[RFC PATCH v3 0/2] ufs: introduce callbacks to get command information

[RFC PATCH v3 0/2] ufs: introduce callbacks to get command information

[Kiwoong Kim]

v2 -> v3
fix build errors

v1 -> v2
change callbacks
allocate memory for ufs_s_dbg_mgr dynamically, not static way

Some SoC specific might need command history for
various reasons, such as stacking command contexts
in system memory to check for debugging in the future
or scaling some DVFS knobs to boost IO throughput.

What you would do with the information could be
variant per SoC vendor.

Kiwoong Kim (2):
  ufs: introduce a callback to get info of command completion
  exynos-ufs: implement dbg_register_dump and compl_xfer_req

 drivers/scsi/ufs/Kconfig          |  14 +++
 drivers/scsi/ufs/Makefile         |   2 +-
 drivers/scsi/ufs/ufs-exynos-dbg.c | 202 ++++++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufs-exynos-if.h  |  17 ++++
 drivers/scsi/ufs/ufs-exynos.c     |  63 +++++++++++-
 drivers/scsi/ufs/ufs-exynos.h     |  13 +++
 drivers/scsi/ufs/ufshcd.c         |   2 +
 drivers/scsi/ufs/ufshcd.h         |   8 ++
 8 files changed, 318 insertions(+), 3 deletions(-)
 create mode 100644 drivers/scsi/ufs/ufs-exynos-dbg.c
 create mode 100644 drivers/scsi/ufs/ufs-exynos-if.h

-- 
2.7.4

[RFC PATCH v3 1/2] ufs: introduce a callback to get info of command completion

[Kiwoong Kim]

Some SoC specific might need command history for
various reasons, such as stacking command contexts
in system memory to check for debugging in the future
or scaling some DVFS knobs to boost IO throughput.

What you would do with the information could be
variant per SoC vendor.

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
---
 drivers/scsi/ufs/ufshcd.c | 2 ++
 drivers/scsi/ufs/ufshcd.h | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 52abe82..3326236 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4882,6 +4882,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
 	for_each_set_bit(index, &completed_reqs, hba->nutrs) {
 		lrbp = &hba->lrb[index];
 		cmd = lrbp->cmd;
+		ufshcd_vops_compl_xfer_req(hba, index, (cmd) ? true : false);
 		if (cmd) {
 			ufshcd_add_command_trace(hba, index, "complete");
 			result = ufshcd_transfer_rsp_status(hba, lrbp);
@@ -4890,6 +4891,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
 			/* Mark completed command as NULL in LRB */
 			lrbp->cmd = NULL;
 			lrbp->compl_time_stamp = ktime_get();
+
 			/* Do not touch lrbp after scsi done */
 			cmd->scsi_done(cmd);
 			__ufshcd_release(hba);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index c774012..5cf9f99 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -307,6 +307,7 @@ struct ufs_hba_variant_ops {
 	void	(*config_scaling_param)(struct ufs_hba *hba,
 					struct devfreq_dev_profile *profile,
 					void *data);
+	void	(*compl_xfer_req)(struct ufs_hba *hba, int tag, bool is_scsi);
 };
 
 /* clock gating state  */
@@ -1137,6 +1138,13 @@ static inline void ufshcd_vops_config_scaling_param(struct ufs_hba *hba,
 		hba->vops->config_scaling_param(hba, profile, data);
 }
 
+static inline void ufshcd_vops_compl_xfer_req(struct ufs_hba *hba,
+					      int tag, bool is_scsi)
+{
+	if (hba->vops && hba->vops->compl_xfer_req)
+		hba->vops->compl_xfer_req(hba, tag, is_scsi);
+}
+
 extern struct ufs_pm_lvl_states ufs_pm_lvl_states[];
 
 /*
-- 
2.7.4

[RFC PATCH v3 2/2] exynos-ufs: implement dbg_register_dump and compl_xfer_req

[Kiwoong Kim]

This patch implements callbacks dbg_register_dump and
compl_xfer_req to store IO contexts or print them.

This includes functions to record contexts of incoming commands
in a circular queue. ufshcd.c has already some function
tracer calls to get command history but ftrace would be
gone when system dies before you get the information,
such as panic cases.

