[RFC PATCH v2 0/5] scsi: ufs: Add Host Performance Booster Support

[RFC PATCH v2 0/5] scsi: ufs: Add Host Performance Booster Support

[Daejun Park]

NAND flash memory-based storage devices use Flash Translation Layer (FTL)
to translate logical addresses of I/O requests to corresponding flash
memory addresses. Mobile storage devices typically have RAM with
constrained size, thus lack in memory to keep the whole mapping table.
Therefore, mapping tables are partially retrieved from NAND flash on
demand, causing random-read performance degradation.

To improve random read performance, JESD220-3 (HPB v1.0) proposes HPB
(Host Performance Booster) which uses host system memory as a cache for the
FTL mapping table. By using HPB, FTL data can be read from host memory
faster than from NAND flash memory. 

The current version only supports the DCM (device control mode).
This patch consists of 4 parts to support HPB feature.

1) UFS-feature layer
2) HPB probe and initialization process
3) READ -> HPB READ using cached map information
4) L2P (logical to physical) map management

The UFS-feature is an additional layer to avoid the structure in which the
UFS-core driver and the UFS-feature are entangled with each other in a 
single module.
By adding the layer, UFS-features composed of various combinations can be
supported. Also, even if a new feature is added, modification of the 
UFS-core driver can be minimized.

In the HPB probe and init process, the device information of the UFS is
queried. After checking supported features, the data structure for the HPB
is initialized according to the device information.

A read I/O in the active sub-region where the map is cached is changed to
HPB READ by the HPB module.

The HPB module manages the L2P map using information received from the
device. For active sub-region, the HPB module caches through ufshpb_map
request. For the in-active region, the HPB module discards the L2P map.
When a write I/O occurs in an active sub-region area, associated dirty
bitmap checked as dirty for preventing stale read.

HPB is shown to have a performance improvement of 58 - 67% for random read
workload. [1]

This series patches are based on the 5.8/scsi-queue branch.

[1]:
https://www.usenix.org/conference/hotstorage17/program/presentation/jeong

Changelog:

v1 -> v2
1. Change sub-region context DS static allocation to dynamic allocation.
2. Change the full boilerplate text to SPDX style.
3. Other cleanups.

Daejun park (5):
 scsi: ufs: Add UFS feature related parameter
 scsi: ufs: Add UFS feature layer
 scsi: ufs: Introduce HPB module
 scsi: ufs: L2P map management for HPB read
 scsi: ufs: Prepare HPB read for cached sub-region
 
 drivers/scsi/ufs/Kconfig      |    9 +
 drivers/scsi/ufs/Makefile     |    3 +-
 drivers/scsi/ufs/ufs.h        |   12 +
 drivers/scsi/ufs/ufsfeature.c |  148 +++
 drivers/scsi/ufs/ufsfeature.h |   69 ++
 drivers/scsi/ufs/ufshcd.c     |   19 +
 drivers/scsi/ufs/ufshcd.h     |    3 +
 drivers/scsi/ufs/ufshpb.c     | 1988 ++++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshpb.h     |  234 +++++
 9 files changed, 2484 insertions(+), 1 deletion(-)
 created mode 100644 drivers/scsi/ufs/ufsfeature.c
 created mode 100644 drivers/scsi/ufs/ufsfeature.h
 created mode 100644 drivers/scsi/ufs/ufshpb.c
 created mode 100644 drivers/scsi/ufs/ufshpb.h

[RFC PATCH v2 1/5] scsi: ufs: Add UFS feature related parameter

[Daejun Park]

This is a patch for parameters to be used for UFS features layer and HPB
module.

Signed-off-by: Daejun Park <daejun7.park@samsung.com>
---
 drivers/scsi/ufs/ufs.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index c70845d41449..f3efa3424fc0 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -146,6 +146,7 @@ enum flag_idn {
 	QUERY_FLAG_IDN_WB_EN                            = 0x0E,
 	QUERY_FLAG_IDN_WB_BUFF_FLUSH_EN                 = 0x0F,
 	QUERY_FLAG_IDN_WB_BUFF_FLUSH_DURING_HIBERN8     = 0x10,
+	QUERY_FLAG_IDN_HPB_RESET                        = 0x11,
 };
 
 /* Attribute idn for Query requests */
@@ -229,6 +230,9 @@ enum unit_desc_param {
 	UNIT_DESC_PARAM_PHY_MEM_RSRC_CNT	= 0x18,
 	UNIT_DESC_PARAM_CTX_CAPABILITIES	= 0x20,
 	UNIT_DESC_PARAM_LARGE_UNIT_SIZE_M1	= 0x22,
+	UNIT_DESC_HPB_LU_MAX_ACTIVE_REGIONS	= 0x23,
+	UNIT_DESC_HPB_LU_PIN_REGION_START_OFFSET	= 0x25,
+	UNIT_DESC_HPB_LU_NUM_PIN_REGIONS	= 0x27,
 	UNIT_DESC_PARAM_WB_BUF_ALLOC_UNITS	= 0x29,
 };
 
@@ -269,6 +273,8 @@ enum device_desc_param {
 	DEVICE_DESC_PARAM_PSA_MAX_DATA		= 0x25,
 	DEVICE_DESC_PARAM_PSA_TMT		= 0x29,
 	DEVICE_DESC_PARAM_PRDCT_REV		= 0x2A,
+	DEVICE_DESC_PARAM_HPB_VER		= 0x40,
+	DEVICE_DESC_PARAM_HPB_CONTROL		= 0x42,
 	DEVICE_DESC_PARAM_EXT_UFS_FEATURE_SUP	= 0x4F,
 	DEVICE_DESC_PARAM_WB_PRESRV_USRSPC_EN	= 0x53,
 	DEVICE_DESC_PARAM_WB_TYPE		= 0x54,
@@ -317,6 +323,10 @@ enum geometry_desc_param {
 	GEOMETRY_DESC_PARAM_ENM4_MAX_NUM_UNITS	= 0x3E,
 	GEOMETRY_DESC_PARAM_ENM4_CAP_ADJ_FCTR	= 0x42,
 	GEOMETRY_DESC_PARAM_OPT_LOG_BLK_SIZE	= 0x44,
+	GEOMETRY_DESC_HPB_REGION_SIZE		= 0x48,
+	GEOMETRY_DESC_HPB_NUMBER_LU		= 0x49,
+	GEOMETRY_DESC_HPB_SUBREGION_SIZE	= 0x4A,
+	GEOMETRY_DESC_HPB_DEVICE_MAX_ACTIVE_REGIONS	= 0x4B,
 	GEOMETRY_DESC_PARAM_WB_MAX_ALLOC_UNITS	= 0x4F,
 	GEOMETRY_DESC_PARAM_WB_MAX_WB_LUNS	= 0x53,
 	GEOMETRY_DESC_PARAM_WB_BUFF_CAP_ADJ	= 0x54,
@@ -361,6 +371,7 @@ enum {
 
 /* Possible values for dExtendedUFSFeaturesSupport */
 enum {
+	UFS_DEV_HPB_SUPPORT		= BIT(7),
 	UFS_DEV_WRITE_BOOSTER_SUP	= BIT(8),
 };
 
@@ -571,6 +582,7 @@ struct ufs_dev_info {
 	u8 *model;
 	u16 wspecversion;
 	u32 clk_gating_wait_us;
+	u8 b_ufs_feature_sup;
 	u32 d_ext_ufs_feature_sup;
 	u8 b_wb_buffer_type;
 	u32 d_wb_alloc_units;
-- 
2.17.1

[RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Daejun Park]

This patch is adding UFS feature layer to UFS core driver.

UFS Driver data structure (struct ufs_hba)
	│
┌--------------┐
│ UFS feature  │ <-- HPB module
│    layer     │ <-- other extended feature module
└--------------┘
Each extended UFS-Feature module has a bus of ufs-ext feature type.
The UFS feature layer manages common APIs used by each extended feature
module. The APIs are set of UFS Query requests and UFS Vendor commands
related to each extended feature module.

Other extended features can also be implemented using the proposed APIs.
For example, in Write Booster, "prep_fn" can be used to guarantee the
lifetime of UFS by updating the amount of write IO.
And reset/reset_host/suspend/resume can be used to manage the kernel task
for checking lifetime of UFS.

The following 6 callback functions have been added to "ufshcd.c".
prep_fn: called after construct upiu structure
reset: called after proving hba
reset_host: called before ufshcd_host_reset_and_restore
suspend: called before ufshcd_suspend
resume: called after ufshcd_resume
rsp_upiu: called in ufshcd_transfer_rsp_status with SAM_STAT_GOOD state

Signed-off-by: Daejun Park <daejun7.park@samsung.com>
---
 drivers/scsi/ufs/Makefile     |   2 +-
 drivers/scsi/ufs/ufsfeature.c | 148 ++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufsfeature.h |  69 ++++++++++++++++
 drivers/scsi/ufs/ufshcd.c     |  17 ++++
 drivers/scsi/ufs/ufshcd.h     |   3 +
 5 files changed, 238 insertions(+), 1 deletion(-)
 create mode 100644 drivers/scsi/ufs/ufsfeature.c
 create mode 100644 drivers/scsi/ufs/ufsfeature.h

diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index 94c6c5d7334b..fe3a92b06c87 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -5,7 +5,7 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-d
 obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
 obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
 obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
-ufshcd-core-y				+= ufshcd.o ufs-sysfs.o
+ufshcd-core-y				+= ufshcd.o ufs-sysfs.o ufsfeature.o
 ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
 obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
 obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o
diff --git a/drivers/scsi/ufs/ufsfeature.c b/drivers/scsi/ufs/ufsfeature.c
new file mode 100644
index 000000000000..94c6be6babd3
--- /dev/null
+++ b/drivers/scsi/ufs/ufsfeature.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Universal Flash Storage Feature Support
+ *
+ * Copyright (C) 2017-2018 Samsung Electronics Co., Ltd.
+ *
+ * Authors:
+ *	Yongmyung Lee <ymhungry.lee@samsung.com>
+ *	Jinyoung Choi <j-young.choi@samsung.com>
+ */
+
+#include "ufshcd.h"
+#include "ufsfeature.h"
+
+inline void ufsf_slave_configure(struct ufs_hba *hba,
+				 struct scsi_device *sdev)
+{
+	/* skip well-known LU */
+	if (sdev->lun >= UFS_UPIU_MAX_UNIT_NUM_ID)
+		return;
+
+	if (!(hba->dev_info.b_ufs_feature_sup & UFS_DEV_HPB_SUPPORT))
+		return;
+
+	atomic_inc(&hba->ufsf.slave_conf_cnt);
+
+	wake_up(&hba->ufsf.sdev_wait);
+}
+
+inline void ufsf_ops_prep_fn(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	struct ufshpb_driver *ufshpb_drv;
+
+	ufshpb_drv = dev_get_drvdata(&hba->ufsf.hpb_dev);
+
+	if (ufshpb_drv && ufshpb_drv->ufshpb_ops.prep_fn)
+		ufshpb_drv->ufshpb_ops.prep_fn(hba, lrbp);
+}
+
+inline void ufsf_ops_rsp_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	struct ufshpb_driver *ufshpb_drv;
+
+	ufshpb_drv = dev_get_drvdata(&hba->ufsf.hpb_dev);
+
+	if (ufshpb_drv && ufshpb_drv->ufshpb_ops.rsp_upiu)
+		ufshpb_drv->ufshpb_ops.rsp_upiu(hba, lrbp);
+}
+
+inline void ufsf_ops_reset_host(struct ufs_hba *hba)
+{
+	struct ufshpb_driver *ufshpb_drv;
+
+	ufshpb_drv = dev_get_drvdata(&hba->ufsf.hpb_dev);
+
+	if (ufshpb_drv && ufshpb_drv->ufshpb_ops.reset_host)
+		ufshpb_drv->ufshpb_ops.reset_host(hba);
+}
+
+inline void ufsf_ops_reset(struct ufs_hba *hba)
+{
+	struct ufshpb_driver *ufshpb_drv;
+
+	ufshpb_drv = dev_get_drvdata(&hba->ufsf.hpb_dev);
+
+	if (ufshpb_drv && ufshpb_drv->ufshpb_ops.reset)
+		ufshpb_drv->ufshpb_ops.reset(hba);
+}
+
+inline void ufsf_ops_suspend(struct ufs_hba *hba)
+{
+	struct ufshpb_driver *ufshpb_drv;
+
+	ufshpb_drv = dev_get_drvdata(&hba->ufsf.hpb_dev);
+
+	if (ufshpb_drv && ufshpb_drv->ufshpb_ops.suspend)
+		ufshpb_drv->ufshpb_ops.suspend(hba);
+}
+
+inline void ufsf_ops_resume(struct ufs_hba *hba)
+{
+	struct ufshpb_driver *ufshpb_drv;
+
+	ufshpb_drv = dev_get_drvdata(&hba->ufsf.hpb_dev);
+
+	if (ufshpb_drv && ufshpb_drv->ufshpb_ops.resume)
+		ufshpb_drv->ufshpb_ops.resume(hba);
+}
+
+struct device_type ufshpb_dev_type = {
+	.name = "ufshpb_device"
+};
+EXPORT_SYMBOL(ufshpb_dev_type);
+
+static int ufsf_bus_match(struct device *dev,
+			 struct device_driver *gendrv)
+{
+	if (dev->type == &ufshpb_dev_type)
+		return 1;
+
+	return 0;
+}
+
+struct bus_type ufsf_bus_type = {
+	.name = "ufsf_bus",
+	.match = ufsf_bus_match,
+};
+EXPORT_SYMBOL(ufsf_bus_type);
+
+static void ufsf_dev_release(struct device *dev)
+{
+	put_device(dev->parent);
+}
+
+void ufsf_scan_features(struct ufs_hba *hba)
+{
+	int ret;
+
+	init_waitqueue_head(&hba->ufsf.sdev_wait);
+	atomic_set(&hba->ufsf.slave_conf_cnt, 0);
+
+	if (hba->dev_info.wspecversion >= HPB_SUPPORTED_VERSION &&
+	    (hba->dev_info.b_ufs_feature_sup & UFS_DEV_HPB_SUPPORT)) {
+		device_initialize(&hba->ufsf.hpb_dev);
+
+		hba->ufsf.hpb_dev.bus = &ufsf_bus_type;
+		hba->ufsf.hpb_dev.type = &ufshpb_dev_type;
+		hba->ufsf.hpb_dev.parent = get_device(hba->dev);
+		hba->ufsf.hpb_dev.release = ufsf_dev_release;
+
+		dev_set_name(&hba->ufsf.hpb_dev, "ufshpb");
+		ret = device_add(&hba->ufsf.hpb_dev);
+		if (ret)
+			dev_warn(hba->dev, "ufshpb: failed to add device\n");
+	}
+}
+
+static int __init ufsf_init(void)
+{
+	int ret;
+
+	ret = bus_register(&ufsf_bus_type);
+	if (ret)
+		pr_err("%s bus_register failed\n", __func__);
+
+	return ret;
+}
+device_initcall(ufsf_init);
diff --git a/drivers/scsi/ufs/ufsfeature.h b/drivers/scsi/ufs/ufsfeature.h
new file mode 100644
index 000000000000..1822d9d8e745
--- /dev/null
+++ b/drivers/scsi/ufs/ufsfeature.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Universal Flash Storage Feature Support
+ *
+ * Copyright (C) 2017-2018 Samsung Electronics Co., Ltd.
+ *
+ * Authors:
+ *	Yongmyung Lee <ymhungry.lee@samsung.com>
+ *	Jinyoung Choi <j-young.choi@samsung.com>
+ */
+
+#ifndef _UFSFEATURE_H_
+#define _UFSFEATURE_H_
+
+#define HPB_SUPPORTED_VERSION			0x0310
+
+struct ufs_hba;
+struct ufshcd_lrb;
+
+/**
+ * struct ufsf_operation - UFS feature specific callbacks
+ * @prep_fn: called after construct upiu structure. The prep_fn should work
+ *	     properly even if it processes the same SCSI command multiple
+ *	     times by requeuing.
+ * @reset: called after probing hba
+ * @reset_host: called before ufshcd_host_reset_and_restore
+ * @suspend: called before ufshcd_suspend
+ * @resume: called after ufshcd_resume
+ * @rsp_upiu: called in ufshcd_transfer_rsp_status with SAM_STAT_GOOD state
+ */
+struct ufsf_operation {
+	void (*prep_fn)(struct ufs_hba *hba, struct ufshcd_lrb *lrbp);
+	void (*reset)(struct ufs_hba *hba);
+	void (*reset_host)(struct ufs_hba *hba);
+	void (*suspend)(struct ufs_hba *hba);
+	void (*resume)(struct ufs_hba *hba);
+	void (*rsp_upiu)(struct ufs_hba *hba, struct ufshcd_lrb *lrbp);
+};
+
+struct ufshpb_driver {
+	struct device_driver drv;
+	struct list_head lh_hpb_lu;
+
+	struct ufsf_operation ufshpb_ops;
+
+	/* memory management */
+	struct kmem_cache *ufshpb_mctx_cache;
+	mempool_t *ufshpb_mctx_pool;
+	mempool_t *ufshpb_page_pool;
+
+	struct workqueue_struct *ufshpb_wq;
+};
+
+struct ufsf_feature_info {
+	atomic_t slave_conf_cnt;
+	wait_queue_head_t sdev_wait;
+	struct device hpb_dev;
+};
+
+void ufsf_slave_configure(struct ufs_hba *hba, struct scsi_device *sdev);
+void ufsf_scan_features(struct ufs_hba *hba);
+void ufsf_ops_prep_fn(struct ufs_hba *hba, struct ufshcd_lrb *lrbp);
+void ufsf_ops_rsp_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp);
+void ufsf_ops_reset_host(struct ufs_hba *hba);
+void ufsf_ops_reset(struct ufs_hba *hba);
+void ufsf_ops_suspend(struct ufs_hba *hba);
+void ufsf_ops_resume(struct ufs_hba *hba);
+
+#endif /* End of Header */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ad4fc829cbb2..74849c742c0f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -2525,6 +2525,8 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 
 	ufshcd_comp_scsi_upiu(hba, lrbp);
 
+	ufsf_ops_prep_fn(hba, lrbp);
+
 	err = ufshcd_map_sg(hba, lrbp);
 	if (err) {
 		lrbp->cmd = NULL;
@@ -4645,6 +4647,8 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
 	struct ufs_hba *hba = shost_priv(sdev->host);
 	struct request_queue *q = sdev->request_queue;
 
