// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SATA specific part of ATA helper library
*
* Copyright 2003-2004 Red Hat, Inc. All rights reserved.
* Copyright 2003-2004 Jeff Garzik
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/libata.h>
#include "libata.h"
/**
* sata_scr_valid - test whether SCRs are accessible
* @link: ATA link to test SCR accessibility for
*
* Test whether SCRs are accessible for @link.
*
* LOCKING:
* None.
*
* RETURNS:
* 1 if SCRs are accessible, 0 otherwise.
*/
int sata_scr_valid(struct ata_link *link)
{
struct ata_port *ap = link->ap;
return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
}
EXPORT_SYMBOL_GPL(sata_scr_valid);
/**
* sata_scr_read - read SCR register of the specified port
* @link: ATA link to read SCR for
* @reg: SCR to read
* @val: Place to store read value
*
* Read SCR register @reg of @link into *@val. This function is
* guaranteed to succeed if @link is ap->link, the cable type of
* the port is SATA and the port implements ->scr_read.
*
* LOCKING:
* None if @link is ap->link. Kernel thread context otherwise.
*
* RETURNS:
* 0 on success, negative errno on failure.
*/
int sata_scr_read(struct ata_link *link, int reg, u32 *val)
{
if (ata_is_host_link(link)) {
if (sata_scr_valid(link))
return link->ap->ops->scr_read(link, reg, val);
return -EOPNOTSUPP;
}
return sata_pmp_scr_read(link, reg, val);
}
EXPORT_SYMBOL_GPL(sata_scr_read);
/**
* sata_scr_write - write SCR register of the specified port
* @link: ATA link to write SCR for
* @reg: SCR to write
* @val: value to write
*
* Write @val to SCR register @reg of @link. This function is
* guaranteed to succeed if @link is ap->link, the cable type of
* the port is SATA and the port implements ->scr_read.
*
* LOCKING:
* None if @link is ap->link. Kernel thread context otherwise.
*
* RETURNS:
* 0 on success, negative errno on failure.
*/
int sata_scr_write(struct ata_link *link, int reg, u32 val)
{
if (ata_is_host_link(link)) {
if (sata_scr_valid(link))
return link->ap->ops->scr_write(link, reg, val);
return -EOPNOTSUPP;
}
return sata_pmp_scr_write(link, reg, val);
}
EXPORT_SYMBOL_GPL(sata_scr_write);
/**
* sata_scr_write_flush - write SCR register of the specified port and flush
* @link: ATA link to write SCR for
* @reg: SCR to write
* @val: value to write
*
* This function is identical to sata_scr_write() except that this
* function performs flush after writing to the register.
*
* LOCKING:
* None if @link is ap->link. Kernel thread context otherwise.
*
* RETURNS:
* 0 on success, negative errno on failure.
*/
int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
{
if (ata_is_host_link(link)) {
int rc;
if (sata_scr_valid(link)) {
rc = link->ap->ops->scr_write(link, reg, val);
if (rc == 0)
rc = link->ap->ops->scr_read(link, reg, &val);
return rc;
}
return -EOPNOTSUPP;
}
return sata_pmp_scr_write(link, reg, val);
}
EXPORT_SYMBOL_GPL(sata_scr_write_flush);
/**
* ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
* @tf: Taskfile to convert
* @pmp: Port multiplier port
* @is_cmd: This FIS is for command
* @fis: Buffer into which data will output
*
* Converts a standard ATA taskfile to a Serial ATA
* FIS structure (Register - Host to Device).
*
* LOCKING:
* Inherited from caller.
