Re: [PATCH v4 1/2] scsi: ufs: Enable power management for wlun

From: Asutosh Das
Date: Tue Feb 23 2021 - 20:02:29 EST

On Tue, Feb 23 2021 at 12:23 -0800, Adrian Hunter wrote:
On 23/02/21 1:04 am, Asutosh Das wrote:
During runtime-suspend of ufs host, the scsi devices are
already suspended and so are the queues associated with them.
But the ufs host sends SSU to wlun during its runtime-suspend.
During the process blk_queue_enter checks if the queue is not in
suspended state. If so, it waits for the queue to resume, and never
comes out of it.
The commit
(d55d15a33: scsi: block: Do not accept any requests while suspended)
adds the check if the queue is in suspended state in blk_queue_enter().

Call trace:
__switch_to+0x174/0x2c4
__schedule+0x478/0x764
schedule+0x9c/0xe0
blk_queue_enter+0x158/0x228
blk_mq_alloc_request+0x40/0xa4
blk_get_request+0x2c/0x70
__scsi_execute+0x60/0x1c4
ufshcd_set_dev_pwr_mode+0x124/0x1e4
ufshcd_suspend+0x208/0x83c
ufshcd_runtime_suspend+0x40/0x154
ufshcd_pltfrm_runtime_suspend+0x14/0x20
pm_generic_runtime_suspend+0x28/0x3c
__rpm_callback+0x80/0x2a4
rpm_suspend+0x308/0x614
rpm_idle+0x158/0x228
pm_runtime_work+0x84/0xac
process_one_work+0x1f0/0x470
worker_thread+0x26c/0x4c8
kthread+0x13c/0x320
ret_from_fork+0x10/0x18

Fix this by registering ufs device wlun as a scsi driver and
registering it for block runtime-pm. Also make this as a
supplier for all other luns. That way, this device wlun
suspends after all the consumers and resumes after
hba resumes.

Hi

Hi Adrian
I have a few more questions and comments.

Thanks for the review.
I'll go through your comments and fix it in the next version.

At a glance it looked to me like the SCSI bus will leave a SCSI device
runtime suspended at system suspend, but UFS device spm_lvl and rpm_lvl need
not be the same. Do you know how SCSI handles that case?


Good point.

Yes, it says that:
/*
* All the high-level SCSI drivers that implement runtime
* PM treat runtime suspend, system suspend, and system
* hibernate nearly identically. In all cases the requirements
* for runtime suspension are stricter.
*/

It's not true in case of ufs.

I can think of a couple of approaches:

Adding a couple of more cb() to ufs device wlun:
1. .prepare() -> runtime resume the ufs device -> pm_runtime_get_noresume()
2. .resume_early() -> pm_runtime_put_noidle()

Or,

Add a check to SCSI pm such that, should a device expose a capability saying
that it's runtime-pm differs from its system-pm, scsi-pm invokes the said device's
system-pm cb(). I'm not sure if this approach would violate any underlying assumptions.

Also, I'm not sure which would be a better approach or if there's another approach entirely.
Appreciate any insights.


Co-developed-by: Can Guo <cang@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 455 +++++++++++++++++++++++++++++++++++----------
drivers/scsi/ufs/ufshcd.h | 4 +
include/trace/events/ufs.h | 20 ++
3 files changed, 382 insertions(+), 97 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 45624c7..1d8044a 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -16,6 +16,7 @@
#include <linux/bitfield.h>
#include <linux/blk-pm.h>
#include <linux/blkdev.h>
+#include <scsi/scsi_driver.h>
#include "ufshcd.h"
#include "ufs_quirks.h"
#include "unipro.h"
@@ -251,6 +252,11 @@ static int ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool set);
static inline int ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool enable);
static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba);
static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba);
+static int ufshcd_wl_runtime_suspend(struct device *dev);
+static int ufshcd_wl_runtime_resume(struct device *dev);
+static int ufshcd_wl_suspend(struct device *dev);
+static int ufshcd_wl_resume(struct device *dev);
+static void ufshcd_wl_shutdown(struct device *dev);

static inline bool ufshcd_valid_tag(struct ufs_hba *hba, int tag)
{
@@ -1556,7 +1562,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
if (value == hba->clk_scaling.is_enabled)
goto out;