+	ufsf_slave_configure(hba, sdev);
+
 	blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
 
 	if (ufshcd_is_rpm_autosuspend_allowed(hba))
@@ -4765,6 +4769,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 				 */
 				pm_runtime_get_noresume(hba->dev);
 			}
+
+			if (scsi_status == SAM_STAT_GOOD)
+				ufsf_ops_rsp_upiu(hba, lrbp);
 			break;
 		case UPIU_TRANSACTION_REJECT_UPIU:
 			/* TODO: handle Reject UPIU Response */
@@ -6508,6 +6515,8 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	 * Stop the host controller and complete the requests
 	 * cleared by h/w
 	 */
+	ufsf_ops_reset_host(hba);
+
 	ufshcd_hba_stop(hba);
 
 	spin_lock_irqsave(hba->host->host_lock, flags);
@@ -6934,6 +6943,7 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 	/* getting Specification Version in big endian format */
 	dev_info->wspecversion = desc_buf[DEVICE_DESC_PARAM_SPEC_VER] << 8 |
 				      desc_buf[DEVICE_DESC_PARAM_SPEC_VER + 1];
+	dev_info->b_ufs_feature_sup = desc_buf[DEVICE_DESC_PARAM_UFS_FEAT];
 
 	model_index = desc_buf[DEVICE_DESC_PARAM_PRDCT_NAME];
 
@@ -7350,6 +7360,7 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
 	}
 
 	ufs_bsg_probe(hba);
+	ufsf_scan_features(hba);
 	scsi_scan_host(hba->host);
 	pm_runtime_put_sync(hba->dev);
 
@@ -7438,6 +7449,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
 	/* Enable Auto-Hibernate if configured */
 	ufshcd_auto_hibern8_enable(hba);
 
+	ufsf_ops_reset(hba);
 out:
 
 	trace_ufshcd_init(dev_name(hba->dev), ret,
@@ -8195,6 +8207,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		req_link_state = UIC_LINK_OFF_STATE;
 	}
 
+	ufsf_ops_suspend(hba);
+
 	/*
 	 * If we can't transition into any of the low power modes
 	 * just gate the clocks.
@@ -8316,6 +8330,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	hba->clk_gating.is_suspended = false;
 	hba->dev_info.b_rpm_dev_flush_capable = false;
 	ufshcd_release(hba);
+	ufsf_ops_resume(hba);
 out:
 	if (hba->dev_info.b_rpm_dev_flush_capable) {
 		schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
@@ -8412,6 +8427,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	/* Enable Auto-Hibernate if configured */
 	ufshcd_auto_hibern8_enable(hba);
 
+	ufsf_ops_resume(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);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index bf97d616e597..47866ab722ff 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -71,6 +71,7 @@
 #include "ufs.h"
 #include "ufs_quirks.h"
 #include "ufshci.h"
+#include "ufsfeature.h"
 
 #define UFSHCD "ufshcd"
 #define UFSHCD_DRIVER_VERSION "0.2"
@@ -746,6 +747,8 @@ struct ufs_hba {
 	bool wb_buf_flush_enabled;
 	bool wb_enabled;
 	struct delayed_work rpm_dev_flush_recheck_work;
+
+	struct ufsf_feature_info ufsf;
 };
 
 /* Returns true if clocks can be gated. Otherwise false */
-- 
2.17.1

[RFC PATCH v2 3/5] scsi: ufs: Introduce HPB module

[Daejun Park]

This is a patch for the HPB module.
The HPB module queries UFS for device information during initialization.
We added the export symbol to two functions in ufshcd.c to initialize
the HPB module.

The HPB module can be loaded or built-in as needed.
The mininum size of the memory pool used in the HPB module is implemented
as a module parameter, so that it can be configurable by the user.

To gurantee a minimum memory pool size of 4MB:
$ insmod ufshpb.ko ufshpb_host_map_kbytes=4096

Signed-off-by: Daejun Park <daejun7.park@samsung.com>
---
 drivers/scsi/ufs/Kconfig  |   9 +
 drivers/scsi/ufs/Makefile |   1 +
 drivers/scsi/ufs/ufshcd.c |   2 +
 drivers/scsi/ufs/ufshpb.c | 789 ++++++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufshpb.h | 162 ++++++++
 5 files changed, 963 insertions(+)
 create mode 100644 drivers/scsi/ufs/ufshpb.c
 create mode 100644 drivers/scsi/ufs/ufshpb.h

diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index e2005aeddc2d..f7c79c369f1d 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -160,3 +160,12 @@ config SCSI_UFS_BSG
 
 	  Select this if you need a bsg device node for your UFS controller.
 	  If unsure, say N.
+
+config UFSHPB
+	tristate "Support UFS Host Performance Booster"
+	depends on SCSI_UFSHCD
+	help
+	  A UFS HPB Feature improves random read performance. It caches
+	  L2P map of UFS to host DRAM. The driver uses HPB read command
+	  by piggybacking physical page number for bypassing FTL's L2P address
+	  translation.
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index fe3a92b06c87..0baf28d674c6 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
 obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
 ufshcd-core-y				+= ufshcd.o ufs-sysfs.o ufsfeature.o
 ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
+obj-$(CONFIG_UFSHPB) += ufshpb.o
 obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
 obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o
 obj-$(CONFIG_SCSI_UFS_HISI) += ufs-hisi.o
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 74849c742c0f..2f334a0b6bd6 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -2855,6 +2855,7 @@ int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
 	ufshcd_release(hba);
 	return err;
 }
+EXPORT_SYMBOL(ufshcd_query_flag);
 
 /**
  * ufshcd_query_attr - API function for sending attribute requests
@@ -3053,6 +3054,7 @@ int ufshcd_query_descriptor_retry(struct ufs_hba *hba,
 
 	return err;
 }
+EXPORT_SYMBOL(ufshcd_query_descriptor_retry);
 
