android_kernel_motorola_sm6225/drivers/ata/pata_acpi.c
Tejun Heo c7087652e1 libata-sff: clean up BMDMA initialization
When BMDMA initialization failed or BMDMA was not available for
whatever reason, bmdma_addr was left at zero and used as an indication
that BMDMA shouldn't be used.  This leads to the following problems.

p1. For BMDMA drivers which don't use traditional BMDMA register,
    ata_bmdma_mode_filter() incorrectly inhibits DMA modes.  Those
    drivers either have to inherit from ata_sff_port_ops or clear
    ->mode_filter explicitly.

p2. non-BMDMA drivers call into BMDMA PRD table allocation.  It
    doesn't actually allocate PRD table if bmdma_addr is not
    initialized but is still confusing.

p3. For BMDMA drivers which don't use traditional BMDMA register, some
    methods might not be invoked as expected (e.g. bmdma_stop from
    ata_sff_post_internal_cmd()).

p4. SFF drivers w/ custom DMA interface implement noop BMDMA ops
    worrying libata core might call into one of them.

These problems are caused by the muddy line between SFF and BMDMA and
the assumption that all BMDMA controllers initialize bmdma_addr.

This patch fixes p1 and p2 by removing the bmdma_addr assumption and
moving prd allocation to BMDMA port start.  Later patches will fix the
remaining issues.

This patch improves BMDMA initialization such that

* When BMDMA register initialization fails, falls back to PIO instead
  of failing.  ata_pci_bmdma_init() never fails now.

* When ata_pci_bmdma_init() falls back to PIO, it clears
  ap->mwdma_mask and udma_mask instead of depending on
  ata_bmdma_mode_filter().  This makes ata_bmdma_mode_filter()
  unnecessary thus resolving p1.

* ata_port_start() which actually is BMDMA specific is moved to
  ata_bmdma_port_start().  ata_port_start() and ata_sff_port_start()
  are killed.

* ata_sff_port_start32() is moved and renamed to
  ata_bmdma_port_start32().

Drivers which no longer call into PRD table allocation are...

  pdc_adma, sata_inic162x, sata_qstor, sata_sx4, pata_cmd640 and all
  drivers which inherit from ata_sff_port_ops.

pata_icside sets ->port_start to ATA_OP_NULL as it doesn't need PRD
but is a BMDMA controller and doesn't have custom port_start like
other such controllers.

Note that with the previous patch which makes all and only BMDMA
drivers inherit from ata_bmdma_port_ops, this change doesn't break
drivers which need PRD table.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2010-05-19 13:32:19 -04:00

