linux/drivers/block/aoe/aoe.h
Tina Ruchandani 85cf955df8 aoe: use ktime_t instead of timeval
'struct frame' uses two variables to store the sent timestamp - 'struct
timeval' and jiffies. jiffies is used to avoid discrepancies caused by
updates to system time. 'struct timeval' is deprecated because it uses
32-bit representation for seconds which will overflow in year 2038.

This patch does the following:
- Replace the use of 'struct timeval' and jiffies with ktime_t, which
  is the recommended type for timestamping
- ktime_t provides both long range (like jiffies) and high resolution
  (like timeval). Using ktime_get (monotonic time) instead of wall-clock
  time prevents any discprepancies caused by updates to system time.

[updates by Arnd below]
The original patch from Tina never went anywhere as we discussed how
to keep the impact on performance minimal. I've started over now but
arrived at basically the same patch that she had originally, except for
an slightly improved tsince_hr() function. I'm making it more robust
against overflows, and also optimize explicitly for the common case
in which a frame is less than 4.2 seconds old, using only a 32-bit
division in that case.

This should make the new version more efficient than the old code,
since we replace the existing two 32-bit division in do_gettimeofday()
plus one multiplication with a single single 32-bit division in
tsince_hr() and drop the double bookkeeping. It's also more efficient
than the ktime_get_us() API we discussed before, since that would
also rely on multiple divisions.

Link: https://lists.linaro.org/pipermail/y2038/2015-May/000276.html
Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Cc: Ed Cashin <ed.cashin@acm.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-17 08:41:07 -07:00

