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Implement ability to turn on/off PHYs for AHCI devices.

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As part of Chuck's work on fixing kernel crashes caused by disk I/O
errors, it is useful to be able to trigger various kinds of
errors. This patch allows causing an AHCI-attached disk to disappear,
by having the driver keep the PHY disabled when the driver would
otherwise enable the PHY. It also allows making the disk reappear by
having the driver go back to setting the PHY enable/disable state as
it normal would and simulating the hardware event that causes a bus
rescan.

Submitted by: Chuck Silvers
Sponsored by: Netflix, Inc
Differential Revision: https://reviews.freebsd.org/D16043
This commit is contained in:
imp 2018-11-03 00:37:51 +00:00
parent 137e3f2353
commit 4ce18bf922
2 changed files with 49 additions and 3 deletions
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50
sys/dev/ahci/ahci.c
View File

@ -39,6 +39,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <machine/stdarg.h>
#include <machine/resource.h>
#include <machine/bus.h>
@ -80,6 +81,8 @@ static void ahci_stop(struct ahci_channel *ch);
static void ahci_clo(struct ahci_channel *ch);
static void ahci_start_fr(struct ahci_channel *ch);
static void ahci_stop_fr(struct ahci_channel *ch);
static int ahci_phy_check_events(struct ahci_channel *ch, u_int32_t serr);
static uint32_t ahci_ch_detval(struct ahci_channel *ch, uint32_t val);
static int ahci_sata_connect(struct ahci_channel *ch);
static int ahci_sata_phy_reset(struct ahci_channel *ch);
@ -100,6 +103,13 @@ static MALLOC_DEFINE(M_AHCI, "AHCI driver", "AHCI driver data buffers");
#define RECOVERY_REQUEST_SENSE 2
#define recovery_slot spriv_field1
static uint32_t
ahci_ch_detval(struct ahci_channel *ch, uint32_t val)
{
return ch->disablephy ? ATA_SC_DET_DISABLE : val;
}
int
ahci_ctlr_setup(device_t dev)
{
@ -664,12 +674,39 @@ ahci_ch_probe(device_t dev)
return (BUS_PROBE_DEFAULT);
}
static int
ahci_ch_disablephy_proc(SYSCTL_HANDLER_ARGS)
{
struct ahci_channel *ch;
int error, value;
ch = arg1;
value = ch->disablephy;
error = sysctl_handle_int(oidp, &value, 0, req);
if (error != 0 || req->newptr == NULL || (value != 0 && value != 1))
return (error);
mtx_lock(&ch->mtx);
ch->disablephy = value;
if (value) {
ahci_ch_deinit(ch->dev);
} else {
ahci_ch_init(ch->dev);
ahci_phy_check_events(ch, ATA_SE_PHY_CHANGED | ATA_SE_EXCHANGED);
}
mtx_unlock(&ch->mtx);
return (0);
}
static int
ahci_ch_attach(device_t dev)
{
struct ahci_controller *ctlr = device_get_softc(device_get_parent(dev));
struct ahci_channel *ch = device_get_softc(dev);
struct cam_devq *devq;
struct sysctl_ctx_list *ctx;
struct sysctl_oid *tree;
int rid, error, i, sata_rev = 0;
u_int32_t version;
@ -787,6 +824,11 @@ ahci_ch_attach(device_t dev)
ahci_ch_pm, ch);
}
mtx_unlock(&ch->mtx);
ctx = device_get_sysctl_ctx(dev);
tree = device_get_sysctl_tree(dev);
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "disable_phy",
CTLFLAG_RW | CTLTYPE_UINT, ch, 0, ahci_ch_disablephy_proc, "IU",
"Disable PHY");
return (0);
err3:
@ -2497,7 +2539,7 @@ static int
ahci_sata_phy_reset(struct ahci_channel *ch)
{
int sata_rev;
uint32_t val;
uint32_t val, detval;
if (ch->listening) {
val = ATA_INL(ch->r_mem, AHCI_P_CMD);
@ -2514,12 +2556,14 @@ ahci_sata_phy_reset(struct ahci_channel *ch)
val = ATA_SC_SPD_SPEED_GEN3;
else
val = 0;
detval = ahci_ch_detval(ch, ATA_SC_DET_RESET);
ATA_OUTL(ch->r_mem, AHCI_P_SCTL,
ATA_SC_DET_RESET | val |
detval | val |
ATA_SC_IPM_DIS_PARTIAL | ATA_SC_IPM_DIS_SLUMBER);
DELAY(1000);
detval = ahci_ch_detval(ch, ATA_SC_DET_IDLE);
ATA_OUTL(ch->r_mem, AHCI_P_SCTL,
ATA_SC_DET_IDLE | val | ((ch->pm_level > 0) ? 0 :
detval | val | ((ch->pm_level > 0) ? 0 :
(ATA_SC_IPM_DIS_PARTIAL | ATA_SC_IPM_DIS_SLUMBER)));
if (!ahci_sata_connect(ch)) {
if (ch->caps & AHCI_CAP_SSS) {

2
sys/dev/ahci/ahci.h
View File

@ -461,6 +461,8 @@ struct ahci_channel {
struct mtx_padalign mtx; /* state lock */
STAILQ_HEAD(, ccb_hdr) doneq; /* queue of completed CCBs */
int batch; /* doneq is in use */
int disablephy; /* keep PHY disabled */
};
struct ahci_enclosure {