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
 25extern 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
 58static 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
 66enum cxlflash_lr_state {
 67	LINK_RESET_INVALID,
 68	LINK_RESET_REQUIRED,
 69	LINK_RESET_COMPLETE
 70};
 71
 72enum cxlflash_init_state {
 73	INIT_STATE_NONE,
 74	INIT_STATE_PCI,
 75	INIT_STATE_AFU,
 76	INIT_STATE_SCSI
 77};
 78
 79enum 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
 90struct 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
128struct 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
143static 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
148static 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
156struct 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
194static 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
202int cxlflash_afu_sync(struct afu *, ctx_hndl_t, res_hndl_t, u8);
203void cxlflash_list_init(void);
204void cxlflash_term_global_luns(void);
205void cxlflash_free_errpage(void);
206int cxlflash_ioctl(struct scsi_device *, int, void __user *);
207void cxlflash_stop_term_user_contexts(struct cxlflash_cfg *);
208int cxlflash_mark_contexts_error(struct cxlflash_cfg *);
209void cxlflash_term_local_luns(struct cxlflash_cfg *);
210void cxlflash_restore_luntable(struct cxlflash_cfg *);
211
212#endif /* ifndef _CXLFLASH_COMMON_H */