1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * CXL Flash Device Driver
4  *
5  * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
6  *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
7  *
8  * Copyright (C) 2015 IBM Corporation
9  */
10 
11 #ifndef _CXLFLASH_COMMON_H
12 #define _CXLFLASH_COMMON_H
13 
14 #include <linux/async.h>
15 #include <linux/cdev.h>
16 #include <linux/irq_poll.h>
17 #include <linux/list.h>
18 #include <linux/rwsem.h>
19 #include <linux/types.h>
20 #include <scsi/scsi.h>
21 #include <scsi/scsi_cmnd.h>
22 #include <scsi/scsi_device.h>
23 
24 #include "backend.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 /* Hardware queue definitions */
64 #define CXLFLASH_DEF_HWQS		1
65 #define CXLFLASH_MAX_HWQS		8
66 #define PRIMARY_HWQ			0
67 
68 
check_sizes(void)69 static inline void check_sizes(void)
70 {
71 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_FC_PORTS_PER_BANK);
72 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_MAX_CMDS);
73 }
74 
75 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
76 #define CMD_BUFSIZE     SIZE_4K
77 
78 enum cxlflash_lr_state {
79 	LINK_RESET_INVALID,
80 	LINK_RESET_REQUIRED,
81 	LINK_RESET_COMPLETE
82 };
83 
84 enum cxlflash_init_state {
85 	INIT_STATE_NONE,
86 	INIT_STATE_PCI,
87 	INIT_STATE_AFU,
88 	INIT_STATE_SCSI,
89 	INIT_STATE_CDEV
90 };
91 
92 enum cxlflash_state {
93 	STATE_PROBING,	/* Initial state during probe */
94 	STATE_PROBED,	/* Temporary state, probe completed but EEH occurred */
95 	STATE_NORMAL,	/* Normal running state, everything good */
96 	STATE_RESET,	/* Reset state, trying to reset/recover */
97 	STATE_FAILTERM	/* Failed/terminating state, error out users/threads */
98 };
99 
100 enum cxlflash_hwq_mode {
101 	HWQ_MODE_RR,	/* Roundrobin (default) */
102 	HWQ_MODE_TAG,	/* Distribute based on block MQ tag */
103 	HWQ_MODE_CPU,	/* CPU affinity */
104 	MAX_HWQ_MODE
105 };
106 
107 /*
108  * Each context has its own set of resource handles that is visible
109  * only from that context.
110  */
111 
112 struct cxlflash_cfg {
113 	struct afu *afu;
114 
115 	const struct cxlflash_backend_ops *ops;
116 	struct pci_dev *dev;
117 	struct pci_device_id *dev_id;
118 	struct Scsi_Host *host;
119 	int num_fc_ports;
120 	struct cdev cdev;
121 	struct device *chardev;
122 
123 	ulong cxlflash_regs_pci;
124 
125 	struct work_struct work_q;
126 	enum cxlflash_init_state init_state;
127 	enum cxlflash_lr_state lr_state;
128 	int lr_port;
129 	atomic_t scan_host_needed;
130 
131 	void *afu_cookie;
132 
133 	atomic_t recovery_threads;
134 	struct mutex ctx_recovery_mutex;
135 	struct mutex ctx_tbl_list_mutex;
136 	struct rw_semaphore ioctl_rwsem;
137 	struct ctx_info *ctx_tbl[MAX_CONTEXT];
138 	struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
139 	struct file_operations cxl_fops;
140 
141 	/* Parameters that are LUN table related */
142 	int last_lun_index[MAX_FC_PORTS];
143 	int promote_lun_index;
144 	struct list_head lluns; /* list of llun_info structs */
145 
146 	wait_queue_head_t tmf_waitq;
147 	spinlock_t tmf_slock;
148 	bool tmf_active;
149 	bool ws_unmap;		/* Write-same unmap supported */
150 	wait_queue_head_t reset_waitq;
151 	enum cxlflash_state state;
152 	async_cookie_t async_reset_cookie;
153 };
154 
155 struct afu_cmd {
156 	struct sisl_ioarcb rcb;	/* IOARCB (cache line aligned) */
157 	struct sisl_ioasa sa;	/* IOASA must follow IOARCB */
158 	struct afu *parent;
159 	struct scsi_cmnd *scp;
160 	struct completion cevent;
161 	struct list_head queue;
162 	u32 hwq_index;
163 
164 	u8 cmd_tmf:1,
165 	   cmd_aborted:1;
166 
167 	struct list_head list;	/* Pending commands link */
168 
169 	/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
170 	 * However for performance reasons the IOARCB/IOASA should be
171 	 * cache line aligned.