 /**
  * ufshcd_read_desc_length - read the specified descriptor length from header
diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
new file mode 100644
index 000000000000..07490679d2f1
--- /dev/null
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -0,0 +1,789 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Universal Flash Storage Host Performance Booster
+ *
+ * Copyright (C) 2017-2018 Samsung Electronics Co., Ltd.
+ *
+ * Authors:
+ *	Yongmyung Lee <ymhungry.lee@samsung.com>
+ *	Jinyoung Choi <j-young.choi@samsung.com>
+ */
+
+#include <asm/unaligned.h>
+
+#include "ufshcd.h"
+#include "ufshpb.h"
+
+static struct ufshpb_driver ufshpb_drv;
+
+static int ufshpb_create_sysfs(struct ufs_hba *hba, struct ufshpb_lu *hpb);
+
+static inline int ufshpb_is_valid_srgn(struct ufshpb_region *rgn,
+			     struct ufshpb_subregion *srgn)
+{
+	return rgn->rgn_state != HPB_RGN_INACTIVE &&
+		srgn->srgn_state == HPB_SRGN_VALID;
+}
+
+static inline int ufshpb_get_state(struct ufshpb_lu *hpb)
+{
+	return atomic_read(&hpb->hpb_state);
+}
+
+static inline void ufshpb_set_state(struct ufshpb_lu *hpb, int state)
+{
+	atomic_set(&hpb->hpb_state, state);
+}
+
+static inline int ufshpb_lu_get_dev(struct ufshpb_lu *hpb)
+{
+	if (get_device(&hpb->hpb_lu_dev))
+		return 0;
+
+	return -ENODEV;
+}
+
+static inline int ufshpb_lu_get(struct ufshpb_lu *hpb)
+{
+	if (!hpb || (ufshpb_get_state(hpb) != HPB_PRESENT))
+		return -ENODEV;
+
+	if (ufshpb_lu_get_dev(hpb))
+		return -ENODEV;
+
+	return 0;
+}
+
+static inline void ufshpb_lu_put(struct ufshpb_lu *hpb)
+{
+	put_device(&hpb->hpb_lu_dev);
+}
+
+static void ufshpb_init_subregion_tbl(struct ufshpb_lu *hpb,
+				      struct ufshpb_region *rgn)
+{
+	int srgn_idx;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		struct ufshpb_subregion *srgn = rgn->srgn_tbl + srgn_idx;
+
+		INIT_LIST_HEAD(&srgn->list_act_srgn);
+
+		srgn->rgn_idx = rgn->rgn_idx;
+		srgn->srgn_idx = srgn_idx;
+		srgn->srgn_state = HPB_SRGN_UNUSED;
+	}
+}
+
+static inline int ufshpb_alloc_subregion_tbl(struct ufshpb_lu *hpb,
+					     struct ufshpb_region *rgn,
+					     int srgn_cnt)
+{
+	rgn->srgn_tbl = kvcalloc(srgn_cnt, sizeof(struct ufshpb_subregion),
+				 GFP_KERNEL);
+	if (!rgn->srgn_tbl)
+		return -ENOMEM;
+
+	rgn->srgn_cnt = srgn_cnt;
+	return 0;
+}
+
+static void ufshpb_init_lu_parameter(struct ufs_hba *hba,
+				     struct ufshpb_lu *hpb,
+				     struct ufshpb_dev_info *hpb_dev_info,
+				     struct ufshpb_lu_info *hpb_lu_info)
+{
+	u32 entries_per_rgn;
+	u64 rgn_mem_size;
+
+
+	hpb->lu_pinned_start = hpb_lu_info->pinned_start;
+	hpb->lu_pinned_end = hpb_lu_info->num_pinned ?
+		(hpb_lu_info->pinned_start + hpb_lu_info->num_pinned - 1)
+		: PINNED_NOT_SET;
+
+	rgn_mem_size = (1ULL << hpb_dev_info->rgn_size) * HPB_RGN_SIZE_UNIT
+		/ HPB_ENTRY_BLOCK_SIZE * HPB_ENTRY_SIZE;
+	hpb->srgn_mem_size = (1ULL << hpb_dev_info->srgn_size)
+		* HPB_RGN_SIZE_UNIT / HPB_ENTRY_BLOCK_SIZE * HPB_ENTRY_SIZE;
+
+	entries_per_rgn = rgn_mem_size / HPB_ENTRY_SIZE;
+	hpb->entries_per_rgn_shift = ilog2(entries_per_rgn);
+	hpb->entries_per_rgn_mask = entries_per_rgn - 1;
+
+	hpb->entries_per_srgn = hpb->srgn_mem_size /  HPB_ENTRY_SIZE;
+	hpb->entries_per_srgn_shift = ilog2(hpb->entries_per_srgn);
+	hpb->entries_per_srgn_mask = hpb->entries_per_srgn - 1;
+
+	hpb->srgns_per_rgn = rgn_mem_size / hpb->srgn_mem_size;
+
+	hpb->rgns_per_lu = DIV_ROUND_UP(hpb_lu_info->num_blocks,
+				(rgn_mem_size / HPB_ENTRY_SIZE));
+	hpb->srgns_per_lu = DIV_ROUND_UP(hpb_lu_info->num_blocks,
+				(hpb->srgn_mem_size / HPB_ENTRY_SIZE));
+
+	hpb->pages_per_srgn = hpb->srgn_mem_size / PAGE_SIZE;
+
+	dev_info(hba->dev, "ufshpb(%d): region memory size - %llu (bytes)\n",
+		 hpb->lun, rgn_mem_size);
+	dev_info(hba->dev, "ufshpb(%d): subregion memory size - %u (bytes)\n",
+		 hpb->lun, hpb->srgn_mem_size);
+	dev_info(hba->dev, "ufshpb(%d): total blocks per lu - %d\n",
+		 hpb->lun, hpb_lu_info->num_blocks);
+	dev_info(hba->dev, "ufshpb(%d): subregions per region - %d, regions per lu - %u",
+		 hpb->lun, hpb->srgns_per_rgn, hpb->rgns_per_lu);
+}
+
+
+static int ufshpb_alloc_region_tbl(struct ufs_hba *hba, struct ufshpb_lu *hpb)
+{
+	struct ufshpb_region *rgn_table, *rgn;
+	int rgn_idx, i;
+	int ret = 0;
+
+	rgn_table = kvcalloc(hpb->rgns_per_lu, sizeof(struct ufshpb_region),
+			    GFP_KERNEL);
+	if (!rgn_table)
+		return -ENOMEM;
+
+	hpb->rgn_tbl = rgn_table;
+
+	for (rgn_idx = 0; rgn_idx < hpb->rgns_per_lu; rgn_idx++) {
+		int srgn_cnt = hpb->srgns_per_rgn;
+
+		rgn = rgn_table + rgn_idx;
+		rgn->rgn_idx = rgn_idx;
+
+		if (rgn_idx == hpb->rgns_per_lu - 1)
+			srgn_cnt = ((hpb->srgns_per_lu - 1) %
+				    hpb->srgns_per_rgn) + 1;
+
+		ret = ufshpb_alloc_subregion_tbl(hpb, rgn, srgn_cnt);
+		if (ret)
+			goto release_srgn_table;
+		ufshpb_init_subregion_tbl(hpb, rgn);
+
+		rgn->rgn_state = HPB_RGN_INACTIVE;
+	}
+
+	return 0;
+
+release_srgn_table:
+	for (i = 0; i < rgn_idx; i++) {
+		rgn = rgn_table + i;
+		if (rgn->srgn_tbl)
+			kvfree(rgn->srgn_tbl);
+	}
+	kvfree(rgn_table);
+	return ret;
+}
+
+static void ufshpb_destroy_subregion_tbl(struct ufshpb_lu *hpb,
+					 struct ufshpb_region *rgn)
+{
+	int srgn_idx;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		struct ufshpb_subregion *srgn;
+
+		srgn = rgn->srgn_tbl + srgn_idx;
+		srgn->srgn_state = HPB_SRGN_UNUSED;
+	}
+}
+
+static void ufshpb_destroy_region_tbl(struct ufshpb_lu *hpb)
+{
+	int rgn_idx;
+
+	for (rgn_idx = 0; rgn_idx < hpb->rgns_per_lu; rgn_idx++) {
+		struct ufshpb_region *rgn;
+
+		rgn = hpb->rgn_tbl + rgn_idx;
+		if (rgn->rgn_state != HPB_RGN_INACTIVE) {
+			rgn->rgn_state = HPB_RGN_INACTIVE;
+
+			ufshpb_destroy_subregion_tbl(hpb, rgn);
+		}
+
+		kvfree(rgn->srgn_tbl);
+	}
+
+	kvfree(hpb->rgn_tbl);
+}
+
+static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb,
+			      struct ufshpb_dev_info *hpb_dev_info)
+{
+	int ret;
+
+	spin_lock_init(&hpb->hpb_state_lock);
+
+	ret = ufshpb_alloc_region_tbl(hba, hpb);
+	if (ret)
+		goto release_m_page_cache;
+
+	ret = ufshpb_create_sysfs(hba, hpb);
+	if (ret)
+		goto release_rgn_table;
+
+	return 0;
+
+release_rgn_table:
+	ufshpb_destroy_region_tbl(hpb);
+	return ret;
+}
+
+static struct ufshpb_lu *ufshpb_alloc_hpb_lu(struct ufs_hba *hba, int lun,
+				     struct ufshpb_dev_info *hpb_dev_info,
+				     struct ufshpb_lu_info *hpb_lu_info)
+{
+	struct ufshpb_lu *hpb;
+	int ret;
+
+	hpb = kzalloc(sizeof(struct ufshpb_lu), GFP_KERNEL);
+	if (!hpb)
+		return NULL;
+
+	hpb->ufsf = &hba->ufsf;
+	hpb->lun = lun;
+
+	ufshpb_init_lu_parameter(hba, hpb, hpb_dev_info, hpb_lu_info);
+
+	ret = ufshpb_lu_hpb_init(hba, hpb, hpb_dev_info);
+	if (ret) {
+		dev_err(hba->dev, "hpb lu init failed. ret %d", ret);
+		goto release_hpb;
+	}
+
+	return hpb;
+release_hpb:
+	kfree(hpb);
+	return NULL;
+}
+
+static void ufshpb_lu_release(struct ufshpb_lu *hpb)
+{
+	ufshpb_destroy_region_tbl(hpb);
+
+	list_del_init(&hpb->list_hpb_lu);
+}
+
+static void ufshpb_issue_hpb_reset_query(struct ufs_hba *hba)
+{
+	int err;
+	int retries;
+
+	for (retries = 0; retries < HPB_RESET_REQ_RETRIES; retries++) {
+		err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_SET_FLAG,
+				QUERY_FLAG_IDN_HPB_RESET, 0, NULL);
+		if (err)
+			dev_dbg(hba->dev,
+				"%s: failed with error %d, retries %d\n",
+				__func__, err, retries);
+		else
+			break;
+	}
+
+	if (err) {
+		dev_err(hba->dev,
+			"%s setting fHpbReset flag failed with error %d\n",
+			__func__, err);
+		return;
+	}
+}
+
+static void ufshpb_check_hpb_reset_query(struct ufs_hba *hba)
+{
+	int err;
+	bool flag_res = true;
+	int try = 0;
+
+	/* wait for the device to complete HPB reset query */
+	do {
+		if (++try == HPB_RESET_REQ_RETRIES)
+			break;
+
+		dev_info(hba->dev,
+			"%s start flag reset polling %d times\n",
+			__func__, try);
+
+		/* Poll fHpbReset flag to be cleared */
+		err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG,
+				QUERY_FLAG_IDN_HPB_RESET, 0, &flag_res);
+		usleep_range(1000, 1100);
+	} while (flag_res);
+
+	if (err) {
+		dev_err(hba->dev,
+			"%s reading fHpbReset flag failed with error %d\n",
+			__func__, err);
+		return;
+	}
+
+	if (flag_res) {
+		dev_err(hba->dev,
+			"%s fHpbReset was not cleared by the device\n",
+			__func__);
+	}
+}
+
+static void ufshpb_reset(struct ufs_hba *hba)
+{
+	struct ufshpb_lu *hpb;
+
+	list_for_each_entry(hpb, &ufshpb_drv.lh_hpb_lu, list_hpb_lu) {
+		if (ufshpb_lu_get_dev(hpb))
+			continue;
+
+		ufshpb_set_state(hpb, HPB_PRESENT);
+		ufshpb_lu_put(hpb);
+	}
+}
+
+static void ufshpb_reset_host(struct ufs_hba *hba)
+{
+	struct ufshpb_lu *hpb;
+
+	list_for_each_entry(hpb, &ufshpb_drv.lh_hpb_lu, list_hpb_lu) {
+		if (ufshpb_lu_get(hpb))
+			continue;
+
+		dev_info(&hpb->hpb_lu_dev, "ufshpb run reset_host");
+
+		ufshpb_set_state(hpb, HPB_RESET);
+		ufshpb_lu_put(hpb);
+	}
+}
+
+static void ufshpb_suspend(struct ufs_hba *hba)
+{
+	struct ufshpb_lu *hpb;
+
+	list_for_each_entry(hpb, &ufshpb_drv.lh_hpb_lu, list_hpb_lu) {
+		if (ufshpb_lu_get(hpb))
+			continue;
+
+		dev_info(&hpb->hpb_lu_dev, "ufshpb goto suspend");
+		ufshpb_set_state(hpb, HPB_SUSPEND);
+
+		ufshpb_lu_put(hpb);
+	}
+}
+
+static void ufshpb_resume(struct ufs_hba *hba)
+{
+	struct ufshpb_lu *hpb;
+
+	list_for_each_entry(hpb, &ufshpb_drv.lh_hpb_lu, list_hpb_lu) {
+		if (ufshpb_lu_get_dev(hpb))
+			continue;
+
+		dev_info(&hpb->hpb_lu_dev, "ufshpb resume");
+		ufshpb_set_state(hpb, HPB_PRESENT);
+		ufshpb_lu_put(hpb);
+	}
+}
+
+static void ufshpb_stat_init(struct ufshpb_lu *hpb)
+{
+	atomic_set(&hpb->stats.hit_cnt, 0);
+	atomic_set(&hpb->stats.miss_cnt, 0);
+	atomic_set(&hpb->stats.rb_noti_cnt, 0);
+	atomic_set(&hpb->stats.rb_active_cnt, 0);
+	atomic_set(&hpb->stats.rb_inactive_cnt, 0);
+	atomic_set(&hpb->stats.map_req_cnt, 0);
+}
+
+/* SYSFS functions */
+#define ufshpb_sysfs_attr_show_func(__name)				\
+static ssize_t __name##_show(struct device *dev,		\
+					 struct device_attribute *attr,	\
+					 char *buf)			\
+{									\
+	struct ufshpb_lu *hpb;						\
+	hpb = container_of(dev, struct ufshpb_lu, hpb_lu_dev);		\
+	return snprintf(buf, PAGE_SIZE, "%d\n",			\
+			atomic_read(&hpb->stats.__name));		\
+}
+
+ufshpb_sysfs_attr_show_func(hit_cnt);
+ufshpb_sysfs_attr_show_func(miss_cnt);
+ufshpb_sysfs_attr_show_func(rb_noti_cnt);
+ufshpb_sysfs_attr_show_func(rb_active_cnt);
+ufshpb_sysfs_attr_show_func(rb_inactive_cnt);
+ufshpb_sysfs_attr_show_func(map_req_cnt);
+
+static DEVICE_ATTR_RO(hit_cnt);
+static DEVICE_ATTR_RO(miss_cnt);
+static DEVICE_ATTR_RO(rb_noti_cnt);
+static DEVICE_ATTR_RO(rb_active_cnt);
+static DEVICE_ATTR_RO(rb_inactive_cnt);
+static DEVICE_ATTR_RO(map_req_cnt);
+
+static struct attribute *hpb_dev_attrs[] = {
+	&dev_attr_hit_cnt.attr,
+	&dev_attr_miss_cnt.attr,
+	&dev_attr_rb_noti_cnt.attr,
+	&dev_attr_rb_active_cnt.attr,
+	&dev_attr_rb_inactive_cnt.attr,
+	&dev_attr_map_req_cnt.attr,
+	NULL,
+};
+
+static struct attribute_group ufshpb_sysfs_group = {
+	.attrs = hpb_dev_attrs,
+};
+
+static inline void ufshpb_dev_release(struct device *dev)
+{
+	struct ufs_hba *hba;
+	struct ufsf_feature_info *ufsf;
+	struct ufshpb_lu *hpb;
+
+	hpb = container_of(dev, struct ufshpb_lu, hpb_lu_dev);
+	ufsf = hpb->ufsf;
+	hba = container_of(ufsf, struct ufs_hba, ufsf);
+
+	ufshpb_lu_release(hpb);
+	dev_info(dev, "%s: release success\n", __func__);
+	put_device(dev->parent);
+
+	kfree(hpb);
+}
+
+static int ufshpb_create_sysfs(struct ufs_hba *hba, struct ufshpb_lu *hpb)
+{
+	int ret;
+
+	device_initialize(&hpb->hpb_lu_dev);
+
+	ufshpb_stat_init(hpb);
+
+	hpb->hpb_lu_dev.parent = get_device(&hba->ufsf.hpb_dev);
+	hpb->hpb_lu_dev.release = ufshpb_dev_release;
+	dev_set_name(&hpb->hpb_lu_dev, "ufshpb_lu%d", hpb->lun);
+
+	ret = device_add(&hpb->hpb_lu_dev);
+	if (ret) {
+		dev_err(hba->dev, "ufshpb(%d) device_add failed",
+			hpb->lun);
+		return -ENODEV;
+	}
+
+	if (device_add_group(&hpb->hpb_lu_dev, &ufshpb_sysfs_group))
+		dev_err(hba->dev, "ufshpb(%d) create file error\n",
+			hpb->lun);
+
+	return 0;
+}
+
+static int ufshpb_read_desc(struct ufs_hba *hba, u8 desc_id, u8 desc_index,
+			  u8 selector, u8 *desc_buf, u32 size)
+{
+	int err = 0;
+
+	pm_runtime_get_sync(hba->dev);
+
+	err = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
+					    desc_id, desc_index,
+					    selector,
+					    desc_buf, &size);
+	if (err)
+		dev_err(hba->dev, "read desc failed: %d, id %d, idx %d\n",
+			err, desc_id, desc_index);
+
+	pm_runtime_put_sync(hba->dev);
+
+	return err;
+}
+
+static int ufshpb_get_geo_info(struct ufs_hba *hba, u8 *geo_buf,
+			       struct ufshpb_dev_info *hpb_dev_info)
+{
+	int hpb_device_max_active_rgns = 0;
+	int hpb_num_lu;
+
+	hpb_num_lu = geo_buf[GEOMETRY_DESC_HPB_NUMBER_LU];
+	if (hpb_num_lu == 0) {
+		dev_err(hba->dev, "No HPB LU supported\n");
+		return -ENODEV;
+	}
+
+	hpb_dev_info->rgn_size = geo_buf[GEOMETRY_DESC_HPB_REGION_SIZE];
+	hpb_dev_info->srgn_size = geo_buf[GEOMETRY_DESC_HPB_SUBREGION_SIZE];
+	hpb_device_max_active_rgns =
+		get_unaligned_be16(geo_buf +
+			GEOMETRY_DESC_HPB_DEVICE_MAX_ACTIVE_REGIONS);
+
+	if (hpb_dev_info->rgn_size == 0 || hpb_dev_info->srgn_size == 0 ||
+	    hpb_device_max_active_rgns == 0) {
+		dev_err(hba->dev, "No HPB supported device\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int ufshpb_get_dev_info(struct ufs_hba *hba,
+			       struct ufshpb_dev_info *hpb_dev_info,
+			       u8 *desc_buf)
+{
+	int ret;
+	int hpb_mode, version;
+
+
+	if (!hba->desc_size.dev_desc)
+		hba->desc_size.dev_desc = QUERY_DESC_DEVICE_DEF_SIZE;
+	ret = ufshpb_read_desc(hba, QUERY_DESC_IDN_DEVICE, 0, 0,
+			     desc_buf, hba->desc_size.dev_desc);
+	if (ret) {
+		dev_err(hba->dev, "%s: idn: %d query request failed\n",
+			__func__, QUERY_DESC_IDN_DEVICE);
+		return -ENODEV;
+	}
+
+	hpb_mode = get_unaligned_be16(desc_buf + DEVICE_DESC_PARAM_HPB_CONTROL);
+	if (hpb_mode == HPB_HOST_CONTROL) {
+		dev_err(hba->dev, "%s: host control mode is not supported.\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	version = get_unaligned_be16(desc_buf + DEVICE_DESC_PARAM_HPB_VER);
+	if (version != HPB_SUPPORT_VERSION) {
+		dev_err(hba->dev, "%s: HPB %x version is not supported.\n",
+			__func__, version);
+		return -ENODEV;
+	}
+
+	/*
+	 * Get the number of user logical unit to check whether all
+	 * scsi_device finish initialization
+	 */
+	hpb_dev_info->num_lu = desc_buf[DEVICE_DESC_PARAM_NUM_LU];
+
+	if (!hba->desc_size.geom_desc)
+		hba->desc_size.geom_desc = QUERY_DESC_GEOMETRY_DEF_SIZE;
+	ret = ufshpb_read_desc(hba, QUERY_DESC_IDN_GEOMETRY, 0, 0,
+			       desc_buf, hba->desc_size.geom_desc);
+	if (ret) {
+		dev_err(hba->dev, "%s: idn: %d query request failed\n",
+			__func__, QUERY_DESC_IDN_DEVICE);
+		return ret;
+	}
+
+	ret = ufshpb_get_geo_info(hba, desc_buf, hpb_dev_info);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int ufshpb_get_lu_info(struct ufs_hba *hba, int lun,
+				    struct ufshpb_lu_info *hpb_lu_info,
+				    u8 *desc_buf)
+{
+	u16 max_active_rgns;
+	u8 lu_enable;
+	int ret;
+
+	ret = ufshpb_read_desc(hba, QUERY_DESC_IDN_UNIT, lun,
+			       0, desc_buf,
+				   hba->desc_size.unit_desc);
+	if (ret) {
+		dev_err(hba->dev,
+			"%s: idn: %d lun: %d  query request failed",
+			__func__, QUERY_DESC_IDN_UNIT, lun);
+		return ret;
+	}
+
+	lu_enable = desc_buf[UNIT_DESC_PARAM_LU_ENABLE];
+	if (lu_enable != LU_ENABLED_HPB_FUNC)
+		return -ENODEV;
+
+	max_active_rgns = get_unaligned_be16(
+			desc_buf + UNIT_DESC_HPB_LU_MAX_ACTIVE_REGIONS);
+	if (!max_active_rgns) {
+		dev_err(hba->dev,
+			"lun %d wrong number of max active regions\n", lun);
+		return -ENODEV;
+	}
+
+	hpb_lu_info->num_blocks = get_unaligned_be64(
+			desc_buf + UNIT_DESC_PARAM_LOGICAL_BLK_COUNT);
+	hpb_lu_info->pinned_start = get_unaligned_be16(
+			desc_buf + UNIT_DESC_HPB_LU_PIN_REGION_START_OFFSET);
+	hpb_lu_info->num_pinned = get_unaligned_be16(
+			desc_buf + UNIT_DESC_HPB_LU_NUM_PIN_REGIONS);
+	hpb_lu_info->max_active_rgns = max_active_rgns;
+
+	return 0;
+}
+
+static void ufshpb_scan_hpb_lu(struct ufs_hba *hba,
+			       struct ufshpb_dev_info *hpb_dev_info,
+			       u8 *desc_buf)
+{
+	struct scsi_device *sdev;
+	struct ufshpb_lu *hpb;
+	int find_hpb_lu = 0;
+	int ret;
+
+	INIT_LIST_HEAD(&ufshpb_drv.lh_hpb_lu);
+
+	shost_for_each_device(sdev, hba->host) {
+		struct ufshpb_lu_info hpb_lu_info = { 0 };
+		int lun = sdev->lun;
+
+		if (lun >= hba->dev_info.max_lu_supported)
+			continue;
+
+		ret = ufshpb_get_lu_info(hba, lun, &hpb_lu_info, desc_buf);
+		if (ret)
+			continue;
+
+		hpb = ufshpb_alloc_hpb_lu(hba, lun, hpb_dev_info,
+					  &hpb_lu_info);
+		if (!hpb)
+			continue;
+
+		hpb->sdev_ufs_lu = sdev;
+		sdev->hostdata = hpb;
+
+		list_add_tail(&hpb->list_hpb_lu, &ufshpb_drv.lh_hpb_lu);
+		find_hpb_lu++;
+	}
+
+	if (find_hpb_lu) {
+		ufshpb_check_hpb_reset_query(hba);
+		dev_set_drvdata(&hba->ufsf.hpb_dev, &ufshpb_drv);
+
+		list_for_each_entry(hpb, &ufshpb_drv.lh_hpb_lu, list_hpb_lu) {
+			dev_info(&hpb->hpb_lu_dev, "set state to present\n");
+			ufshpb_set_state(hpb, HPB_PRESENT);
+		}
+	}
+}
+
+static int ufshpb_probe(struct device *dev)
+{
+	struct ufs_hba *hba;
+	struct ufsf_feature_info *ufsf;
+	struct ufshpb_dev_info hpb_dev_info = { 0 };
+	char *desc_buf;
+	int ret;
+
+	if (dev->type != &ufshpb_dev_type)
+		return -ENODEV;
+
+	ufsf = container_of(dev, struct ufsf_feature_info, hpb_dev);
+	hba = container_of(ufsf, struct ufs_hba, ufsf);
+
+	desc_buf = kzalloc(QUERY_DESC_MAX_SIZE, GFP_KERNEL);
+	if (!desc_buf)
+		goto release_desc_buf;
+
+	ret = ufshpb_get_dev_info(hba, &hpb_dev_info, desc_buf);
+	if (ret)
+		goto release_desc_buf;
+
+	/*
+	 * Because HPB driver uses scsi_device data structure,
+	 * we should wait at this point until finishing initialization of all
+	 * scsi devices. Even if timeout occurs, HPB driver will search
+	 * the scsi_device list on struct scsi_host (shost->__host list_head)
+	 * and can find out HPB logical units in all scsi_devices
+	 */
+	wait_event_timeout(hba->ufsf.sdev_wait,
+			   (atomic_read(&hba->ufsf.slave_conf_cnt)
+				== hpb_dev_info.num_lu),
+			   SDEV_WAIT_TIMEOUT);
+
+	ufshpb_issue_hpb_reset_query(hba);
+
+	dev_dbg(hba->dev, "ufshpb: slave count %d, lu count %d\n",
+		atomic_read(&hba->ufsf.slave_conf_cnt), hpb_dev_info.num_lu);
+
+	ufshpb_scan_hpb_lu(hba, &hpb_dev_info, desc_buf);
+
+release_desc_buf:
+	kfree(desc_buf);
+	return 0;
+}
+
+static int ufshpb_remove(struct device *dev)
+{
+	struct ufshpb_lu *hpb, *n_hpb;
+	struct ufsf_feature_info *ufsf;
+	struct scsi_device *sdev;
+
+	ufsf = container_of(dev, struct ufsf_feature_info, hpb_dev);
+
+	dev_set_drvdata(&ufsf->hpb_dev, NULL);
+
+	list_for_each_entry_safe(hpb, n_hpb, &ufshpb_drv.lh_hpb_lu,
+				 list_hpb_lu) {
+		ufshpb_set_state(hpb, HPB_FAILED);
+
+		sdev = hpb->sdev_ufs_lu;
+		sdev->hostdata = NULL;
+
+		device_del(&hpb->hpb_lu_dev);
+
+		dev_info(&hpb->hpb_lu_dev, "hpb_lu_dev refcnt %d\n",
+			 kref_read(&hpb->hpb_lu_dev.kobj.kref));
+		put_device(&hpb->hpb_lu_dev);
+	}
+	dev_info(dev, "ufshpb: remove success\n");
+
+	return 0;
+}
+
+static struct ufshpb_driver ufshpb_drv = {
+	.drv = {
+		.name = "ufshpb_driver",
+		.owner = THIS_MODULE,
+		.probe = ufshpb_probe,
+		.remove = ufshpb_remove,
+		.bus = &ufsf_bus_type,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.ufshpb_ops = {
+		.prep_fn = ufshpb_prep_fn,
+		.reset = ufshpb_reset,
+		.reset_host = ufshpb_reset_host,
+		.suspend = ufshpb_suspend,
+		.resume = ufshpb_resume,
+		.rsp_upiu = ufshpb_rsp_upiu,
+	},
+};
+
+unsigned int ufshpb_host_map_kbytes = 1 * 1024;
+module_param(ufshpb_host_map_kbytes, uint, 0644);
+MODULE_PARM_DESC(ufshpb_host_map_kbytes,
+	 "ufshpb host mapping memory kilo-bytes for ufshpb memory-pool");
+
+static int __init ufshpb_init(void)
+{
+	unsigned int pool_size;
+	int ret;
+
+	ret = driver_register(&ufshpb_drv.drv);
+	if (ret)
+		pr_err("ufshpb: driver register failed\n");
+
+	return ret;
+}
+
+static void __exit ufshpb_exit(void)
+{
+	driver_unregister(&ufshpb_drv.drv);
+}
+
+MODULE_AUTHOR("Yongmyong Lee <ymhungry.lee@samsung.com>");
+MODULE_AUTHOR("Jinyoung Choi <j-young.choi@samsung.com>");
+MODULE_DESCRIPTION("UFS Host Performance Booster Driver");
+
+module_init(ufshpb_init);
+module_exit(ufshpb_exit);
+MODULE_LICENSE("GPL");
diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
new file mode 100644
index 000000000000..eaa4a3e035b1
--- /dev/null
+++ b/drivers/scsi/ufs/ufshpb.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Universal Flash Storage Host Performance Booster
+ *
+ * Copyright (C) 2017-2018 Samsung Electronics Co., Ltd.
+ *
+ * Authors:
+ *	Yongmyung Lee <ymhungry.lee@samsung.com>
+ *	Jinyoung Choi <j-young.choi@samsung.com>
+ */
+
+#ifndef _UFSHPB_H_
+#define _UFSHPB_H_
+
+/* hpb response UPIU macro */
+#define MAX_ACTIVE_NUM				2
+#define MAX_INACTIVE_NUM			2
+#define HPB_RSP_NONE				0x00
+#define HPB_RSP_REQ_REGION_UPDATE		0x01
+#define HPB_RSP_DEV_RESET			0x02
+#define DEV_DATA_SEG_LEN			0x14
+#define DEV_SENSE_SEG_LEN			0x12
+#define DEV_DES_TYPE				0x80
+#define DEV_ADDITIONAL_LEN			0x10
+
+/* hpb map & entries macro */
+#define HPB_RGN_SIZE_UNIT			512
+#define HPB_ENTRY_BLOCK_SIZE			4096
+#define HPB_ENTRY_SIZE				0x8
+#define PINNED_NOT_SET				U32_MAX
+
+/* hpb support chunk size */
+#define HPB_MULTI_CHUNK_HIGH			1
+
+/* hpb vender defined opcode */
+#define UFSHPB_READ				0xF8
+#define UFSHPB_READ_BUFFER			0xF9
+#define UFSHPB_WRITE_BUFFER			0xFA
+#define UFSHPB_READ_BUFFER_ID			0x01
+#define UFSHPB_WRITE_BUFFER_ID			0x02
+#define HPB_READ_BUFFER_CMD_LENGTH		10
+#define LU_ENABLED_HPB_FUNC			0x02
+
+#define SDEV_WAIT_TIMEOUT			(10 * HZ)
+#define MAP_REQ_TIMEOUT				(30 * HZ)
+#define HPB_RESET_REQ_RETRIES			10
+#define HPB_RESET_REQ_MSLEEP			2
+
+#define HPB_SUPPORT_VERSION			0x100
+
+enum UFSHPB_MODE {
+	HPB_HOST_CONTROL,
+	HPB_DEVICE_CONTROL,
+};
+
+enum UFSHPB_STATE {
+	HPB_PRESENT = 1,
+	HPB_SUSPEND,
+	HPB_FAILED,
+	HPB_RESET,
+};
+
+enum HPB_RGN_STATE {
+	HPB_RGN_INACTIVE,
+	HPB_RGN_ACTIVE,
+	/* pinned regions are always active */
+	HPB_RGN_PINNED,
+};
+
+enum HPB_SRGN_STATE {
+	HPB_SRGN_UNUSED,
+	HPB_SRGN_INVALID,
+	HPB_SRGN_VALID,
+	HPB_SRGN_ISSUED,
+};
+
+/**
+ * struct ufshpb_dev_info - UFSHPB device related info
+ * @num_lu: the number of user logical unit to check whether all lu finished
+ *          initialization
+ * @rgn_size: device reported HPB region size
+ * @srgn_size: device reported HPB sub-region size
+ */
+struct ufshpb_dev_info {
+	int num_lu;
+	int rgn_size;
+	int srgn_size;
+};
+
+/**
+ * struct ufshpb_lu_info - UFSHPB logical unit related info
+ * @num_blocks: the number of logical block
+ * @pinned_start: the start region number of pinned region
+ * @num_pinned: the number of pinned regions
+ * @max_active_rgns: maximum number of active regions
+ */
+struct ufshpb_lu_info {
+	int num_blocks;
+	int pinned_start;
+	int num_pinned;
+	int max_active_rgns;
+};
+
+struct ufshpb_subregion {
+	enum HPB_SRGN_STATE srgn_state;
+	int rgn_idx;
+	int srgn_idx;
+};
+
+struct ufshpb_region {
+	struct ufshpb_subregion *srgn_tbl;
+	enum HPB_RGN_STATE rgn_state;
+	int rgn_idx;
+	int srgn_cnt;
+};
+
+struct ufshpb_stats {
+	atomic_t hit_cnt;
+	atomic_t miss_cnt;
+	atomic_t rb_noti_cnt;
+	atomic_t rb_active_cnt;
+	atomic_t rb_inactive_cnt;
+	atomic_t map_req_cnt;
+};
+
+struct ufshpb_lu {
+	int lun;
+
+	struct device hpb_lu_dev;
+	struct scsi_device *sdev_ufs_lu;
+
+	struct ufshpb_region *rgn_tbl;
+
+	spinlock_t hpb_state_lock;
+	atomic_t hpb_state; /* hpb_state_lock */
+
+	/* pinned region information */
+	u32 lu_pinned_start;
+	u32 lu_pinned_end;
+
+	/* HPB related configuration */
+	u32 rgns_per_lu;
+	u32 srgns_per_lu;
+	int srgns_per_rgn;
+	u32 srgn_mem_size;
+	u32 entries_per_rgn_mask;
+	u32 entries_per_rgn_shift;
+	u32 entries_per_srgn;
+	u32 entries_per_srgn_mask;
+	u32 entries_per_srgn_shift;
+	u32 pages_per_srgn;
+
+	struct ufshpb_stats stats;
+
+	struct ufsf_feature_info *ufsf;
+	struct list_head list_hpb_lu;
+};
+
+extern struct device_type ufshpb_dev_type;
+extern struct bus_type ufsf_bus_type;
+
+#endif /* End of Header */
-- 
2.17.1

[RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Daejun Park]

This is a patch for managing L2P map in HPB module.

The HPB divides logical addresses into several regions. A region consists
of several sub-regions. The sub-region is a basic unit where L2P mapping is
managed. The driver loads L2P mapping data of each sub-region. The loaded
sub-region is called active-state. The HPB driver unloads L2P mapping data
as region unit. The unloaded region is called inactive-state.

Sub-region/region candidates to be loaded and unloaded are delivered from
the UFS device. The UFS device delivers the recommended active sub-region
and inactivate region to the driver using sensedata.
The HPB module performs L2P mapping management on the host through the
delivered information.

A pinned region is a pre-set regions on the UFS device that is always
activate-state.

The data structure for map data request and L2P map uses mempool API,
minimizing allocation overhead while avoiding static allocation.

The map_work manages active/inactive by 2 "to-do" lists.
Each hpb lun maintains 2 "to-do" lists:
  hpb->lh_inact_rgn - regions to be inactivated, and
  hpb->lh_act_srgn - subregions to be activated
Those lists are maintained on IO completion.

Signed-off-by: Daejun Park <daejun7.park@samsung.com>
---
 drivers/scsi/ufs/ufshpb.c | 971 +++++++++++++++++++++++++++++++++++++-
 drivers/scsi/ufs/ufshpb.h |  72 +++
 2 files changed, 1040 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index 07490679d2f1..6229c6fcb5e1 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -25,6 +25,63 @@ static inline int ufshpb_is_valid_srgn(struct ufshpb_region *rgn,
 		srgn->srgn_state == HPB_SRGN_VALID;
 }
 
+static inline bool ufshpb_is_general_lun(int lun)
+{
+	return lun < UFS_UPIU_MAX_UNIT_NUM_ID;
+}
+
+static inline bool
+ufshpb_is_pinned_region(struct ufshpb_lu *hpb, int rgn_idx)
+{
+	if (hpb->lu_pinned_end != PINNED_NOT_SET &&
+	    rgn_idx >= hpb->lu_pinned_start &&
+	    rgn_idx <= hpb->lu_pinned_end)
+		return true;
+
+	return false;
+}
+
+static bool ufshpb_is_empty_rsp_lists(struct ufshpb_lu *hpb)
+{
+	bool ret = true;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	if (!list_empty(&hpb->lh_inact_rgn) || !list_empty(&hpb->lh_act_srgn))
+		ret = false;
+	spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+
+	return ret;
+}
+
+static inline int ufshpb_may_field_valid(struct ufs_hba *hba,
+					 struct ufshcd_lrb *lrbp,
+					 struct ufshpb_rsp_field *rsp_field)
+{
+	if (be16_to_cpu(rsp_field->sense_data_len) != DEV_SENSE_SEG_LEN ||
+	    rsp_field->desc_type != DEV_DES_TYPE ||
+	    rsp_field->additional_len != DEV_ADDITIONAL_LEN ||
+	    rsp_field->hpb_type == HPB_RSP_NONE ||
+	    rsp_field->active_rgn_cnt > MAX_ACTIVE_NUM ||
+	    rsp_field->inactive_rgn_cnt > MAX_INACTIVE_NUM ||
+	    (!rsp_field->active_rgn_cnt && !rsp_field->inactive_rgn_cnt))
+		return -EINVAL;
+
+	if (!ufshpb_is_general_lun(lrbp->lun)) {
+		dev_warn(hba->dev, "ufshpb: lun(%d) not supported\n",
+			 lrbp->lun);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+
+static inline struct ufshpb_lu *ufshpb_get_hpb_data(struct scsi_cmnd *cmd)
+{
+	return cmd->device->hostdata;
+}
+
 static inline int ufshpb_get_state(struct ufshpb_lu *hpb)
 {
 	return atomic_read(&hpb->hpb_state);
@@ -59,6 +116,767 @@ static inline void ufshpb_lu_put(struct ufshpb_lu *hpb)
 	put_device(&hpb->hpb_lu_dev);
 }
 
