linux/drivers/ide/ide-timings.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

199 lines
5.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 1999-2001 Vojtech Pavlik
* Copyright (c) 2007-2008 Bartlomiej Zolnierkiewicz
*
* Should you need to contact me, the author, you can do so either by
* e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
* Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
*/
#include <linux/kernel.h>
#include <linux/ide.h>
#include <linux/module.h>
/*
* PIO 0-5, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
* These were taken from ATA/ATAPI-6 standard, rev 0a, except
* for PIO 5, which is a nonstandard extension and UDMA6, which
* is currently supported only by Maxtor drives.
*/
static struct ide_timing ide_timing[] = {
{ XFER_UDMA_6, 0, 0, 0, 0, 0, 0, 0, 15 },
{ XFER_UDMA_5, 0, 0, 0, 0, 0, 0, 0, 20 },
{ XFER_UDMA_4, 0, 0, 0, 0, 0, 0, 0, 30 },
{ XFER_UDMA_3, 0, 0, 0, 0, 0, 0, 0, 45 },
{ XFER_UDMA_2, 0, 0, 0, 0, 0, 0, 0, 60 },
{ XFER_UDMA_1, 0, 0, 0, 0, 0, 0, 0, 80 },
{ XFER_UDMA_0, 0, 0, 0, 0, 0, 0, 0, 120 },
{ XFER_MW_DMA_4, 25, 0, 0, 0, 55, 20, 80, 0 },
{ XFER_MW_DMA_3, 25, 0, 0, 0, 65, 25, 100, 0 },
{ XFER_MW_DMA_2, 25, 0, 0, 0, 70, 25, 120, 0 },
{ XFER_MW_DMA_1, 45, 0, 0, 0, 80, 50, 150, 0 },
{ XFER_MW_DMA_0, 60, 0, 0, 0, 215, 215, 480, 0 },
{ XFER_SW_DMA_2, 60, 0, 0, 0, 120, 120, 240, 0 },
{ XFER_SW_DMA_1, 90, 0, 0, 0, 240, 240, 480, 0 },
{ XFER_SW_DMA_0, 120, 0, 0, 0, 480, 480, 960, 0 },
{ XFER_PIO_6, 10, 55, 20, 80, 55, 20, 80, 0 },
{ XFER_PIO_5, 15, 65, 25, 100, 65, 25, 100, 0 },
{ XFER_PIO_4, 25, 70, 25, 120, 70, 25, 120, 0 },
{ XFER_PIO_3, 30, 80, 70, 180, 80, 70, 180, 0 },
{ XFER_PIO_2, 30, 290, 40, 330, 100, 90, 240, 0 },
{ XFER_PIO_1, 50, 290, 93, 383, 125, 100, 383, 0 },
{ XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0 },
{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960, 0 },
{ 0xff }
};
struct ide_timing *ide_timing_find_mode(u8 speed)
{
struct ide_timing *t;
for (t = ide_timing; t->mode != speed; t++)
if (t->mode == 0xff)
return NULL;
return t;
}
EXPORT_SYMBOL_GPL(ide_timing_find_mode);
u16 ide_pio_cycle_time(ide_drive_t *drive, u8 pio)
{
u16 *id = drive->id;
struct ide_timing *t = ide_timing_find_mode(XFER_PIO_0 + pio);
u16 cycle = 0;
if (id[ATA_ID_FIELD_VALID] & 2) {
if (ata_id_has_iordy(drive->id))
cycle = id[ATA_ID_EIDE_PIO_IORDY];
else
cycle = id[ATA_ID_EIDE_PIO];
/* conservative "downgrade" for all pre-ATA2 drives */
if (pio < 3 && cycle < t->cycle)
cycle = 0; /* use standard timing */
/* Use the standard timing for the CF specific modes too */
if (pio > 4 && ata_id_is_cfa(id))
cycle = 0;
}
return cycle ? cycle : t->cycle;
}
EXPORT_SYMBOL_GPL(ide_pio_cycle_time);
#define ENOUGH(v, unit) (((v) - 1) / (unit) + 1)
#define EZ(v, unit) ((v) ? ENOUGH((v) * 1000, unit) : 0)
static void ide_timing_quantize(struct ide_timing *t, struct ide_timing *q,
int T, int UT)
{
q->setup = EZ(t->setup, T);
q->act8b = EZ(t->act8b, T);
q->rec8b = EZ(t->rec8b, T);
q->cyc8b = EZ(t->cyc8b, T);
q->active = EZ(t->active, T);
q->recover = EZ(t->recover, T);
q->cycle = EZ(t->cycle, T);
q->udma = EZ(t->udma, UT);
}
void ide_timing_merge(struct ide_timing *a, struct ide_timing *b,
struct ide_timing *m, unsigned int what)
{
if (what & IDE_TIMING_SETUP)
m->setup = max(a->setup, b->setup);
if (what & IDE_TIMING_ACT8B)
m->act8b = max(a->act8b, b->act8b);
if (what & IDE_TIMING_REC8B)
m->rec8b = max(a->rec8b, b->rec8b);
if (what & IDE_TIMING_CYC8B)
m->cyc8b = max(a->cyc8b, b->cyc8b);
if (what & IDE_TIMING_ACTIVE)
m->active = max(a->active, b->active);
if (what & IDE_TIMING_RECOVER)
m->recover = max(a->recover, b->recover);
if (what & IDE_TIMING_CYCLE)
m->cycle = max(a->cycle, b->cycle);
if (what & IDE_TIMING_UDMA)
m->udma = max(a->udma, b->udma);
}
EXPORT_SYMBOL_GPL(ide_timing_merge);
int ide_timing_compute(ide_drive_t *drive, u8 speed,
struct ide_timing *t, int T, int UT)
{
u16 *id = drive->id;
struct ide_timing *s, p;
/*
* Find the mode.
*/
s = ide_timing_find_mode(speed);
if (s == NULL)
return -EINVAL;
/*
* Copy the timing from the table.
*/
*t = *s;
/*
* If the drive is an EIDE drive, it can tell us it needs extended
* PIO/MWDMA cycle timing.
*/
if (id[ATA_ID_FIELD_VALID] & 2) { /* EIDE drive */
memset(&p, 0, sizeof(p));
if (speed >= XFER_PIO_0 && speed < XFER_SW_DMA_0) {
if (speed <= XFER_PIO_2)
p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO];
else if ((speed <= XFER_PIO_4) ||
(speed == XFER_PIO_5 && !ata_id_is_cfa(id)))
p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO_IORDY];
} else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2)
p.cycle = id[ATA_ID_EIDE_DMA_MIN];
ide_timing_merge(&p, t, t, IDE_TIMING_CYCLE | IDE_TIMING_CYC8B);
}
/*
* Convert the timing to bus clock counts.
*/
ide_timing_quantize(t, t, T, UT);
/*
* Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
* S.M.A.R.T and some other commands. We have to ensure that the
* DMA cycle timing is slower/equal than the current PIO timing.
*/
if (speed >= XFER_SW_DMA_0) {
ide_timing_compute(drive, drive->pio_mode, &p, T, UT);
ide_timing_merge(&p, t, t, IDE_TIMING_ALL);
}
/*
* Lengthen active & recovery time so that cycle time is correct.
*/
if (t->act8b + t->rec8b < t->cyc8b) {
t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
t->rec8b = t->cyc8b - t->act8b;
}
if (t->active + t->recover < t->cycle) {
t->active += (t->cycle - (t->active + t->recover)) / 2;
t->recover = t->cycle - t->active;
}
return 0;
}
EXPORT_SYMBOL_GPL(ide_timing_compute);