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ata: move sata_link_{debounce,resume}() to libata-sata.c
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* move sata_link_{debounce,resume}() to libata-sata.c

* add static inline for CONFIG_SATA_HOST=n case (only one,
  for sata_link_resume() is needed)

Code size savings on m68k arch using (modified) atari_defconfig:

   text    data     bss     dec     hex filename
before:
  32816     572      40   33428    8294 drivers/ata/libata-core.o
after:
  32724     572      40   33336    8238 drivers/ata/libata-core.o

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
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bzolnier authored and axboe committed Mar 26, 2020
1 parent ab4117c commit 9d3158f
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Showing 3 changed files with 148 additions and 142 deletions.
138 changes: 0 additions & 138 deletions drivers/ata/libata-core.c
Original file line number Diff line number Diff line change
Expand Up @@ -3485,144 +3485,6 @@ int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
}
EXPORT_SYMBOL_GPL(ata_wait_after_reset);

/**
* sata_link_debounce - debounce SATA phy status
* @link: ATA link to debounce SATA phy status for
* @params: timing parameters { interval, duration, timeout } in msec
* @deadline: deadline jiffies for the operation
*
* Make sure SStatus of @link reaches stable state, determined by
* holding the same value where DET is not 1 for @duration polled
* every @interval, before @timeout. Timeout constraints the
* beginning of the stable state. Because DET gets stuck at 1 on
* some controllers after hot unplugging, this functions waits
* until timeout then returns 0 if DET is stable at 1.
*
* @timeout is further limited by @deadline. The sooner of the
* two is used.
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int sata_link_debounce(struct ata_link *link, const unsigned long *params,
unsigned long deadline)
{
unsigned long interval = params[0];
unsigned long duration = params[1];
unsigned long last_jiffies, t;
u32 last, cur;
int rc;

t = ata_deadline(jiffies, params[2]);
if (time_before(t, deadline))
deadline = t;

if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
return rc;
cur &= 0xf;

last = cur;
last_jiffies = jiffies;

while (1) {
ata_msleep(link->ap, interval);
if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
return rc;
cur &= 0xf;

/* DET stable? */
if (cur == last) {
if (cur == 1 && time_before(jiffies, deadline))
continue;
if (time_after(jiffies,
ata_deadline(last_jiffies, duration)))
return 0;
continue;
}

/* unstable, start over */
last = cur;
last_jiffies = jiffies;

/* Check deadline. If debouncing failed, return
* -EPIPE to tell upper layer to lower link speed.
*/
if (time_after(jiffies, deadline))
return -EPIPE;
}
}
EXPORT_SYMBOL_GPL(sata_link_debounce);

/**
* sata_link_resume - resume SATA link
* @link: ATA link to resume SATA
* @params: timing parameters { interval, duration, timeout } in msec
* @deadline: deadline jiffies for the operation
*
* Resume SATA phy @link and debounce it.
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int sata_link_resume(struct ata_link *link, const unsigned long *params,
unsigned long deadline)
{
int tries = ATA_LINK_RESUME_TRIES;
u32 scontrol, serror;
int rc;

if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
return rc;

/*
* Writes to SControl sometimes get ignored under certain
* controllers (ata_piix SIDPR). Make sure DET actually is
* cleared.
*/
do {
scontrol = (scontrol & 0x0f0) | 0x300;
if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
return rc;
/*
* Some PHYs react badly if SStatus is pounded
* immediately after resuming. Delay 200ms before
* debouncing.
*/
if (!(link->flags & ATA_LFLAG_NO_DB_DELAY))
ata_msleep(link->ap, 200);

/* is SControl restored correctly? */
if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
return rc;
} while ((scontrol & 0xf0f) != 0x300 && --tries);

if ((scontrol & 0xf0f) != 0x300) {
ata_link_warn(link, "failed to resume link (SControl %X)\n",
scontrol);
return 0;
}

if (tries < ATA_LINK_RESUME_TRIES)
ata_link_warn(link, "link resume succeeded after %d retries\n",
ATA_LINK_RESUME_TRIES - tries);

if ((rc = sata_link_debounce(link, params, deadline)))
return rc;

/* clear SError, some PHYs require this even for SRST to work */
if (!(rc = sata_scr_read(link, SCR_ERROR, &serror)))
rc = sata_scr_write(link, SCR_ERROR, serror);

return rc != -EINVAL ? rc : 0;
}
EXPORT_SYMBOL_GPL(sata_link_resume);

/**
* ata_std_prereset - prepare for reset
* @link: ATA link to be reset
Expand Down
138 changes: 138 additions & 0 deletions drivers/ata/libata-sata.c
Original file line number Diff line number Diff line change
Expand Up @@ -196,6 +196,144 @@ void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
}
EXPORT_SYMBOL_GPL(ata_tf_from_fis);

