xref: /openbmc/linux/drivers/scsi/cxlflash/common.h (revision f3539c12)
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_device.h>
23 
24 extern const struct file_operations cxlflash_cxl_fops;
25 
26 #define MAX_CONTEXT  CXLFLASH_MAX_CONTEXT       /* num contexts per afu */
27 
28 #define CXLFLASH_BLOCK_SIZE	4096	/* 4K blocks */
29 #define CXLFLASH_MAX_XFER_SIZE	16777216	/* 16MB transfer */
30 #define CXLFLASH_MAX_SECTORS	(CXLFLASH_MAX_XFER_SIZE/512)	/* SCSI wants
31 								   max_sectors
32 								   in units of
33 								   512 byte
34 								   sectors
35 								*/
36 
37 #define MAX_RHT_PER_CONTEXT (PAGE_SIZE / sizeof(struct sisl_rht_entry))
38 
39 /* AFU command retry limit */
40 #define MC_RETRY_CNT         5	/* sufficient for SCSI check and
41 				   certain AFU errors */
42 
43 /* Command management definitions */
44 #define CXLFLASH_NUM_CMDS	(2 * CXLFLASH_MAX_CMDS)	/* Must be a pow2 for
45 							   alignment and more
46 							   efficient array
47 							   index derivation
48 							 */
49 
50 #define CXLFLASH_MAX_CMDS               256
51 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
52 
53 /* RRQ for master issued cmds */
54 #define NUM_RRQ_ENTRY                   CXLFLASH_MAX_CMDS
55 
56 
57 static inline void check_sizes(void)
58 {
59 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
60 }
61 
62 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
63 #define CMD_BUFSIZE     SIZE_4K
64 
65 /* flags in IOA status area for host use */
66 #define B_DONE       0x01
67 #define B_ERROR      0x02	/* set with B_DONE */
68 #define B_TIMEOUT    0x04	/* set with B_DONE & B_ERROR */
69 
70 enum cxlflash_lr_state {
71 	LINK_RESET_INVALID,
72 	LINK_RESET_REQUIRED,
73 	LINK_RESET_COMPLETE
74 };
75 
76 enum cxlflash_init_state {
77 	INIT_STATE_NONE,
78 	INIT_STATE_PCI,
79 	INIT_STATE_AFU,
80 	INIT_STATE_SCSI
81 };
82 
83 enum cxlflash_state {
84 	STATE_NORMAL,	/* Normal running state, everything good */
85 	STATE_RESET,	/* Reset state, trying to reset/recover */
86 	STATE_FAILTERM	/* Failed/terminating state, error out users/threads */
87 };
88 
89 /*
90  * Each context has its own set of resource handles that is visible
91  * only from that context.
92  */
93 
94 struct cxlflash_cfg {
95 	struct afu *afu;
96 	struct cxl_context *mcctx;
97 
98 	struct pci_dev *dev;
99 	struct pci_device_id *dev_id;
100 	struct Scsi_Host *host;
101 
102 	ulong cxlflash_regs_pci;
103 
104 	struct work_struct work_q;
105 	enum cxlflash_init_state init_state;
106 	enum cxlflash_lr_state lr_state;
107 	int lr_port;
108 	atomic_t scan_host_needed;
109 
110 	struct cxl_afu *cxl_afu;
111 
112 	atomic_t recovery_threads;
113 	struct mutex ctx_recovery_mutex;
114 	struct mutex ctx_tbl_list_mutex;
115 	struct rw_semaphore ioctl_rwsem;
116 	struct ctx_info *ctx_tbl[MAX_CONTEXT];
117 	struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
118 	struct file_operations cxl_fops;
119 
120 	/* Parameters that are LUN table related */
121 	int last_lun_index[CXLFLASH_NUM_FC_PORTS];
122 	int promote_lun_index;
123 	struct list_head lluns; /* list of llun_info structs */
124 
125 	wait_queue_head_t tmf_waitq;
126 	spinlock_t tmf_slock;
127 	bool tmf_active;
128 	wait_queue_head_t reset_waitq;
129 	enum cxlflash_state state;
130 };
131 
132 struct afu_cmd {
133 	struct sisl_ioarcb rcb;	/* IOARCB (cache line aligned) */
134 	struct sisl_ioasa sa;	/* IOASA must follow IOARCB */
135 	spinlock_t slock;
136 	struct completion cevent;
137 	char *buf;		/* per command buffer */
138 	struct afu *parent;
139 	int slot;
140 	atomic_t free;
141 
142 	u8 cmd_tmf:1;
143 
144 	/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
145 	 * However for performance reasons the IOARCB/IOASA should be
146 	 * cache line aligned.
147 	 */
148 } __aligned(cache_line_size());
149 
150 struct afu {
151 	/* Stuff requiring alignment go first. */
152 
153 	u64 rrq_entry[NUM_RRQ_ENTRY];	/* 2K RRQ */
154 	/*
155 	 * Command & data for AFU commands.
156 	 */
157 	struct afu_cmd cmd[CXLFLASH_NUM_CMDS];
158 
159 	/* Beware of alignment till here. Preferably introduce new
160 	 * fields after this point
161 	 */
162 
163 	/* AFU HW */
164 	struct cxl_ioctl_start_work work;
165 	struct cxlflash_afu_map __iomem *afu_map;	/* entire MMIO map */
166 	struct sisl_host_map __iomem *host_map;		/* MC host map */
167 	struct sisl_ctrl_map __iomem *ctrl_map;		/* MC control map */
168 
169 	struct kref mapcount;
170 
171 	ctx_hndl_t ctx_hndl;	/* master's context handle */
172 	u64 *hrrq_start;
173 	u64 *hrrq_end;
174 	u64 *hrrq_curr;
175 	bool toggle;
176 	bool read_room;
177 	atomic64_t room;
178 	u64 hb;
179 	u32 cmd_couts;		/* Number of command checkouts */
180 	u32 internal_lun;	/* User-desired LUN mode for this AFU */
181 
182 	char version[16];
183 	u64 interface_version;
184 
185 	struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
186 
187 };
188 
189 static inline u64 lun_to_lunid(u64 lun)
190 {
191 	__be64 lun_id;
192 
193 	int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
194 	return be64_to_cpu(lun_id);
195 }
196 
197 int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
198 void cxlflash_list_init(void);
199 void cxlflash_term_global_luns(void);
200 void cxlflash_free_errpage(void);
201 int cxlflash_ioctl(struct scsi_device *, int, void __user *);
202 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
203 int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
204 void cxlflash_term_local_luns(struct cxlflash_cfg *);
205 void cxlflash_restore_luntable(struct cxlflash_cfg *);
206 
207 #endif /* ifndef _CXLFLASH_COMMON_H */
208