Enable power management for ufs wlun

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 (START_STOP_UNIT) 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.

Co-developed-by Can Guo <[email protected]>

Signed-off-by Can Guo <[email protected]>

Signed-off-by Asutosh Das <[email protected]>

---
 drivers/scsi/ufs/cdns-pltfrm.c     |   2 +
 drivers/scsi/ufs/tc-dwc-g210-pci.c |   2 +
 drivers/scsi/ufs/ufs-debugfs.c     |   2 +-
 drivers/scsi/ufs/ufs-debugfs.h     |   2 +-
 drivers/scsi/ufs/ufs-exynos.c      |   2 +
 drivers/scsi/ufs/ufs-hisi.c        |   2 +
 drivers/scsi/ufs/ufs-mediatek.c    |  12 +-
 drivers/scsi/ufs/ufs-qcom.c        |   2 +
 drivers/scsi/ufs/ufs_bsg.c         |   6 +-
 drivers/scsi/ufs/ufshcd-pci.c      |  36 +--
 drivers/scsi/ufs/ufshcd.c          | 627 ++++++++++++++++++++++++++-----------
 drivers/scsi/ufs/ufshcd.h          |   6 +
 include/trace/events/ufs.h         |  20 ++
 13 files changed, 496 insertions(+), 225 deletions(-)

drivers/scsi/ufs/cdns-pltfrm.c +2 -0

index 149391f..3e70c23 100644
@@ -319,6 +319,8 @@ static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver cdns_ufs_pltfrm_driver = {

drivers/scsi/ufs/tc-dwc-g210-pci.c +2 -0

index 67a6a61..b01db12 100644
@@ -148,6 +148,8 @@ static const struct dev_pm_ops tc_dwc_g210_pci_pm_ops = {
 	.runtime_suspend = tc_dwc_g210_pci_runtime_suspend,
 	.runtime_resume  = tc_dwc_g210_pci_runtime_resume,
 	.runtime_idle    = tc_dwc_g210_pci_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static const struct pci_device_id tc_dwc_g210_pci_tbl[] = {

drivers/scsi/ufs/ufs-debugfs.c +1 -1

index dee98dc..06457d5 100644
@@ -13,7 +13,7 @@ void __init ufs_debugfs_init(void)
 	ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
 }
 
-void __exit ufs_debugfs_exit(void)
+void ufs_debugfs_exit(void)
 {
 	debugfs_remove_recursive(ufs_debugfs_root);
 }

drivers/scsi/ufs/ufs-debugfs.h +1 -1

index f35b39c..12c2730 100644
@@ -9,7 +9,7 @@ struct ufs_hba;
 
 #ifdef CONFIG_DEBUG_FS
 void __init ufs_debugfs_init(void);
-void __exit ufs_debugfs_exit(void);
+void ufs_debugfs_exit(void);
 void ufs_debugfs_hba_init(struct ufs_hba *hba);
 void ufs_debugfs_hba_exit(struct ufs_hba *hba);
 #else

drivers/scsi/ufs/ufs-exynos.c +2 -0

index 267943a1..45c0b02 100644
@@ -1268,6 +1268,8 @@ static const struct dev_pm_ops exynos_ufs_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver exynos_ufs_pltform = {

drivers/scsi/ufs/ufs-hisi.c +2 -0

index 0aa5813..d463b44 100644
@@ -574,6 +574,8 @@ static const struct dev_pm_ops ufs_hisi_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver ufs_hisi_pltform = {

drivers/scsi/ufs/ufs-mediatek.c +6 -6

index c55202b..51c82e3 100644
@@ -810,12 +810,10 @@ static int ufs_mtk_post_link(struct ufs_hba *hba)
 	/* enable unipro clock gating feature */
 	ufs_mtk_cfg_unipro_cg(hba, true);
 
-	/* configure auto-hibern8 timer to 10ms */
-	if (ufshcd_is_auto_hibern8_supported(hba)) {
-		ufshcd_auto_hibern8_update(hba,
-			FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
-			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3));
-	}
+	/* will be configured during probe hba */
+	if (ufshcd_is_auto_hibern8_supported(hba))
+		hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 10) |
+			FIELD_PREP(UFSHCI_AHIBERN8_SCALE_MASK, 3);
 
 	ufs_mtk_setup_clk_gating(hba);
 

@@ -1097,6 +1095,8 @@ static const struct dev_pm_ops ufs_mtk_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver ufs_mtk_pltform = {

drivers/scsi/ufs/ufs-qcom.c +2 -0

index f97d7b0..9aa098a 100644
@@ -1546,6 +1546,8 @@ static const struct dev_pm_ops ufs_qcom_pm_ops = {
 	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
 	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
 	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+	.prepare	 = ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
 };
 
 static struct platform_driver ufs_qcom_pltform = {

drivers/scsi/ufs/ufs_bsg.c +3 -3

index 5b2bc1a..cbb5a90 100644
@@ -97,7 +97,7 @@ static int ufs_bsg_request(struct bsg_job *job)
 
 	bsg_reply->reply_payload_rcv_len = 0;
 