- pm_runtime_get_sync(hba->dev);
+ scsi_autopm_get_device(hba->sdev_ufs_device);
ufshcd_hold(hba, false);

hba->clk_scaling.is_enabled = value;
@@ -1572,7 +1578,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
}

ufshcd_release(hba);
- pm_runtime_put_sync(hba->dev);
+ scsi_autopm_put_device(hba->sdev_ufs_device);
out:
up(&hba->host_sem);
return err ? err : count;
@@ -2572,6 +2578,17 @@ static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
}

+static inline bool is_rpmb_wlun(struct scsi_device *sdev)
+{
+ return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
+}
+
+static inline bool is_device_wlun(struct scsi_device *sdev)
+{
+ return (sdev->lun ==
+ ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
+}
+
static void ufshcd_init_lrb(struct ufs_hba *hba, struct ufshcd_lrb *lrb, int i)
{
struct utp_transfer_cmd_desc *cmd_descp = hba->ucdl_base_addr;
@@ -4808,6 +4825,41 @@ static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
}

/**
+ * ufshcd_setup_links - associate link b/w device wlun and other luns
+ * @sdev: pointer to SCSI device
+ * @hba: pointer to ufs hba
+ */
+static void ufshcd_setup_links(struct ufs_hba *hba, struct scsi_device *sdev)
+{
+ struct device_link *link;
+
+ /*
+ * device wlun is the supplier & rest of the luns are consumers
+ * This ensures that device wlun suspends after all other luns.
+ */
+ if (hba->sdev_ufs_device) {
+ link = device_link_add(&sdev->sdev_gendev,
+ &hba->sdev_ufs_device->sdev_gendev,
+ DL_FLAG_PM_RUNTIME);
+ if (!link) {
+ dev_err(&sdev->sdev_gendev, "Failed establishing link - %s\n",
+ dev_name(&hba->sdev_ufs_device->sdev_gendev));
+ return;
+ }
+ hba->luns_avail--;
+ /* Ignore REPORT_LUN wlun probing */
+ if (hba->luns_avail != 1)
+ return;
+
+ pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
+ pm_runtime_mark_last_busy(&hba->sdev_ufs_device->sdev_gendev);
+ } else {
+ /* device wlun is probed */
+ hba->luns_avail--;
+ }
+}
+
+/**
* ufshcd_slave_alloc - handle initial SCSI device configurations
* @sdev: pointer to SCSI device
*
@@ -4838,6 +4890,8 @@ static int ufshcd_slave_alloc(struct scsi_device *sdev)

ufshcd_get_lu_power_on_wp_status(hba, sdev);

+ ufshcd_setup_links(hba, sdev);
+
return 0;
}

@@ -4984,16 +5038,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
* solution could be to abort the system suspend if
* UFS device needs urgent BKOPs.
*/
- if (!hba->pm_op_in_progress &&
- ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&
- schedule_work(&hba->eeh_work)) {
- /*
- * Prevent suspend once eeh_work is scheduled
- * to avoid deadlock between ufshcd_suspend
- * and exception event handler.
- */
- pm_runtime_get_noresume(hba->dev);
- }
+ if (ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
+ /* Flushed in suspend */
+ schedule_work(&hba->eeh_work);
break;
case UPIU_TRANSACTION_REJECT_UPIU:
/* TODO: handle Reject UPIU Response */
@@ -5589,8 +5636,8 @@ static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct *work)
* after a certain delay to recheck the threshold by next runtime
* suspend.
*/
- pm_runtime_get_sync(hba->dev);
- pm_runtime_put_sync(hba->dev);
+ scsi_autopm_get_device(hba->sdev_ufs_device);
+ scsi_autopm_put_device(hba->sdev_ufs_device);
}

/**
@@ -5607,7 +5654,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
u32 status = 0;
hba = container_of(work, struct ufs_hba, eeh_work);

