ata: separate PATA timings code from libata-core.c

Separate PATA timings code from libata-core.c:

* add PATA_TIMINGS config option and make corresponding PATA
  host drivers (and ATA ACPI code) select it

* move following PATA timings code to libata-pata-timings.c:
  - ata_timing_quantize()
  - ata_timing_merge()
  - ata_timing_find_mode()
  - ata_timing_compute()

* group above functions together in <linux/libata.h>

* include libata-pata-timings.c in the build when PATA_TIMINGS
  config option is enabled

* cover ata_timing_cycle2mode() with CONFIG_ATA_ACPI ifdef (it
  depends on code from libata-core.c and libata-pata-timings.c
  while its only user is ATA ACPI)

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

   text    data     bss     dec     hex filename
before:
  39688     573      40   40301    9d6d drivers/ata/libata-core.o
after:
  37820     572      40   38432    9620 drivers/ata/libata-core.o

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Bartlomiej Zolnierkiewicz 2020-03-26 16:58:07 +01:00 committed by Jens Axboe
parent 4e16818704
commit a9b2c120e3
5 changed files with 226 additions and 187 deletions

View File

@ -37,6 +37,9 @@ config ATA_NONSTANDARD
config SATA_HOST
bool
config PATA_TIMINGS
bool
config ATA_VERBOSE_ERROR
bool "Verbose ATA error reporting"
default y
@ -51,6 +54,7 @@ config ATA_VERBOSE_ERROR
config ATA_ACPI
bool "ATA ACPI Support"
depends on ACPI
select PATA_TIMINGS
default y
help
This option adds support for ATA-related ACPI objects.
@ -341,6 +345,7 @@ config PDC_ADMA
config PATA_OCTEON_CF
tristate "OCTEON Boot Bus Compact Flash support"
depends on CAVIUM_OCTEON_SOC
select PATA_TIMINGS
help
This option enables a polled compact flash driver for use with
compact flash cards attached to the OCTEON boot bus.
@ -536,6 +541,7 @@ comment "PATA SFF controllers with BMDMA"
config PATA_ALI
tristate "ALi PATA support"
depends on PCI
select PATA_TIMINGS
help
This option enables support for the ALi ATA interfaces
found on the many ALi chipsets.
@ -545,6 +551,7 @@ config PATA_ALI
config PATA_AMD
tristate "AMD/NVidia PATA support"
depends on PCI
select PATA_TIMINGS
help
This option enables support for the AMD and NVidia PATA
interfaces found on the chipsets for Athlon/Athlon64.
@ -579,6 +586,7 @@ config PATA_ATIIXP
config PATA_ATP867X
tristate "ARTOP/Acard ATP867X PATA support"
depends on PCI
select PATA_TIMINGS
help
This option enables support for ARTOP/Acard ATP867X PATA
controllers.
@ -588,6 +596,7 @@ config PATA_ATP867X
config PATA_BK3710
tristate "Palmchip BK3710 PATA support"
depends on ARCH_DAVINCI
select PATA_TIMINGS
help
This option enables support for the integrated IDE controller on
the TI DaVinci SoC.
@ -597,6 +606,7 @@ config PATA_BK3710
config PATA_CMD64X
tristate "CMD64x PATA support"
depends on PCI
select PATA_TIMINGS
help
This option enables support for the CMD64x series chips
except for the CMD640.
@ -642,6 +652,7 @@ config PATA_CS5536
config PATA_CYPRESS
tristate "Cypress CY82C693 PATA support (Very Experimental)"
depends on PCI
select PATA_TIMINGS
help
This option enables support for the Cypress/Contaq CY82C693
chipset found in some Alpha systems
@ -660,6 +671,7 @@ config PATA_EFAR
config PATA_EP93XX
tristate "Cirrus Logic EP93xx PATA support"
depends on ARCH_EP93XX
select PATA_TIMINGS
help
This option enables support for the PATA controller in
the Cirrus Logic EP9312 and EP9315 ARM CPU.
@ -724,6 +736,7 @@ config PATA_HPT3X3_DMA
config PATA_ICSIDE
tristate "Acorn ICS PATA support"
depends on ARM && ARCH_ACORN
select PATA_TIMINGS
help
On Acorn systems, say Y here if you wish to use the ICS PATA
interface card. This is not required for ICS partition support.
@ -732,6 +745,7 @@ config PATA_ICSIDE
config PATA_IMX
tristate "PATA support for Freescale iMX"
depends on ARCH_MXC
select PATA_TIMINGS
help
This option enables support for the PATA host available on Freescale
iMX SoCs.
@ -817,6 +831,7 @@ config PATA_NINJA32
config PATA_NS87415
tristate "Nat Semi NS87415 PATA support"
depends on PCI
select PATA_TIMINGS
help
This option enables support for the National Semiconductor
NS87415 PCI-IDE controller.
@ -941,6 +956,7 @@ config PATA_TRIFLEX
config PATA_VIA
tristate "VIA PATA support"
depends on PCI
select PATA_TIMINGS
help
This option enables support for the VIA PATA interfaces
found on the many VIA chipsets.
@ -974,6 +990,7 @@ comment "PIO-only SFF controllers"
config PATA_CMD640_PCI
tristate "CMD640 PCI PATA support (Experimental)"
depends on PCI
select PATA_TIMINGS
help
This option enables support for the CMD640 PCI IDE
interface chip. Only the primary channel is currently
@ -1044,6 +1061,7 @@ config PATA_MPIIX
config PATA_NS87410
tristate "Nat Semi NS87410 PATA support"
depends on PCI
select PATA_TIMINGS
help
This option enables support for the National Semiconductor
NS87410 PCI-IDE controller.
@ -1124,6 +1142,7 @@ config PATA_RZ1000
config PATA_SAMSUNG_CF
tristate "Samsung SoC PATA support"
depends on SAMSUNG_DEV_IDE
select PATA_TIMINGS
help
This option enables basic support for Samsung's S3C/S5P board
PATA controllers via the new ATA layer
@ -1143,6 +1162,7 @@ comment "Generic fallback / legacy drivers"
config PATA_ACPI
tristate "ACPI firmware driver for PATA"
depends on ATA_ACPI && ATA_BMDMA && PCI
select PATA_TIMINGS
help
This option enables an ACPI method driver which drives
motherboard PATA controller interfaces through the ACPI
@ -1162,6 +1182,7 @@ config ATA_GENERIC
config PATA_LEGACY
tristate "Legacy ISA PATA support (Experimental)"
depends on (ISA || PCI)
select PATA_TIMINGS
help
This option enables support for ISA/VLB/PCI bus legacy PATA
ports and allows them to be accessed via the new ATA layer.