-	pm_runtime_get_sync(hba->dev);
+	scsi_autopm_get_device(hba->sdev_ufs_device);
 
 	msgcode = bsg_request->msgcode;
 	switch (msgcode) {

@@ -106,7 +106,7 @@ static int ufs_bsg_request(struct bsg_job *job)
 		ret = ufs_bsg_alloc_desc_buffer(hba, job, &desc_buff,
 						&desc_len, desc_op);
 		if (ret) {
-			pm_runtime_put_sync(hba->dev);
+			scsi_autopm_put_device(hba->sdev_ufs_device);
 			goto out;
 		}
 

@@ -138,7 +138,7 @@ static int ufs_bsg_request(struct bsg_job *job)
 		break;
 	}
 
-	pm_runtime_put_sync(hba->dev);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
 
 	if (!desc_buff)
 		goto out;

drivers/scsi/ufs/ufshcd-pci.c +5 -31

index fadd566..5d4ffd2 100644
@@ -247,29 +247,6 @@ static int ufshcd_pci_resume(struct device *dev)
 	return ufshcd_system_resume(dev_get_drvdata(dev));
 }
 
-/**
- * ufshcd_pci_poweroff - suspend-to-disk poweroff function
- * @dev: pointer to PCI device handle
- *
- * Returns 0 if successful
- * Returns non-zero otherwise
- */
-static int ufshcd_pci_poweroff(struct device *dev)
-{
-	struct ufs_hba *hba = dev_get_drvdata(dev);
-	int spm_lvl = hba->spm_lvl;
-	int ret;
-
-	/*
-	 * For poweroff we need to set the UFS device to PowerDown mode.
-	 * Force spm_lvl to ensure that.
-	 */
-	hba->spm_lvl = 5;
-	ret = ufshcd_system_suspend(hba);
-	hba->spm_lvl = spm_lvl;
-	return ret;
-}
-
 #endif /* !CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM

@@ -365,17 +342,14 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 }
 
 static const struct dev_pm_ops ufshcd_pci_pm_ops = {
-#ifdef CONFIG_PM_SLEEP
-	.suspend	= ufshcd_pci_suspend,
-	.resume		= ufshcd_pci_resume,
-	.freeze		= ufshcd_pci_suspend,
-	.thaw		= ufshcd_pci_resume,
-	.poweroff	= ufshcd_pci_poweroff,
-	.restore	= ufshcd_pci_resume,
-#endif
 	SET_RUNTIME_PM_OPS(ufshcd_pci_runtime_suspend,
 			   ufshcd_pci_runtime_resume,
 			   ufshcd_pci_runtime_idle)
+	SET_SYSTEM_SLEEP_PM_OPS(ufshcd_pci_suspend, ufshcd_pci_resume)
+#ifdef CONFIG_PM_SLEEP
+	.prepare	= ufshcd_suspend_prepare,
+	.complete	= ufshcd_resume_complete,
+#endif
 };
 
 static const struct pci_device_id ufshcd_pci_tbl[] = {

drivers/scsi/ufs/ufshcd.c +286 -178

index 45624c7..8f8a013 100644
@@ -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"

@@ -78,6 +79,8 @@
 /* Polling time to wait for fDeviceInit */
 #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
 
+#define wlun_dev_to_hba(dv) shost_priv(to_scsi_device(dv)->host)
+
 #define ufshcd_toggle_vreg(_dev, _vreg, _on)				\
 	({                                                              \
 		int _ret;                                               \

@@ -1556,7 +1559,7 @@ 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 +1575,7 @@ 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 +2575,17 @@ 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;

@@ -4106,11 +4120,11 @@ void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	if (update && !pm_runtime_suspended(hba->dev)) {
-		pm_runtime_get_sync(hba->dev);
+		scsi_autopm_get_device(hba->sdev_ufs_device);
 		ufshcd_hold(hba, false);
 		ufshcd_auto_hibern8_enable(hba);
 		ufshcd_release(hba);
-		pm_runtime_put(hba->dev);
+		scsi_autopm_put_device(hba->sdev_ufs_device);
 	}
 }
 EXPORT_SYMBOL_GPL(ufshcd_auto_hibern8_update);

@@ -4808,6 +4822,40 @@ 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|DL_FLAG_RPM_ACTIVE);
+		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) {
+			pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
+			return;
+		}
+	} else {
+		/* device wlun is probed */
+		hba->luns_avail--;
+	}
+}
+
+/**
  * ufshcd_slave_alloc - handle initial SCSI device configurations
  * @sdev: pointer to SCSI device
  *