When you turn on CONFIG_SCSI_UFS_EXYNOS_CMD_LOG,
information in the circular queue whenever ufshcd.c
invokes a dbg_register_dump callback.

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
---
 drivers/scsi/ufs/Kconfig          |  14 +++
 drivers/scsi/ufs/Makefile         |   2 +-
 drivers/scsi/ufs/ufs-exynos-dbg.c | 202 ++++++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufs-exynos-if.h  |  17 ++++
 drivers/scsi/ufs/ufs-exynos.c     |  63 +++++++++++-
 drivers/scsi/ufs/ufs-exynos.h     |  13 +++
 6 files changed, 308 insertions(+), 3 deletions(-)
 create mode 100644 drivers/scsi/ufs/ufs-exynos-dbg.c
 create mode 100644 drivers/scsi/ufs/ufs-exynos-if.h

diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index 8cd9026..ebab446 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -172,3 +172,17 @@ config SCSI_UFS_EXYNOS
 
 	  Select this if you have UFS host controller on EXYNOS chipset.
 	  If unsure, say N.
+
+config SCSI_UFS_EXYNOS_CMD_LOG
+	bool "EXYNOS specific command log"
+	default n
+	depends on SCSI_UFS_EXYNOS
+	help
+	  This selects EXYNOS specific functions to get and even print
+	  some information to see what's happening at both command
+	  issue time completion time.
+	  The information may contain gerernal things as well as
+	  EXYNOS specific, such as vendor specific hardware contexts.
+
+	  Select this if you want to get and print the information.
+	  If unsure, say N.
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index f0c5b95..d9e4da7 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -4,7 +4,7 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210.
 obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o
 obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
 obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
-obj-$(CONFIG_SCSI_UFS_EXYNOS) += ufs-exynos.o
+obj-$(CONFIG_SCSI_UFS_EXYNOS) += ufs-exynos.o ufs-exynos-dbg.o
 obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
 ufshcd-core-y				+= ufshcd.o ufs-sysfs.o
 ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
diff --git a/drivers/scsi/ufs/ufs-exynos-dbg.c b/drivers/scsi/ufs/ufs-exynos-dbg.c
new file mode 100644
index 0000000..39a79b6
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-exynos-dbg.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * UFS Exynos debugging functions
+ *
+ * Copyright (C) 2020 Samsung Electronics Co., Ltd.
+ * Author: Kiwoong Kim <kwmad.kim@samsung.com>
+ *
+ */
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include "ufshcd.h"
+#include "ufs-exynos.h"
+#include "ufs-exynos-if.h"
+
+#define MAX_CMD_LOGS    32
+
+struct cmd_data {
+	unsigned int tag;
+	unsigned int sct;
+	u64 lba;
+	u64 start_time;
+	u64 end_time;
+	u64 outstanding_reqs;
+	int retries;
+	u8 op;
+};
+
+struct ufs_cmd_info {
+	u32 total;
+	u32 last;
+	struct cmd_data data[MAX_CMD_LOGS];
+	struct cmd_data *pdata[MAX_CMD_LOGS];
+};
+
+/*
+ * This structure points out several contexts on debugging
+ * per one host instant.
+ * Now command history exists in here but later handle may
+ * contains some mmio base addresses including vendor specific
+ * regions to get hardware contexts.
+ */
+struct ufs_s_dbg_mgr {
+	struct ufs_exynos_handle *handle;
+	int active;
+	u64 first_time;
+	u64 time;
+
+	/* cmd log */
+	struct ufs_cmd_info cmd_info;
+	struct cmd_data cmd_log;		/* temp buffer to put */
+	spinlock_t cmd_lock;
+};
+
+static void ufs_s_print_cmd_log(struct ufs_s_dbg_mgr *mgr, struct device *dev)
+{
+	struct ufs_cmd_info *cmd_info = &mgr->cmd_info;
+	struct cmd_data *data = cmd_info->data;
+	u32 i;
+	u32 last;
+	u32 max = MAX_CMD_LOGS;
+	unsigned long flags;
+	u32 total;
+
+	spin_lock_irqsave(&mgr->cmd_lock, flags);
+	total = cmd_info->total;
+	if (cmd_info->total < max)
+		max = cmd_info->total;
+	last = (cmd_info->last + MAX_CMD_LOGS - 1) % MAX_CMD_LOGS;
+	spin_unlock_irqrestore(&mgr->cmd_lock, flags);
+
+	dev_err(dev, ":---------------------------------------------------\n");
+	dev_err(dev, ":\t\tSCSI CMD(%u)\n", total - 1);
+	dev_err(dev, ":---------------------------------------------------\n");
+	dev_err(dev, ":OP, TAG, LBA, SCT, RETRIES, STIME, ETIME, REQS\n\n");
+
+	for (i = 0 ; i < max ; i++, data++) {
+		dev_err(dev, ": 0x%02x, %02d, 0x%08llx, 0x%04x, %d, %llu, %llu, 0x%llx %s",