172 	 */
173 } __aligned(cache_line_size());
174 
sc_to_afuc(struct scsi_cmnd * sc)175 static inline struct afu_cmd *sc_to_afuc(struct scsi_cmnd *sc)
176 {
177 	return PTR_ALIGN(scsi_cmd_priv(sc), __alignof__(struct afu_cmd));
178 }
179 
sc_to_afuci(struct scsi_cmnd * sc)180 static inline struct afu_cmd *sc_to_afuci(struct scsi_cmnd *sc)
181 {
182 	struct afu_cmd *afuc = sc_to_afuc(sc);
183 
184 	INIT_LIST_HEAD(&afuc->queue);
185 	return afuc;
186 }
187 
sc_to_afucz(struct scsi_cmnd * sc)188 static inline struct afu_cmd *sc_to_afucz(struct scsi_cmnd *sc)
189 {
190 	struct afu_cmd *afuc = sc_to_afuc(sc);
191 
192 	memset(afuc, 0, sizeof(*afuc));
193 	return sc_to_afuci(sc);
194 }
195 
196 struct hwq {
197 	/* Stuff requiring alignment go first. */
198 	struct sisl_ioarcb sq[NUM_SQ_ENTRY];		/* 16K SQ */
199 	u64 rrq_entry[NUM_RRQ_ENTRY];			/* 2K RRQ */
200 
201 	/* Beware of alignment till here. Preferably introduce new
202 	 * fields after this point
203 	 */
204 	struct afu *afu;
205 	void *ctx_cookie;
206 	struct sisl_host_map __iomem *host_map;		/* MC host map */
207 	struct sisl_ctrl_map __iomem *ctrl_map;		/* MC control map */
208 	ctx_hndl_t ctx_hndl;	/* master's context handle */
209 	u32 index;		/* Index of this hwq */
210 	int num_irqs;		/* Number of interrupts requested for context */
211 	struct list_head pending_cmds;	/* Commands pending completion */
212 
213 	atomic_t hsq_credits;
214 	spinlock_t hsq_slock;	/* Hardware send queue lock */
215 	struct sisl_ioarcb *hsq_start;
216 	struct sisl_ioarcb *hsq_end;
217 	struct sisl_ioarcb *hsq_curr;
218 	spinlock_t hrrq_slock;
219 	u64 *hrrq_start;
220 	u64 *hrrq_end;
221 	u64 *hrrq_curr;
222 	bool toggle;
223 	bool hrrq_online;
224 
225 	s64 room;
226 
227 	struct irq_poll irqpoll;
228 } __aligned(cache_line_size());
229 
230 struct afu {
231 	struct hwq hwqs[CXLFLASH_MAX_HWQS];
232 	int (*send_cmd)(struct afu *afu, struct afu_cmd *cmd);
233 	int (*context_reset)(struct hwq *hwq);
234 
235 	/* AFU HW */
236 	struct cxlflash_afu_map __iomem *afu_map;	/* entire MMIO map */
237 
238 	atomic_t cmds_active;	/* Number of currently active AFU commands */
239 	struct mutex sync_active;	/* Mutex to serialize AFU commands */
240 	u64 hb;
241 	u32 internal_lun;	/* User-desired LUN mode for this AFU */
242 
243 	u32 num_hwqs;		/* Number of hardware queues */
244 	u32 desired_hwqs;	/* Desired h/w queues, effective on AFU reset */
245 	enum cxlflash_hwq_mode hwq_mode; /* Steering mode for h/w queues */
246 	u32 hwq_rr_count;	/* Count to distribute traffic for roundrobin */
247 
248 	char version[16];
249 	u64 interface_version;
250 
251 	u32 irqpoll_weight;
252 	struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
253 };
254 
get_hwq(struct afu * afu,u32 index)255 static inline struct hwq *get_hwq(struct afu *afu, u32 index)
256 {
257 	WARN_ON(index >= CXLFLASH_MAX_HWQS);
258 