@@ -4838,6 +4886,8 @@ 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;
 }
 

@@ -4869,8 +4919,13 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
 	blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
 	if (hba->quirks & UFSHCD_QUIRK_ALIGN_SG_WITH_PAGE_SIZE)
 		blk_queue_update_dma_alignment(q, PAGE_SIZE - 1);
-
-	if (ufshcd_is_rpm_autosuspend_allowed(hba))
+	/*
+	 * Block runtime-pm until all consumers are added.
+	 * Refer ufshcd_setup_links().
+	 */
+	if (is_device_wlun(sdev))
+		pm_runtime_get_noresume(&sdev->sdev_gendev);
+	else if (ufshcd_is_rpm_autosuspend_allowed(hba))
 		sdev->rpm_autosuspend = 1;
 
 	ufshcd_crypto_setup_rq_keyslot_manager(hba, q);

@@ -4985,15 +5040,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 			 * 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);
-			}
+			    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 +5638,8 @@ 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 +5656,6 @@ 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 +5671,6 @@ 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;
 }
 

@@ -5755,12 +5795,13 @@ static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
 
 static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
 {
-	pm_runtime_get_sync(hba->dev);
-	if (pm_runtime_status_suspended(hba->dev) || hba->is_sys_suspended) {
+	scsi_autopm_get_device(hba->sdev_ufs_device);
+	if (pm_runtime_status_suspended(&hba->sdev_ufs_device->sdev_gendev) ||
+	    hba->is_sys_suspended) {
 		enum ufs_pm_op pm_op;
 
 		/*
-		 * Don't assume anything of pm_runtime_get_sync(), if
+		 * Don't assume anything of resume, if
 		 * resume fails, irq and clocks can be OFF, and powers
 		 * can be OFF or in LPM.
 		 */

@@ -5789,7 +5830,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
 	ufshcd_release(hba);
 	if (ufshcd_is_clkscaling_supported(hba))
 		ufshcd_clk_scaling_suspend(hba, false);
-	pm_runtime_put(hba->dev);
+	pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);
 }
 
 static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)

@@ -5810,14 +5851,14 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)
 
 	hba->is_sys_suspended = false;
 	/*
-	 * Set RPM status of hba device to RPM_ACTIVE,
+	 * Set RPM status of wlun device to RPM_ACTIVE,
 	 * this also clears its runtime error.
 	 */
-	ret = pm_runtime_set_active(hba->dev);
+	ret = pm_runtime_set_active(&hba->sdev_ufs_device->sdev_gendev);
 	/*
-	 * If hba device had runtime error, we also need to resume those
-	 * scsi devices under hba in case any of them has failed to be
-	 * resumed due to hba runtime resume failure. This is to unblock
+	 * If wlun device had runtime error, we also need to resume those
+	 * consumer scsi devices in case any of them has failed to be
+	 * resumed due to supplier runtime resume failure. This is to unblock
 	 * blk_queue_enter in case there are bios waiting inside it.
 	 */
 	if (!ret) {

@@ -7253,8 +7294,7 @@ static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
 		hba->sdev_ufs_device = NULL;
 		goto out;
 	}
-	ufshcd_blk_pm_runtime_init(hba->sdev_ufs_device);
-	scsi_device_put(hba->sdev_ufs_device);
+	scsi_device_put(sdev_ufs_device);
 
 	hba->sdev_rpmb = __scsi_add_device(hba->host, 0, 0,
 		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN), NULL);

@@ -7417,6 +7457,9 @@ 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);

@@ -7892,6 +7935,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
 	ufshcd_set_ufs_dev_active(hba);
 	ufshcd_force_reset_auto_bkops(hba);
 	hba->wlun_dev_clr_ua = true;
+	hba->wlun_rpmb_clr_ua = true;
 
 	/* Gear up to HS gear if supported */
 	if (hba->max_pwr_info.is_valid) {

@@ -8475,7 +8519,8 @@ 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;
 

@@ -8650,23 +8695,7 @@ 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;

@@ -8674,7 +8703,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	enum ufs_dev_pwr_mode req_dev_pwr_mode;
 	enum uic_link_state req_link_state;
 
-	hba->pm_op_in_progress = 1;
+	hba->pm_op_in_progress = true;
 	if (!ufshcd_is_shutdown_pm(pm_op)) {
 		pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
 			 hba->rpm_lvl : hba->spm_lvl;

@@ -8697,17 +8726,17 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 
 	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 +8748,7 @@ 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);

@@ -8747,7 +8776,7 @@ 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;
+				goto enable_scaling;
 		}
 	}
 

@@ -8760,7 +8789,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	if (ret)
 		goto set_dev_active;
 