- pm_runtime_get_sync(hba->dev);
ufshcd_scsi_block_requests(hba);
err = ufshcd_get_ee_status(hba, &status);
if (err) {
@@ -5623,14 +5669,6 @@ static void ufshcd_exception_event_handler(struct work_struct *work)

out:
ufshcd_scsi_unblock_requests(hba);
- /*
- * pm_runtime_get_noresume is called while scheduling
- * eeh_work to avoid suspend racing with exception work.
- * Hence decrement usage counter using pm_runtime_put_noidle
- * to allow suspend on completion of exception event handler.
- */
- pm_runtime_put_noidle(hba->dev);
- pm_runtime_put(hba->dev);
return;
}

@@ -7254,6 +7292,15 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
goto out;
}
ufshcd_blk_pm_runtime_init(hba->sdev_ufs_device);
+ /*
+ * A pm_runtime_put_sync is invoked when this device enables blk_pm_runtime
+ * & would suspend the device-wlun upon timer expiry.
+ * But suspending device wlun _may_ put the ufs device in the pre-defined
+ * low power mode (SSU <rpm_lvl>). Probing of other luns may fail then.
+ * Don't allow this suspend until all the luns have been probed.
+ * See pm_runtime_mark_last_busy in ufshcd_setup_links.
+ */
+ pm_runtime_get_noresume(&hba->sdev_ufs_device->sdev_gendev);
scsi_device_put(hba->sdev_ufs_device);

hba->sdev_rpmb = __scsi_add_device(hba->host, 0, 0,
@@ -7417,6 +7464,9 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
goto out;
}

+ hba->luns_avail = desc_buf[DEVICE_DESC_PARAM_NUM_LU] +
+ desc_buf[DEVICE_DESC_PARAM_NUM_WLU];
+
ufs_fixup_device_setup(hba);

ufshcd_wb_probe(hba, desc_buf);
@@ -7747,6 +7797,54 @@ static int ufshcd_device_params_init(struct ufs_hba *hba)
return ret;
}

+static int ufshcd_wl_probe(struct device *dev)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+
+ /*
+ * Use this driver for both device wlun and rpmb lun
+ * It's used to send uac to rpmb wlun and ssu to device wlun
+ */
+ if (sdev && (is_rpmb_wlun(sdev) || is_device_wlun(sdev)))
+ return 0;
+ return -ENODEV;
+}
+
+static int ufshcd_wl_remove(struct device *dev)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+
+ scsi_remove_device(sdev);

The 'probe' did not do the __scsi_add_device(), so does the 'remove' need to
do scsi_remove_device()?

+ return 0;
+}
+
+static const struct dev_pm_ops ufshcd_wl_pm_ops = {
+ SET_RUNTIME_PM_OPS(ufshcd_wl_runtime_suspend, ufshcd_wl_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(ufshcd_wl_suspend, ufshcd_wl_resume)

.poweroff needs to set the power mode to PowerDown irrespective of spm_lvl,
so not exactly the same as ufshcd_wl_suspend.

Also, ufshcd_pci_poweroff() in ufshcd-pci.c should be removed since it won't
work anymore.

+};
+
+/**
+ * ufs_wlun - describes 2 wluns:
+ * ufs-device wlun - used to send pm commands
+ * and rpmb wlun - for rpmb commands
+ * All luns including rpmb are consumers of ufs-device wlun.
+ *
+ * Currently, no sd driver is present for wluns.
+ * Hence the no specific pm operations are performed.
+ * With ufs design, SSU should be sent to ufs-device wlun.
+ * Hence register a scsi driver for ufs wluns only.
+ */
+static struct scsi_driver ufs_wlun = {
+ .gendrv = {
+ .name = "ufs_device_wlun",
+ .owner = THIS_MODULE,
+ .probe = ufshcd_wl_probe,
+ .remove = ufshcd_wl_remove,
+ .pm = &ufshcd_wl_pm_ops,
+ .shutdown = ufshcd_wl_shutdown,
+ },
+};

WRT to RPMB, aren't all the callbacks optional, so that would leave only
something like below. Would that work?