*/
void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
{
fis[0] = 0x27; /* Register - Host to Device FIS */
fis[1] = pmp & 0xf; /* Port multiplier number*/
if (is_cmd)
fis[1] |= (1 << 7); /* bit 7 indicates Command FIS */
fis[2] = tf->command;
fis[3] = tf->feature;
fis[4] = tf->lbal;
fis[5] = tf->lbam;
fis[6] = tf->lbah;
fis[7] = tf->device;
fis[8] = tf->hob_lbal;
fis[9] = tf->hob_lbam;
fis[10] = tf->hob_lbah;
fis[11] = tf->hob_feature;
fis[12] = tf->nsect;
fis[13] = tf->hob_nsect;
fis[14] = 0;
fis[15] = tf->ctl;
fis[16] = tf->auxiliary & 0xff;
fis[17] = (tf->auxiliary >> 8) & 0xff;
fis[18] = (tf->auxiliary >> 16) & 0xff;
fis[19] = (tf->auxiliary >> 24) & 0xff;
}
EXPORT_SYMBOL_GPL(ata_tf_to_fis);
/**
* ata_tf_from_fis - Convert SATA FIS to ATA taskfile
* @fis: Buffer from which data will be input
* @tf: Taskfile to output
*
* Converts a serial ATA FIS structure to a standard ATA taskfile.
*
* LOCKING:
* Inherited from caller.
*/
void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
{
tf->command = fis[2]; /* status */
tf->feature = fis[3]; /* error */
tf->lbal = fis[4];
tf->lbam = fis[5];
tf->lbah = fis[6];
tf->device = fis[7];
tf->hob_lbal = fis[8];
tf->hob_lbam = fis[9];
tf->hob_lbah = fis[10];
tf->nsect = fis[12];
tf->hob_nsect = fis[13];
}
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
* @policy: LPM policy to configure
* @spm_wakeup: initiate LPM transition to active state
*
* Manipulate the IPM field of the SControl register of @link
* according to @policy. If @policy is ATA_LPM_MAX_POWER and
* @spm_wakeup is %true, the SPM field is manipulated to wake up
* the link. This function also clears PHYRDY_CHG before
* returning.
*
* LOCKING:
* EH context.
*
* RETURNS:
* 0 on success, -errno otherwise.
*/
int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
bool spm_wakeup)
{
struct ata_eh_context *ehc = &link->eh_context;
bool woken_up = false;
u32 scontrol;
int rc;
rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
if (rc)
return rc;
switch (policy) {
case ATA_LPM_MAX_POWER:
/* disable all LPM transitions */
scontrol |= (0x7 << 8);
/* initiate transition to active state */
if (spm_wakeup) {
scontrol |= (0x4 << 12);
woken_up = true;
}
break;
case ATA_LPM_MED_POWER:
/* allow LPM to PARTIAL */
scontrol &= ~(0x1 << 8);
scontrol |= (0x6 << 8);
break;
case ATA_LPM_MED_POWER_WITH_DIPM:
case ATA_LPM_MIN_POWER_WITH_PARTIAL:
case ATA_LPM_MIN_POWER:
if (ata_link_nr_enabled(link) > 0)
/* no restrictions on LPM transitions */
scontrol &= ~(0x7 << 8);
else {
/* empty port, power off */
scontrol &= ~0xf;
scontrol |= (0x1 << 2);
}
break;
default:
WARN_ON(1);
}
rc = sata_scr_write(link, SCR_CONTROL, scontrol);
if (rc)
return rc;
/* give the link time to transit out of LPM state */
if (woken_up)
msleep(10);
/* clear PHYRDY_CHG from SError */
ehc->i.serror &= ~SERR_PHYRDY_CHG;
return sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
}
EXPORT_SYMBOL_GPL(sata_link_scr_lpm);
static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
{
struct ata_link *host_link = &link->ap->link;
u32 limit, target, spd;
limit = link->sata_spd_limit;
/* Don't configure downstream link faster than upstream link.
* It doesn't speed up anything and some PMPs choke on such
* configuration.
*/
if (!ata_is_host_link(link) && host_link->sata_spd)
limit &= (1 << host_link->sata_spd) - 1;
if (limit == UINT_MAX)
target = 0;
else
target = fls(limit);
spd = (*scontrol >> 4) & 0xf;
*scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4);
return spd != target;
}
/**
* sata_set_spd_needed - is SATA spd configuration needed
* @link: Link in question
*
* Test whether the spd limit in SControl matches
* @link->sata_spd_limit. This function is used to determine
* whether hardreset is necessary to apply SATA spd
* configuration.