+			data->op, data->tag, data->lba, data->sct, data->retries,
+			data->start_time, data->end_time, data->outstanding_reqs,
+			((last == i) ? "<--" : " "));
+		if (last == i)
+			dev_err(dev, "\n");
+	}
+}
+
+static void ufs_s_put_cmd_log(struct ufs_s_dbg_mgr *mgr,
+			      struct cmd_data *cmd_data)
+{
+	struct ufs_cmd_info *cmd_info = &mgr->cmd_info;
+	unsigned long flags;
+	struct cmd_data *pdata;
+
+	spin_lock_irqsave(&mgr->cmd_lock, flags);
+	pdata = &cmd_info->data[cmd_info->last];
+	++cmd_info->total;
+	++cmd_info->last;
+	cmd_info->last = cmd_info->last % MAX_CMD_LOGS;
+	spin_unlock_irqrestore(&mgr->cmd_lock, flags);
+
+	pdata->op = cmd_data->op;
+	pdata->tag = cmd_data->tag;
+	pdata->lba = cmd_data->lba;
+	pdata->sct = cmd_data->sct;
+	pdata->retries = cmd_data->retries;
+	pdata->start_time = cmd_data->start_time;
+	pdata->end_time = 0;
+	pdata->outstanding_reqs = cmd_data->outstanding_reqs;
+	cmd_info->pdata[cmd_data->tag] = pdata;
+}
+
+/*
+ * EXTERNAL FUNCTIONS
+ *
+ * There are two classes that are to initialize data structures for debug
+ * and to define actual behavior.
+ */
+void exynos_ufs_dump_info(struct ufs_exynos_handle *handle, struct device *dev)
+{
+	struct ufs_s_dbg_mgr *mgr = (struct ufs_s_dbg_mgr *)handle->private;
+
+	if (mgr->active == 0)
+		goto out;
+
+	mgr->time = cpu_clock(raw_smp_processor_id());
+
+#ifdef CONFIG_SCSI_UFS_EXYNOS_CMD_LOG
+	ufs_s_print_cmd_log(mgr, dev);
+#endif
+
+	if (mgr->first_time == 0ULL)
+		mgr->first_time = mgr->time;
+out:
+	return;
+}
+
+void exynos_ufs_cmd_log_start(struct ufs_exynos_handle *handle,
+			      struct ufs_hba *hba, struct scsi_cmnd *cmd)
+{
+	struct ufs_s_dbg_mgr *mgr = (struct ufs_s_dbg_mgr *)handle->private;
+	int cpu = raw_smp_processor_id();
+	struct cmd_data *cmd_log = &mgr->cmd_log;	/* temp buffer to put */
+	u64 lba = (cmd->cmnd[2] << 24) |
+					(cmd->cmnd[3] << 16) |
+					(cmd->cmnd[4] << 8) |
+					(cmd->cmnd[5] << 0);
+	unsigned int sct = (cmd->cmnd[7] << 8) |
+					(cmd->cmnd[8] << 0);
+
+	if (mgr->active == 0)
+		return;
+
+	cmd_log->start_time = cpu_clock(cpu);
+	cmd_log->op = cmd->cmnd[0];
+	cmd_log->tag = cmd->request->tag;
+
+	/* This function runtime is protected by spinlock from outside */
+	cmd_log->outstanding_reqs = hba->outstanding_reqs;
+
+	/* unmap */
+	if (cmd->cmnd[0] != UNMAP)
+		cmd_log->lba = lba;
+
+	cmd_log->sct = sct;
+	cmd_log->retries = cmd->allowed;
+
+	ufs_s_put_cmd_log(mgr, cmd_log);
+}
+
+void exynos_ufs_cmd_log_end(struct ufs_exynos_handle *handle,
+			    struct ufs_hba *hba, struct scsi_cmnd *cmd)
+{
+	struct ufs_s_dbg_mgr *mgr = (struct ufs_s_dbg_mgr *)handle->private;
+	struct ufs_cmd_info *cmd_info = &mgr->cmd_info;
+	int cpu = raw_smp_processor_id();
+	int tag = cmd->request->tag;
+
+	if (mgr->active == 0)
+		return;
+
+	cmd_info->pdata[tag]->end_time = cpu_clock(cpu);
+}
+
+int exynos_ufs_init_dbg(struct ufs_exynos_handle *handle, struct device *dev)
+{
+	struct ufs_s_dbg_mgr *mgr;
+
+	mgr = devm_kzalloc(dev, sizeof(struct ufs_s_dbg_mgr), GFP_KERNEL);
+	if (!mgr)
+		return -ENOMEM;
+	handle->private = (void *)mgr;
+	mgr->handle = handle;
+	mgr->active = 1;
+
+	/* cmd log */
+	spin_lock_init(&mgr->cmd_lock);
+
+	return 0;
+}
+MODULE_AUTHOR("Kiwoong Kim <kwmad.kim@samsung.com>");
+MODULE_DESCRIPTION("Exynos UFS debug information");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");
diff --git a/drivers/scsi/ufs/ufs-exynos-if.h b/drivers/scsi/ufs/ufs-exynos-if.h
new file mode 100644
index 0000000..c746f59
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-exynos-if.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * UFS Exynos debugging functions
+ *
+ * Copyright (C) 2020 Samsung Electronics Co., Ltd.
+ * Author: Kiwoong Kim <kwmad.kim@samsung.com>
+ *
+ */
+#ifndef _UFS_EXYNOS_IF_H_
+#define _UFS_EXYNOS_IF_H_
+
+/* more members would be added in the future */
+struct ufs_exynos_handle {
+	void *private;
+};
+
+#endif /* _UFS_EXYNOS_IF_H_ */
diff --git a/drivers/scsi/ufs/ufs-exynos.c b/drivers/scsi/ufs/ufs-exynos.c
index 440f2af..e7df18c 100644
--- a/drivers/scsi/ufs/ufs-exynos.c
+++ b/drivers/scsi/ufs/ufs-exynos.c
@@ -700,12 +700,31 @@ static int exynos_ufs_post_pwr_mode(struct ufs_hba *hba,
 	return 0;
 }
 
