock to rrin queuing and cmd_room updates */
200 	u64 hb;
201 	u32 internal_lun;	/* User-desired LUN mode for this AFU */
202 
203 	char version[16];
204 	u64 interface_version;
205 
206 	u32 irqpoll_weight;
207 	struct irq_poll irqpoll;
208 	struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
209 
210 };
211 
212 static inline bool afu_is_irqpoll_enabled(struct afu *afu)
213 {
214 	return !!afu->irqpoll_weight;
215 }
216 
217 static inline bool afu_is_cmd_mode(struct afu *afu, u64 cmd_mode)
218 {
219 	u64 afu_cap = afu->interface_version >> SISL_INTVER_CAP_SHIFT;
220 
221 	return afu_cap & cmd_mode;
222 }
223 
224 static inline bool afu_is_sq_cmd_mode(struct afu *afu)
225 {
226 	return afu_is_cmd_mode(afu, SISL_INTVER_CAP_SQ_CMD_MODE);
227 }
228 
229 static inline bool afu_is_ioarrin_cmd_mode(struct afu *afu)
230 {
231 	return afu_is_cmd_mode(afu, SISL_INTVER_CAP_IOARRIN_CMD_MODE);
232 }
233 
234 static inline u64 lun_to_lunid(u64 lun)
235 {
236 	__be64 lun_id;
237 
238 	int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
239 	return be64_to_cpu(lun_id);
240 }
241 
242 static inline struct fc_port_bank __iomem *get_fc_port_bank(
243 					    struct cxlflash_cfg *cfg, int i)
244 {
245 	struct afu *afu = cfg->afu;
246 
247 	return &afu->afu_map->global.bank[CHAN2PORTBANK(i)];
248 }
249 
250 static inline __be64 __iomem *get_fc_port_regs(struct cxlflash_cfg *cfg, int i)
251 {
252 	struct fc_port_bank __iomem *fcpb = get_fc_port_bank(cfg, i);
253 
254 	return &fcpb->fc_port_regs[CHAN2BANKPORT(i)][0];
255 }
256 
257 static inline __be64 __iomem *get_fc_port_luns(struct cxlflash_cfg *cfg, int i)
258 {
259 	struct fc_port_bank __iomem *fcpb = get_fc_port_bank(cfg, i);
260 
261 	return &fcpb->fc_port_luns[CHAN2BANKPORT(i)][0];
262 }
263 
264 int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t c, res_hndl_t r, u8 mode);
265 void cxlflash_list_init(void);
266 void cxlflash_term_global_luns(void);
267 void cxlflash_free_errpage(void);
268 int cxlflash_ioctl(struct scsi_device *sdev, int cmd, void __user *arg);
269 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *cfg);
270 int cxlflash_mark_contexts_error(struct cxlflash_cfg *cfg);
271 void cxlflash_term_local_luns(struct cxlflash_cfg *cfg);
272 void cxlflash_restore_luntable(struct cxlflash_cfg *cfg);
273 
274 #endif /* ifndef _CXLFLASH_COMMON_H */
275