[V3] scsi: ufs-debugfs: Add error counters
diff mbox series

Message ID 20201218122027.27472-1-adrian.hunter@intel.com
State Accepted
Commit b6cacaf2044fd9b82e5ceac88d8d17e04a01982f
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Series
  • [V3] scsi: ufs-debugfs: Add error counters
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Commit Message

Adrian Hunter Dec. 18, 2020, 12:20 p.m. UTC
People testing have a need to know how many errors might be occurring
over time. Add error counters and expose them via debugfs.

A module initcall is used to create a debugfs root directory for
ufshcd-related items. In the case that modules are built-in, then
initialization is done in link order, so move ufshcd-core to the top of
the Makefile.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
---


Changes in V3:
	Fixed link order to ensure correct initcall ordering when
	modules are built-in.
	Amended commit message accordingly.

Changes in V2:
	Add missing '#include "ufs-debugfs.h"' in ufs-debugfs.c
	Reported-by: kernel test robot <lkp@intel.com>


 drivers/scsi/ufs/Makefile      | 13 +++++---
 drivers/scsi/ufs/ufs-debugfs.c | 56 ++++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufs-debugfs.h | 22 +++++++++++++
 drivers/scsi/ufs/ufshcd.c      | 19 ++++++++++++
 drivers/scsi/ufs/ufshcd.h      |  5 +++
 5 files changed, 111 insertions(+), 4 deletions(-)
 create mode 100644 drivers/scsi/ufs/ufs-debugfs.c
 create mode 100644 drivers/scsi/ufs/ufs-debugfs.h

Comments

Bean Huo Dec. 18, 2020, 3:17 p.m. UTC | #1
On Fri, 2020-12-18 at 14:20 +0200, Adrian Hunter wrote:
> People testing have a need to know how many errors might be occurring
> over time. Add error counters and expose them via debugfs.
> 
> A module initcall is used to create a debugfs root directory for
> ufshcd-related items. In the case that modules are built-in, then
> initialization is done in link order, so move ufshcd-core to the top
> of
> the Makefile.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> Reviewed-by: Avri Altman <avri.altman@wdc.com>
> ---
> 
> 
> Changes in V3:
> 	Fixed link order to ensure correct initcall ordering when
> 	modules are built-in.
> 	Amended commit message accordingly.
> 
> Changes in V2:
> 	Add missing '#include "ufs-debugfs.h"' in ufs-debugfs.c
> 	Reported-by: kernel test robot <lkp@intel.com>
> 
> 
>  drivers/scsi/ufs/Makefile      | 13 +++++---
>  drivers/scsi/ufs/ufs-debugfs.c | 56
> ++++++++++++++++++++++++++++++++++
>  drivers/scsi/ufs/ufs-debugfs.h | 22 +++++++++++++
>  drivers/scsi/ufs/ufshcd.c      | 19 ++++++++++++
>  drivers/scsi/ufs/ufshcd.h      |  5 +++
>  5 files changed, 111 insertions(+), 4 deletions(-)
>  create mode 100644 drivers/scsi/ufs/ufs-debugfs.c
>  create mode 100644 drivers/scsi/ufs/ufs-debugfs.h
> 
> diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
> index 4679af1b564e..06f3a3fe4a44 100644
> --- a/drivers/scsi/ufs/Makefile
> +++ b/drivers/scsi/ufs/Makefile
> @@ -1,5 +1,14 @@
>  # SPDX-License-Identifier: GPL-2.0
>  # UFSHCD makefile
> +
> +# The link order is important here. ufshcd-core must initialize
> +# before vendor drivers.
> +obj-$(CONFIG_SCSI_UFSHCD)		+= ufshcd-core.o
> +ufshcd-core-y				+= ufshcd.o ufs-sysfs.o
> +ufshcd-core-$(CONFIG_DEBUG_FS)		+= ufs-debugfs.o
> +ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
> +ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO)	+= ufshcd-crypto.o
> +
>  obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o
> tc-dwc-g210.o
>  obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o
> ufshcd-dwc.o tc-dwc-g210.o
>  obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
> @@ -7,10 +16,6 @@ obj-$(CONFIG_SCSI_UFS_QCOM) += ufs_qcom.o
>  ufs_qcom-y += ufs-qcom.o
>  ufs_qcom-$(CONFIG_SCSI_UFS_CRYPTO) += ufs-qcom-ice.o
>  obj-$(CONFIG_SCSI_UFS_EXYNOS) += ufs-exynos.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
> -ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO) += ufshcd-crypto.o
>  obj-$(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/ufs-debugfs.c b/drivers/scsi/ufs/ufs-
> debugfs.c
> new file mode 100644
> index 000000000000..dee98dc72d29
> --- /dev/null
> +++ b/drivers/scsi/ufs/ufs-debugfs.c
> @@ -0,0 +1,56 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2020 Intel Corporation
> +
> +#include <linux/debugfs.h>
> +
> +#include "ufs-debugfs.h"
> +#include "ufshcd.h"
> +
> +static struct dentry *ufs_debugfs_root;
> +
> +void __init ufs_debugfs_init(void)
> +{
> +	ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
> +}
> +
> +void __exit ufs_debugfs_exit(void)
> +{
> +	debugfs_remove_recursive(ufs_debugfs_root);
> +}
> +
> +static int ufs_debugfs_stats_show(struct seq_file *s, void *data)
> +{
> +	struct ufs_hba *hba = s->private;
> +	struct ufs_event_hist *e = hba->ufs_stats.event;
> +
> +#define PRT(fmt, typ) \
> +	seq_printf(s, fmt, e[UFS_EVT_ ## typ].cnt)
> +
> +	PRT("PHY Adapter Layer errors (except LINERESET): %llu\n",
> PA_ERR);
> +	PRT("Data Link Layer errors: %llu\n", DL_ERR);
> +	PRT("Network Layer errors: %llu\n", NL_ERR);
> +	PRT("Transport Layer errors: %llu\n", TL_ERR);
> +	PRT("Generic DME errors: %llu\n", DME_ERR);
> +	PRT("Auto-hibernate errors: %llu\n", AUTO_HIBERN8_ERR);
> +	PRT("IS Fatal errors (CEFES, SBFES, HCFES, DFES): %llu\n",
> FATAL_ERR);
> +	PRT("DME Link Startup errors: %llu\n", LINK_STARTUP_FAIL);
> +	PRT("PM Resume errors: %llu\n", RESUME_ERR);
> +	PRT("PM Suspend errors : %llu\n", SUSPEND_ERR);
> +	PRT("Logical Unit Resets: %llu\n", DEV_RESET);
> +	PRT("Host Resets: %llu\n", HOST_RESET);
> +	PRT("SCSI command aborts: %llu\n", ABORT);
> +#undef PRT
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(ufs_debugfs_stats);
> +
> +void ufs_debugfs_hba_init(struct ufs_hba *hba)
> +{