300 lines
6.9 KiB
C

/*
* ACPI PATA driver
*
* (c) 2007 Red Hat
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gfp.h>
#include <scsi/scsi_host.h>
#include <acpi/acpi_bus.h>
#include <linux/libata.h>
#include <linux/ata.h>
#define DRV_NAME "pata_acpi"
#define DRV_VERSION "0.2.3"
struct pata_acpi {
struct ata_acpi_gtm gtm;
void *last;
unsigned long mask[2];
};
/**
* pacpi_pre_reset - check for 40/80 pin
* @ap: Port
* @deadline: deadline jiffies for the operation
*
* Perform the PATA port setup we need.
*/
static int pacpi_pre_reset(struct ata_link *link, unsigned long deadline)
{
struct ata_port *ap = link->ap;
struct pata_acpi *acpi = ap->private_data;
if (ap->acpi_handle == NULL || ata_acpi_gtm(ap, &acpi->gtm) < 0)
return -ENODEV;
return ata_sff_prereset(link, deadline);
}
/**
* pacpi_cable_detect - cable type detection
* @ap: port to detect
*
* Perform device specific cable detection
*/
static int pacpi_cable_detect(struct ata_port *ap)
{
struct pata_acpi *acpi = ap->private_data;
if ((acpi->mask[0] | acpi->mask[1]) & (0xF8 << ATA_SHIFT_UDMA))
return ATA_CBL_PATA80;
else
return ATA_CBL_PATA40;
}
/**
* pacpi_discover_modes - filter non ACPI modes
* @adev: ATA device
* @mask: proposed modes
*
* Try the modes available and see which ones the ACPI method will
* set up sensibly. From this we get a mask of ACPI modes we can use
*/
static unsigned long pacpi_discover_modes(struct ata_port *ap, struct ata_device *adev)
{
struct pata_acpi *acpi = ap->private_data;
struct ata_acpi_gtm probe;
unsigned int xfer_mask;
probe = acpi->gtm;
ata_acpi_gtm(ap, &probe);
xfer_mask = ata_acpi_gtm_xfermask(adev, &probe);
if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
ap->cbl = ATA_CBL_PATA80;
return xfer_mask;
}
/**
* pacpi_mode_filter - mode filter for ACPI
* @adev: device
* @mask: mask of valid modes
*
* Filter the valid mode list according to our own specific rules, in
* this case the list of discovered valid modes obtained by ACPI probing
*/
static unsigned long pacpi_mode_filter(struct ata_device *adev, unsigned long mask)
{
struct pata_acpi *acpi = adev->link->ap->private_data;
return mask & acpi->mask[adev->devno];
}
/**
* pacpi_set_piomode - set initial PIO mode data
* @ap: ATA interface
* @adev: ATA device
*/
static void pacpi_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
int unit = adev->devno;
struct pata_acpi *acpi = ap->private_data;
const struct ata_timing *t;
if (!(acpi->gtm.flags & 0x10))
unit = 0;
/* Now stuff the nS values into the structure */
t = ata_timing_find_mode(adev->pio_mode);
acpi->gtm.drive[unit].pio = t->cycle;
ata_acpi_stm(ap, &acpi->gtm);
/* See what mode we actually got */
ata_acpi_gtm(ap, &acpi->gtm);
}
/**
* pacpi_set_dmamode - set initial DMA mode data
* @ap: ATA interface
* @adev: ATA device
*/
static void pacpi_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
int unit = adev->devno;
struct pata_acpi *acpi = ap->private_data;
const struct ata_timing *t;
if (!(acpi->gtm.flags & 0x10))
unit = 0;
/* Now stuff the nS values into the structure */
t = ata_timing_find_mode(adev->dma_mode);
if (adev->dma_mode >= XFER_UDMA_0) {
acpi->gtm.drive[unit].dma = t->udma;
acpi->gtm.flags |= (1 << (2 * unit));
} else {
acpi->gtm.drive[unit].dma = t->cycle;
acpi->gtm.flags &= ~(1 << (2 * unit));
}
ata_acpi_stm(ap, &acpi->gtm);
/* See what mode we actually got */
ata_acpi_gtm(ap, &acpi->gtm);
}
/**
* pacpi_qc_issue - command issue
* @qc: command pending
*
* Called when the libata layer is about to issue a command. We wrap
* this interface so that we can load the correct ATA timings if
* necessary.
*/
static unsigned int pacpi_qc_issue(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
struct ata_device *adev = qc->dev;
struct pata_acpi *acpi = ap->private_data;
if (acpi->gtm.flags & 0x10)
return ata_sff_qc_issue(qc);
if (adev != acpi->last) {
pacpi_set_piomode(ap, adev);
if (ata_dma_enabled(adev))
pacpi_set_dmamode(ap, adev);
acpi->last = adev;
}
return ata_sff_qc_issue(qc);
}
/**
* pacpi_port_start - port setup
* @ap: ATA port being set up
*
* Use the port_start hook to maintain private control structures
*/
static int pacpi_port_start(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
struct pata_acpi *acpi;
int ret;
if (ap->acpi_handle == NULL)
return -ENODEV;
acpi = ap->private_data = devm_kzalloc(&pdev->dev, sizeof(struct pata_acpi), GFP_KERNEL);
if (ap->private_data == NULL)
return -ENOMEM;
acpi->mask[0] = pacpi_discover_modes(ap, &ap->link.device[0]);
acpi->mask[1] = pacpi_discover_modes(ap, &ap->link.device[1]);
ret = ata_bmdma_port_start(ap);
if (ret < 0)
return ret;
return ret;
}
static struct scsi_host_template pacpi_sht = {
ATA_BMDMA_SHT(DRV_NAME),
};
static struct ata_port_operations pacpi_ops = {
.inherits = &ata_bmdma_port_ops,
.qc_issue = pacpi_qc_issue,
.cable_detect = pacpi_cable_detect,
.mode_filter = pacpi_mode_filter,
.set_piomode = pacpi_set_piomode,
.set_dmamode = pacpi_set_dmamode,
.prereset = pacpi_pre_reset,
.port_start = pacpi_port_start,
};
/**
* pacpi_init_one - Register ACPI ATA PCI device with kernel services
* @pdev: PCI device to register
* @ent: Entry in pacpi_pci_tbl matching with @pdev
*
* Called from kernel PCI layer.
*
* LOCKING:
* Inherited from PCI layer (may sleep).
*
* RETURNS:
* Zero on success, or -ERRNO value.
*/
static int pacpi_init_one (struct pci_dev *pdev, const struct pci_device_id *id)
{
static const struct ata_port_info info = {
.flags = ATA_FLAG_SLAVE_POSS | ATA_FLAG_SRST,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.udma_mask = ATA_UDMA6,
.port_ops = &pacpi_ops,
};
const struct ata_port_info *ppi[] = { &info, NULL };
if (pdev->vendor == PCI_VENDOR_ID_ATI) {
int rc = pcim_enable_device(pdev);
if (rc < 0)
return rc;
pcim_pin_device(pdev);
}
return ata_pci_sff_init_one(pdev, ppi, &pacpi_sht, NULL, 0);
}
static const struct pci_device_id pacpi_pci_tbl[] = {
{ PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_CLASS_STORAGE_IDE << 8, 0xFFFFFF00UL, 1},
{ } /* terminate list */
};
static struct pci_driver pacpi_pci_driver = {
.name = DRV_NAME,
.id_table = pacpi_pci_tbl,
.probe = pacpi_init_one,
.remove = ata_pci_remove_one,
#ifdef CONFIG_PM
.suspend = ata_pci_device_suspend,
.resume = ata_pci_device_resume,
#endif
};
static int __init pacpi_init(void)
{
return pci_register_driver(&pacpi_pci_driver);
}
static void __exit pacpi_exit(void)
{
pci_unregister_driver(&pacpi_pci_driver);
}
module_init(pacpi_init);
module_exit(pacpi_exit);
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("SCSI low-level driver for ATA in ACPI mode");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, pacpi_pci_tbl);
MODULE_VERSION(DRV_VERSION);