path: root/drivers/ata/libata-sata.c

// 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