#define wlun_dev_to_hba(dv) shost_priv(to_scsi_device(dv)->host)

static int ufs_rpmb_probe(struct device *dev)
{
return is_rpmb_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
}

static int ufs_rpmb_runtime_resume(struct device *dev)
{
struct ufs_hba *hba = wlun_dev_to_hba(dev);

if (hba->sdev_rpmb)
return ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
return 0;
}

static int ufs_rpmb_resume(struct device *dev)
{
struct ufs_hba *hba = wlun_dev_to_hba(dev);

if (hba->sdev_rpmb && !pm_runtime_suspended(dev))
return ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
return 0;
}

static const struct dev_pm_ops ufs_rpmb_pm_ops = {
SET_RUNTIME_PM_OPS(NULL, ufs_rpmb_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(NULL, ufs_rpmb_resume)
};

static struct scsi_driver ufs_rpmb_template = {
.gendrv = {
.name = "ufs_rpmb_wlun",
.owner = THIS_MODULE,
.probe = ufs_rpmb_probe,
.pm = &ufs_rpmb_pm_ops,
},
};


+
/**
* ufshcd_add_lus - probe and add UFS logical units
* @hba: per-adapter instance
@@ -7755,6 +7853,12 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
{
int ret;

+ ret = scsi_register_driver(&ufs_wlun.gendrv);

That will attempt to register the driver every time a UFS host controller is
added (e.g. what happens if you unbind and re-bind the host controller).
Probably needs to be in ufshcd_core_init() with corresponding unregister in
ufshcd_core_exit()

+ if (ret) {
+ dev_err(hba->dev, "Register device wlun driver failed: %d\n",
+ ret);
+ return ret;
+ }
/* Add required well known logical units to scsi mid layer */
ret = ufshcd_scsi_add_wlus(hba);
if (ret)
@@ -7964,6 +8068,7 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
pm_runtime_put_sync(hba->dev);
ufshcd_hba_exit(hba);
}
+ hba->init_done = true;
}

static const struct attribute_group *ufshcd_driver_groups[] = {
@@ -8475,7 +8580,8 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
* handling context.
*/
hba->host->eh_noresume = 1;
- ufshcd_clear_ua_wluns(hba);
+ if (hba->wlun_dev_clr_ua)
+ ufshcd_clear_ua_wlun(hba, UFS_UPIU_UFS_DEVICE_WLUN);

cmd[4] = pwr_mode << 4;

@@ -8650,31 +8756,19 @@ static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
ufshcd_setup_hba_vreg(hba, true);
}

-/**
- * ufshcd_suspend - helper function for suspend operations
- * @hba: per adapter instance
- * @pm_op: desired low power operation type
- *
- * This function will try to put the UFS device and link into low power
- * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
- * (System PM level).
- *
- * If this function is called during shutdown, it will make sure that
- * both UFS device and UFS link is powered off.
- *
- * NOTE: UFS device & link must be active before we enter in this function.
- *
- * Returns 0 for success and non-zero for failure
- */
-static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
{
int ret = 0;
- int check_for_bkops;
enum ufs_pm_level pm_lvl;
enum ufs_dev_pwr_mode req_dev_pwr_mode;
enum uic_link_state req_link_state;

- hba->pm_op_in_progress = 1;
+ /*
+ * Is invoked when the device wlun is added to sysfs
+ * But by then hba->sdev_ufs_device may not be initialized.
+ */
+ if (!hba->init_done)
+ return 0;
if (!ufshcd_is_shutdown_pm(pm_op)) {
pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
hba->rpm_lvl : hba->spm_lvl;
@@ -8690,24 +8784,23 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
* just gate the clocks.
*/
ufshcd_hold(hba, false);
- hba->clk_gating.is_suspended = true;

if (ufshcd_is_clkscaling_supported(hba))
ufshcd_clk_scaling_suspend(hba, true);

if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
req_link_state == UIC_LINK_ACTIVE_STATE) {
- goto disable_clks;
+ goto enable_scaling;
}

if ((req_dev_pwr_mode == hba->curr_dev_pwr_mode) &&
(req_link_state == hba->uic_link_state))
- goto enable_gating;
+ goto enable_scaling;