-disable_clks:
 	/*
 	 * Call vendor specific suspend callback. As these callbacks may access
 	 * vendor specific host controller register space call them before the

@@ -8769,28 +8797,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	ret = ufshcd_vops_suspend(hba, pm_op);
 	if (ret)
 		goto set_link_active;
-	/*
-	 * Disable the host irq as host controller as there won't be any
-	 * host controller transaction expected till resume.
-	 */
-	ufshcd_disable_irq(hba);
-
-	ufshcd_setup_clocks(hba, false);
-
-	if (ufshcd_is_clkgating_allowed(hba)) {
-		hba->clk_gating.state = CLKS_OFF;
-		trace_ufshcd_clk_gating(dev_name(hba->dev),
-					hba->clk_gating.state);
-	}
-
-	ufshcd_vreg_set_lpm(hba);
-
-	/* Put the host controller in low power mode if possible */
-	ufshcd_hba_vreg_set_lpm(hba);
 	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

@@ -8812,57 +8821,32 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	}
 	if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
 		ufshcd_disable_auto_bkops(hba);
-enable_gating:
+enable_scaling:
 	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)
-		ufshcd_update_evt_hist(hba, UFS_EVT_SUSPEND_ERR, (u32)ret);
+	if (ret) {
+		ufshcd_update_evt_hist(hba, UFS_EVT_WL_SUSP_ERR, (u32)ret);
+		hba->clk_gating.is_suspended = false;
+		ufshcd_release(hba);
+	}
+	hba->pm_op_in_progress = false;
 	return ret;
 }
 
-/**
- * ufshcd_resume - helper function for resume operations
- * @hba: per adapter instance
- * @pm_op: runtime PM or system PM
- *
- * This function basically brings the UFS device, UniPro link and controller
- * to active state.
- *
- * Returns 0 for success and non-zero for failure
- */
-static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+static int __ufshcd_wl_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;
+	enum uic_link_state old_link_state = hba->uic_link_state;
 
-	ufshcd_hba_vreg_set_hpm(hba);
-	ret = ufshcd_vreg_set_hpm(hba);
-	if (ret)
-		goto out;
-
-	/* Make sure clocks are enabled before accessing controller */
-	ret = ufshcd_setup_clocks(hba, true);
-	if (ret)
-		goto disable_vreg;
-
-	/* enable the host irq as host controller would be active soon */
-	ufshcd_enable_irq(hba);
+	hba->pm_op_in_progress = true;
 
 	/*
 	 * Call vendor specific resume callback. As these callbacks may access

@@ -8871,7 +8855,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	 */
 	ret = ufshcd_vops_resume(hba, pm_op);
 	if (ret)
-		goto disable_irq_and_vops_clks;
+		goto out;
 
 	/* For DeepSleep, the only supported option is to have the link off */
 	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));

@@ -8916,31 +8900,147 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		 */
 		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->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);
 	}
 
-	ufshcd_clear_ua_wluns(hba);
-
-	/* Schedule clock gating in case of no access to UFS device yet */
-	ufshcd_release(hba);
-
+	/* Enable Auto-Hibernate if configured */
+	ufshcd_auto_hibern8_enable(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:
+out:
+	if (ret)
+		ufshcd_update_evt_hist(hba, UFS_EVT_WL_RES_ERR, (u32)ret);
+	hba->clk_gating.is_suspended = false;
+	ufshcd_release(hba);
+	hba->pm_op_in_progress = false;
+	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);
+
+	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 = 0;
+	ktime_t start = ktime_get();
+
+	hba = shost_priv(sdev->host);
+
+	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;
+}
+
+#ifdef CONFIG_PM_SLEEP
+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();
+
+	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 = 0;
+	ktime_t start = ktime_get();
+
+	if (pm_runtime_suspended(dev))
+		return 0;
+	hba = shost_priv(sdev->host);
+
+	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;
+}
+#endif
+
+static void ufshcd_wl_shutdown(struct device *dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	struct ufs_hba *hba;
+
+	hba = shost_priv(sdev->host);
+	/* Turn on everything while shutting down */
+	scsi_autopm_get_device(sdev);
+	scsi_device_quiesce(sdev);
+	shost_for_each_device(sdev, hba->host) {
+		if (sdev == hba->sdev_ufs_device)
+			continue;
+		scsi_device_quiesce(sdev);
+	}
+	__ufshcd_wl_suspend(hba, UFS_SHUTDOWN_PM);
+}
+
+/**
+ * ufshcd_suspend - helper function for suspend operations
+ * @hba: per adapter instance
+ *
+ * This function will put disable irqs, turn off clocks
+ * and set vreg and hba-vreg in lpm mode.
+ * Also check the description of __ufshcd_wl_suspend().
+ */
+static void ufshcd_suspend(struct ufs_hba *hba)
+{
+	hba->pm_op_in_progress = 1;
+
+	/*
+	 * Disable the host irq as host controller as there won't be any
+	 * host controller transaction expected till resume.
+	 */
 	ufshcd_disable_irq(hba);
 	ufshcd_setup_clocks(hba, false);
 	if (ufshcd_is_clkgating_allowed(hba)) {