View File

@ -127,3 +127,4 @@ libata-$(CONFIG_ATA_SFF) += libata-sff.o
libata-$(CONFIG_SATA_PMP) += libata-pmp.o
libata-$(CONFIG_ATA_ACPI) += libata-acpi.o
libata-$(CONFIG_SATA_ZPODD) += libata-zpodd.o
libata-$(CONFIG_PATA_TIMINGS) += libata-pata-timings.o

View File

@ -3204,187 +3204,7 @@ int sata_set_spd(struct ata_link *link)
}
EXPORT_SYMBOL_GPL(sata_set_spd);
/*
* This mode timing computation functionality is ported over from
* drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
*/
/*
* PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
* These were taken from ATA/ATAPI-6 standard, rev 0a, except
* for UDMA6, which is currently supported only by Maxtor drives.
*
* For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
*/
static const struct ata_timing ata_timing[] = {
/* { XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 0, 960, 0 }, */
{ XFER_PIO_0, 70, 290, 240, 600, 165, 150, 0, 600, 0 },
{ XFER_PIO_1, 50, 290, 93, 383, 125, 100, 0, 383, 0 },
{ XFER_PIO_2, 30, 290, 40, 330, 100, 90, 0, 240, 0 },
{ XFER_PIO_3, 30, 80, 70, 180, 80, 70, 0, 180, 0 },
{ XFER_PIO_4, 25, 70, 25, 120, 70, 25, 0, 120, 0 },
{ XFER_PIO_5, 15, 65, 25, 100, 65, 25, 0, 100, 0 },
{ XFER_PIO_6, 10, 55, 20, 80, 55, 20, 0, 80, 0 },
{ XFER_SW_DMA_0, 120, 0, 0, 0, 480, 480, 50, 960, 0 },
{ XFER_SW_DMA_1, 90, 0, 0, 0, 240, 240, 30, 480, 0 },
{ XFER_SW_DMA_2, 60, 0, 0, 0, 120, 120, 20, 240, 0 },
{ XFER_MW_DMA_0, 60, 0, 0, 0, 215, 215, 20, 480, 0 },
{ XFER_MW_DMA_1, 45, 0, 0, 0, 80, 50, 5, 150, 0 },
{ XFER_MW_DMA_2, 25, 0, 0, 0, 70, 25, 5, 120, 0 },
{ XFER_MW_DMA_3, 25, 0, 0, 0, 65, 25, 5, 100, 0 },
{ XFER_MW_DMA_4, 25, 0, 0, 0, 55, 20, 5, 80, 0 },
/* { XFER_UDMA_SLOW, 0, 0, 0, 0, 0, 0, 0, 0, 150 }, */
{ XFER_UDMA_0, 0, 0, 0, 0, 0, 0, 0, 0, 120 },
{ XFER_UDMA_1, 0, 0, 0, 0, 0, 0, 0, 0, 80 },
{ XFER_UDMA_2, 0, 0, 0, 0, 0, 0, 0, 0, 60 },
{ XFER_UDMA_3, 0, 0, 0, 0, 0, 0, 0, 0, 45 },
{ XFER_UDMA_4, 0, 0, 0, 0, 0, 0, 0, 0, 30 },
{ XFER_UDMA_5, 0, 0, 0, 0, 0, 0, 0, 0, 20 },
{ XFER_UDMA_6, 0, 0, 0, 0, 0, 0, 0, 0, 15 },
{ 0xFF }
};
#define ENOUGH(v, unit) (((v)-1)/(unit)+1)
#define EZ(v, unit) ((v)?ENOUGH(((v) * 1000), unit):0)
static void ata_timing_quantize(const struct ata_timing *t,
struct ata_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->dmack_hold = EZ(t->dmack_hold, T);
q->cycle = EZ(t->cycle, T);
q->udma = EZ(t->udma, UT);
}
void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