+#ifdef CONFIG_SCSI_UFS_EXYNOS_CMD_LOG
+static void exynos_ufs_cmd_log(struct ufs_hba *hba,
+					 struct scsi_cmnd *cmd, int enter)
+{
+	struct exynos_ufs *ufs = ufshcd_get_variant(hba);
+	struct ufs_exynos_handle *handle = ufs->handle;
+
+	if (enter == 1)
+		exynos_ufs_cmd_log_start(handle, hba, cmd);
+	else if (enter == 2)
+		exynos_ufs_cmd_log_end(handle, hba, cmd);
+}
+#endif
+
 static void exynos_ufs_specify_nexus_t_xfer_req(struct ufs_hba *hba,
 						int tag, bool op)
 {
 	struct exynos_ufs *ufs = ufshcd_get_variant(hba);
 	u32 type;
+#ifdef CONFIG_SCSI_UFS_EXYNOS_CMD_LOG
+	struct scsi_cmnd *cmd = hba->lrb[tag].cmd;
 
+	if (op)
+		exynos_ufs_cmd_log(hba, cmd, 1);
+#endif
 	type =  hci_readl(ufs, HCI_UTRL_NEXUS_TYPE);
 
 	if (op)
@@ -714,8 +733,7 @@ static void exynos_ufs_specify_nexus_t_xfer_req(struct ufs_hba *hba,
 		hci_writel(ufs, type & ~(1 << tag), HCI_UTRL_NEXUS_TYPE);
 }
 