/**
* sata_link_debounce - debounce SATA phy status
* @link: ATA link to debounce SATA phy status for
* @params: timing parameters { interval, duration, timeout } in msec
* @deadline: deadline jiffies for the operation
*
* Make sure SStatus of @link reaches stable state, determined by
* holding the same value where DET is not 1 for @duration polled
* every @interval, before @timeout. Timeout constraints the
* beginning of the stable state. Because DET gets stuck at 1 on
* some controllers after hot unplugging, this functions waits
* until timeout then returns 0 if DET is stable at 1.
*
* @timeout is further limited by @deadline. The sooner of the
* two is used.
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int sata_link_debounce(struct ata_link *link, const unsigned long *params,
unsigned long deadline)
{
unsigned long interval = params[0];
unsigned long duration = params[1];
unsigned long last_jiffies, t;
u32 last, cur;
int rc;

t = ata_deadline(jiffies, params[2]);
if (time_before(t, deadline))
deadline = t;

if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
return rc;
cur &= 0xf;

last = cur;
last_jiffies = jiffies;

while (1) {
ata_msleep(link->ap, interval);
if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
return rc;
cur &= 0xf;

/* DET stable? */
if (cur == last) {
if (cur == 1 && time_before(jiffies, deadline))
continue;
if (time_after(jiffies,
ata_deadline(last_jiffies, duration)))
return 0;
continue;
}

/* unstable, start over */
last = cur;
last_jiffies = jiffies;

/* Check deadline. If debouncing failed, return
* -EPIPE to tell upper layer to lower link speed.
*/
if (time_after(jiffies, deadline))
return -EPIPE;
}
}
EXPORT_SYMBOL_GPL(sata_link_debounce);

/**
* sata_link_resume - resume SATA link
* @link: ATA link to resume SATA
* @params: timing parameters { interval, duration, timeout } in msec
* @deadline: deadline jiffies for the operation
*
* Resume SATA phy @link and debounce it.
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int sata_link_resume(struct ata_link *link, const unsigned long *params,
unsigned long deadline)
{
int tries = ATA_LINK_RESUME_TRIES;
u32 scontrol, serror;
int rc;

if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
return rc;

/*
* Writes to SControl sometimes get ignored under certain
* controllers (ata_piix SIDPR). Make sure DET actually is
* cleared.
*/
do {
scontrol = (scontrol & 0x0f0) | 0x300;
if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
return rc;
/*
* Some PHYs react badly if SStatus is pounded
* immediately after resuming. Delay 200ms before
* debouncing.
*/
if (!(link->flags & ATA_LFLAG_NO_DB_DELAY))
ata_msleep(link->ap, 200);

/* is SControl restored correctly? */
if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
return rc;
} while ((scontrol & 0xf0f) != 0x300 && --tries);

if ((scontrol & 0xf0f) != 0x300) {
ata_link_warn(link, "failed to resume link (SControl %X)\n",
scontrol);
return 0;
}

if (tries < ATA_LINK_RESUME_TRIES)
ata_link_warn(link, "link resume succeeded after %d retries\n",
ATA_LINK_RESUME_TRIES - tries);

if ((rc = sata_link_debounce(link, params, deadline)))
return rc;

/* clear SError, some PHYs require this even for SRST to work */
if (!(rc = sata_scr_read(link, SCR_ERROR, &serror)))
rc = sata_scr_write(link, SCR_ERROR, serror);

return rc != -EINVAL ? rc : 0;
}
EXPORT_SYMBOL_GPL(sata_link_resume);

/**
* sata_link_scr_lpm - manipulate SControl IPM and SPM fields
* @link: ATA link to manipulate SControl for
Expand Down
14 changes: 10 additions & 4 deletions include/linux/libata.h
Original file line number Diff line number Diff line change
Expand Up @@ -1077,10 +1077,6 @@ static inline int ata_port_is_dummy(struct ata_port *ap)
extern int ata_std_prereset(struct ata_link *link, unsigned long deadline);
extern int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
int (*check_ready)(struct ata_link *link));
extern int sata_link_debounce(struct ata_link *link,
const unsigned long *params, unsigned long deadline);
extern int sata_link_resume(struct ata_link *link, const unsigned long *params,
unsigned long deadline);
extern int sata_link_hardreset(struct ata_link *link,
const unsigned long *timing, unsigned long deadline,
bool *online, int (*check_ready)(struct ata_link *));
Expand Down Expand Up @@ -1194,6 +1190,8 @@ extern int sata_scr_read(struct ata_link *link, int reg, u32 *val);
extern int sata_scr_write(struct ata_link *link, int reg, u32 val);
extern int sata_scr_write_flush(struct ata_link *link, int reg, u32 val);
extern int sata_set_spd(struct ata_link *link);
extern int sata_link_resume(struct ata_link *link, const unsigned long *params,
unsigned long deadline);
#else
static inline int sata_scr_valid(struct ata_link *link) { return 0; }
static inline int sata_scr_read(struct ata_link *link, int reg, u32 *val)
Expand All @@ -1209,7 +1207,15 @@ static inline int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
return -EOPNOTSUPP;
}
static inline int sata_set_spd(struct ata_link *link) { return -EOPNOTSUPP; }
static inline int sata_link_resume(struct ata_link *link,
const unsigned long *params,
unsigned long deadline)
{
return -EOPNOTSUPP;
}
#endif
extern int sata_link_debounce(struct ata_link *link,
const unsigned long *params, unsigned long deadline);
extern int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
bool spm_wakeup);
extern int ata_slave_link_init(struct ata_port *ap);
Expand Down

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