@@ -8948,6 +9048,43 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		trace_ufshcd_clk_gating(dev_name(hba->dev),
 					hba->clk_gating.state);
 	}
+
+	ufshcd_vreg_set_lpm(hba);
+	/* Put the host controller in low power mode if possible */
+	ufshcd_hba_vreg_set_lpm(hba);
+	hba->pm_op_in_progress = 0;
+}
+
+/**
+ * ufshcd_resume - helper function for resume operations
+ * @hba: per adapter instance
+ *
+ * This function basically turns on the regulators, clocks and
+ * irqs of the hba.
+ * Also check the description of __ufshcd_wl_resume().
+ *
+ * Returns 0 for success and non-zero for failure
+ */
+static int ufshcd_resume(struct ufs_hba *hba)
+{
+	int ret;
+
+	hba->pm_op_in_progress = 1;
+
+	ufshcd_hba_vreg_set_hpm(hba);
+	ret = ufshcd_vreg_set_hpm(hba);
+	if (ret)
+		goto out;
+
+	/* Make sure clocks are enabled before accessing controller */
+	ret = ufshcd_setup_clocks(hba, true);
+	if (ret)
+		goto disable_vreg;
+
+	/* enable the host irq as host controller would be active soon */
+	ufshcd_enable_irq(hba);
+	goto out;
+
 disable_vreg:
 	ufshcd_vreg_set_lpm(hba);
 out:

@@ -8962,6 +9099,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
  * @hba: per adapter instance
  *
  * Check the description of ufshcd_suspend() function for more details.
+ * Also check the description of __ufshcd_wl_suspend().
  *
  * Returns 0 for success and non-zero for failure
  */

@@ -8987,21 +9125,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
 	     !hba->dev_info.b_rpm_dev_flush_capable)
 		goto out;
 
-	if (pm_runtime_suspended(hba->dev)) {
-		/*
-		 * UFS device and/or UFS link low power states during runtime
-		 * suspend seems to be different than what is expected during
-		 * system suspend. Hence runtime resume the devic & link and
-		 * let the system suspend low power states to take effect.
-		 * TODO: If resume takes longer time, we might have optimize
-		 * it in future by not resuming everything if possible.
-		 */
-		ret = ufshcd_runtime_resume(hba);
-		if (ret)
-			goto out;
-	}
-
-	ret = ufshcd_suspend(hba, UFS_SYSTEM_PM);
+	ufshcd_suspend(hba);
 out:
 	trace_ufshcd_system_suspend(dev_name(hba->dev), ret,
 		ktime_to_us(ktime_sub(ktime_get(), start)),

@@ -9023,7 +9147,6 @@ EXPORT_SYMBOL(ufshcd_system_suspend);
 
 int ufshcd_system_resume(struct ufs_hba *hba)
 {
-	int ret = 0;
 	ktime_t start = ktime_get();
 
 	if (!hba)

@@ -9034,22 +9157,18 @@ int ufshcd_system_resume(struct ufs_hba *hba)
 		down(&hba->host_sem);
 	}
 
-	if (!hba->is_powered || pm_runtime_suspended(hba->dev))
-		/*
-		 * Let the runtime resume take care of resuming
-		 * if runtime suspended.
-		 */
+	if (!hba->is_powered)
 		goto out;
 	else
-		ret = ufshcd_resume(hba, UFS_SYSTEM_PM);
+		ufshcd_resume(hba);
 out:
-	trace_ufshcd_system_resume(dev_name(hba->dev), ret,
+	trace_ufshcd_system_resume(dev_name(hba->dev), 0,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
 		hba->curr_dev_pwr_mode, hba->uic_link_state);
-	if (!ret)
-		hba->is_sys_suspended = false;
+
+	hba->is_sys_suspended = false;
 	up(&hba->host_sem);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(ufshcd_system_resume);
 

@@ -9058,12 +9177,12 @@ EXPORT_SYMBOL(ufshcd_system_resume);
  * @hba: per adapter instance
  *
  * Check the description of ufshcd_suspend() function for more details.
+ * Also check the description of __ufshcd_wl_suspend().
  *
  * Returns 0 for success and non-zero for failure
  */
 int ufshcd_runtime_suspend(struct ufs_hba *hba)
 {
-	int ret = 0;
 	ktime_t start = ktime_get();
 
 	if (!hba)