-static void exynos_ufs_specify_nexus_t_tm_req(struct ufs_hba *hba,
-						int tag, u8 func)
+static void exynos_ufs_specify_nexus_t_tm_req(struct ufs_hba *hba, int tag, u8 func)
 {
 	struct exynos_ufs *ufs = ufshcd_get_variant(hba);
 	u32 type;
@@ -1008,6 +1026,12 @@ static int exynos_ufs_init(struct ufs_hba *hba)
 		goto out;
 	exynos_ufs_specify_phy_time_attr(ufs);
 	exynos_ufs_config_smu(ufs);
+
+	/* init dbg */
+	ret = exynos_ufs_init_dbg(ufs->handle, dev);
+	if (ret)
+		return ret;
+	spin_lock_init(&ufs->dbg_lock);
 	return 0;
 
 phy_off:
@@ -1210,6 +1234,39 @@ static int exynos_ufs_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	return 0;
 }
 
+static void exynos_ufs_dbg_register_dump(struct ufs_hba *hba)
+{
+	struct exynos_ufs *ufs = ufshcd_get_variant(hba);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ufs->dbg_lock, flags);
+	if (ufs->under_dump == 0)
+		ufs->under_dump = 1;
+	else {
+		spin_unlock_irqrestore(&ufs->dbg_lock, flags);
+		goto out;
+	}
+	spin_unlock_irqrestore(&ufs->dbg_lock, flags);
+
+	exynos_ufs_dump_info(ufs->handle, hba->dev);
+
+	spin_lock_irqsave(&ufs->dbg_lock, flags);
+	ufs->under_dump = 0;
+	spin_unlock_irqrestore(&ufs->dbg_lock, flags);
+out:
+	return;
+}
+
+static void exynos_ufs_compl_xfer_req(struct ufs_hba *hba, int tag, bool op)
+{
+#ifdef CONFIG_SCSI_UFS_EXYNOS_CMD_LOG
+	struct scsi_cmnd *cmd = hba->lrb[tag].cmd;
+
+	if (op)
+		exynos_ufs_cmd_log(hba, cmd, 2);
+#endif
+}
+
 static struct ufs_hba_variant_ops ufs_hba_exynos_ops = {
 	.name				= "exynos_ufs",
 	.init				= exynos_ufs_init,
@@ -1221,6 +1278,8 @@ static struct ufs_hba_variant_ops ufs_hba_exynos_ops = {
 	.hibern8_notify			= exynos_ufs_hibern8_notify,
 	.suspend			= exynos_ufs_suspend,
 	.resume				= exynos_ufs_resume,
+	.dbg_register_dump		= exynos_ufs_dbg_register_dump,
+	.compl_xfer_req			= exynos_ufs_compl_xfer_req,
 };
 
 static int exynos_ufs_probe(struct platform_device *pdev)
diff --git a/drivers/scsi/ufs/ufs-exynos.h b/drivers/scsi/ufs/ufs-exynos.h
index 76d6e39..0c79a30 100644
--- a/drivers/scsi/ufs/ufs-exynos.h
+++ b/drivers/scsi/ufs/ufs-exynos.h
@@ -8,6 +8,7 @@
 
 #ifndef _UFS_EXYNOS_H_
 #define _UFS_EXYNOS_H_
+#include "ufs-exynos-if.h"
 
 /*
  * UNIPRO registers
@@ -212,6 +213,10 @@ struct exynos_ufs {
 #define EXYNOS_UFS_OPT_BROKEN_AUTO_CLK_CTRL	BIT(2)
 #define EXYNOS_UFS_OPT_BROKEN_RX_SEL_IDX	BIT(3)
 #define EXYNOS_UFS_OPT_USE_SW_HIBERN8_TIMER	BIT(4)
+
+	struct ufs_exynos_handle *handle;
+	spinlock_t dbg_lock;
+	int under_dump;
 };
 
