xref: /linux/drivers/scsi/cxlflash/common.h (revision 1b62d134d3c5f9e67de096af7ea3e9fe48966f17)
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/rwsem.h>
20 #include <linux/types.h>
21 #include <scsi/scsi.h>
22 #include <scsi/scsi_cmnd.h>
23 #include <scsi/scsi_device.h>
24 
25 extern const struct file_operations cxlflash_cxl_fops;
26 
27 #define MAX_CONTEXT  CXLFLASH_MAX_CONTEXT       /* num contexts per afu */
28 
29 #define CXLFLASH_BLOCK_SIZE	4096	/* 4K blocks */
30 #define CXLFLASH_MAX_XFER_SIZE	16777216	/* 16MB transfer */
31 #define CXLFLASH_MAX_SECTORS	(CXLFLASH_MAX_XFER_SIZE/512)	/* SCSI wants
32 								   max_sectors
33 								   in units of
34 								   512 byte
35 								   sectors
36 								*/
37 
38 #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
39 
40 /* AFU command retry limit */
41 #define MC_RETRY_CNT         5	/* sufficient for SCSI check and
42 				   certain AFU errors */
43 
44 /* Command management definitions */
45 #define CXLFLASH_NUM_CMDS	(2 * CXLFLASH_MAX_CMDS)	/* Must be a pow2 for
46 							   alignment and more
47 							   efficient array
48 							   index derivation
49 							 */
50 
51 #define CXLFLASH_MAX_CMDS               256
52 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
53 
54 /* RRQ for master issued cmds */
55 #define NUM_RRQ_ENTRY                   CXLFLASH_MAX_CMDS
56 
57 
58 static inline void check_sizes(void)
59 {
60 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
61 }
62 
63 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
64 #define CMD_BUFSIZE     SIZE_4K
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_RESET,	/* Reset 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 	atomic_t scan_host_needed;
105 
106 	struct cxl_afu *cxl_afu;
107 
108 	atomic_t recovery_threads;
109 	struct mutex ctx_recovery_mutex;
110 	struct mutex ctx_tbl_list_mutex;
111 	struct rw_semaphore ioctl_rwsem;
112 	struct ctx_info *ctx_tbl[MAX_CONTEXT];
113 	struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
114 	struct file_operations cxl_fops;
115 
116 	/* Parameters that are LUN table related */
117 	int last_lun_index[CXLFLASH_NUM_FC_PORTS];
118 	int promote_lun_index;
119 	struct list_head lluns; /* list of llun_info structs */
120 
121 	wait_queue_head_t tmf_waitq;
122 	spinlock_t tmf_slock;
123 	bool tmf_active;
124 	wait_queue_head_t reset_waitq;
125 	enum cxlflash_state state;
126 };
127 
128 struct afu_cmd {
129 	struct sisl_ioarcb rcb;	/* IOARCB (cache line aligned) */
130 	struct sisl_ioasa sa;	/* IOASA must follow IOARCB */
131 	struct afu *parent;
132 	struct scsi_cmnd *scp;
133 	struct completion cevent;
134 
135 	u8 cmd_tmf:1;
136 
137 	/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
138 	 * However for performance reasons the IOARCB/IOASA should be
139 	 * cache line aligned.
140 	 */
141 } __aligned(cache_line_size());
142 
143 static inline struct afu_cmd *sc_to_afuc(struct scsi_cmnd *sc)
144 {
145 	return PTR_ALIGN(scsi_cmd_priv(sc), __alignof__(struct afu_cmd));
146 }
147 
148 static inline struct afu_cmd *sc_to_afucz(struct scsi_cmnd *sc)
149 {
150 	struct afu_cmd *afuc = sc_to_afuc(sc);
151 
152 	memset(afuc, 0, sizeof(*afuc));
153 	return afuc;
154 }
155 
156 struct afu {
157 	/* Stuff requiring alignment go first. */
158 
159 	u64 rrq_entry[NUM_RRQ_ENTRY];	/* 2K RRQ */
160 
161 	/* Beware of alignment till here. Preferably introduce new
162 	 * fields after this point
163 	 */
164 
165 	int (*send_cmd)(struct afu *, struct afu_cmd *);
166 	void (*context_reset)(struct afu_cmd *);
167 
168 	/* AFU HW */
169 	struct cxl_ioctl_start_work work;
170 	struct cxlflash_afu_map __iomem *afu_map;	/* entire MMIO map */
171 	struct sisl_host_map __iomem *host_map;		/* MC host map */
172 	struct sisl_ctrl_map __iomem *ctrl_map;		/* MC control map */
173 
174 	struct kref mapcount;
175 
176 	ctx_hndl_t ctx_hndl;	/* master's context handle */
177 	u64 *hrrq_start;
178 	u64 *hrrq_end;
179 	u64 *hrrq_curr;
180 	bool toggle;
181 	atomic_t cmds_active;	/* Number of currently active AFU commands */
182 	s64 room;
183 	spinlock_t rrin_slock; /* Lock to rrin queuing and cmd_room updates */
184 	u64 hb;
185 	u32 internal_lun;	/* User-desired LUN mode for this AFU */
186 
187 	char version[16];
188 	u64 interface_version;
189 
190 	struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
191 
192 };
193 
194 static inline u64 lun_to_lunid(u64 lun)
195 {
196 	__be64 lun_id;
197 
198 	int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
199 	return be64_to_cpu(lun_id);
200 }
201 
202 int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
203 void cxlflash_list_init(void);
204 void cxlflash_term_global_luns(void);
205 void cxlflash_free_errpage(void);
206 int cxlflash_ioctl(struct scsi_device *, int, void __user *);
207 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
208 int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
209 void cxlflash_term_local_luns(struct cxlflash_cfg *);
210 void cxlflash_restore_luntable(struct cxlflash_cfg *);
211 
212 #endif /* ifndef _CXLFLASH_COMMON_H */
213