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libata-acpi: implement _GTF command filtering
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Implement _GTF command filtering which can be controlled by
libata.acpi_filter kernel parameter.  Currently SETXFER and LOCK
commands are filtered.

libata configures transfer mode by itself and _GTF SETXFER commands
can potentially disrupt device configuration.  _GTM/_STM mechanism
can't handle hotplugging too well and when _GTF is executed,
controller is in PIO0 rather than the mode _STM configured.

Note that detecting SET MAX LOCK requires looking at the previous
command.  This adds a bit to code complexity.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
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Tejun Heo authored and Jeff Garzik committed Dec 18, 2007
1 parent 0e8634b commit 3264a8d
Showing 1 changed file with 115 additions and 44 deletions.
159 changes: 115 additions & 44 deletions drivers/ata/libata-acpi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
* Copyright (C) 2006 Randy Dunlap
*/

#include <linux/module.h>
#include <linux/ata.h>
#include <linux/delay.h>
#include <linux/device.h>
Expand All @@ -25,6 +26,18 @@
#include <acpi/acmacros.h>
#include <acpi/actypes.h>

enum {
ATA_ACPI_FILTER_SETXFER = 1 << 0,
ATA_ACPI_FILTER_LOCK = 1 << 1,

ATA_ACPI_FILTER_DEFAULT = ATA_ACPI_FILTER_SETXFER |
ATA_ACPI_FILTER_LOCK,
};

static unsigned int ata_acpi_gtf_filter = ATA_ACPI_FILTER_DEFAULT;
module_param_named(acpi_gtf_filter, ata_acpi_gtf_filter, int, 0644);
MODULE_PARM_DESC(acpi_gtf_filter, "filter mask for ACPI _GTF commands, set to filter out (0x1=set xfermode, 0x2=lock/freeze lock)");

#define NO_PORT_MULT 0xffff
#define SATA_ADR(root, pmp) (((root) << 16) | (pmp))

Expand Down Expand Up @@ -465,6 +478,60 @@ int ata_acpi_cbl_80wire(struct ata_port *ap)

EXPORT_SYMBOL_GPL(ata_acpi_cbl_80wire);

static void ata_acpi_gtf_to_tf(struct ata_device *dev,
const struct ata_acpi_gtf *gtf,
struct ata_taskfile *tf)
{
ata_tf_init(dev, tf);

tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
tf->protocol = ATA_PROT_NODATA;
tf->feature = gtf->tf[0]; /* 0x1f1 */
tf->nsect = gtf->tf[1]; /* 0x1f2 */
tf->lbal = gtf->tf[2]; /* 0x1f3 */
tf->lbam = gtf->tf[3]; /* 0x1f4 */
tf->lbah = gtf->tf[4]; /* 0x1f5 */
tf->device = gtf->tf[5]; /* 0x1f6 */
tf->command = gtf->tf[6]; /* 0x1f7 */
}

static int ata_acpi_filter_tf(const struct ata_taskfile *tf,
const struct ata_taskfile *ptf)
{
if (ata_acpi_gtf_filter & ATA_ACPI_FILTER_SETXFER) {
/* libata doesn't use ACPI to configure transfer mode.
* It will only confuse device configuration. Skip.
*/
if (tf->command == ATA_CMD_SET_FEATURES &&
tf->feature == SETFEATURES_XFER)
return 1;
}

if (ata_acpi_gtf_filter & ATA_ACPI_FILTER_LOCK) {
/* BIOS writers, sorry but we don't wanna lock
* features unless the user explicitly said so.
*/

/* DEVICE CONFIGURATION FREEZE LOCK */
if (tf->command == ATA_CMD_CONF_OVERLAY &&
tf->feature == ATA_DCO_FREEZE_LOCK)
return 1;

/* SECURITY FREEZE LOCK */
if (tf->command == ATA_CMD_SEC_FREEZE_LOCK)
return 1;