/* UFS device & link must be active before we enter in this function */
if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba)) {
ret = -EINVAL;
- goto enable_gating;
+ goto enable_scaling;
}

if (ufshcd_is_runtime_pm(pm_op)) {
@@ -8719,7 +8812,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
*/
ret = ufshcd_urgent_bkops(hba);
if (ret)
- goto enable_gating;
+ goto enable_scaling;
} else {
/* make sure that auto bkops is disabled */
ufshcd_disable_auto_bkops(hba);
@@ -8746,10 +8839,224 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)

if (!hba->dev_info.b_rpm_dev_flush_capable) {
ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
- if (ret)
- goto enable_gating;
+ if (!ret)
+ goto out;
}
}
+enable_scaling:
+ if (ufshcd_is_clkscaling_supported(hba))
+ ufshcd_clk_scaling_suspend(hba, false);
+
+ hba->dev_info.b_rpm_dev_flush_capable = false;
+out:
+ if (hba->dev_info.b_rpm_dev_flush_capable) {
+ schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
+ msecs_to_jiffies(RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS));
+ }
+ if (ret)
+ ufshcd_update_evt_hist(hba, UFS_EVT_WL_SUSP_ERR, (u32)ret);
+ ufshcd_release(hba);
+ return ret;
+}
+
+static int __ufshcd_wl_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+ int ret = 0;
+
+ if (!hba->init_done)
+ return 0;
+
+ ufshcd_hold(hba, false);
+ if (ufshcd_is_ufs_dev_deepsleep(hba)) {
+ /* The device is in DeepSleep but hba was not suspended */
+ ret = ufshcd_reset_and_restore(hba);
+ if (ret)
+ goto out;
+ }
+
+ if (!ufshcd_is_ufs_dev_active(hba)) {
+ ret = ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE);
+ if (ret)
+ goto out;
+ }
+
+ if (ufshcd_keep_autobkops_enabled_except_suspend(hba))
+ ufshcd_enable_auto_bkops(hba);
+ else
+ /*
+ * If BKOPs operations are urgently needed at this moment then
+ * keep auto-bkops enabled or else disable it.
+ */
+ ufshcd_urgent_bkops(hba);
+
+ if (hba->clk_scaling.is_allowed)
+ ufshcd_resume_clkscaling(hba);
+
+ if (hba->dev_info.b_rpm_dev_flush_capable) {
+ hba->dev_info.b_rpm_dev_flush_capable = false;
+ cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
+ }
+
+out:
+ if (ret)
+ ufshcd_update_evt_hist(hba, UFS_EVT_WL_RES_ERR, (u32)ret);
+ ufshcd_release(hba);
+ return ret;
+}
+
+static int ufshcd_wl_runtime_suspend(struct device *dev)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufs_hba *hba;
+ int ret;
+ ktime_t start = ktime_get();
+
+ hba = shost_priv(sdev->host);
+
+ if (is_rpmb_wlun(sdev))
+ return 0;
+ ret = __ufshcd_wl_suspend(hba, UFS_RUNTIME_PM);
+ if (ret)
+ dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
+
+ trace_ufshcd_wl_runtime_suspend(dev_name(dev), ret,
+ ktime_to_us(ktime_sub(ktime_get(), start)),
+ hba->curr_dev_pwr_mode, hba->uic_link_state);
+
+ return ret;
+}
+
+static int ufshcd_wl_runtime_resume(struct device *dev)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufs_hba *hba;
+ int ret;
+ ktime_t start = ktime_get();
+
+ hba = shost_priv(sdev->host);
+
+ if (is_rpmb_wlun(sdev)) {
+ if (hba->sdev_rpmb)
+ return ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
+ return 0;
+ }
+
+ ret = __ufshcd_wl_resume(hba, UFS_RUNTIME_PM);
+ if (ret)
+ dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
+
+ trace_ufshcd_wl_runtime_resume(dev_name(dev), ret,
+ ktime_to_us(ktime_sub(ktime_get(), start)),
+ hba->curr_dev_pwr_mode, hba->uic_link_state);
+
+ return ret;
+}
+
+static int ufshcd_wl_suspend(struct device *dev)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufs_hba *hba;
+ int ret;
+ ktime_t start = ktime_get();
+
+ if (is_rpmb_wlun(sdev))
+ return 0;
+ hba = shost_priv(sdev->host);
+ ret = __ufshcd_wl_suspend(hba, UFS_SYSTEM_PM);
+ if (ret)
+ dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
+
+ trace_ufshcd_wl_suspend(dev_name(dev), ret,
+ ktime_to_us(ktime_sub(ktime_get(), start)),
+ hba->curr_dev_pwr_mode, hba->uic_link_state);
+
+ return ret;
+}
+
+static int ufshcd_wl_resume(struct device *dev)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufs_hba *hba;
+ int ret;
+ ktime_t start = ktime_get();
+
+ if (pm_runtime_suspended(dev))
+ return 0;
+ hba = shost_priv(sdev->host);
+
+ if (is_rpmb_wlun(sdev)) {
+ if (hba->sdev_rpmb)
+ return ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
+ return 0;
+ }
+
+ ret = __ufshcd_wl_resume(hba, UFS_SYSTEM_PM);
+ if (ret)
+ dev_err(&sdev->sdev_gendev, "%s failed: %d\n", __func__, ret);
+
+ trace_ufshcd_wl_resume(dev_name(dev), ret,
+ ktime_to_us(ktime_sub(ktime_get(), start)),
+ hba->curr_dev_pwr_mode, hba->uic_link_state);
+
+ return ret;
+}
+
+static void ufshcd_wl_shutdown(struct device *dev)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufs_hba *hba;
+
+ if (is_rpmb_wlun(sdev))
+ return;
+ hba = shost_priv(sdev->host);
+ scsi_device_quiesce(sdev);
+ shost_for_each_device(sdev, hba->host) {
+ if (sdev == hba->sdev_ufs_device)
+ continue;
+ scsi_remove_device(sdev);