struct ata_timing *m, unsigned int what)
{
if (what & ATA_TIMING_SETUP)
m->setup = max(a->setup, b->setup);
if (what & ATA_TIMING_ACT8B)
m->act8b = max(a->act8b, b->act8b);
if (what & ATA_TIMING_REC8B)
m->rec8b = max(a->rec8b, b->rec8b);
if (what & ATA_TIMING_CYC8B)
m->cyc8b = max(a->cyc8b, b->cyc8b);
if (what & ATA_TIMING_ACTIVE)
m->active = max(a->active, b->active);
if (what & ATA_TIMING_RECOVER)
m->recover = max(a->recover, b->recover);
if (what & ATA_TIMING_DMACK_HOLD)
m->dmack_hold = max(a->dmack_hold, b->dmack_hold);
if (what & ATA_TIMING_CYCLE)
m->cycle = max(a->cycle, b->cycle);
if (what & ATA_TIMING_UDMA)
m->udma = max(a->udma, b->udma);
}
EXPORT_SYMBOL_GPL(ata_timing_merge);
const struct ata_timing *ata_timing_find_mode(u8 xfer_mode)
{
const struct ata_timing *t = ata_timing;
while (xfer_mode > t->mode)
t++;
if (xfer_mode == t->mode)
return t;
WARN_ONCE(true, "%s: unable to find timing for xfer_mode 0x%x\n",
__func__, xfer_mode);
return NULL;
}
EXPORT_SYMBOL_GPL(ata_timing_find_mode);
int ata_timing_compute(struct ata_device *adev, unsigned short speed,
struct ata_timing *t, int T, int UT)
{
const u16 *id = adev->id;
const struct ata_timing *s;
struct ata_timing p;
/*
* Find the mode.
*/
s = ata_timing_find_mode(speed);
if (!s)
return -EINVAL;
memcpy(t, s, sizeof(*s));
/*
* If the drive is an EIDE drive, it can tell us it needs extended
* PIO/MW_DMA 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];
ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
}
/*
* Convert the timing to bus clock counts.
*/
ata_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 fastest PIO timing.
*/
if (speed > XFER_PIO_6) {
ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
ata_timing_merge(&p, t, t, ATA_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;
}
/*
* In a few cases quantisation may produce enough errors to
* leave t->cycle too low for the sum of active and recovery
* if so we must correct this.
*/
if (t->active + t->recover > t->cycle)
t->cycle = t->active + t->recover;
return 0;
}
EXPORT_SYMBOL_GPL(ata_timing_compute);
#ifdef CONFIG_ATA_ACPI
/**
* ata_timing_cycle2mode - find xfer mode for the specified cycle duration
* @xfer_shift: ATA_SHIFT_* value for transfer type to examine.
@ -3435,6 +3255,7 @@ u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle)
return last_mode;
}
#endif
/**
* ata_down_xfermask_limit - adjust dev xfer masks downward