@@ -9072,12 +9191,12 @@ int ufshcd_runtime_suspend(struct ufs_hba *hba)
 	if (!hba->is_powered)
 		goto out;
 	else
-		ret = ufshcd_suspend(hba, UFS_RUNTIME_PM);
+		ufshcd_suspend(hba);
 out:
-	trace_ufshcd_runtime_suspend(dev_name(hba->dev), ret,
+	trace_ufshcd_runtime_suspend(dev_name(hba->dev), 0,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
 		hba->curr_dev_pwr_mode, hba->uic_link_state);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(ufshcd_runtime_suspend);
 

@@ -9085,26 +9204,14 @@ EXPORT_SYMBOL(ufshcd_runtime_suspend);
  * ufshcd_runtime_resume - runtime resume routine
  * @hba: per adapter instance
  *
- * This function basically brings the UFS device, UniPro link and controller
+ * This function basically brings controller
  * to active state. Following operations are done in this function:
  *
  * 1. Turn on all the controller related clocks
- * 2. Bring the UniPro link out of Hibernate state
- * 3. If UFS device is in sleep state, turn ON VCC rail and bring the UFS device
- *    to active state.
- * 4. If auto-bkops is enabled on the device, disable it.
- *
- * So following would be the possible power state after this function return
- * successfully:
- *	S1: UFS device in Active state with VCC rail ON
- *	    UniPro link in Active state
- *	    All the UFS/UniPro controller clocks are ON
- *
- * Returns 0 for success and non-zero for failure
+ * 2. Turn ON VCC rail
  */
 int ufshcd_runtime_resume(struct ufs_hba *hba)
 {
-	int ret = 0;
 	ktime_t start = ktime_get();
 
 	if (!hba)

@@ -9113,12 +9220,12 @@ int ufshcd_runtime_resume(struct ufs_hba *hba)
 	if (!hba->is_powered)
 		goto out;
 	else
-		ret = ufshcd_resume(hba, UFS_RUNTIME_PM);
+		ufshcd_resume(hba);
 out:
-	trace_ufshcd_runtime_resume(dev_name(hba->dev), ret,
+	trace_ufshcd_runtime_resume(dev_name(hba->dev), 0,
 		ktime_to_us(ktime_sub(ktime_get(), start)),
 		hba->curr_dev_pwr_mode, hba->uic_link_state);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(ufshcd_runtime_resume);
 

@@ -9132,14 +9239,13 @@ EXPORT_SYMBOL(ufshcd_runtime_idle);
  * ufshcd_shutdown - shutdown routine
  * @hba: per adapter instance
  *
- * This function would power off both UFS device and UFS link.
+ * This function would turn off both UFS device and UFS hba
+ * regulators. It would also disable clocks.

drivers/scsi/ufs/ufshcd.c +153 -0

@@ -9477,15 +9581,172 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 }
 EXPORT_SYMBOL_GPL(ufshcd_init);
 