Shutdown needs to quiesce devices. Removing devices is not advisable
because the upper layers cannot respond at this point, causing deadlocks.
Is scsi_remove_device() really needed here?

+ }
+ __ufshcd_wl_suspend(hba, UFS_SHUTDOWN_PM);
+}
+
+/**
+ * ufshcd_suspend - helper function for suspend operations
+ * @hba: per adapter instance
+ * @pm_op: desired low power operation type
+ *
+ * This function will try to put the UFS link into low power
+ * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
+ * (System PM level).
+ *
+ * If this function is called during shutdown, it will make sure that
+ * link is powered off.
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+ int ret = 0;
+ int check_for_bkops;
+ enum ufs_pm_level pm_lvl;
+ enum ufs_dev_pwr_mode req_dev_pwr_mode;
+ enum uic_link_state req_link_state;
+
+ hba->pm_op_in_progress = 1;
+ if (!ufshcd_is_shutdown_pm(pm_op)) {
+ pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
+ hba->rpm_lvl : hba->spm_lvl;
+ req_dev_pwr_mode = ufs_get_pm_lvl_to_dev_pwr_mode(pm_lvl);
+ req_link_state = ufs_get_pm_lvl_to_link_pwr_state(pm_lvl);
+ } else {
+ req_dev_pwr_mode = UFS_POWERDOWN_PWR_MODE;
+ req_link_state = UIC_LINK_OFF_STATE;
+ }
+
+ /*
+ * If we can't transition into any of the low power modes
+ * just gate the clocks.
+ */
+ ufshcd_hold(hba, false);
+ hba->clk_gating.is_suspended = true;

/*
* In the case of DeepSleep, the device is expected to remain powered
@@ -8758,9 +9065,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
check_for_bkops = !ufshcd_is_ufs_dev_deepsleep(hba);
ret = ufshcd_link_state_transition(hba, req_link_state, check_for_bkops);
if (ret)
- goto set_dev_active;
+ goto enable_gating;

-disable_clks:
/*
* Call vendor specific suspend callback. As these callbacks may access
* vendor specific host controller register space call them before the
@@ -8790,7 +9096,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
goto out;

set_link_active:
- ufshcd_vreg_set_hpm(hba);
/*
* Device hardware reset is required to exit DeepSleep. Also, for
* DeepSleep, the link is off so host reset and restore will be done
@@ -8804,28 +9109,15 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
ufshcd_set_link_active(hba);
else if (ufshcd_is_link_off(hba))
ufshcd_host_reset_and_restore(hba);
-set_dev_active:
/* Can also get here needing to exit DeepSleep */
if (ufshcd_is_ufs_dev_deepsleep(hba)) {
ufshcd_device_reset(hba);
ufshcd_host_reset_and_restore(hba);
}
- if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
- ufshcd_disable_auto_bkops(hba);
enable_gating:
- if (ufshcd_is_clkscaling_supported(hba))
- ufshcd_clk_scaling_suspend(hba, false);
-
hba->clk_gating.is_suspended = false;
- hba->dev_info.b_rpm_dev_flush_capable = false;
- ufshcd_clear_ua_wluns(hba);
ufshcd_release(hba);
out:
- if (hba->dev_info.b_rpm_dev_flush_capable) {
- schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
- msecs_to_jiffies(RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS));
- }
-
hba->pm_op_in_progress = 0;