+static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
+					     struct ufshpb_subregion *srgn)
+{
+	struct ufshpb_req *map_req;
+	struct request *req;
+	struct bio *bio;
+
+	map_req = kmem_cache_alloc(hpb->map_req_cache, GFP_KERNEL);
+	if (!map_req)
+		return NULL;
+
+	req = blk_get_request(hpb->sdev_ufs_lu->request_queue,
+			      REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT);
+	if (IS_ERR(req))
+		goto free_map_req;
+
+	bio = bio_alloc(GFP_KERNEL, hpb->pages_per_srgn);
+	if (!bio) {
+		blk_put_request(req);
+		goto free_map_req;
+	}
+
+	map_req->hpb = hpb;
+	map_req->req = req;
+	map_req->bio = bio;
+
+	map_req->rgn_idx = srgn->rgn_idx;
+	map_req->srgn_idx = srgn->srgn_idx;
+	map_req->mctx = srgn->mctx;
+	map_req->lun = hpb->lun;
+
+	return map_req;
+
+free_map_req:
+	kmem_cache_free(hpb->map_req_cache, map_req);
+	return NULL;
+}
+
+static inline void ufshpb_put_map_req(struct ufshpb_lu *hpb,
+				      struct ufshpb_req *map_req)
+{
+	bio_put(map_req->bio);
+	blk_put_request(map_req->req);
+	kmem_cache_free(hpb->map_req_cache, map_req);
+}
+
+
+static inline int ufshpb_clear_dirty_bitmap(struct ufshpb_lu *hpb,
+				     struct ufshpb_subregion *srgn)
+{
+	WARN_ON(!srgn->mctx);
+	bitmap_zero(srgn->mctx->ppn_dirty, hpb->entries_per_srgn);
+	return 0;
+}
+
+static void ufshpb_update_active_info(struct ufshpb_lu *hpb, int rgn_idx,
+				      int srgn_idx)
+{
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+
+	rgn = hpb->rgn_tbl + rgn_idx;
+	srgn = rgn->srgn_tbl + srgn_idx;
+
+	list_del_init(&rgn->list_inact_rgn);
+
+	if (list_empty(&srgn->list_act_srgn))
+		list_add_tail(&srgn->list_act_srgn, &hpb->lh_act_srgn);
+}
+
+static void ufshpb_update_inactive_info(struct ufshpb_lu *hpb, int rgn_idx)
+{
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+	int srgn_idx;
+
+	rgn = hpb->rgn_tbl + rgn_idx;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn = rgn->srgn_tbl + srgn_idx;
+
+		list_del_init(&srgn->list_act_srgn);
+	}
+
+	if (list_empty(&rgn->list_inact_rgn))
+		list_add_tail(&rgn->list_inact_rgn, &hpb->lh_inact_rgn);
+}
+
+static void ufshpb_activate_subregion(struct ufshpb_lu *hpb,
+					  struct ufshpb_subregion *srgn)
+{
+	struct ufshpb_region *rgn;
+
+	/*
+	 * If there is no mctx in subregion
+	 * after I/O progress for HPB_READ_BUFFER, the region to which the
+	 * subregion belongs was evicted.
+	 * Mask sure the the region must not evict in I/O progress
+	 */
+	WARN_ON(!srgn->mctx);
+
+	rgn = hpb->rgn_tbl + srgn->rgn_idx;
+
+	if (unlikely(rgn->rgn_state == HPB_RGN_INACTIVE)) {
+		dev_err(&hpb->hpb_lu_dev,
+			"region %d subregion %d evicted\n",
+			srgn->rgn_idx, srgn->srgn_idx);
+		return;
+	}
+	srgn->srgn_state = HPB_SRGN_VALID;
+}
+
+static void ufshpb_map_req_compl_fn(struct request *req, blk_status_t error)
+{
+	struct ufshpb_req *map_req = (struct ufshpb_req *) req->end_io_data;
+	struct ufshpb_lu *hpb = map_req->hpb;
+	struct ufshpb_subregion *srgn;
+	unsigned long flags;
+
+	srgn = hpb->rgn_tbl[map_req->rgn_idx].srgn_tbl +
+		map_req->srgn_idx;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	ufshpb_activate_subregion(hpb, srgn);
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+
+	ufshpb_put_map_req(map_req->hpb, map_req);
+	ufshpb_lu_put(hpb);
+}
+
+static inline void ufshpb_set_read_buf_cmd(unsigned char *cdb, int rgn_idx,
+					   int srgn_idx, int srgn_mem_size)
+{
+	cdb[0] = UFSHPB_READ_BUFFER;
+	cdb[1] = UFSHPB_READ_BUFFER_ID;
+
+	put_unaligned_be16(rgn_idx, &cdb[2]);
+	put_unaligned_be16(srgn_idx, &cdb[4]);
+	put_unaligned_be24(srgn_mem_size, &cdb[6]);
+
+	cdb[9] = 0x00;
+}
+
+static int ufshpb_map_req_add_bio_page(struct ufshpb_lu *hpb,
+				       struct request_queue *q, struct bio *bio,
+				       struct ufshpb_map_ctx *mctx)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < hpb->pages_per_srgn; i++) {
+		ret = bio_add_pc_page(q, bio, mctx->m_page[i], PAGE_SIZE, 0);
+		if (ret != PAGE_SIZE) {
+			dev_notice(&hpb->hpb_lu_dev,
+				   "bio_add_pc_page fail %d\n", ret);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
+				  struct ufshpb_req *map_req)
+{
+	struct request_queue *q;
+	struct request *req;
+	struct scsi_request *rq;
+	int ret = 0;
+
+	q = hpb->sdev_ufs_lu->request_queue;
+	ret = ufshpb_map_req_add_bio_page(hpb, q, map_req->bio,
+					  map_req->mctx);
+	if (ret) {
+		dev_notice(&hpb->hpb_lu_dev,
+			   "map_req_add_bio_page fail %d - %d\n",
+			   map_req->rgn_idx, map_req->srgn_idx);
+		return ret;
+	}
+
+	req = map_req->req;
+
+	blk_rq_append_bio(req, &map_req->bio);
+
+	req->timeout = 0;
+	req->end_io_data = (void *)map_req;
+
+	rq = scsi_req(req);
+	ufshpb_set_read_buf_cmd(rq->cmd, map_req->rgn_idx,
+				map_req->srgn_idx, hpb->srgn_mem_size);
+	rq->cmd_len = HPB_READ_BUFFER_CMD_LENGTH;
+
+	blk_execute_rq_nowait(q, NULL, req, 1, ufshpb_map_req_compl_fn);
+
+	atomic_inc(&hpb->stats.map_req_cnt);
+	return 0;
+}
+
+static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu *hpb)
+{
+	struct ufshpb_map_ctx *mctx;
+	int i, j;
+
+	mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
+	if (!mctx)
+		return NULL;
+
+	mctx->m_page = kmem_cache_alloc(hpb->m_page_cache, GFP_KERNEL);
+	if (!mctx->m_page)
+		goto release_mctx;
+
+	mctx->ppn_dirty = bitmap_zalloc(hpb->entries_per_srgn, GFP_KERNEL);
+	if (!mctx->ppn_dirty)
+		goto release_m_page;
+
+	for (i = 0; i < hpb->pages_per_srgn; i++) {
+		mctx->m_page[i] = mempool_alloc(ufshpb_drv.ufshpb_page_pool,
+						GFP_KERNEL);
+		if (!mctx->m_page[i]) {
+			for (j = 0; j < i; j++)
+				mempool_free(mctx->m_page[j],
+					     ufshpb_drv.ufshpb_page_pool);
+			goto release_ppn_dirty;
+		}
+		clear_page(page_address(mctx->m_page[i]));
+	}
+
+	return mctx;
+release_ppn_dirty:
+	bitmap_free(mctx->ppn_dirty);
+release_m_page:
+	kmem_cache_free(hpb->m_page_cache, mctx->m_page);
+release_mctx:
+	mempool_free(mctx, ufshpb_drv.ufshpb_mctx_pool);
+	return NULL;
+}
+
+static inline void ufshpb_put_map_ctx(struct ufshpb_lu *hpb,
+				      struct ufshpb_map_ctx *mctx)
+{
+	int i;
+
+	for (i = 0; i < hpb->pages_per_srgn; i++)
+		mempool_free(mctx->m_page[i],
+			     ufshpb_drv.ufshpb_page_pool);
+
+	bitmap_free(mctx->ppn_dirty);
+	kmem_cache_free(hpb->m_page_cache, mctx->m_page);
+	mempool_free(mctx, ufshpb_drv.ufshpb_mctx_pool);
+}
+
+static int ufshpb_check_issue_state_srgns(struct ufshpb_lu *hpb,
+					  struct ufshpb_region *rgn)
+{
+	struct ufshpb_subregion *srgn;
+	int srgn_idx;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn  = rgn->srgn_tbl + srgn_idx;
+
+		if (srgn->srgn_state == HPB_SRGN_ISSUED)
+			return -EPERM;
+	}
+	return 0;
+}
+
+static inline void ufshpb_add_lru_info(struct victim_select_info *lru_info,
+				       struct ufshpb_region *rgn)
+{
+	rgn->rgn_state = HPB_RGN_ACTIVE;
+	list_add_tail(&rgn->list_lru_rgn, &lru_info->lh_lru_rgn);
+	atomic_inc(&lru_info->active_cnt);
+}
+
+static inline void ufshpb_hit_lru_info(struct victim_select_info *lru_info,
+				       struct ufshpb_region *rgn)
+{
+	list_move_tail(&rgn->list_lru_rgn, &lru_info->lh_lru_rgn);
+}
+
+static struct ufshpb_region *ufshpb_victim_lru_info(struct ufshpb_lu *hpb)
+{
+	struct victim_select_info *lru_info = &hpb->lru_info;
+	struct ufshpb_region *rgn, *victim_rgn = NULL;
+
+	list_for_each_entry(rgn, &lru_info->lh_lru_rgn, list_lru_rgn) {
+		WARN_ON(!rgn);
+		if (ufshpb_check_issue_state_srgns(hpb, rgn))
+			continue;
+
+		victim_rgn = rgn;
+		break;
+	}
+
+	return victim_rgn;
+}
+
+static inline void ufshpb_cleanup_lru_info(struct victim_select_info *lru_info,
+					   struct ufshpb_region *rgn)
+{
+	list_del_init(&rgn->list_lru_rgn);
+	rgn->rgn_state = HPB_RGN_INACTIVE;
+	atomic_dec(&lru_info->active_cnt);
+}
+
+static inline void ufshpb_purge_active_subregion(struct ufshpb_lu *hpb,
+						 struct ufshpb_subregion *srgn)
+{
+	if (srgn->srgn_state != HPB_SRGN_UNUSED) {
+		ufshpb_put_map_ctx(hpb, srgn->mctx);
+		srgn->srgn_state = HPB_SRGN_UNUSED;
+		srgn->mctx = NULL;
+	}
+}
+
+static void __ufshpb_evict_region(struct ufshpb_lu *hpb,
+				  struct ufshpb_region *rgn)
+{
+	struct victim_select_info *lru_info;
+	struct ufshpb_subregion *srgn;
+	int srgn_idx;
+
+	lru_info = &hpb->lru_info;
+
+	dev_dbg(&hpb->hpb_lu_dev, "evict region %d\n", rgn->rgn_idx);
+
+	ufshpb_cleanup_lru_info(lru_info, rgn);
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn = rgn->srgn_tbl + srgn_idx;
+
+		ufshpb_purge_active_subregion(hpb, srgn);
+	}
+}
+
+static int ufshpb_evict_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	if (rgn->rgn_state == HPB_RGN_PINNED) {
+		dev_warn(&hpb->hpb_lu_dev,
+			 "pinned region cannot drop-out. region %d\n",
+			 rgn->rgn_idx);
+		goto out;
+	}
+	if (!list_empty(&rgn->list_lru_rgn)) {
+		if (ufshpb_check_issue_state_srgns(hpb, rgn)) {
+			ret = -EBUSY;
+			goto out;
+		}
+
+		__ufshpb_evict_region(hpb, rgn);
+	}
+out:
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+	return ret;
+}
+
+static inline struct
+ufshpb_rsp_field *ufshpb_get_hpb_rsp(struct ufshcd_lrb *lrbp)
+{
+	return (struct ufshpb_rsp_field *)&lrbp->ucd_rsp_ptr->sr.sense_data_len;
+}
+
+static int ufshpb_issue_map_req(struct ufshpb_lu *hpb,
+				struct ufshpb_region *rgn,
+				struct ufshpb_subregion *srgn)
+{
+	struct ufshpb_req *map_req;
+	unsigned long flags;
+	int ret;
+	int err = -EAGAIN;
+	bool alloc_required = false;
+	enum HPB_RGN_STATE state = HPB_SRGN_INVALID;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	/*
+	 * Since the region state change occurs only in the map_work,
+	 * the state of the region cannot HPB_RGN_INACTIVE at this point.
+	 * The region state must be changed in the map_work
+	 */
+	WARN_ON(rgn->rgn_state == HPB_RGN_INACTIVE);
+
+	if (srgn->srgn_state == HPB_SRGN_UNUSED)
+		alloc_required = true;
+
+	/*
+	 * If the subregion is already ISSUED state,
+	 * a specific event (e.g., GC or wear-leveling, etc.) occurs in
+	 * the device and HPB response for map loading is received.
+	 * In this case, after finishing the HPB_READ_BUFFER,
+	 * the next HPB_READ_BUFFER is performed again to obtain the latest
+	 * map data.
+	 */
+	if (srgn->srgn_state == HPB_SRGN_ISSUED)
+		goto unlock_out;
+
+	srgn->srgn_state = HPB_SRGN_ISSUED;
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+
+	if (alloc_required) {
+		WARN_ON(srgn->mctx);
+		srgn->mctx = ufshpb_get_map_ctx(hpb);
+		if (!srgn->mctx) {
+			dev_notice(&hpb->hpb_lu_dev,
+			    "get map_ctx failed. region %d - %d\n",
+			    rgn->rgn_idx, srgn->srgn_idx);
+			state = HPB_SRGN_UNUSED;
+			goto change_srgn_state;
+		}
+	}
+
+	ufshpb_clear_dirty_bitmap(hpb, srgn);
+	map_req = ufshpb_get_map_req(hpb, srgn);
+	if (!map_req)
+		goto change_srgn_state;
+
+	ret = ufshpb_lu_get(hpb);
+	if (unlikely(ret)) {
+		dev_notice(&hpb->hpb_lu_dev,
+			   "%s: ufshpb_lu_get failed: %d", __func__, ret);
+		goto free_map_req;
+	}
+
+	ret = ufshpb_execute_map_req(hpb, map_req);
+	if (ret) {
+		dev_notice(&hpb->hpb_lu_dev,
+			   "%s: issue map_req failed: %d, region %d - %d\n",
+			   __func__, ret, srgn->rgn_idx, srgn->srgn_idx);
+		ufshpb_lu_put(hpb);
+		goto free_map_req;
+	}
+	return 0;
+
+free_map_req:
+	ufshpb_put_map_req(hpb, map_req);
+change_srgn_state:
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	srgn->srgn_state = state;
+unlock_out:
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+	return err;
+}
+
+static int ufshpb_add_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
+{
+	struct ufshpb_region *victim_rgn;
+	struct victim_select_info *lru_info = &hpb->lru_info;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	/*
+	 * If region belongs to lru_list, just move the region
+	 * to the front of lru list. because the state of the region
+	 * is already active-state
+	 */
+	if (!list_empty(&rgn->list_lru_rgn)) {
+		ufshpb_hit_lru_info(lru_info, rgn);
+		goto out;
+	}
+
+	if (rgn->rgn_state == HPB_RGN_INACTIVE) {
+		if (atomic_read(&lru_info->active_cnt)
+		    == lru_info->max_lru_active_cnt) {
+			/*
+			 * If the maximum number of active regions
+			 * is exceeded, evict the least recently used region.
+			 * This case may occur when the device responds
+			 * to the eviction information late.
+			 * It is okay to evict the least recently used region,
+			 * because the device could detect this region
+			 * by not issuing HPB_READ
+			 */
+			victim_rgn = ufshpb_victim_lru_info(hpb);
+			if (!victim_rgn) {
+				dev_warn(&hpb->hpb_lu_dev,
+				    "cannot get victim region error\n");
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			dev_dbg(&hpb->hpb_lu_dev,
+				"LRU full (%d), choost victim %d\n",
+				atomic_read(&lru_info->active_cnt),
+				victim_rgn->rgn_idx);
+			__ufshpb_evict_region(hpb, victim_rgn);
+		}
+
+		/*
+		 * When a region is added to lru_info list_head,
+		 * it is guaranteed that the subregion has been
+		 * assigned all mctx. If failed, try to receive mctx again
+		 * without being added to lru_info list_head
+		 */
+		ufshpb_add_lru_info(lru_info, rgn);
+	}
+out:
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+	return ret;
+}
+
+static void ufshpb_rsp_req_region_update(struct ufshpb_lu *hpb,
+					 struct ufshpb_rsp_field *rsp_field)
+{
+	int i, rgn_idx, srgn_idx;
+
+	/*
+	 * If the active region and the inactive region are the same,
+	 * we will inactivate this region.
+	 * The device could check this (region inactivated) and
+	 * will response the proper active region information
+	 */
+	spin_lock(&hpb->rsp_list_lock);
+	for (i = 0; i < rsp_field->active_rgn_cnt; i++) {
+		rgn_idx =
+			be16_to_cpu(rsp_field->hpb_active_field[i].active_rgn);
+		srgn_idx =
+			be16_to_cpu(rsp_field->hpb_active_field[i].active_srgn);
+
+		dev_dbg(&hpb->hpb_lu_dev, "activate(%d) region %d - %d\n",
+			i, rgn_idx, srgn_idx);
+		ufshpb_update_active_info(hpb, rgn_idx, srgn_idx);
+		atomic_inc(&hpb->stats.rb_active_cnt);
+	}
+
+	for (i = 0; i < rsp_field->inactive_rgn_cnt; i++) {
+		rgn_idx = be16_to_cpu(rsp_field->hpb_inactive_field[i]);
+		dev_dbg(&hpb->hpb_lu_dev, "inactivate(%d) region %d\n",
+			i, rgn_idx);
+		ufshpb_update_inactive_info(hpb, rgn_idx);
+		atomic_inc(&hpb->stats.rb_inactive_cnt);
+	}
+	spin_unlock(&hpb->rsp_list_lock);
+
+	dev_dbg(&hpb->hpb_lu_dev, "Noti: #ACT %u #INACT %u\n",
+		rsp_field->active_rgn_cnt, rsp_field->inactive_rgn_cnt);
+
+	queue_work(ufshpb_drv.ufshpb_wq, &hpb->map_work);
+}
+
+/* routine : isr (ufs) */
+static void ufshpb_rsp_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	struct ufshpb_lu *hpb;
+	struct ufshpb_rsp_field *rsp_field;
+	int data_seg_len, ret;
+
+	data_seg_len = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_2)
+		& MASK_RSP_UPIU_DATA_SEG_LEN;
+
+	/* To flush remained rsp_list, we queue the map_work task */
+	if (!data_seg_len) {
+		if (!ufshpb_is_general_lun(lrbp->lun))
+			return;
+
+		hpb = ufshpb_get_hpb_data(lrbp->cmd);
+		ret = ufshpb_lu_get(hpb);
+		if (ret)
+			return;
+
+		if (!ufshpb_is_empty_rsp_lists(hpb))
+			queue_work(ufshpb_drv.ufshpb_wq, &hpb->map_work);
+
+		goto put_hpb;
+	}
+
+	/* Check HPB_UPDATE_ALERT */
+	if (!(lrbp->ucd_rsp_ptr->header.dword_2 &
+	      UPIU_HEADER_DWORD(0, 2, 0, 0)))
+		return;
+
+	rsp_field = ufshpb_get_hpb_rsp(lrbp);
+	if (ufshpb_may_field_valid(hba, lrbp, rsp_field))
+		return;
+
+	hpb = ufshpb_get_hpb_data(lrbp->cmd);
+	ret = ufshpb_lu_get(hpb);
+	if (ret)
+		return;
+
+	atomic_inc(&hpb->stats.rb_noti_cnt);
+
+	switch (rsp_field->hpb_type) {
+	case HPB_RSP_REQ_REGION_UPDATE:
+		WARN_ON(data_seg_len != DEV_DATA_SEG_LEN);
+		ufshpb_rsp_req_region_update(hpb, rsp_field);
+		break;
+	case HPB_RSP_DEV_RESET:
+		dev_warn(&hpb->hpb_lu_dev,
+			 "UFS device lost HPB information during PM.\n");
+		break;
+	default:
+		dev_notice(&hpb->hpb_lu_dev, "hpb_type is not available: %d\n",
+			   rsp_field->hpb_type);
+		break;
+	}
+put_hpb:
+	ufshpb_lu_put(hpb);
+}
+
+static void ufshpb_add_active_list(struct ufshpb_lu *hpb,
+				   struct ufshpb_region *rgn,
+				   struct ufshpb_subregion *srgn)
+{
+	if (!list_empty(&rgn->list_inact_rgn))
+		return;
+
+	if (!list_empty(&srgn->list_act_srgn)) {
+		list_move(&srgn->list_act_srgn, &hpb->lh_act_srgn);
+		return;
+	}
+
+	list_add(&srgn->list_act_srgn, &hpb->lh_act_srgn);
+}
+
+static void ufshpb_add_pending_evict_list(struct ufshpb_lu *hpb,
+				    struct ufshpb_region *rgn,
+				    struct list_head *pending_list)
+{
+	struct ufshpb_subregion *srgn;
+	int srgn_idx;
+
+	if (!list_empty(&rgn->list_inact_rgn))
+		return;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn = rgn->srgn_tbl + srgn_idx;
+
+		if (!list_empty(&srgn->list_act_srgn))
+			return;
+	}
+
+	list_add_tail(&rgn->list_inact_rgn, pending_list);
+}
+
+static void ufshpb_run_active_subregion_list(struct ufshpb_lu *hpb)
+{
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+	struct ufshpb_map_ctx *mctx;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	while ((srgn = list_first_entry_or_null(&hpb->lh_act_srgn,
+						struct ufshpb_subregion,
+						list_act_srgn))) {
+		list_del_init(&srgn->list_act_srgn);
+		spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+
+		rgn = hpb->rgn_tbl + srgn->rgn_idx;
+		mctx = NULL;
+		ret = ufshpb_add_region(hpb, rgn);
+		if (ret)
+			break;
+
+		ret = ufshpb_issue_map_req(hpb, rgn, srgn);
+		if (ret) {
+			dev_notice(&hpb->hpb_lu_dev,
+			    "issue map_req failed. ret %d, region %d - %d\n",
+			    ret, rgn->rgn_idx, srgn->srgn_idx);
+			break;
+		}
+		spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	}
+
+	if (ret) {
+		dev_notice(&hpb->hpb_lu_dev, "region %d - %d, will retry\n",
+			   rgn->rgn_idx, srgn->srgn_idx);
+		spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+		ufshpb_add_active_list(hpb, rgn, srgn);
+	}
+	spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+}
+
+static void ufshpb_run_inactive_region_list(struct ufshpb_lu *hpb)
+{
+	struct ufshpb_region *rgn;
+	unsigned long flags;
+	int ret;
+	LIST_HEAD(pending_list);
+
+	spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	while ((rgn = list_first_entry_or_null(&hpb->lh_inact_rgn,
+					       struct ufshpb_region,
+					       list_inact_rgn))) {
+		list_del_init(&rgn->list_inact_rgn);
+		spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+
+		ret = ufshpb_evict_region(hpb, rgn);
+		if (ret) {
+			spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+			ufshpb_add_pending_evict_list(hpb, rgn, &pending_list);
+			spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+		}
+
+		spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	}
+
+	list_splice(&pending_list, &hpb->lh_inact_rgn);
+	spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+}
+
+static void ufshpb_map_work_handler(struct work_struct *work)
+{
+	struct ufshpb_lu *hpb;
+	int ret;
+
+	hpb = container_of(work, struct ufshpb_lu, map_work);
+	ret = ufshpb_lu_get(hpb);
+	if (ret) {
+		dev_info(&hpb->hpb_lu_dev, "%s: exit, state %d\n",
+			 __func__, ufshpb_get_state(hpb));
+		return;
+	}
+
+	ufshpb_run_inactive_region_list(hpb);
+	ufshpb_run_active_subregion_list(hpb);
+
+	ufshpb_lu_put(hpb);
+}
+
+/*
+ * this function doesn't need to hold lock due to be called in init.
+ * (hpb_state_lock, rsp_list_lock, etc..)
+ */
+static int ufshpb_init_pinned_active_region(struct ufs_hba *hba,
+					    struct ufshpb_lu *hpb,
+					    struct ufshpb_region *rgn)
+{
+	struct ufshpb_subregion *srgn;
+	int srgn_idx, i;
+	int err = 0;
+
+	for (srgn_idx = 0; srgn_idx < rgn->srgn_cnt; srgn_idx++) {
+		srgn = rgn->srgn_tbl + srgn_idx;
+
+		srgn->mctx = ufshpb_get_map_ctx(hpb);
+		srgn->srgn_state = HPB_SRGN_INVALID;
+		if (!srgn->mctx) {
+			dev_err(hba->dev,
+				"alloc mctx for pinned region failed\n");
+			goto release;
+		}
+
+		list_add_tail(&srgn->list_act_srgn, &hpb->lh_act_srgn);
+	}
+
+	rgn->rgn_state = HPB_RGN_PINNED;
+	return 0;
+
+release:
+	for (i = 0; i < srgn_idx; i++) {
+		srgn = rgn->srgn_tbl + i;
+		ufshpb_put_map_ctx(hpb, srgn->mctx);
+	}
+	return err;
+}
+
 static void ufshpb_init_subregion_tbl(struct ufshpb_lu *hpb,
 				      struct ufshpb_region *rgn)
 {
@@ -101,6 +919,8 @@ static void ufshpb_init_lu_parameter(struct ufs_hba *hba,
 	hpb->lu_pinned_end = hpb_lu_info->num_pinned ?
 		(hpb_lu_info->pinned_start + hpb_lu_info->num_pinned - 1)
 		: PINNED_NOT_SET;
+	hpb->lru_info.max_lru_active_cnt =
+		hpb_lu_info->max_active_rgns - hpb_lu_info->num_pinned;
 
 	rgn_mem_size = (1ULL << hpb_dev_info->rgn_size) * HPB_RGN_SIZE_UNIT
 		/ HPB_ENTRY_BLOCK_SIZE * HPB_ENTRY_SIZE;
@@ -154,6 +974,9 @@ static int ufshpb_alloc_region_tbl(struct ufs_hba *hba, struct ufshpb_lu *hpb)
 		rgn = rgn_table + rgn_idx;
 		rgn->rgn_idx = rgn_idx;
 
+		INIT_LIST_HEAD(&rgn->list_inact_rgn);
+		INIT_LIST_HEAD(&rgn->list_lru_rgn);
+
 		if (rgn_idx == hpb->rgns_per_lu - 1)
 			srgn_cnt = ((hpb->srgns_per_lu - 1) %
 				    hpb->srgns_per_rgn) + 1;
@@ -163,7 +986,13 @@ static int ufshpb_alloc_region_tbl(struct ufs_hba *hba, struct ufshpb_lu *hpb)
 			goto release_srgn_table;
 		ufshpb_init_subregion_tbl(hpb, rgn);
 
-		rgn->rgn_state = HPB_RGN_INACTIVE;
+		if (ufshpb_is_pinned_region(hpb, rgn_idx)) {
+			ret = ufshpb_init_pinned_active_region(hba, hpb, rgn);
+			if (ret)
+				goto release_srgn_table;
+		} else {
+			rgn->rgn_state = HPB_RGN_INACTIVE;
+		}
 	}
 
 	return 0;
@@ -187,7 +1016,10 @@ static void ufshpb_destroy_subregion_tbl(struct ufshpb_lu *hpb,
 		struct ufshpb_subregion *srgn;
 
 		srgn = rgn->srgn_tbl + srgn_idx;
-		srgn->srgn_state = HPB_SRGN_UNUSED;
+		if (srgn->srgn_state != HPB_SRGN_UNUSED) {
+			srgn->srgn_state = HPB_SRGN_UNUSED;
+			ufshpb_put_map_ctx(hpb, srgn->mctx);
+		}
 	}
 }
 
@@ -217,6 +1049,33 @@ static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb,
 	int ret;
 
 	spin_lock_init(&hpb->hpb_state_lock);
+	spin_lock_init(&hpb->rsp_list_lock);
+
+	INIT_LIST_HEAD(&hpb->lru_info.lh_lru_rgn);
+	INIT_LIST_HEAD(&hpb->lh_act_srgn);
+	INIT_LIST_HEAD(&hpb->lh_inact_rgn);
+	INIT_LIST_HEAD(&hpb->list_hpb_lu);
+
+	INIT_WORK(&hpb->map_work, ufshpb_map_work_handler);
+
+	hpb->map_req_cache = kmem_cache_create("ufshpb_req_cache",
+			  sizeof(struct ufshpb_req), 0, 0, NULL);
+	if (!hpb->map_req_cache) {
+		dev_err(hba->dev, "ufshpb(%d) ufshpb_req_cache create fail",
+			hpb->lun);
+		return -ENOMEM;
+	}
+
+	hpb->m_page_cache = kmem_cache_create("ufshpb_m_page_cache",
+			  sizeof(struct page *) * hpb->pages_per_srgn,
+			  0, 0, NULL);
+	if (!hpb->m_page_cache) {
+		dev_err(hba->dev, "ufshpb(%d) ufshpb_m_page_cache create fail",
+			hpb->lun);
+		ret = -ENOMEM;
+		goto release_req_cache;
+	}
+
 
 	ret = ufshpb_alloc_region_tbl(hba, hpb);
 	if (ret)
@@ -230,6 +1089,10 @@ static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb,
 
 release_rgn_table:
 	ufshpb_destroy_region_tbl(hpb);
+release_m_page_cache:
+	kmem_cache_destroy(hpb->m_page_cache);
+release_req_cache:
+	kmem_cache_destroy(hpb->map_req_cache);
 	return ret;
 }
 