 #define for_each_ufs_rx_lane(ufs, i) \
@@ -284,4 +289,12 @@ struct exynos_ufs_uic_attr exynos7_uic_attr = {
 	.rx_hs_g3_prep_sync_len_cap	= PREP_LEN(0xf),
 	.pa_dbg_option_suite		= 0x30103,
 };
+
+/* public function declarations */
+void exynos_ufs_dump_info(struct ufs_exynos_handle *handle, struct device *dev);
+void exynos_ufs_cmd_log_start(struct ufs_exynos_handle *handle,
+			      struct ufs_hba *hba, struct scsi_cmnd *cmd);
+void exynos_ufs_cmd_log_end(struct ufs_exynos_handle *handle,
+			    struct ufs_hba *hba, struct scsi_cmnd *cmd);
+int exynos_ufs_init_dbg(struct ufs_exynos_handle *handle, struct device *dev);
 #endif /* _UFS_EXYNOS_H_ */
-- 
2.7.4

Re: [RFC PATCH v3 1/2] ufs: introduce a callback to get info of command completion

[Stanley Chu]

Hi Kiwoong,

On Fri, 2020-07-03 at 14:31 +0900, Kiwoong Kim wrote:
> Some SoC specific might need command history for
> various reasons, such as stacking command contexts
> in system memory to check for debugging in the future
> or scaling some DVFS knobs to boost IO throughput.
> 
> What you would do with the information could be
> variant per SoC vendor.
> 
> Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> ---

Please help collect all tags received in previous versions and add them
to any future new versions, for example, for this patch,

Acked-By: Stanley Chu <stanley.chu@mediatek.com>

RE: [RFC PATCH v3 1/2] ufs: introduce a callback to get info of command completion

[Kiwoong Kim]

> Hi Kiwoong,
> 
> On Fri, 2020-07-03 at 14:31 +0900, Kiwoong Kim wrote:
> > Some SoC specific might need command history for various reasons, such
> > as stacking command contexts in system memory to check for debugging
> > in the future or scaling some DVFS knobs to boost IO throughput.
> >
> > What you would do with the information could be variant per SoC
> > vendor.
> >
> > Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> > ---
> 
> Please help collect all tags received in previous versions and add them to
> any future new versions, for example, for this patch,
> 
> Acked-By: Stanley Chu <stanley.chu@mediatek.com>
> 
> 

Oh, got it.

Thanks.
Kiwoong Kim

Re: [RFC PATCH v3 2/2] exynos-ufs: implement dbg_register_dump and compl_xfer_req

[kernel test robot]

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Hi Kiwoong,

[FYI, it's a private test report for your RFC patch.]
[auto build test ERROR on scsi/for-next]
[also build test ERROR on mkp-scsi/for-next next-20200703]
[cannot apply to v5.8-rc3]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Kiwoong-Kim/ufs-introduce-callbacks-to-get-command-information/20200703-134050
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git for-next
config: h8300-allmodconfig (attached as .config)
compiler: h8300-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=h8300 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "exynos_ufs_cmd_log_start" [drivers/scsi/ufs/ufs-exynos.ko] undefined!
>> ERROR: modpost: "exynos_ufs_init_dbg" [drivers/scsi/ufs/ufs-exynos.ko] undefined!
>> ERROR: modpost: "exynos_ufs_cmd_log_end" [drivers/scsi/ufs/ufs-exynos.ko] undefined!
>> ERROR: modpost: "exynos_ufs_dump_info" [drivers/scsi/ufs/ufs-exynos.ko] undefined!

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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RE: [RFC PATCH v3 1/2] ufs: introduce a callback to get info of command completion

[Avri Altman]