if (ret)
@@ -8846,10 +9138,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
{
int ret;
- enum uic_link_state old_link_state;

hba->pm_op_in_progress = 1;
- old_link_state = hba->uic_link_state;

ufshcd_hba_vreg_set_hpm(hba);
ret = ufshcd_vreg_set_hpm(hba);
@@ -8901,43 +9191,14 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
goto vendor_suspend;
}

- if (!ufshcd_is_ufs_dev_active(hba)) {
- ret = ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE);
- if (ret)
- goto set_old_link_state;
- }
-
- if (ufshcd_keep_autobkops_enabled_except_suspend(hba))
- ufshcd_enable_auto_bkops(hba);
- else
- /*
- * If BKOPs operations are urgently needed at this moment then
- * keep auto-bkops enabled or else disable it.
- */
- ufshcd_urgent_bkops(hba);
-
- hba->clk_gating.is_suspended = false;
-
- if (ufshcd_is_clkscaling_supported(hba))
- ufshcd_clk_scaling_suspend(hba, false);
-
/* Enable Auto-Hibernate if configured */
ufshcd_auto_hibern8_enable(hba);

- if (hba->dev_info.b_rpm_dev_flush_capable) {
- hba->dev_info.b_rpm_dev_flush_capable = false;
- cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
- }
-
- ufshcd_clear_ua_wluns(hba);
-
/* Schedule clock gating in case of no access to UFS device yet */
ufshcd_release(hba);

goto out;

-set_old_link_state:
- ufshcd_link_state_transition(hba, old_link_state, 0);
vendor_suspend:
ufshcd_vops_suspend(hba, pm_op);
disable_irq_and_vops_clks:
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index ee61f82..7662387 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -72,6 +72,8 @@ enum ufs_event_type {
UFS_EVT_LINK_STARTUP_FAIL,
UFS_EVT_RESUME_ERR,
UFS_EVT_SUSPEND_ERR,
+ UFS_EVT_WL_SUSP_ERR,
+ UFS_EVT_WL_RES_ERR,

/* abnormal events */
UFS_EVT_DEV_RESET,
@@ -841,6 +843,8 @@ struct ufs_hba {
#ifdef CONFIG_DEBUG_FS
struct dentry *debugfs_root;
#endif
+ bool init_done;
+ u32 luns_avail;
};

/* Returns true if clocks can be gated. Otherwise false */
diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
index e151477..d9d233b 100644
--- a/include/trace/events/ufs.h
+++ b/include/trace/events/ufs.h
@@ -246,6 +246,26 @@ DEFINE_EVENT(ufshcd_template, ufshcd_init,
int dev_state, int link_state),
TP_ARGS(dev_name, err, usecs, dev_state, link_state));

+DEFINE_EVENT(ufshcd_template, ufshcd_wl_suspend,
+ TP_PROTO(const char *dev_name, int err, s64 usecs,
+ int dev_state, int link_state),
+ TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
+DEFINE_EVENT(ufshcd_template, ufshcd_wl_resume,
+ TP_PROTO(const char *dev_name, int err, s64 usecs,
+ int dev_state, int link_state),
+ TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
+DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_suspend,
+ TP_PROTO(const char *dev_name, int err, s64 usecs,
+ int dev_state, int link_state),
+ TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
+DEFINE_EVENT(ufshcd_template, ufshcd_wl_runtime_resume,
+ TP_PROTO(const char *dev_name, int err, s64 usecs,
+ int dev_state, int link_state),
+ TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
TRACE_EVENT(ufshcd_command,
TP_PROTO(const char *dev_name, enum ufs_trace_str_t str_t,
unsigned int tag, u32 doorbell, int transfer_len, u32 intr,