+void ufshcd_resume_complete(struct device *dev)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	pm_runtime_put_noidle(&hba->sdev_ufs_device->sdev_gendev);
+}
+EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
+
+int ufshcd_suspend_prepare(struct device *dev)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+
+	/*
+	 * SCSI assumes that runtime-pm and system-pm for scsi drivers
+	 * are same. And it doesn't wake up the device for system-suspend
+	 * if it's runtime suspended. But ufs doesn't follow that.
+	 * The rpm-lvl and spm-lvl can be different in ufs.
+	 * Force it to honor system-suspend.
+	 */
+	scsi_autopm_get_device(hba->sdev_ufs_device);
+	/* Refer ufshcd_resume_complete() */
+	pm_runtime_get_noresume(&hba->sdev_ufs_device->sdev_gendev);
+	scsi_autopm_put_device(hba->sdev_ufs_device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
+
+#ifdef CONFIG_PM_SLEEP
+static int ufshcd_wl_poweroff(struct device *dev)
+{
+	ufshcd_wl_shutdown(dev);
+	return 0;
+}
+#endif
+
+static int ufshcd_wl_probe(struct device *dev)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+
+	if (!is_device_wlun(sdev))
+		return -ENODEV;
+
+	blk_pm_runtime_init(sdev->request_queue, dev);
+	pm_runtime_set_autosuspend_delay(dev, 0);
+	pm_runtime_allow(dev);
+
+	return  0;
+}
+
+static int ufshcd_wl_remove(struct device *dev)
+{
+	pm_runtime_forbid(dev);
+	return 0;
+}
+
+static const struct dev_pm_ops ufshcd_wl_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend = ufshcd_wl_suspend,
+	.resume = ufshcd_wl_resume,
+	.freeze = ufshcd_wl_suspend,
+	.thaw = ufshcd_wl_resume,
+	.poweroff = ufshcd_wl_poweroff,
+	.restore = ufshcd_wl_resume,
+#endif
+	SET_RUNTIME_PM_OPS(ufshcd_wl_runtime_suspend, ufshcd_wl_runtime_resume, NULL)
+};
+
+/**
+ * ufs_dev_wlun_template - describes ufs device wlun
+ * ufs-device wlun - used to send pm commands
+ * All luns 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_dev_wlun_template = {
+	.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,
+	},
+};
+
+static int ufshcd_rpmb_probe(struct device *dev)
+{
+	return is_rpmb_wlun(to_scsi_device(dev)) ? 0 : -ENODEV;
+}
+
+static inline int ufshcd_clear_rpmb_uac(struct ufs_hba *hba)
+{
+	int ret = 0;
+
+	if (!hba->wlun_rpmb_clr_ua)
+		return 0;
+	ret = ufshcd_clear_ua_wlun(hba, UFS_UPIU_RPMB_WLUN);
+	if (!ret)
+		hba->wlun_rpmb_clr_ua = 0;
+	return ret;
+}
+
+static int ufshcd_rpmb_runtime_resume(struct device *dev)
+{
+	struct ufs_hba *hba = wlun_dev_to_hba(dev);
+
+	if (hba->sdev_rpmb)
+		return ufshcd_clear_rpmb_uac(hba);
+	return 0;
+}
+
+static int ufshcd_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_rpmb_uac(hba);
+	return 0;
+}
+
+static const struct dev_pm_ops ufs_rpmb_pm_ops = {
+	SET_RUNTIME_PM_OPS(NULL, ufshcd_rpmb_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(NULL, ufshcd_rpmb_resume)
+};
+
+/**
+ * Describes the ufs rpmb wlun.
+ * Used only to send uac.
+ */
+static struct scsi_driver ufs_rpmb_wlun_template = {
+	.gendrv = {
+		.name = "ufs_rpmb_wlun",
+		.owner = THIS_MODULE,
+		.probe = ufshcd_rpmb_probe,
+		.pm = &ufs_rpmb_pm_ops,
+	},
+};
+
 static int __init ufshcd_core_init(void)
 {
+	int ret;
+
 	ufs_debugfs_init();
+
+	ret = scsi_register_driver(&ufs_dev_wlun_template.gendrv);
+	if (ret) {
+		ufs_debugfs_exit();
+		return ret;
+	}
+	ret = scsi_register_driver(&ufs_rpmb_wlun_template.gendrv);
+	if (ret) {
+		ufs_debugfs_exit();
+		scsi_unregister_driver(&ufs_dev_wlun_template.gendrv);

drivers/scsi/ufs/ufshcd.c +0 -0

 }
 
 module_init(ufshcd_core_init);

drivers/scsi/ufs/ufshcd.h +6 -0

index ee61f82..7841b2a 100644
@@ -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,

@@ -804,6 +806,7 @@ struct ufs_hba {
 	struct list_head clk_list_head;
 
 	bool wlun_dev_clr_ua;
+	bool wlun_rpmb_clr_ua;
 
 	/* Number of requests aborts */
 	int req_abort_count;

@@ -841,6 +844,7 @@ struct ufs_hba {
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs_root;
 #endif
+	u32 luns_avail;
 };
 
 /* Returns true if clocks can be gated. Otherwise false */

@@ -1100,6 +1104,8 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
 			     enum query_opcode desc_op);
 
 int ufshcd_wb_ctrl(struct ufs_hba *hba, bool enable);
+int ufshcd_suspend_prepare(struct device *dev);
+void ufshcd_resume_complete(struct device *dev);
 
 /* Wrapper functions for safely calling variant operations */
 static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)

include/trace/events/ufs.h +13 -0

index e151477..d9d233b 100644
@@ -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),

This patch attempts to fix a deadlock in ufs while sending SSU. Recently, blk_queue_enter() added a check to not process requests if the queue is suspended. That leads to a resume of the associated device which is suspended. In ufs, that device is ufs device wlun and it's parent is ufs_hba. This resume tries to resume ufs device wlun which in turn tries to resume ufs_hba, which is already in the process of suspending, thus causing a deadlock.