@@ -261,10 +1124,42 @@ static struct ufshpb_lu *ufshpb_alloc_hpb_lu(struct ufs_hba *hba, int lun,
 	return NULL;
 }
 
+static void ufshpb_discard_rsp_lists(struct ufshpb_lu *hpb)
+{
+	struct ufshpb_region *rgn, *next_rgn;
+	struct ufshpb_subregion *srgn, *next_srgn;
+	unsigned long flags;
+
+	/*
+	 * If the device reset occurred, the remained HPB region information
+	 * may be stale. Therefore, by dicarding the lists of HPB response
+	 * that remained after reset, it prevents unnecessary work.
+	 */
+	spin_lock_irqsave(&hpb->rsp_list_lock, flags);
+	list_for_each_entry_safe(rgn, next_rgn, &hpb->lh_inact_rgn,
+				 list_inact_rgn)
+		list_del_init(&rgn->list_inact_rgn);
+
+	list_for_each_entry_safe(srgn, next_srgn, &hpb->lh_act_srgn,
+				 list_act_srgn)
+		list_del_init(&srgn->list_act_srgn);
+	spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
+}
+
+static inline void ufshpb_cancel_jobs(struct ufshpb_lu *hpb)
+{
+	cancel_work_sync(&hpb->map_work);
+}
+
 static void ufshpb_lu_release(struct ufshpb_lu *hpb)
 {
+	ufshpb_cancel_jobs(hpb);
+
 	ufshpb_destroy_region_tbl(hpb);
 
+	kmem_cache_destroy(hpb->map_req_cache);
+	kmem_cache_destroy(hpb->m_page_cache);
+
 	list_del_init(&hpb->list_hpb_lu);
 }
 
@@ -351,6 +1246,9 @@ static void ufshpb_reset_host(struct ufs_hba *hba)
 		dev_info(&hpb->hpb_lu_dev, "ufshpb run reset_host");
 
 		ufshpb_set_state(hpb, HPB_RESET);
+		ufshpb_cancel_jobs(hpb);
+		ufshpb_discard_rsp_lists(hpb);
+
 		ufshpb_lu_put(hpb);
 	}
 }
@@ -365,6 +1263,7 @@ static void ufshpb_suspend(struct ufs_hba *hba)
 
 		dev_info(&hpb->hpb_lu_dev, "ufshpb goto suspend");
 		ufshpb_set_state(hpb, HPB_SUSPEND);
+		ufshpb_cancel_jobs(hpb);
 
 		ufshpb_lu_put(hpb);
 	}
@@ -380,6 +1279,9 @@ static void ufshpb_resume(struct ufs_hba *hba)
 
 		dev_info(&hpb->hpb_lu_dev, "ufshpb resume");
 		ufshpb_set_state(hpb, HPB_PRESENT);
+		if (!ufshpb_is_empty_rsp_lists(hpb))
+			queue_work(ufshpb_drv.ufshpb_wq, &hpb->map_work);
+
 		ufshpb_lu_put(hpb);
 	}
 }
@@ -661,6 +1563,14 @@ static void ufshpb_scan_hpb_lu(struct ufs_hba *hba,
 		list_for_each_entry(hpb, &ufshpb_drv.lh_hpb_lu, list_hpb_lu) {
 			dev_info(&hpb->hpb_lu_dev, "set state to present\n");
 			ufshpb_set_state(hpb, HPB_PRESENT);
+
+			if ((hpb->lu_pinned_end - hpb->lu_pinned_start) > 0) {
+				dev_info(&hpb->hpb_lu_dev,
+				    "loading pinned regions %d - %d\n",
+				    hpb->lu_pinned_start, hpb->lu_pinned_end);
+				queue_work(ufshpb_drv.ufshpb_wq,
+					&hpb->map_work);
+			}
 		}
 	}
 }
@@ -728,6 +1638,8 @@ static int ufshpb_remove(struct device *dev)
 		sdev = hpb->sdev_ufs_lu;
 		sdev->hostdata = NULL;
 
+		ufshpb_cancel_jobs(hpb);
+
 		device_del(&hpb->hpb_lu_dev);
 
 		dev_info(&hpb->hpb_lu_dev, "hpb_lu_dev refcnt %d\n",
@@ -768,16 +1680,69 @@ static int __init ufshpb_init(void)
 	unsigned int pool_size;
 	int ret;
 
+
+	ufshpb_drv.ufshpb_mctx_cache = kmem_cache_create("ufshpb_mctx_cache",
+					sizeof(struct ufshpb_map_ctx),
+					0, 0, NULL);
+	if (!ufshpb_drv.ufshpb_mctx_cache) {
+		pr_err("ufshpb: cannot init mctx cache\n");
+		return -ENOMEM;
+	}
+
+	pool_size = DIV_ROUND_UP(ufshpb_host_map_kbytes * 1024, 4096);
+	pr_info("%s:%d ufshpb_host_map_kbytes %u pool_size %u\n",
+	       __func__, __LINE__, ufshpb_host_map_kbytes, pool_size);
+
+	ufshpb_drv.ufshpb_mctx_pool = mempool_create_slab_pool(
+				     pool_size, ufshpb_drv.ufshpb_mctx_cache);
+	if (!ufshpb_drv.ufshpb_mctx_pool) {
+		pr_err("ufshpb: cannot init mctx pool\n");
+		ret = -ENOMEM;
+		goto release_mctx_cache;
+	}
+
+	ufshpb_drv.ufshpb_page_pool = mempool_create_page_pool(pool_size, 0);
+	if (!ufshpb_drv.ufshpb_page_pool) {
+		pr_err("ufshpb: cannot init page pool\n");
+		ret = -ENOMEM;
+		goto release_mctx_pool;
+	}
+
+	ufshpb_drv.ufshpb_wq = alloc_workqueue("ufshpb-wq",
+					WQ_UNBOUND | WQ_MEM_RECLAIM, 0);
+	if (!ufshpb_drv.ufshpb_wq) {
+		pr_err("ufshpb: alloc workqueue failed\n");
+		ret = -ENOMEM;
+		goto release_page_pool;
+	}
+
 	ret = driver_register(&ufshpb_drv.drv);
-	if (ret)
+	if (ret) {
 		pr_err("ufshpb: driver register failed\n");
+		goto release_wq;
+	}
 
+	return 0;
+release_wq:
+	destroy_workqueue(ufshpb_drv.ufshpb_wq);
+release_page_pool:
+	mempool_destroy(ufshpb_drv.ufshpb_page_pool);
+release_mctx_pool:
+	mempool_destroy(ufshpb_drv.ufshpb_mctx_pool);
+release_mctx_cache:
+	kmem_cache_destroy(ufshpb_drv.ufshpb_mctx_cache);
 	return ret;
 }
 
 static void __exit ufshpb_exit(void)
 {
 	driver_unregister(&ufshpb_drv.drv);
+
+	mempool_destroy(ufshpb_drv.ufshpb_page_pool);
+	mempool_destroy(ufshpb_drv.ufshpb_mctx_pool);
+	kmem_cache_destroy(ufshpb_drv.ufshpb_mctx_cache);
+
+	destroy_workqueue(ufshpb_drv.ufshpb_wq);
 }
 
 MODULE_AUTHOR("Yongmyong Lee <ymhungry.lee@samsung.com>");
diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
index eaa4a3e035b1..d9c27348d354 100644
--- a/drivers/scsi/ufs/ufshpb.h
+++ b/drivers/scsi/ufs/ufshpb.h
@@ -101,10 +101,36 @@ struct ufshpb_lu_info {
 	int max_active_rgns;
 };
 
+struct ufshpb_active_field {
+	__be16 active_rgn;
+	__be16 active_srgn;
+} __packed;
+
+struct ufshpb_rsp_field {
+	__be16 sense_data_len;
+	u8 desc_type;
+	u8 additional_len;
+	u8 hpb_type;
+	u8 reserved;
+	u8 active_rgn_cnt;
+	u8 inactive_rgn_cnt;
+	struct ufshpb_active_field hpb_active_field[2];
+	__be16 hpb_inactive_field[2];
+} __packed;
+
+struct ufshpb_map_ctx {
+	struct page **m_page;
+	unsigned long *ppn_dirty;
+};
+
 struct ufshpb_subregion {
+	struct ufshpb_map_ctx *mctx;
 	enum HPB_SRGN_STATE srgn_state;
 	int rgn_idx;
 	int srgn_idx;
+
+	/* below information is used by rsp_list */
+	struct list_head list_act_srgn;
 };
 
 struct ufshpb_region {
@@ -112,6 +138,39 @@ struct ufshpb_region {
 	enum HPB_RGN_STATE rgn_state;
 	int rgn_idx;
 	int srgn_cnt;
+
+	/* below information is used by rsp_list */
+	struct list_head list_inact_rgn;
+
+	/* below information is used by lru */
+	struct list_head list_lru_rgn;
+};
+
+/**
+ * struct ufshpb_req - UFSHPB READ BUFFER (for caching map) request structure
+ * @req: block layer request for READ BUFFER
+ * @bio: bio for holding map page
+ * @hpb: ufshpb_lu structure that related to the L2P map
+ * @mctx: L2P map information
+ * @rgn_idx: target region index
+ * @srgn_idx: target sub-region index
+ * @lun: target logical unit number
+ */
+struct ufshpb_req {
+	struct request *req;
+	struct bio *bio;
+	struct ufshpb_lu *hpb;
+	struct ufshpb_map_ctx *mctx;
+
+	unsigned int rgn_idx;
+	unsigned int srgn_idx;
+	unsigned int lun;
+};
+
+struct victim_select_info {
+	struct list_head lh_lru_rgn;
+	int max_lru_active_cnt; /* supported hpb #region - pinned #region */
+	atomic_t active_cnt;
 };
 
 struct ufshpb_stats {
@@ -134,6 +193,16 @@ struct ufshpb_lu {
 	spinlock_t hpb_state_lock;
 	atomic_t hpb_state; /* hpb_state_lock */
 
+	spinlock_t rsp_list_lock;
+	struct list_head lh_act_srgn; /* rsp_list_lock */
+	struct list_head lh_inact_rgn; /* rsp_list_lock */
+
+	/* cached L2P map management worker */
+	struct work_struct map_work;
+
+	/* for selecting victim */
+	struct victim_select_info lru_info;
+
 	/* pinned region information */
 	u32 lu_pinned_start;
 	u32 lu_pinned_end;
@@ -152,6 +221,9 @@ struct ufshpb_lu {
 
 	struct ufshpb_stats stats;
 
+	struct kmem_cache *map_req_cache;
+	struct kmem_cache *m_page_cache;
+
 	struct ufsf_feature_info *ufsf;
 	struct list_head list_hpb_lu;
 };
-- 
2.17.1

[RFC PATCH v2 5/5] scsi: ufs: Prepare HPB read for cached sub-region

[Daejun Park]

This patch changes the read I/O to the HPB read I/O.

If the logical address of the read I/O belongs to active sub-region, the
HPB driver modifies the read I/O command to HPB read. It modifies the upiu
command of UFS instead of modifying the existing SCSI command.

In the HPB version 1.0, the maximum read I/O size that can be converted to
HPB read is 4KB.

The dirty map of the active sub-region prevents an incorrect HPB read that
has stale physical page number which is updated by previous write I/O.

Signed-off-by: Daejun Park <daejun7.park@samsung.com>
---
 drivers/scsi/ufs/ufshpb.c | 234 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 234 insertions(+)

diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index 6229c6fcb5e1..848f51e9a1a1 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -25,6 +25,22 @@ static inline int ufshpb_is_valid_srgn(struct ufshpb_region *rgn,
 		srgn->srgn_state == HPB_SRGN_VALID;
 }
 
+static inline bool ufshpb_is_read_cmd(struct scsi_cmnd *cmd)
+{
+	return req_op(cmd->request) == REQ_OP_READ;
+}
+
+static inline bool ufshpb_is_write_discard_cmd(struct scsi_cmnd *cmd)
+{
+	return op_is_write(req_op(cmd->request)) ||
+	       op_is_discard(req_op(cmd->request));
+}
+
+static inline bool ufshpb_is_support_chunk(int transfer_len)
+{
+	return transfer_len <= HPB_MULTI_CHUNK_HIGH;
+}
+
 static inline bool ufshpb_is_general_lun(int lun)
 {
 	return lun < UFS_UPIU_MAX_UNIT_NUM_ID;
@@ -116,6 +132,224 @@ static inline void ufshpb_lu_put(struct ufshpb_lu *hpb)
 	put_device(&hpb->hpb_lu_dev);
 }
 
+static inline u32 ufshpb_get_lpn(struct scsi_cmnd *cmnd)
+{
+	return blk_rq_pos(cmnd->request) >>
+		(ilog2(cmnd->device->sector_size) - 9);
+}
+
+static inline unsigned int ufshpb_get_len(struct scsi_cmnd *cmnd)
+{
+	return blk_rq_sectors(cmnd->request) >>
+		(ilog2(cmnd->device->sector_size) - 9);
+}
+
+static void ufshpb_set_ppn_dirty(struct ufshpb_lu *hpb, int rgn_idx,
+			     int srgn_idx, int srgn_offset, int cnt)
+{
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+	int set_bit_len;
+	int bitmap_len = hpb->entries_per_srgn;
+
+next_srgn:
+	rgn = hpb->rgn_tbl + rgn_idx;
+	srgn = rgn->srgn_tbl + srgn_idx;
+
+	if ((srgn_offset + cnt) > bitmap_len)
+		set_bit_len = bitmap_len - srgn_offset;
+	else
+		set_bit_len = cnt;
+
+	if (rgn->rgn_state != HPB_RGN_INACTIVE &&
+	    srgn->srgn_state == HPB_SRGN_VALID)
+		bitmap_set(srgn->mctx->ppn_dirty, srgn_offset, set_bit_len);
+
+	srgn_offset = 0;
+	if (++srgn_idx == hpb->srgns_per_rgn) {
+		srgn_idx = 0;
+		rgn_idx++;
+	}
+
+	cnt -= set_bit_len;
+	if (cnt > 0)
+		goto next_srgn;
+
+	WARN_ON(cnt < 0);
+}
+
+static bool ufshpb_test_ppn_dirty(struct ufshpb_lu *hpb, int rgn_idx,
+				   int srgn_idx, int srgn_offset, int cnt)
+{
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+	int bitmap_len = hpb->entries_per_srgn;
+	int bit_len;
+
+next_srgn:
+	rgn = hpb->rgn_tbl + rgn_idx;
+	srgn = rgn->srgn_tbl + srgn_idx;
+
+	if (!ufshpb_is_valid_srgn(rgn, srgn))
+		return true;
+
+	/*
+	 * If the region state is active, mctx must be allocated.
+	 * In this case, check whether the region is evicted or
+	 * mctx allcation fail.
+	 */
+	WARN_ON(!srgn->mctx);
+
+	if ((srgn_offset + cnt) > bitmap_len)
+		bit_len = bitmap_len - srgn_offset;
+	else
+		bit_len = cnt;
+
+	if (find_next_bit(srgn->mctx->ppn_dirty,
+			  bit_len, srgn_offset) >= srgn_offset)
+		return true;
+
+	srgn_offset = 0;
+	if (++srgn_idx == hpb->srgns_per_rgn) {
+		srgn_idx = 0;
+		rgn_idx++;
+	}
+
+	cnt -= bit_len;
+	if (cnt > 0)
+		goto next_srgn;
+
+	return false;
+}
+
+static u64 ufshpb_get_ppn(struct ufshpb_lu *hpb,
+			  struct ufshpb_map_ctx *mctx, int pos, int *error)
+{
+	u64 *ppn_table;
+	struct page *page;
+	int index, offset;
+
+	index = pos / (PAGE_SIZE / HPB_ENTRY_SIZE);
+	offset = pos % (PAGE_SIZE / HPB_ENTRY_SIZE);
+
+	page = mctx->m_page[index];
+	if (unlikely(!page)) {
+		*error = -ENOMEM;
+		dev_err(&hpb->hpb_lu_dev,
+			"error. cannot find page in mctx\n");
+		return 0;
+	}
+
+	ppn_table = page_address(page);
+	if (unlikely(!ppn_table)) {
+		*error = -ENOMEM;
+		dev_err(&hpb->hpb_lu_dev, "error. cannot get ppn_table\n");
+		return 0;
+	}
+
+	return ppn_table[offset];
+}
+
+static inline void
+ufshpb_get_pos_from_lpn(struct ufshpb_lu *hpb, unsigned long lpn, int *rgn_idx,
+			int *srgn_idx, int *offset)
+{
+	int rgn_offset;
+
+	*rgn_idx = lpn >> hpb->entries_per_rgn_shift;
+	rgn_offset = lpn & hpb->entries_per_rgn_mask;
+	*srgn_idx = rgn_offset >> hpb->entries_per_srgn_shift;
+	*offset = rgn_offset & hpb->entries_per_srgn_mask;
+}
+
+static void
+ufshpb_set_hpb_read_to_upiu(struct ufshpb_lu *hpb, struct ufshcd_lrb *lrbp,
+				  u32 lpn, u64 ppn,  unsigned int transfer_len)
+{
+	unsigned char *cdb = lrbp->ucd_req_ptr->sc.cdb;
+
+	cdb[0] = UFSHPB_READ;
+
+	put_unaligned_be64(ppn, &cdb[6]);
+	cdb[14] = transfer_len;
+}
+
+/* routine : READ10 -> HPB_READ  */
+static void ufshpb_prep_fn(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	struct ufshpb_lu *hpb;
+	struct ufshpb_region *rgn;
+	struct ufshpb_subregion *srgn;
+	struct scsi_cmnd *cmd = lrbp->cmd;
+	u32 lpn;
+	u64 ppn;
+	unsigned long flags;
+	int transfer_len, rgn_idx, srgn_idx, srgn_offset;
+	int err = 0;
+
+	hpb = ufshpb_get_hpb_data(cmd);
+	err = ufshpb_lu_get(hpb);
+	if (unlikely(err))
+		return;
+
+	WARN_ON(hpb->lun != cmd->device->lun);
+	if (!ufshpb_is_write_discard_cmd(cmd) &&
+	    !ufshpb_is_read_cmd(cmd))
+		goto put_hpb;
+
+	transfer_len = ufshpb_get_len(cmd);
+	if (unlikely(!transfer_len))
+		goto put_hpb;
+
+	lpn = ufshpb_get_lpn(cmd);
+	ufshpb_get_pos_from_lpn(hpb, lpn, &rgn_idx, &srgn_idx, &srgn_offset);
+	rgn = hpb->rgn_tbl + rgn_idx;
+	srgn = rgn->srgn_tbl + srgn_idx;
+
+	/* If command type is WRITE or DISCARD, set bitmap as drity */
+	if (ufshpb_is_write_discard_cmd(cmd)) {
+		spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+		ufshpb_set_ppn_dirty(hpb, rgn_idx, srgn_idx, srgn_offset,
+				 transfer_len);
+		spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+		goto put_hpb;
+	}
+
+	WARN_ON(!ufshpb_is_read_cmd(cmd));
+
+	if (!ufshpb_is_support_chunk(transfer_len))
+		goto put_hpb;
+
+	spin_lock_irqsave(&hpb->hpb_state_lock, flags);
+	if (ufshpb_test_ppn_dirty(hpb, rgn_idx, srgn_idx, srgn_offset,
+				   transfer_len)) {
+		atomic_inc(&hpb->stats.miss_cnt);
+		spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+		goto put_hpb;
+	}
+
+	ppn = ufshpb_get_ppn(hpb, srgn->mctx, srgn_offset, &err);
+	spin_unlock_irqrestore(&hpb->hpb_state_lock, flags);
+	if (unlikely(err)) {
+		/*
+		 * In this case, the region state is active,
+		 * but the ppn table is not allocated.
+		 * Make sure that ppn table must be allocated on
+		 * active state.
+		 */
+		WARN_ON(true);
+		dev_err(&hpb->hpb_lu_dev,
+			"ufshpb_get_ppn failed. err %d\n", err);
+		goto put_hpb;
+	}
+
+	ufshpb_set_hpb_read_to_upiu(hpb, lrbp, lpn, ppn, transfer_len);
+
+	atomic_inc(&hpb->stats.hit_cnt);
+put_hpb:
+	ufshpb_lu_put(hpb);
+}
+
 static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
 					     struct ufshpb_subregion *srgn)
 {
-- 
2.17.1