> 
> 
> Some SoC specific might need command history for
> various reasons, such as stacking command contexts
> in system memory to check for debugging in the future
> or scaling some DVFS knobs to boost IO throughput.
> 
> What you would do with the information could be
> variant per SoC vendor.
> 
> Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> ---
>  drivers/scsi/ufs/ufshcd.c | 2 ++
>  drivers/scsi/ufs/ufshcd.h | 8 ++++++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 52abe82..3326236 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -4882,6 +4882,7 @@ static void __ufshcd_transfer_req_compl(struct
> ufs_hba *hba,
>         for_each_set_bit(index, &completed_reqs, hba->nutrs) {
>                 lrbp = &hba->lrb[index];
>                 cmd = lrbp->cmd;
> +               ufshcd_vops_compl_xfer_req(hba, index, (cmd) ? true : false);
>                 if (cmd) {
>                         ufshcd_add_command_trace(hba, index, "complete");
>                         result = ufshcd_transfer_rsp_status(hba, lrbp);
> @@ -4890,6 +4891,7 @@ static void __ufshcd_transfer_req_compl(struct
> ufs_hba *hba,
>                         /* Mark completed command as NULL in LRB */
>                         lrbp->cmd = NULL;
>                         lrbp->compl_time_stamp = ktime_get();
> +
>                         /* Do not touch lrbp after scsi done */
>                         cmd->scsi_done(cmd);
>                         __ufshcd_release(hba);
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index c774012..5cf9f99 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -307,6 +307,7 @@ struct ufs_hba_variant_ops {
>         void    (*config_scaling_param)(struct ufs_hba *hba,
>                                         struct devfreq_dev_profile *profile,
>                                         void *data);
> +       void    (*compl_xfer_req)(struct ufs_hba *hba, int tag, bool is_scsi);
Maybe add it right after setup_xfer_req?
Makes more sense as it is its counterpart.

Thanks,
Avri

>  };

RE: [RFC PATCH v3 2/2] exynos-ufs: implement dbg_register_dump and compl_xfer_req

[Avri Altman]

> 
> 
> This patch implements callbacks dbg_register_dump and
> compl_xfer_req to store IO contexts or print them.
Each callback deserves its own patch.

Thanks,
Avri

RE: [RFC PATCH v3 1/2] ufs: introduce a callback to get info of command completion

[Kiwoong Kim]

> > Some SoC specific might need command history for various reasons, such
> > as stacking command contexts in system memory to check for debugging
> > in the future or scaling some DVFS knobs to boost IO throughput.
> >
> > What you would do with the information could be variant per SoC
> > vendor.
> >
> > Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> > ---
> >  drivers/scsi/ufs/ufshcd.c | 2 ++
> >  drivers/scsi/ufs/ufshcd.h | 8 ++++++++
> >  2 files changed, 10 insertions(+)
> >
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index 52abe82..3326236 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -4882,6 +4882,7 @@ static void __ufshcd_transfer_req_compl(struct
> > ufs_hba *hba,
> >         for_each_set_bit(index, &completed_reqs, hba->nutrs) {
> >                 lrbp = &hba->lrb[index];
> >                 cmd = lrbp->cmd;
> > +               ufshcd_vops_compl_xfer_req(hba, index, (cmd) ? true :
> > + false);
> >                 if (cmd) {
> >                         ufshcd_add_command_trace(hba, index, "complete");
> >                         result = ufshcd_transfer_rsp_status(hba,
> > lrbp); @@ -4890,6 +4891,7 @@ static void
> > __ufshcd_transfer_req_compl(struct
> > ufs_hba *hba,
> >                         /* Mark completed command as NULL in LRB */
> >                         lrbp->cmd = NULL;
> >                         lrbp->compl_time_stamp = ktime_get();
> > +
> >                         /* Do not touch lrbp after scsi done */
> >                         cmd->scsi_done(cmd);
> >                         __ufshcd_release(hba); diff --git
> > a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index
> > c774012..5cf9f99 100644
> > --- a/drivers/scsi/ufs/ufshcd.h
> > +++ b/drivers/scsi/ufs/ufshcd.h
> > @@ -307,6 +307,7 @@ struct ufs_hba_variant_ops {
> >         void    (*config_scaling_param)(struct ufs_hba *hba,
> >                                         struct devfreq_dev_profile *profile,
> >                                         void *data);
> > +       void    (*compl_xfer_req)(struct ufs_hba *hba, int tag, bool
> is_scsi);
> Maybe add it right after setup_xfer_req?
> Makes more sense as it is its counterpart.
> 
> Thanks,
> Avri
> 
> >  };

Got it

Thanks.
Kiwoong Kim

RE: [RFC PATCH v3 2/2] exynos-ufs: implement dbg_register_dump and compl_xfer_req

[Kiwoong Kim]

> > This patch implements callbacks dbg_register_dump and compl_xfer_req
> > to store IO contexts or print them.
> Each callback deserves its own patch.
> 
> Thanks,
> Avri

Got it

Thanks.
Kiwoong Kim