xref: /openbmc/linux/drivers/scsi/cxlflash/common.h (revision abfbd895)
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 NUM_RRQ_ENTRY    16     /* for master issued cmds */
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               16
52 #define CXLFLASH_MAX_CMDS_PER_LUN       CXLFLASH_MAX_CMDS
53 
54 
55 static inline void check_sizes(void)
56 {
57 	BUILD_BUG_ON_NOT_POWER_OF_2(CXLFLASH_NUM_CMDS);
58 }
59 
60 /* AFU defines a fixed size of 4K for command buffers (borrow 4K page define) */
61 #define CMD_BUFSIZE     SIZE_4K
62 
63 /* flags in IOA status area for host use */
64 #define B_DONE       0x01
65 #define B_ERROR      0x02	/* set with B_DONE */
66 #define B_TIMEOUT    0x04	/* set with B_DONE & B_ERROR */
67 
68 enum cxlflash_lr_state {
69 	LINK_RESET_INVALID,
70 	LINK_RESET_REQUIRED,
71 	LINK_RESET_COMPLETE
72 };
73 
74 enum cxlflash_init_state {
75 	INIT_STATE_NONE,
76 	INIT_STATE_PCI,
77 	INIT_STATE_AFU,
78 	INIT_STATE_SCSI
79 };
80 
81 enum cxlflash_state {
82 	STATE_NORMAL,	/* Normal running state, everything good */
83 	STATE_RESET,	/* Reset state, trying to reset/recover */
84 	STATE_FAILTERM	/* Failed/terminating state, error out users/threads */
85 };
86 
87 /*
88  * Each context has its own set of resource handles that is visible
89  * only from that context.
90  */
91 
92 struct cxlflash_cfg {
93 	struct afu *afu;
94 	struct cxl_context *mcctx;
95 
96 	struct pci_dev *dev;
97 	struct pci_device_id *dev_id;
98 	struct Scsi_Host *host;
99 
100 	ulong cxlflash_regs_pci;
101 
102 	struct work_struct work_q;
103 	enum cxlflash_init_state init_state;
104 	enum cxlflash_lr_state lr_state;
105 	int lr_port;
106 	atomic_t scan_host_needed;
107 
108 	struct cxl_afu *cxl_afu;
109 	struct pci_dev *parent_dev;
110 
111 	atomic_t recovery_threads;
112 	struct mutex ctx_recovery_mutex;
113 	struct mutex ctx_tbl_list_mutex;
114 	struct rw_semaphore ioctl_rwsem;
115 	struct ctx_info *ctx_tbl[MAX_CONTEXT];
116 	struct list_head ctx_err_recovery; /* contexts w/ recovery pending */
117 	struct file_operations cxl_fops;
118 
119 	/* Parameters that are LUN table related */
120 	int last_lun_index[CXLFLASH_NUM_FC_PORTS];
121 	int promote_lun_index;
122 	struct list_head lluns; /* list of llun_info structs */
123 
124 	wait_queue_head_t tmf_waitq;
125 	spinlock_t tmf_slock;
126 	bool tmf_active;
127 	wait_queue_head_t reset_waitq;
128 	enum cxlflash_state state;
129 };
130 
131 struct afu_cmd {
132 	struct sisl_ioarcb rcb;	/* IOARCB (cache line aligned) */
133 	struct sisl_ioasa sa;	/* IOASA must follow IOARCB */
134 	spinlock_t slock;
135 	struct completion cevent;
136 	char *buf;		/* per command buffer */
137 	struct afu *parent;
138 	int slot;
139 	atomic_t free;
140 
141 	u8 cmd_tmf:1;
142 
143 	/* As per the SISLITE spec the IOARCB EA has to be 16-byte aligned.
144 	 * However for performance reasons the IOARCB/IOASA should be
145 	 * cache line aligned.
146 	 */
147 } __aligned(cache_line_size());
148 
149 struct afu {
150 	/* Stuff requiring alignment go first. */
151 
152 	u64 rrq_entry[NUM_RRQ_ENTRY];	/* 128B RRQ */
153 	/*
154 	 * Command & data for AFU commands.
155 	 */
156 	struct afu_cmd cmd[CXLFLASH_NUM_CMDS];
157 
158 	/* Beware of alignment till here. Preferably introduce new
159 	 * fields after this point
160 	 */
161 
162 	/* AFU HW */
163 	struct cxl_ioctl_start_work work;
164 	struct cxlflash_afu_map __iomem *afu_map;	/* entire MMIO map */
165 	struct sisl_host_map __iomem *host_map;		/* MC host map */
166 	struct sisl_ctrl_map __iomem *ctrl_map;		/* MC control map */
167 
168 	ctx_hndl_t ctx_hndl;	/* master's context handle */
169 	u64 *hrrq_start;
170 	u64 *hrrq_end;
171 	u64 *hrrq_curr;
172 	bool toggle;
173 	bool read_room;
174 	atomic64_t room;
175 	u64 hb;
176 	u32 cmd_couts;		/* Number of command checkouts */
177 	u32 internal_lun;	/* User-desired LUN mode for this AFU */
178 
179 	char version[16];
180 	u64 interface_version;
181 
182 	struct cxlflash_cfg *parent; /* Pointer back to parent cxlflash_cfg */
183 
184 };
185 
186 static inline u64 lun_to_lunid(u64 lun)
187 {
188 	__be64 lun_id;
189 
190 	int_to_scsilun(lun, (struct scsi_lun *)&lun_id);
191 	return be64_to_cpu(lun_id);
192 }
193 
194 int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
195 void cxlflash_list_init(void);
196 void cxlflash_term_global_luns(void);
197 void cxlflash_free_errpage(void);
198 int cxlflash_ioctl(struct scsi_device *, int, void __user *);
199 void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
200 int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
201 void cxlflash_term_local_luns(struct cxlflash_cfg *);
202 void cxlflash_restore_luntable(struct cxlflash_cfg *);
203 
204 #endif /* ifndef _CXLFLASH_COMMON_H */
205