Re: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Bean Huo]

Hi, Daejun

On Mon, 2020-06-15 at 16:23 +0900, Daejun Park wrote:
> +void ufsf_scan_features(struct ufs_hba *hba)
> +{
> +       int ret;
> +
> +       init_waitqueue_head(&hba->ufsf.sdev_wait);
> +       atomic_set(&hba->ufsf.slave_conf_cnt, 0);
> +
> +       if (hba->dev_info.wspecversion >= HPB_SUPPORTED_VERSION &&
> +           (hba->dev_info.b_ufs_feature_sup & UFS_DEV_HPB_SUPPORT)) 

How about removing this check "(hba->dev_info.wspecversion >=
HPB_SUPPORTED_VERSION" since ufs with lower version than v3.1 can add
HPB feature by FFU, 
if (hba->dev_info.b_ufs_feature_sup  &UFS_FEATURE_SUPPORT_HPB_BIT) is
enough.


> 
> +#define HPB_SUPPORTED_VERSION                  0x0310



Thank,
Bean

Re: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Bean Huo]

Hi Daejun


On Mon, 2020-06-15 at 18:30 +0900, Daejun Park wrote:
> +static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
> +                                 struct ufshpb_req *map_req)
> +{
> +       struct request_queue *q;
> +       struct request *req;
> +       struct scsi_request *rq;
> +       int ret = 0;
> +
> +       q = hpb->sdev_ufs_lu->request_queue;
> +       ret = ufshpb_map_req_add_bio_page(hpb, q, map_req->bio,
> +                                         map_req->mctx);
> +       if (ret) {
> +               dev_notice(&hpb->hpb_lu_dev,
> +                          "map_req_add_bio_page fail %d - %d\n",
> +                          map_req->rgn_idx, map_req->srgn_idx);
> +               return ret;
> +       }
> +
> +       req = map_req->req;
> +
> +       blk_rq_append_bio(req, &map_req->bio);
> +
> +       req->timeout = 0;
> +       req->end_io_data = (void *)map_req;
> +
> +       rq = scsi_req(req);
> +       ufshpb_set_read_buf_cmd(rq->cmd, map_req->rgn_idx,
> +                               map_req->srgn_idx, hpb-
> >srgn_mem_size);
> +       rq->cmd_len = HPB_READ_BUFFER_CMD_LENGTH;
> +
> +       blk_execute_rq_nowait(q, NULL, req, 1,
> ufshpb_map_req_compl_fn);


HPB map_req is now being en-queued in sdev->request_queue.
This is ok for the HPB v1.0. Have you ever been thinking about
changing this way to directly issue HPB requests to UFS?

Actually, there are two reasons for this way:

1. Latency of loading mapping entries is lower comparing to your curret
approach.
2. Also, it is preparing for the HPB v2.0.  After all HPB 1.0 only
supports 4KB read, this is useless, I am looking for the HPB v2.0.


Thanks,
Bean

Re: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Daejun Park]

Hi Bean
> 
> 
> On Mon, 2020-06-15 at 18:30 +0900, Daejun Park wrote:
> > +static int ufshpb_execute_map_req(struct ufshpb_lu *hpb,
> > +                                 struct ufshpb_req *map_req)
> > +{
> > +       struct request_queue *q;
> > +       struct request *req;
> > +       struct scsi_request *rq;
> > +       int ret = 0;
> > +
> > +       q = hpb->sdev_ufs_lu->request_queue;
> > +       ret = ufshpb_map_req_add_bio_page(hpb, q, map_req->bio,
> > +                                         map_req->mctx);
> > +       if (ret) {
> > +               dev_notice(&hpb->hpb_lu_dev,
> > +                          "map_req_add_bio_page fail %d - %d\n",
> > +                          map_req->rgn_idx, map_req->srgn_idx);
> > +               return ret;
> > +       }
> > +
> > +       req = map_req->req;
> > +
> > +       blk_rq_append_bio(req, &map_req->bio);
> > +
> > +       req->timeout = 0;
> > +       req->end_io_data = (void *)map_req;
> > +
> > +       rq = scsi_req(req);
> > +       ufshpb_set_read_buf_cmd(rq->cmd, map_req->rgn_idx,
> > +                               map_req->srgn_idx, hpb-
> > >srgn_mem_size);
> > +       rq->cmd_len = HPB_READ_BUFFER_CMD_LENGTH;
> > +
> > +       blk_execute_rq_nowait(q, NULL, req, 1,
> > ufshpb_map_req_compl_fn);
> 
> 
> HPB map_req is now being en-queued in sdev->request_queue.
> This is ok for the HPB v1.0. Have you ever been thinking about
> changing this way to directly issue HPB requests to UFS?
I think it is enough to support HPB.

> Actually, there are two reasons for this way:
> 
> 1. Latency of loading mapping entries is lower comparing to your curret
> approach.
Our map request style utilizes block layer API. It makes the codes keep
simple and reliable. Also, I think the latency of loading mapping entries 
is not critical for HPB. Futhermore, I think the other requests from
user is important than loading mapping entries. If the map_work issues map
request directly, the user requests can be disturbed by map requests.

> 2. Also, it is preparing for the HPB v2.0.  After all HPB 1.0 only
> supports 4KB read, this is useless, I am looking for the HPB v2.0.
I don't understand this comment. In HPB v2.0, this code can be used without
changing.

Thanks,
Daejun

Re: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Daejun Park]

Hi, Bean
> 
> On Mon, 2020-06-15 at 16:23 +0900, Daejun Park wrote:
> > +void ufsf_scan_features(struct ufs_hba *hba)
> > +{
> > +       int ret;
> > +
> > +       init_waitqueue_head(&hba->ufsf.sdev_wait);
> > +       atomic_set(&hba->ufsf.slave_conf_cnt, 0);
> > +
> > +       if (hba->dev_info.wspecversion >= HPB_SUPPORTED_VERSION &&
> > +           (hba->dev_info.b_ufs_feature_sup & UFS_DEV_HPB_SUPPORT)) 
> 
> How about removing this check "(hba->dev_info.wspecversion >=
> HPB_SUPPORTED_VERSION" since ufs with lower version than v3.1 can add
> HPB feature by FFU, 
> if (hba->dev_info.b_ufs_feature_sup  &UFS_FEATURE_SUPPORT_HPB_BIT) is
> enough.
OK, changing it seems no problem. But I want to know what other people think
about this version checking code.

Thanks,
Daejun

RE: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Avri Altman]

> 
> Hi, Bean
> >
> > On Mon, 2020-06-15 at 16:23 +0900, Daejun Park wrote:
> > > +void ufsf_scan_features(struct ufs_hba *hba)
> > > +{
> > > +       int ret;
> > > +
> > > +       init_waitqueue_head(&hba->ufsf.sdev_wait);
> > > +       atomic_set(&hba->ufsf.slave_conf_cnt, 0);
> > > +
> > > +       if (hba->dev_info.wspecversion >= HPB_SUPPORTED_VERSION &&
> > > +           (hba->dev_info.b_ufs_feature_sup & UFS_DEV_HPB_SUPPORT))
> >
> > How about removing this check "(hba->dev_info.wspecversion >=
> > HPB_SUPPORTED_VERSION" since ufs with lower version than v3.1 can add
> > HPB feature by FFU,
> > if (hba->dev_info.b_ufs_feature_sup  &UFS_FEATURE_SUPPORT_HPB_BIT) is
> > enough.
> OK, changing it seems no problem. But I want to know what other people
> think
> about this version checking code.
HPB1.0 isn't part of ufs3.1, but published only later.
Allowing earlier versions will required to quirk the descriptor sizes.
I see Bean's point here, but I vote for adding it in a single quirk, when the time comes. 

Thanks,
Avri

RE: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Avri Altman]

 
> 
> This patch is adding UFS feature layer to UFS core driver.
> 
> UFS Driver data structure (struct ufs_hba)
>         │
> ┌--------------┐
> │ UFS feature  │ <-- HPB module
> │    layer     │ <-- other extended feature module
> └--------------┘
> Each extended UFS-Feature module has a bus of ufs-ext feature type.
> The UFS feature layer manages common APIs used by each extended feature
> module. The APIs are set of UFS Query requests and UFS Vendor commands
> related to each extended feature module.
> 
> Other extended features can also be implemented using the proposed APIs.
> For example, in Write Booster, "prep_fn" can be used to guarantee the
> lifetime of UFS by updating the amount of write IO.
> And reset/reset_host/suspend/resume can be used to manage the kernel task
> for checking lifetime of UFS.
> 
> The following 6 callback functions have been added to "ufshcd.c".
> prep_fn: called after construct upiu structure
> reset: called after proving hba
> reset_host: called before ufshcd_host_reset_and_restore
> suspend: called before ufshcd_suspend
> resume: called after ufshcd_resume
> rsp_upiu: called in ufshcd_transfer_rsp_status with SAM_STAT_GOOD state
> 
> Signed-off-by: Daejun Park <daejun7.park@samsung.com>
> ---
>  drivers/scsi/ufs/Makefile     |   2 +-
>  drivers/scsi/ufs/ufsfeature.c | 148 ++++++++++++++++++++++++++++++++++
>  drivers/scsi/ufs/ufsfeature.h |  69 ++++++++++++++++
>  drivers/scsi/ufs/ufshcd.c     |  17 ++++
>  drivers/scsi/ufs/ufshcd.h     |   3 +
>  5 files changed, 238 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/scsi/ufs/ufsfeature.c
>  create mode 100644 drivers/scsi/ufs/ufsfeature.h
> 
> diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
> index 94c6c5d7334b..fe3a92b06c87 100644
> --- a/drivers/scsi/ufs/Makefile
> +++ b/drivers/scsi/ufs/Makefile
> @@ -5,7 +5,7 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-
> g210-pltfrm.o ufshcd-dwc.o tc-d
>  obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
>  obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
>  obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
> -ufshcd-core-y                          += ufshcd.o ufs-sysfs.o
> +ufshcd-core-y                          += ufshcd.o ufs-sysfs.o ufsfeature.o
How about making it
>  ufshcd-core-$(CONFIG_UFS_FEATURES)     += ufsfeature.o
So that you won't check none-hpb driver on every response etc.

RE: [RFC PATCH v2 3/5] scsi: ufs: Introduce HPB module

[Avri Altman]

 
> 
> This is a patch for the HPB module.
> The HPB module queries UFS for device information during initialization.
> We added the export symbol to two functions in ufshcd.c to initialize
> the HPB module.
> 
> The HPB module can be loaded or built-in as needed.
> The mininum size of the memory pool used in the HPB module is
Typo minimum

> implemented
> as a module parameter, so that it can be configurable by the user.
> 
> To gurantee a minimum memory pool size of 4MB:
> $ insmod ufshpb.ko ufshpb_host_map_kbytes=4096
You are going through a lot of troubles to make it a loadable module.
What are, in your opinion, the pros and cons of this design decision?

Re: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Alim Akhtar]

On Wed, Jun 17, 2020 at 12:27 PM Avri Altman <Avri.Altman@wdc.com> wrote:
>
> >
> > Hi, Bean
> > >
> > > On Mon, 2020-06-15 at 16:23 +0900, Daejun Park wrote:
> > > > +void ufsf_scan_features(struct ufs_hba *hba)
> > > > +{
> > > > +       int ret;
> > > > +
> > > > +       init_waitqueue_head(&hba->ufsf.sdev_wait);
> > > > +       atomic_set(&hba->ufsf.slave_conf_cnt, 0);
> > > > +
> > > > +       if (hba->dev_info.wspecversion >= HPB_SUPPORTED_VERSION &&
> > > > +           (hba->dev_info.b_ufs_feature_sup & UFS_DEV_HPB_SUPPORT))
> > >
> > > How about removing this check "(hba->dev_info.wspecversion >=
> > > HPB_SUPPORTED_VERSION" since ufs with lower version than v3.1 can add
> > > HPB feature by FFU,
> > > if (hba->dev_info.b_ufs_feature_sup  &UFS_FEATURE_SUPPORT_HPB_BIT) is
> > > enough.
> > OK, changing it seems no problem. But I want to know what other people
> > think
> > about this version checking code.
> HPB1.0 isn't part of ufs3.1, but published only later.
> Allowing earlier versions will required to quirk the descriptor sizes.
> I see Bean's point here, but I vote for adding it in a single quirk, when the time comes.
>
I second Avri here, older devices need a quirk to handle, let do that
as a separate patch.
> Thanks,
> Avri



-- 
Regards,
Alim

Re: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Bean Huo]

On Wed, 2020-06-17 at 14:27 +0530, Alim Akhtar wrote:
> > > > > +       init_waitqueue_head(&hba->ufsf.sdev_wait);
> > > > > +       atomic_set(&hba->ufsf.slave_conf_cnt, 0);
> > > > > +
> > > > > +       if (hba->dev_info.wspecversion >=
> > > > > HPB_SUPPORTED_VERSION &&
> > > > > +           (hba->dev_info.b_ufs_feature_sup &
> > > > > UFS_DEV_HPB_SUPPORT))
> > > > 
> > > > How about removing this check "(hba->dev_info.wspecversion >=
> > > > HPB_SUPPORTED_VERSION" since ufs with lower version than v3.1
> > > > can add
> > > > HPB feature by FFU,
> > > > if (hba->dev_info.b_ufs_feature_sup 
> > > > &UFS_FEATURE_SUPPORT_HPB_BIT) is
> > > > enough.
> > > 
> > > OK, changing it seems no problem. But I want to know what other
> > > people
> > > think
> > > about this version checking code.
> > 
> > HPB1.0 isn't part of ufs3.1, but published only later.
> > Allowing earlier versions will required to quirk the descriptor
> > sizes.
> > I see Bean's point here, but I vote for adding it in a single
> > quirk, when the time comes.
> > 
> 
> I second Avri here, older devices need a quirk to handle, let do that
> as a separate patch.
> > Thanks,
> > Avri
> 
> 

what is useful point of adding a quirk for this?

From the customer side piont, they just get our FW image, and then do
FFU. If adding a quirk here, that means they also need to change UFS
driver. Also,  you expand the qurik structure.


from cambridge dictionary: 
Qurik: 
	an unusual habit or part of someone's personality, or something
	that
is strange and unexpected.

HPB feature is unexpected??


please tell me the useful point of adding a Quirk.