240 lines
5.9 KiB
C

/* Copyright (c) 2013 Coraid, Inc. See COPYING for GPL terms. */
#define VERSION "85"
#define AOE_MAJOR 152
#define DEVICE_NAME "aoe"
/* set AOE_PARTITIONS to 1 to use whole-disks only
* default is 16, which is 15 partitions plus the whole disk
*/
#ifndef AOE_PARTITIONS
#define AOE_PARTITIONS (16)
#endif
#define WHITESPACE " \t\v\f\n,"
enum {
AOECMD_ATA,
AOECMD_CFG,
AOECMD_VEND_MIN = 0xf0,
AOEFL_RSP = (1<<3),
AOEFL_ERR = (1<<2),
AOEAFL_EXT = (1<<6),
AOEAFL_DEV = (1<<4),
AOEAFL_ASYNC = (1<<1),
AOEAFL_WRITE = (1<<0),
AOECCMD_READ = 0,
AOECCMD_TEST,
AOECCMD_PTEST,
AOECCMD_SET,
AOECCMD_FSET,
AOE_HVER = 0x10,
};
struct aoe_hdr {
unsigned char dst[6];
unsigned char src[6];
__be16 type;
unsigned char verfl;
unsigned char err;
__be16 major;
unsigned char minor;
unsigned char cmd;
__be32 tag;
};
struct aoe_atahdr {
unsigned char aflags;
unsigned char errfeat;
unsigned char scnt;
unsigned char cmdstat;
unsigned char lba0;
unsigned char lba1;
unsigned char lba2;
unsigned char lba3;
unsigned char lba4;
unsigned char lba5;
unsigned char res[2];
};
struct aoe_cfghdr {
__be16 bufcnt;
__be16 fwver;
unsigned char scnt;
unsigned char aoeccmd;
unsigned char cslen[2];
};
enum {
DEVFL_UP = 1, /* device is installed in system and ready for AoE->ATA commands */
DEVFL_TKILL = (1<<1), /* flag for timer to know when to kill self */
DEVFL_EXT = (1<<2), /* device accepts lba48 commands */
DEVFL_GDALLOC = (1<<3), /* need to alloc gendisk */
DEVFL_GD_NOW = (1<<4), /* allocating gendisk */
DEVFL_KICKME = (1<<5), /* slow polling network card catch */
DEVFL_NEWSIZE = (1<<6), /* need to update dev size in block layer */
DEVFL_FREEING = (1<<7), /* set when device is being cleaned up */
DEVFL_FREED = (1<<8), /* device has been cleaned up */
};
enum {
DEFAULTBCNT = 2 * 512, /* 2 sectors */
MIN_BUFS = 16,
NTARGETS = 4,
NAOEIFS = 8,
NSKBPOOLMAX = 256,
NFACTIVE = 61,
TIMERTICK = HZ / 10,
RTTSCALE = 8,
RTTDSCALE = 3,
RTTAVG_INIT = USEC_PER_SEC / 4 << RTTSCALE,
RTTDEV_INIT = RTTAVG_INIT / 4,
HARD_SCORN_SECS = 10, /* try another remote port after this */
MAX_TAINT = 1000, /* cap on aoetgt taint */
};
struct buf {
ulong nframesout;
struct bio *bio;
struct bvec_iter iter;
struct request *rq;
};
enum frame_flags {
FFL_PROBE = 1,
};
struct frame {
struct list_head head;
u32 tag;
ktime_t sent; /* high-res time packet was sent */
ulong waited;
ulong waited_total;
struct aoetgt *t; /* parent target I belong to */
struct sk_buff *skb; /* command skb freed on module exit */
struct sk_buff *r_skb; /* response skb for async processing */
struct buf *buf;
struct bvec_iter iter;
char flags;
};
struct aoeif {
struct net_device *nd;
ulong lost;
int bcnt;
};
struct aoetgt {
unsigned char addr[6];
ushort nframes; /* cap on frames to use */
struct aoedev *d; /* parent device I belong to */
struct list_head ffree; /* list of free frames */
struct aoeif ifs[NAOEIFS];
struct aoeif *ifp; /* current aoeif in use */
ushort nout; /* number of AoE commands outstanding */
ushort maxout; /* current value for max outstanding */
ushort next_cwnd; /* incr maxout after decrementing to zero */
ushort ssthresh; /* slow start threshold */
ulong falloc; /* number of allocated frames */
int taint; /* how much we want to avoid this aoetgt */
int minbcnt;
int wpkts, rpkts;
char nout_probes;
};
struct aoedev {
struct aoedev *next;
ulong sysminor;
ulong aoemajor;
u32 rttavg; /* scaled AoE round trip time average */
u32 rttdev; /* scaled round trip time mean deviation */
u16 aoeminor;
u16 flags;
u16 nopen; /* (bd_openers isn't available without sleeping) */
u16 fw_ver; /* version of blade's firmware */
u16 lasttag; /* last tag sent */
u16 useme;
ulong ref;
struct work_struct work;/* disk create work struct */
struct gendisk *gd;
struct dentry *debugfs;
struct request_queue *blkq;
struct hd_geometry geo;
sector_t ssize;
struct timer_list timer;
spinlock_t lock;
struct sk_buff_head skbpool;
mempool_t *bufpool; /* for deadlock-free Buf allocation */
struct { /* pointers to work in progress */
struct buf *buf;
struct bio *nxbio;
struct request *rq;
} ip;
ulong maxbcnt;
struct list_head factive[NFACTIVE]; /* hash of active frames */
struct list_head rexmitq; /* deferred retransmissions */
struct aoetgt **targets;
ulong ntargets; /* number of allocated aoetgt pointers */
struct aoetgt **tgt; /* target in use when working */
ulong kicked;
char ident[512];
};
/* kthread tracking */
struct ktstate {
struct completion rendez;
struct task_struct *task;
wait_queue_head_t *waitq;
int (*fn) (int);
char name[12];
spinlock_t *lock;
int id;
int active;
};
int aoeblk_init(void);
void aoeblk_exit(void);
void aoeblk_gdalloc(void *);
void aoedisk_rm_debugfs(struct aoedev *d);
void aoedisk_rm_sysfs(struct aoedev *d);
int aoechr_init(void);
void aoechr_exit(void);
void aoechr_error(char *);
void aoecmd_work(struct aoedev *d);
void aoecmd_cfg(ushort aoemajor, unsigned char aoeminor);
struct sk_buff *aoecmd_ata_rsp(struct sk_buff *);
void aoecmd_cfg_rsp(struct sk_buff *);
void aoecmd_sleepwork(struct work_struct *);
void aoecmd_wreset(struct aoetgt *t);
void aoecmd_cleanslate(struct aoedev *);
void aoecmd_exit(void);
int aoecmd_init(void);
struct sk_buff *aoecmd_ata_id(struct aoedev *);
void aoe_freetframe(struct frame *);
void aoe_flush_iocq(void);
void aoe_flush_iocq_by_index(int);
void aoe_end_request(struct aoedev *, struct request *, int);
int aoe_ktstart(struct ktstate *k);
void aoe_ktstop(struct ktstate *k);
int aoedev_init(void);
void aoedev_exit(void);
struct aoedev *aoedev_by_aoeaddr(ulong maj, int min, int do_alloc);
void aoedev_downdev(struct aoedev *d);
int aoedev_flush(const char __user *str, size_t size);
void aoe_failbuf(struct aoedev *, struct buf *);
void aoedev_put(struct aoedev *);
int aoenet_init(void);
void aoenet_exit(void);
void aoenet_xmit(struct sk_buff_head *);
int is_aoe_netif(struct net_device *ifp);
int set_aoe_iflist(const char __user *str, size_t size);