View File

@ -0,0 +1,192 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Helper library for PATA timings
*
* 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>
/*
* This mode timing computation functionality is ported over from
* drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
*/
/*
* PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
* These were taken from ATA/ATAPI-6 standard, rev 0a, except
* for UDMA6, which is currently supported only by Maxtor drives.
*
* For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
*/
static const struct ata_timing ata_timing[] = {
/* { XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 0, 960, 0 }, */
{ XFER_PIO_0, 70, 290, 240, 600, 165, 150, 0, 600, 0 },
{ XFER_PIO_1, 50, 290, 93, 383, 125, 100, 0, 383, 0 },
{ XFER_PIO_2, 30, 290, 40, 330, 100, 90, 0, 240, 0 },
{ XFER_PIO_3, 30, 80, 70, 180, 80, 70, 0, 180, 0 },
{ XFER_PIO_4, 25, 70, 25, 120, 70, 25, 0, 120, 0 },
{ XFER_PIO_5, 15, 65, 25, 100, 65, 25, 0, 100, 0 },
{ XFER_PIO_6, 10, 55, 20, 80, 55, 20, 0, 80, 0 },
{ XFER_SW_DMA_0, 120, 0, 0, 0, 480, 480, 50, 960, 0 },
{ XFER_SW_DMA_1, 90, 0, 0, 0, 240, 240, 30, 480, 0 },
{ XFER_SW_DMA_2, 60, 0, 0, 0, 120, 120, 20, 240, 0 },
{ XFER_MW_DMA_0, 60, 0, 0, 0, 215, 215, 20, 480, 0 },
{ XFER_MW_DMA_1, 45, 0, 0, 0, 80, 50, 5, 150, 0 },
{ XFER_MW_DMA_2, 25, 0, 0, 0, 70, 25, 5, 120, 0 },
{ XFER_MW_DMA_3, 25, 0, 0, 0, 65, 25, 5, 100, 0 },
{ XFER_MW_DMA_4, 25, 0, 0, 0, 55, 20, 5, 80, 0 },
/* { XFER_UDMA_SLOW, 0, 0, 0, 0, 0, 0, 0, 0, 150 }, */
{ XFER_UDMA_0, 0, 0, 0, 0, 0, 0, 0, 0, 120 },
{ XFER_UDMA_1, 0, 0, 0, 0, 0, 0, 0, 0, 80 },
{ XFER_UDMA_2, 0, 0, 0, 0, 0, 0, 0, 0, 60 },
{ XFER_UDMA_3, 0, 0, 0, 0, 0, 0, 0, 0, 45 },
{ XFER_UDMA_4, 0, 0, 0, 0, 0, 0, 0, 0, 30 },
{ XFER_UDMA_5, 0, 0, 0, 0, 0, 0, 0, 0, 20 },
{ XFER_UDMA_6, 0, 0, 0, 0, 0, 0, 0, 0, 15 },
{ 0xFF }
};
#define ENOUGH(v, unit) (((v)-1)/(unit)+1)
#define EZ(v, unit) ((v)?ENOUGH(((v) * 1000), unit):0)
static void ata_timing_quantize(const struct ata_timing *t,
struct ata_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->dmack_hold = EZ(t->dmack_hold, T);
q->cycle = EZ(t->cycle, T);
q->udma = EZ(t->udma, UT);
}
void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
struct ata_timing *m, unsigned int what)
{
if (what & ATA_TIMING_SETUP)
m->setup = max(a->setup, b->setup);
if (what & ATA_TIMING_ACT8B)
m->act8b = max(a->act8b, b->act8b);
if (what & ATA_TIMING_REC8B)
m->rec8b = max(a->rec8b, b->rec8b);
if (what & ATA_TIMING_CYC8B)
m->cyc8b = max(a->cyc8b, b->cyc8b);
if (what & ATA_TIMING_ACTIVE)
m->active = max(a->active, b->active);
if (what & ATA_TIMING_RECOVER)
m->recover = max(a->recover, b->recover);
if (what & ATA_TIMING_DMACK_HOLD)
m->dmack_hold = max(a->dmack_hold, b->dmack_hold);