Bean
> 

Re: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Alim Akhtar]

Hi Bean,

On Wed, Jun 17, 2020 at 3:12 PM Bean Huo <huobean@gmail.com> wrote:
>
> > > HPB1.0 isn't part of ufs3.1, but published only later.
> > > Allowing earlier versions will required to quirk the descriptor
> > > sizes.
> > > I see Bean's point here, but I vote for adding it in a single
> > > quirk, when the time comes.
> > >
> >
> > I second Avri here, older devices need a quirk to handle, let do that
> > as a separate patch.
> > > Thanks,
> > > Avri
> >
> >
>
> what is useful point of adding a quirk for this?
>
> From the customer side piont, they just get our FW image, and then do
> FFU. If adding a quirk here, that means they also need to change UFS
> driver. Also,  you expand the qurik structure.
>
>
> from cambridge dictionary:
> Qurik:
>         an unusual habit or part of someone's personality, or something
>         that
> is strange and unexpected.
>
> HPB feature is unexpected??
>
>
> please tell me the useful point of adding a Quirk.
>
The point is not about adding a quirk per say, it's about  doing that
as a separate patch so that we know which device/ features are added
and why it is added. Please understand there is no denial about your
proposal or thought.
Thanks!!
> Bean
> >
>


-- 
Regards,
Alim

RE: [RFC PATCH v2 2/5] scsi: ufs: Add UFS-feature layer

[Daejun Park]

> > This patch is adding UFS feature layer to UFS core driver.
> > 
> > UFS Driver data structure (struct ufs_hba)
> >         │
> > ┌--------------┐
> > │ UFS feature  │ <-- HPB module
> > │    layer     │ <-- other extended feature module
> > └--------------┘
> > Each extended UFS-Feature module has a bus of ufs-ext feature type.
> > The UFS feature layer manages common APIs used by each extended feature
> > module. The APIs are set of UFS Query requests and UFS Vendor commands
> > related to each extended feature module.
> > 
> > Other extended features can also be implemented using the proposed APIs.
> > For example, in Write Booster, "prep_fn" can be used to guarantee the
> > lifetime of UFS by updating the amount of write IO.
> > And reset/reset_host/suspend/resume can be used to manage the kernel task
> > for checking lifetime of UFS.
> > 
> > The following 6 callback functions have been added to "ufshcd.c".
> > prep_fn: called after construct upiu structure
> > reset: called after proving hba
> > reset_host: called before ufshcd_host_reset_and_restore
> > suspend: called before ufshcd_suspend
> > resume: called after ufshcd_resume
> > rsp_upiu: called in ufshcd_transfer_rsp_status with SAM_STAT_GOOD state
> > 
> > Signed-off-by: Daejun Park <daejun7.park@samsung.com>
> > ---
> >  drivers/scsi/ufs/Makefile     |   2 +-
> >  drivers/scsi/ufs/ufsfeature.c | 148 ++++++++++++++++++++++++++++++++++
> >  drivers/scsi/ufs/ufsfeature.h |  69 ++++++++++++++++
> >  drivers/scsi/ufs/ufshcd.c     |  17 ++++
> >  drivers/scsi/ufs/ufshcd.h     |   3 +
> >  5 files changed, 238 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/scsi/ufs/ufsfeature.c
> >  create mode 100644 drivers/scsi/ufs/ufsfeature.h
> > 
> > diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
> > index 94c6c5d7334b..fe3a92b06c87 100644
> > --- a/drivers/scsi/ufs/Makefile
> > +++ b/drivers/scsi/ufs/Makefile
> > @@ -5,7 +5,7 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-
> > g210-pltfrm.o ufshcd-dwc.o tc-d
> >  obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
> >  obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
> >  obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
> > -ufshcd-core-y                          += ufshcd.o ufs-sysfs.o
> > +ufshcd-core-y                          += ufshcd.o ufs-sysfs.o ufsfeature.o
> How about making it
> >  ufshcd-core-$(CONFIG_UFS_FEATURES)     += ufsfeature.o
> So that you won't check none-hpb driver on every response etc.

It's not a big problem because it only needs a simple checking.
In addition, I think that it is not necessary to separate them because the UFS feature is enabled in most of the user cases.

Thanks,
Daejun

RE: [RFC PATCH v2 3/5] scsi: ufs: Introduce HPB module

[Daejun Park]

> 
> > This is a patch for the HPB module.
> > The HPB module queries UFS for device information during initialization.
> > We added the export symbol to two functions in ufshcd.c to initialize
> > the HPB module.
> > 
> > The HPB module can be loaded or built-in as needed.
> > The mininum size of the memory pool used in the HPB module is
> Typo minimum
> 
> > implemented
> > as a module parameter, so that it can be configurable by the user.
> > 
> > To gurantee a minimum memory pool size of 4MB:
> > $ insmod ufshpb.ko ufshpb_host_map_kbytes=4096
> You are going through a lot of troubles to make it a loadable module.
> What are, in your opinion, the pros and cons of this design decision?

In my opinion...

pros:
1. A user can unload an unnecessary module when there is an insufficient
memory situation (HPB case).
2. Since each UFS vendor has a different way of implementing UFS features,
it can be supported as a separate module. Otherwise, many quirks must
be attached to module, which is not desirable way.
3. It is possible to distinguish parts that are not necessary for essential
ufs operation.
4. It is advantageous to implement the latest functions according to the
development speed of UFS.

cons:
1. It is difficult work to be implemented as a module.
2. Modifying "ufsfeature.c" is required to implement the feature that can
not supported by the exsiting "ufsf_operation".

Thanks,
Daejun

RE: [RFC PATCH v2 3/5] scsi: ufs: Introduce HPB module

[Avri Altman]

> +static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb,
> +                             struct ufshpb_dev_info *hpb_dev_info)
> +{
> +       int ret;
> +
> +       spin_lock_init(&hpb->hpb_state_lock);
> +
> +       ret = ufshpb_alloc_region_tbl(hba, hpb);
> +       if (ret)
> +               goto release_m_page_cache;
This label is added only on 4/5

> +static int __init ufshpb_init(void)
> +{
> +       unsigned int pool_size;
Unused variable

> +       int ret;
> +
> +       ret = driver_register(&ufshpb_drv.drv);
> +       if (ret)
> +               pr_err("ufshpb: driver register failed\n");
> +
> +       return ret;
> +}

RE: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Avri Altman]

> +
> +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu *hpb)
> +{
> +       struct ufshpb_map_ctx *mctx;
> +       int i, j;
> +
> +       mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> +       if (!mctx)
> +               return NULL;
So you use ufshpb_host_map_kbytes as the min_nr in your mempool_create,
But you know that you need max_lru_active_cnt x srgns_per_rgn such mapping context elements.
So you are
a) failing to provide the slab allocator an information that you already have, and
b) selecting from a finite pool will assure that you'll never exceed max-active-regions,
   even if some corner case fails your logic.

Re: [RFC PATCH v2 3/5] scsi: ufs: Introduce HPB module

[Bean Huo]

On Wed, 2020-06-17 at 19:30 +0900, Daejun Park wrote:
> > > implemented
> > > as a module parameter, so that it can be configurable by the
> > > user.
> > > 
> > > To gurantee a minimum memory pool size of 4MB:
> > > $ insmod ufshpb.ko ufshpb_host_map_kbytes=4096
> > 
> > You are going through a lot of troubles to make it a loadable
> > module.
> > What are, in your opinion, the pros and cons of this design
> > decision?
> 
> In my opinion...
> 
> pros:
> 1. A user can unload an unnecessary module when there is an
> insufficient
> memory situation (HPB case).
> 2. Since each UFS vendor has a different way of implementing UFS
> features,
> it can be supported as a separate module. Otherwise, many quirks must
> be attached to module, which is not desirable way.
> 3. It is possible to distinguish parts that are not necessary for
> essential
> ufs operation.
> 4. It is advantageous to implement the latest functions according to
> the
> development speed of UFS.
> 
> cons:
> 1. It is difficult work to be implemented as a module.
> 2. Modifying "ufsfeature.c" is required to implement the feature that
> can
> not supported by the exsiting "ufsf_operation".
> 
> Thanks,
> Daejun

Dear Avri, Daejun, Bart

It is true that it is very difficult to make everyone happy.
We now have three HPB drivers in the patchwork, but I still didn't see
a final agreement. Please tell me which one do you want to focus on?

Bean

RE: [RFC PATCH v2 3/5] scsi: ufs: Introduce HPB module

[Daejun Park]

> +static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb,
> > +                             struct ufshpb_dev_info *hpb_dev_info)
> > +{
> > +       int ret;
> > +
> > +       spin_lock_init(&hpb->hpb_state_lock);
> > +
> > +       ret = ufshpb_alloc_region_tbl(hba, hpb);
> > +       if (ret)
> > +               goto release_m_page_cache;
> This label is added only on 4/5
> 
> > +static int __init ufshpb_init(void)
> > +{
> > +       unsigned int pool_size;
> Unused variable
> 
> > +       int ret;
> > +
> > +       ret = driver_register(&ufshpb_drv.drv);
> > +       if (ret)
> > +               pr_err("ufshpb: driver register failed\n");
> > +
> > +       return ret;
> > +}

OK, I will fix it.

RE: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Daejun Park]

> +
> > +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu *hpb)
> > +{
> > +       struct ufshpb_map_ctx *mctx;
> > +       int i, j;
> > +
> > +       mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> > +       if (!mctx)
> > +               return NULL;
> So you use ufshpb_host_map_kbytes as the min_nr in your mempool_create,
> But you know that you need max_lru_active_cnt x srgns_per_rgn such mapping context elements.
> So you are
> a) failing to provide the slab allocator an information that you already have, and
> b) selecting from a finite pool will assure that you'll never exceed max-active-regions,
>    even if some corner case fails your logic.
It was intend to provide user-configurable pre-allocated memory to reduce
latency due to memory allocation. The value of ufshpb_host_map_kbytes can
be set to max_lru_active_cnt x srgns_per_rgn, if the user want to.

Thanks,
Daejun

Re: [RFC PATCH v2 3/5] scsi: ufs: Introduce HPB module

[Daejun Park]

> > > implemented
> > > > as a module parameter, so that it can be configurable by the
> > > > user.
> > > > 
> > > > To gurantee a minimum memory pool size of 4MB:
> > > > $ insmod ufshpb.ko ufshpb_host_map_kbytes=4096
> > > 
> > > You are going through a lot of troubles to make it a loadable
> > > module.
> > > What are, in your opinion, the pros and cons of this design
> > > decision?
> > 
> > In my opinion...
> > 
> > pros:
> > 1. A user can unload an unnecessary module when there is an
> > insufficient
> > memory situation (HPB case).
> > 2. Since each UFS vendor has a different way of implementing UFS
> > features,
> > it can be supported as a separate module. Otherwise, many quirks must
> > be attached to module, which is not desirable way.
> > 3. It is possible to distinguish parts that are not necessary for
> > essential
> > ufs operation.
> > 4. It is advantageous to implement the latest functions according to
> > the
> > development speed of UFS.
> > 
> > cons:
> > 1. It is difficult work to be implemented as a module.
> > 2. Modifying "ufsfeature.c" is required to implement the feature that
> > can
> > not supported by the exsiting "ufsf_operation".
> > 
> > Thanks,
> > Daejun
> 
> Dear Avri, Daejun, Bart
> 
> It is true that it is very difficult to make everyone happy.
> We now have three HPB drivers in the patchwork, but I still didn't see
> a final agreement. Please tell me which one do you want to focus on?
The HPB driver has been greatly improved in the process of being applied to
mobile devices since the release of the first HPB version in openMPDK. We
want to contribute to the linux mainline with the knowledge obtained
through the experience.
I find it difficult to make everyone happy, but I think it is possible that
everyone can accept the HPB driver through several revisions.

Thanks,
Daejun

RE: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Avri Altman]

 
> > +
> > > +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu
> *hpb)
> > > +{
> > > +       struct ufshpb_map_ctx *mctx;
> > > +       int i, j;
> > > +
> > > +       mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> > > +       if (!mctx)
> > > +               return NULL;
> > So you use ufshpb_host_map_kbytes as the min_nr in your
> mempool_create,
> > But you know that you need max_lru_active_cnt x srgns_per_rgn such
> mapping context elements.
> > So you are
> > a) failing to provide the slab allocator an information that you already have,
> and
> > b) selecting from a finite pool will assure that you'll never exceed max-
> active-regions,
> >    even if some corner case fails your logic.
> It was intend to provide user-configurable pre-allocated memory to reduce
> latency due to memory allocation. The value of ufshpb_host_map_kbytes can
> be set to max_lru_active_cnt x srgns_per_rgn, if the user want to.
Ok, I see your point.
It is as if you expect that a "user" will query the unit descriptors first,
Make some calculations, and then will run modprobe with the proper value.
Are you assuming that an "intelligent" user does all that?

The reasonable scenario IMO, is that OEMs will initiate a service in their
ramdisk/init.rc with some default value.

Don't you see the damage potential in using a wrong value here?

RE: [RFC PATCH v2 3/5] scsi: ufs: Introduce HPB module

[Avri Altman]

 
> 
> > > > implemented
> > > > > as a module parameter, so that it can be configurable by the
> > > > > user.
> > > > >
> > > > > To gurantee a minimum memory pool size of 4MB:
> > > > > $ insmod ufshpb.ko ufshpb_host_map_kbytes=4096
> > > >
> > > > You are going through a lot of troubles to make it a loadable
> > > > module.
> > > > What are, in your opinion, the pros and cons of this design
> > > > decision?
> > >
> > > In my opinion...
> > >
> > > pros:
> > > 1. A user can unload an unnecessary module when there is an
> > > insufficient
> > > memory situation (HPB case).
> > > 2. Since each UFS vendor has a different way of implementing UFS
> > > features,
> > > it can be supported as a separate module. Otherwise, many quirks must
> > > be attached to module, which is not desirable way.
> > > 3. It is possible to distinguish parts that are not necessary for
> > > essential
> > > ufs operation.
> > > 4. It is advantageous to implement the latest functions according to
> > > the
> > > development speed of UFS.
> > >
> > > cons:
> > > 1. It is difficult work to be implemented as a module.
> > > 2. Modifying "ufsfeature.c" is required to implement the feature that
> > > can
> > > not supported by the exsiting "ufsf_operation".
> > >
> > > Thanks,
> > > Daejun
> >
> > Dear Avri, Daejun, Bart
> >
> > It is true that it is very difficult to make everyone happy.
> > We now have three HPB drivers in the patchwork, but I still didn't see
> > a final agreement. Please tell me which one do you want to focus on?
> The HPB driver has been greatly improved in the process of being applied to
> mobile devices since the release of the first HPB version in openMPDK. We
> want to contribute to the linux mainline with the knowledge obtained
> through the experience.
> I find it difficult to make everyone happy, but I think it is possible that
> everyone can accept the HPB driver through several revisions.
Ack on that.
For me, it was very clear that Bart prefers the Samsung approach,
Hence I withdrew from my RFC and switch to support Daejun's.

Thanks,
Avri

RE: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Avri Altman]

> +static void ufshpb_run_active_subregion_list(struct ufshpb_lu *hpb)
> +{
> +       struct ufshpb_region *rgn;
> +       struct ufshpb_subregion *srgn;
> +       struct ufshpb_map_ctx *mctx;
mctx  doesn't really do anything here

> +       unsigned long flags;
> +       int ret = 0;
> +
> +       spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> +       while ((srgn = list_first_entry_or_null(&hpb->lh_act_srgn,
> +                                               struct ufshpb_subregion,
> +                                               list_act_srgn))) {
> +               list_del_init(&srgn->list_act_srgn);
> +               spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> +
> +               rgn = hpb->rgn_tbl + srgn->rgn_idx;
> +               mctx = NULL;
> +               ret = ufshpb_add_region(hpb, rgn);
> +               if (ret)
> +                       break;
> +
> +               ret = ufshpb_issue_map_req(hpb, rgn, srgn);
> +               if (ret) {
> +                       dev_notice(&hpb->hpb_lu_dev,
> +                           "issue map_req failed. ret %d, region %d - %d\n",
> +                           ret, rgn->rgn_idx, srgn->srgn_idx);
> +                       break;
> +               }
> +               spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> +       }
> +
> +       if (ret) {
> +               dev_notice(&hpb->hpb_lu_dev, "region %d - %d, will retry\n",
> +                          rgn->rgn_idx, srgn->srgn_idx);
> +               spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> +               ufshpb_add_active_list(hpb, rgn, srgn);
> +       }
> +       spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> +}

RE: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Daejun Park]

> +static void ufshpb_run_active_subregion_list(struct ufshpb_lu *hpb)
> > +{
> > +       struct ufshpb_region *rgn;
> > +       struct ufshpb_subregion *srgn;
> > +       struct ufshpb_map_ctx *mctx;
> mctx  doesn't really do anything here

OK, I will delete it.

> > +       unsigned long flags;
> > +       int ret = 0;
> > +
> > +       spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> > +       while ((srgn = list_first_entry_or_null(&hpb->lh_act_srgn,
> > +                                               struct ufshpb_subregion,
> > +                                               list_act_srgn))) {
> > +               list_del_init(&srgn->list_act_srgn);
> > +               spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> > +
> > +               rgn = hpb->rgn_tbl + srgn->rgn_idx;
> > +               mctx = NULL;
> > +               ret = ufshpb_add_region(hpb, rgn);
> > +               if (ret)
> > +                       break;
> > +
> > +               ret = ufshpb_issue_map_req(hpb, rgn, srgn);
> > +               if (ret) {
> > +                       dev_notice(&hpb->hpb_lu_dev,
> > +                           "issue map_req failed. ret %d, region %d - %d\n",
> > +                           ret, rgn->rgn_idx, srgn->srgn_idx);
> > +                       break;
> > +               }
> > +               spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> > +       }
> > +
> > +       if (ret) {
> > +               dev_notice(&hpb->hpb_lu_dev, "region %d - %d, will retry\n",
> > +                          rgn->rgn_idx, srgn->srgn_idx);
> > +               spin_lock_irqsave(&hpb->rsp_list_lock, flags);
> > +               ufshpb_add_active_list(hpb, rgn, srgn);
> > +       }
> > +       spin_unlock_irqrestore(&hpb->rsp_list_lock, flags);
> > +}
> 
> 

RE: [RFC PATCH v2 4/5] scsi: ufs: L2P map management for HPB read

[Daejun Park]

> > > +
> > > > +static struct ufshpb_map_ctx *ufshpb_get_map_ctx(struct ufshpb_lu
> > *hpb)
> > > > +{
> > > > +       struct ufshpb_map_ctx *mctx;
> > > > +       int i, j;
> > > > +
> > > > +       mctx = mempool_alloc(ufshpb_drv.ufshpb_mctx_pool, GFP_KERNEL);
> > > > +       if (!mctx)
> > > > +               return NULL;
> > > So you use ufshpb_host_map_kbytes as the min_nr in your
> > mempool_create,
> > > But you know that you need max_lru_active_cnt x srgns_per_rgn such
> > mapping context elements.
> > > So you are
> > > a) failing to provide the slab allocator an information that you already have,
> > and
> > > b) selecting from a finite pool will assure that you'll never exceed max-
> > active-regions,
> > >    even if some corner case fails your logic.
> > It was intend to provide user-configurable pre-allocated memory to reduce
> > latency due to memory allocation. The value of ufshpb_host_map_kbytes can
> > be set to max_lru_active_cnt x srgns_per_rgn, if the user want to.
> Ok, I see your point.
> It is as if you expect that a "user" will query the unit descriptors first,
> Make some calculations, and then will run modprobe with the proper value.
> Are you assuming that an "intelligent" user does all that?
> 
> The reasonable scenario IMO, is that OEMs will initiate a service in their
> ramdisk/init.rc with some default value.
> 
> Don't you see the damage potential in using a wrong value here?
> 
I understand your scenario. I will remove module parameter and set min_nr
value of memory pool as "max_lru_active_cnt x srgns_per_rgn" size.

Thanks,
Daejun

Re: [RFC PATCH v2 0/5] scsi: ufs: Add Host Performance Booster Support

[Bart Van Assche]

On 2020-06-14 23:27, Daejun Park wrote:
> The current version only supports the DCM (device control mode).
> This patch consists of 4 parts to support HPB feature.
> 
> 1) UFS-feature layer
> 2) HPB probe and initialization process
> 3) READ -> HPB READ using cached map information
> 4) L2P (logical to physical) map management

I'm still not enthusiast about the choice for a bus to connect UFS core
and the HPB module. But if others are fine with this choice, I won't object.

Bart.