259 	return &afu->hwqs[index];
260 }
261 
afu_is_irqpoll_enabled(struct afu * afu)262 static inline bool afu_is_irqpoll_enabled(struct afu *afu)
263 {
264 	return !!afu->irqpoll_weight;
265 }
266 
afu_has_cap(struct afu * afu,u64 cap)267 static inline bool afu_has_cap(struct afu *afu, u64 cap)
268 {
269 	u64 afu_cap = afu->interface_version >> SISL_INTVER_CAP_SHIFT;
270 
271 	return afu_cap & cap;
272 }
273 
afu_is_ocxl_lisn(struct afu * afu)274 static inline bool afu_is_ocxl_lisn(struct afu *afu)
275 {
276 	return afu_has_cap(afu, SISL_INTVER_CAP_OCXL_LISN);
277 }
278 
afu_is_afu_debug(struct afu * afu)279 static inline bool afu_is_afu_debug(struct afu *afu)
280 {
281 	return afu_has_cap(afu, SISL_INTVER_CAP_AFU_DEBUG);
282 }
283 
afu_is_lun_provision(struct afu * afu)284 static inline bool afu_is_lun_provision(struct afu *afu)
285 {
286 	return afu_has_cap(afu, SISL_INTVER_CAP_LUN_PROVISION);
287 }
288 
afu_is_sq_cmd_mode(struct afu * afu)289 static inline bool afu_is_sq_cmd_mode(struct afu *afu)
290 {
291 	return afu_has_cap(afu, SISL_INTVER_CAP_SQ_CMD_MODE);
292 }
293 
afu_is_ioarrin_cmd_mode(struct afu * afu)294 static inline bool afu_is_ioarrin_cmd_mode(struct afu *afu)
295 {
296 	return afu_has_cap(afu, SISL_INTVER_CAP_IOARRIN_CMD_MODE);
297 }
298 
lun_to_lunid(u64 lun)299 static inline u64 lun_to_lunid(u64 lun)
300 {
301 	__be64 lun_id;
302 
303 	int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
304 	return be64_to_cpu(lun_id);
305 }
306 
get_fc_port_bank(struct cxlflash_cfg * cfg,int i)307 static inline struct fc_port_bank __iomem *get_fc_port_bank(
308 					    struct cxlflash_cfg *cfg, int i)
309 {
310 	struct afu *afu = cfg->afu;
311 
312 	return &afu->afu_map->global.bank[CHAN2PORTBANK(i)];
313 }
314 
get_fc_port_regs(struct cxlflash_cfg * cfg,int i)315 static inline __be64 __iomem *get_fc_port_regs(struct cxlflash_cfg *cfg, int i)
316 {
317 	struct fc_port_bank __iomem *fcpb = get_fc_port_bank(cfg, i);
318 
319 	return &fcpb->fc_port_regs[CHAN2BANKPORT(i)][0];
320 }
321 
get_fc_port_luns(struct cxlflash_cfg * cfg,int i)322 static inline __be64 __iomem *get_fc_port_luns(struct cxlflash_cfg *cfg, int i)
323 {
324 	struct fc_port_bank __iomem *fcpb = get_fc_port_bank(cfg, i);
325 
326 	return &fcpb->fc_port_luns[CHAN2BANKPORT(i)][0];
327 }
328 
329 int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t c, res_hndl_t r, u8 mode);
330 void cxlflash_list_init(void);
331 void cxlflash_term_global_luns(void);
332 void cxlflash_free_errpage(void);
333 int cxlflash_ioctl(struct scsi_device *sdev, unsigned int cmd,
334 		   void __user *arg);
335 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *cfg);
336 int cxlflash_mark_contexts_error(struct cxlflash_cfg *cfg);
337 void cxlflash_term_local_luns(struct cxlflash_cfg *cfg);
338 void cxlflash_restore_luntable(struct cxlflash_cfg *cfg);
339 
340 #endif /* ifndef _CXLFLASH_COMMON_H */
341