This patch takes care of:
* Suspending the ufs device lun only after all other luns are suspended
* Sending SSU during ufs device wlun suspend
* Clearing uac for rpmb and ufs device wlun
* Not sending commands to the device during host suspend

v12 -> v13:
- Addressed Adrian's comments
* Paired pm_runtime_get_noresume() with pm_runtime_put()
* no rpm_autosuspend for ufs device wlun
* Moved runtime-pm init functionality to ufshcd_wl_probe()
- Addressed Bart's comments
* Expanded abbrevs in commit message

v11 -> v12:
- Addressed Adrian's comments
* Fixed ahit for Mediatek driver
* Fixed error handling in ufshcd_core_init()
* Tested this patch and the issue is still seen.

v10 -> v11:
- Fixed supplier suspending before consumer race
- Addressed Adrian's comments
* Added proper resume/suspend cb to ufshcd_auto_hibern8_update()
* Cosmetic changes to ufshcd-pci.c
* Cleaned up ufshcd_system_suspend()
* Added ufshcd_debugfs_eh_exit to ufshcd_core_init()

v9 -> v10:
- Addressed Adrian's comments
* Moved suspend/resume vops to __ufshcd_wl_[suspend/resume]()
* Added correct resume in ufs_bsg

v8 -> v9:
- Addressed Adrian's comments
* Moved link transition to __ufshcd_wl_[suspend/resume]()
* Fixed the other minor comments

v7 -> v8:
- Addressed Adrian's comments
* Removed separate autosuspend delay for ufs-device lun
* Fixed the ee handler getting scheduled during pm
* Always runtime resume in suspend_prepare()
* Added CONFIG_PM_SLEEP where needed

v6 -> v7:
* Resume the ufs device before shutting it down

v5 -> v6:
- Addressed Adrian's comments
* Added complete() cb
* Added suspend_prepare() and complete() to all drivers
* Moved suspend_prepare() and complete() to ufshcd
* .poweroff() uses ufhcd_wl_poweroff()
* Removed several forward declarations
* Moved scsi_register_driver() to ufshcd_core_init()

v4 -> v5:
- Addressed Adrian's comments
* Used the rpmb driver contributed by Adrian
* Runtime-resume the ufs device during suspend to honor spm-lvl
* Unregister the scsi_driver in ufshcd_remove()
* Currently shutdown() puts the ufs device to power-down mode so, just removed ufshcd_pci_poweroff()
* Quiesce the scsi device during shutdown instead of remove

v3 RFC -> v4:
- Addressed Bart's comments
* Except that I didn't get any checkpatch failures
- Addressed Avri's comments
- Addressed Adrian's comments
* Added a check for deepsleep power mode
* Removed a couple of forward declarations
* Didn't separate the scsi drivers because in rpmb case it just sends uac in resume and it seemed pretty neat to me.
- Added sysfs changes to resume the devices before accessing

Asutosh Das (2):
scsi: ufs: Enable power management for wlun
ufs: sysfs: Resume the proper scsi device

  drivers/scsi/ufs/cdns-pltfrm.c     |   2 +
  drivers/scsi/ufs/tc-dwc-g210-pci.c |   2 +
  drivers/scsi/ufs/ufs-debugfs.c     |   2 +-
  drivers/scsi/ufs/ufs-debugfs.h     |   2 +-
  drivers/scsi/ufs/ufs-exynos.c      |   2 +
  drivers/scsi/ufs/ufs-hisi.c        |   2 +
  drivers/scsi/ufs/ufs-mediatek.c    |  12 +-
  drivers/scsi/ufs/ufs-qcom.c        |   2 +
  drivers/scsi/ufs/ufs-sysfs.c       |  30 +-
  drivers/scsi/ufs/ufs_bsg.c         |   6 +-
  drivers/scsi/ufs/ufshcd-pci.c      |  36 +--
  drivers/scsi/ufs/ufshcd.c          | 627 ++++++++++++++++++++++++++-----------
  drivers/scsi/ufs/ufshcd.h          |   6 +
  include/trace/events/ufs.h         |  20 ++
  14 files changed, 513 insertions(+), 238 deletions(-)

Quoted 14 lines · Asutosh Das

This patch attempts to fix a deadlock in ufs while sending SSU. Recently, blk_queue_enter() added a check to not process requests if the queue is suspended. That leads to a resume of the associated device which is suspended. In ufs, that device is ufs device wlun and it's parent is ufs_hba. This resume tries to resume ufs device wlun which in turn tries to resume ufs_hba, which is already in the process of suspending, thus causing a deadlock.

This patch takes care of:
* Suspending the ufs device lun only after all other luns are suspended
* Sending SSU during ufs device wlun suspend
* Clearing uac for rpmb and ufs device wlun
* Not sending commands to the device during host suspend

Quoted 8 lines

v12 -> v13:
- Addressed Adrian's comments
   * Paired pm_runtime_get_noresume() with pm_runtime_put()
   * no rpm_autosuspend for ufs device wlun
   * Moved runtime-pm init functionality to ufshcd_wl_probe()
- Addressed Bart's comments
   * Expanded abbrevs in commit message

Hi Adrian
I did a limited testing on your fix in the pm framework along with this v13 patchset. I couldn't reproduce the issue.

I'd appreciate if you can please take a look at the v13 changes. If all looks good in that, I'd do an extensive testing.