*
* LOCKING:
* Inherited from caller.
*
* RETURNS:
* 1 if SATA spd configuration is needed, 0 otherwise.
*/
int sata_set_spd_needed(struct ata_link *link)
{
u32 scontrol;
if (sata_scr_read(link, SCR_CONTROL, &scontrol))
return 1;
return __sata_set_spd_needed(link, &scontrol);
}
/**
* sata_set_spd - set SATA spd according to spd limit
* @link: Link to set SATA spd for
*
* Set SATA spd of @link according to sata_spd_limit.
*
* LOCKING:
* Inherited from caller.
*
* RETURNS:
* 0 if spd doesn't need to be changed, 1 if spd has been
* changed. Negative errno if SCR registers are inaccessible.
*/
int sata_set_spd(struct ata_link *link)
{
u32 scontrol;
int rc;
if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
return rc;
if (!__sata_set_spd_needed(link, &scontrol))
return 0;
if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
return rc;
return 1;
}
EXPORT_SYMBOL_GPL(sata_set_spd);
/**
* ata_slave_link_init - initialize slave link
* @ap: port to initialize slave link for
*
* Create and initialize slave link for @ap. This enables slave
* link handling on the port.
*
* In libata, a port contains links and a link contains devices.
* There is single host link but if a PMP is attached to it,
* there can be multiple fan-out links. On SATA, there's usually
* a single device connected to a link but PATA and SATA
* controllers emulating TF based interface can have two - master
* and slave.
*
* However, there are a few controllers which don't fit into this
* abstraction too well - SATA controllers which emulate TF
* interface with both master and slave devices but also have
* separate SCR register sets for each device. These controllers
* need separate links for physical link handling
* (e.g. onlineness, link speed) but should be treated like a
* traditional M/S controller for everything else (e.g. command
* issue, softreset).
*
* slave_link is libata's way of handling this class of
* controllers without impacting core layer too much. For
* anything other than physical link handling, the default host
* link is used for both master and slave. For physical link
* handling, separate @ap->slave_link is used. All dirty details
* are implemented inside libata core layer. From LLD's POV, the
* only difference is that prereset, hardreset and postreset are
* called once more for the slave link, so the reset sequence
* looks like the following.
*
* prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
* softreset(M) -> postreset(M) -> postreset(S)
*
* Note that softreset is called only for the master. Softreset
* resets both M/S by definition, so SRST on master should handle
* both (the standard method will work just fine).
*
* LOCKING:
* Should be called before host is registered.
*
* RETURNS:
* 0 on success, -errno on failure.
*/
int ata_slave_link_init(struct ata_port *ap)
{
struct ata_link *link;
WARN_ON(ap->slave_link);
WARN_ON(ap->flags & ATA_FLAG_PMP);
link = kzalloc(sizeof(*link), GFP_KERNEL);
if (!link)
return -ENOMEM;
ata_link_init(ap, link, 1);
ap->slave_link = link;
return 0;
}
EXPORT_SYMBOL_GPL(ata_slave_link_init);
/**
* sata_lpm_ignore_phy_events - test if PHY event should be ignored
* @link: Link receiving the event
*
* Test whether the received PHY event has to be ignored or not.
*
* LOCKING:
* None:
*
* RETURNS:
* True if the event has to be ignored.
*/
bool sata_lpm_ignore_phy_events(struct ata_link *link)
{
unsigned long lpm_timeout = link->last_lpm_change +
msecs_to_jiffies(ATA_TMOUT_SPURIOUS_PHY);
/* if LPM is enabled, PHYRDY doesn't mean anything */
if (link->lpm_policy > ATA_LPM_MAX_POWER)
return true;
/* ignore the first PHY event after the LPM policy changed
* as it is might be spurious
*/
if ((link->flags & ATA_LFLAG_CHANGED) &&
time_before(jiffies, lpm_timeout))
return true;
return false;
}
EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events);