if (what & ATA_TIMING_CYCLE)
m->cycle = max(a->cycle, b->cycle);
if (what & ATA_TIMING_UDMA)
m->udma = max(a->udma, b->udma);
}
EXPORT_SYMBOL_GPL(ata_timing_merge);
const struct ata_timing *ata_timing_find_mode(u8 xfer_mode)
{
const struct ata_timing *t = ata_timing;
while (xfer_mode > t->mode)
t++;
if (xfer_mode == t->mode)
return t;
WARN_ONCE(true, "%s: unable to find timing for xfer_mode 0x%x\n",
__func__, xfer_mode);
return NULL;
}
EXPORT_SYMBOL_GPL(ata_timing_find_mode);
int ata_timing_compute(struct ata_device *adev, unsigned short speed,
struct ata_timing *t, int T, int UT)
{
const u16 *id = adev->id;
const struct ata_timing *s;
struct ata_timing p;
/*
* Find the mode.
*/
s = ata_timing_find_mode(speed);
if (!s)
return -EINVAL;
memcpy(t, s, sizeof(*s));
/*
* If the drive is an EIDE drive, it can tell us it needs extended
* PIO/MW_DMA 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];
ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
}
/*
* Convert the timing to bus clock counts.
*/
ata_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 fastest PIO timing.
*/
if (speed > XFER_PIO_6) {
ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
ata_timing_merge(&p, t, t, ATA_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;
}
/*
* In a few cases quantisation may produce enough errors to
* leave t->cycle too low for the sum of active and recovery
* if so we must correct this.
*/
if (t->active + t->recover > t->cycle)
t->cycle = t->active + t->recover;
return 0;
}
EXPORT_SYMBOL_GPL(ata_timing_compute);

View File

@ -1205,12 +1205,6 @@ extern int ata_cable_unknown(struct ata_port *ap);
/* Timing helpers */
extern unsigned int ata_pio_need_iordy(const struct ata_device *);
extern const struct ata_timing *ata_timing_find_mode(u8 xfer_mode);
extern int ata_timing_compute(struct ata_device *, unsigned short,
struct ata_timing *, int, int);
extern void ata_timing_merge(const struct ata_timing *,
const struct ata_timing *, struct ata_timing *,
unsigned int);
extern u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle);
/* PCI */
@ -1807,6 +1801,16 @@ static inline int ata_dma_enabled(struct ata_device *adev)
return (adev->dma_mode == 0xFF ? 0 : 1);
}
/**************************************************************************
* PATA timings - drivers/ata/libata-pata-timings.c
*/
extern const struct ata_timing *ata_timing_find_mode(u8 xfer_mode);
extern int ata_timing_compute(struct ata_device *, unsigned short,
struct ata_timing *, int, int);
extern void ata_timing_merge(const struct ata_timing *,
const struct ata_timing *, struct ata_timing *,
unsigned int);
/**************************************************************************
* PMP - drivers/ata/libata-pmp.c
*/