/* SET MAX LOCK and SET MAX FREEZE LOCK */
if ((!ptf || ptf->command != ATA_CMD_READ_NATIVE_MAX) &&
tf->command == ATA_CMD_SET_MAX &&
(tf->feature == ATA_SET_MAX_LOCK ||
tf->feature == ATA_SET_MAX_FREEZE_LOCK))
return 1;
}

return 0;
}

/**
* ata_acpi_run_tf - send taskfile registers to host controller
* @dev: target ATA device
Expand All @@ -485,13 +552,15 @@ EXPORT_SYMBOL_GPL(ata_acpi_cbl_80wire);
* EH context.
*
* RETURNS:
* 1 if command is executed successfully. 0 if ignored or rejected,
* -errno on other errors.
* 1 if command is executed successfully. 0 if ignored, rejected or
* filtered out, -errno on other errors.
*/
static int ata_acpi_run_tf(struct ata_device *dev,
const struct ata_acpi_gtf *gtf)
const struct ata_acpi_gtf *gtf,
const struct ata_acpi_gtf *prev_gtf)
{
struct ata_taskfile tf, rtf;
struct ata_taskfile *pptf = NULL;
struct ata_taskfile tf, ptf, rtf;
unsigned int err_mask;
const char *level;
char msg[60];
Expand All @@ -502,44 +571,44 @@ static int ata_acpi_run_tf(struct ata_device *dev,
&& (gtf->tf[6] == 0))
return 0;

ata_tf_init(dev, &tf);

/* convert gtf to tf */
tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; /* TBD */
tf.protocol = ATA_PROT_NODATA;
tf.feature = gtf->tf[0]; /* 0x1f1 */
tf.nsect = gtf->tf[1]; /* 0x1f2 */
tf.lbal = gtf->tf[2]; /* 0x1f3 */
tf.lbam = gtf->tf[3]; /* 0x1f4 */
tf.lbah = gtf->tf[4]; /* 0x1f5 */
tf.device = gtf->tf[5]; /* 0x1f6 */
tf.command = gtf->tf[6]; /* 0x1f7 */

rtf = tf;
err_mask = ata_exec_internal(dev, &rtf, NULL, DMA_NONE, NULL, 0, 0);

switch (err_mask) {
case 0:
level = KERN_DEBUG;
snprintf(msg, sizeof(msg), "succeeded");
rc = 1;
break;

case AC_ERR_DEV:
ata_acpi_gtf_to_tf(dev, gtf, &tf);
if (prev_gtf) {
ata_acpi_gtf_to_tf(dev, prev_gtf, &ptf);
pptf = &ptf;
}

if (!ata_acpi_filter_tf(&tf, pptf)) {
rtf = tf;
err_mask = ata_exec_internal(dev, &rtf, NULL,
DMA_NONE, NULL, 0, 0);

switch (err_mask) {
case 0:
level = KERN_DEBUG;
snprintf(msg, sizeof(msg), "succeeded");
rc = 1;
break;

case AC_ERR_DEV:
level = KERN_INFO;
snprintf(msg, sizeof(msg),
"rejected by device (Stat=0x%02x Err=0x%02x)",
rtf.command, rtf.feature);
rc = 0;
break;

default:
level = KERN_ERR;
snprintf(msg, sizeof(msg),
"failed (Emask=0x%x Stat=0x%02x Err=0x%02x)",
err_mask, rtf.command, rtf.feature);
rc = -EIO;
break;
}
} else {
level = KERN_INFO;
snprintf(msg, sizeof(msg),
"rejected by device (Stat=0x%02x Err=0x%02x)",
rtf.command, rtf.feature);
snprintf(msg, sizeof(msg), "filtered out");
rc = 0;
break;

default:
level = KERN_ERR;
snprintf(msg, sizeof(msg),
"failed (Emask=0x%x Stat=0x%02x Err=0x%02x)",
err_mask, rtf.command, rtf.feature);
rc = -EIO;
break;
}

ata_dev_printk(dev, level,
Expand All @@ -566,7 +635,7 @@ static int ata_acpi_run_tf(struct ata_device *dev,
*/
static int ata_acpi_exec_tfs(struct ata_device *dev, int *nr_executed)
{
struct ata_acpi_gtf *gtf = NULL;
struct ata_acpi_gtf *gtf = NULL, *pgtf = NULL;
int gtf_count, i, rc;

/* get taskfiles */
Expand All @@ -576,12 +645,14 @@ static int ata_acpi_exec_tfs(struct ata_device *dev, int *nr_executed)
gtf_count = rc;

/* execute them */
for (i = 0; i < gtf_count; i++) {
rc = ata_acpi_run_tf(dev, gtf++);
for (i = 0; i < gtf_count; i++, gtf++) {
rc = ata_acpi_run_tf(dev, gtf, pgtf);
if (rc < 0)
break;
if (rc)
if (rc) {
(*nr_executed)++;
pgtf = gtf;
}
}

ata_acpi_clear_gtf(dev);
Expand Down

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