I prefer adding:
	if (!ufs_debugfs_root)
		return;

> +	hba->debugfs_root = debugfs_create_dir(dev_name(hba->dev),
> ufs_debugfs_root);

> +	debugfs_create_file("stats", 0400, hba->debugfs_root, hba,
> &ufs_debugfs_stats_fops);

	if (!debugfs_create_file("stats", 0400, hba->debugfs_root, hba,
		&ufs_debugfs_stats_fops)) {
		debugfs_remove(hba->debugfs_root);
		return -ENOMEM;
	}


Thanks,
Bean
Adrian Hunter Dec. 18, 2020, 6:34 p.m. UTC | #2
On 18/12/20 5:17 pm, Bean Huo wrote:
> On Fri, 2020-12-18 at 14:20 +0200, Adrian Hunter wrote:
>> People testing have a need to know how many errors might be occurring
>> over time. Add error counters and expose them via debugfs.
>>
>> A module initcall is used to create a debugfs root directory for
>> ufshcd-related items. In the case that modules are built-in, then
>> initialization is done in link order, so move ufshcd-core to the top
>> of
>> the Makefile.
>>
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>> Reviewed-by: Avri Altman <avri.altman@wdc.com>
>> ---
>>
>>
>> Changes in V3:
>> 	Fixed link order to ensure correct initcall ordering when
>> 	modules are built-in.
>> 	Amended commit message accordingly.
>>
>> Changes in V2:
>> 	Add missing '#include "ufs-debugfs.h"' in ufs-debugfs.c
>> 	Reported-by: kernel test robot <lkp@intel.com>
>>
>>
>>  drivers/scsi/ufs/Makefile      | 13 +++++---
>>  drivers/scsi/ufs/ufs-debugfs.c | 56
>> ++++++++++++++++++++++++++++++++++
>>  drivers/scsi/ufs/ufs-debugfs.h | 22 +++++++++++++
>>  drivers/scsi/ufs/ufshcd.c      | 19 ++++++++++++
>>  drivers/scsi/ufs/ufshcd.h      |  5 +++
>>  5 files changed, 111 insertions(+), 4 deletions(-)
>>  create mode 100644 drivers/scsi/ufs/ufs-debugfs.c
>>  create mode 100644 drivers/scsi/ufs/ufs-debugfs.h
>>
>> diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
>> index 4679af1b564e..06f3a3fe4a44 100644
>> --- a/drivers/scsi/ufs/Makefile
>> +++ b/drivers/scsi/ufs/Makefile
>> @@ -1,5 +1,14 @@
>>  # SPDX-License-Identifier: GPL-2.0
>>  # UFSHCD makefile
>> +
>> +# The link order is important here. ufshcd-core must initialize
>> +# before vendor drivers.
>> +obj-$(CONFIG_SCSI_UFSHCD)		+= ufshcd-core.o
>> +ufshcd-core-y				+= ufshcd.o ufs-sysfs.o
>> +ufshcd-core-$(CONFIG_DEBUG_FS)		+= ufs-debugfs.o
>> +ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
>> +ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO)	+= ufshcd-crypto.o
>> +
>>  obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o
>> tc-dwc-g210.o
>>  obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o
>> ufshcd-dwc.o tc-dwc-g210.o
>>  obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
>> @@ -7,10 +16,6 @@ obj-$(CONFIG_SCSI_UFS_QCOM) += ufs_qcom.o
>>  ufs_qcom-y += ufs-qcom.o
>>  ufs_qcom-$(CONFIG_SCSI_UFS_CRYPTO) += ufs-qcom-ice.o
>>  obj-$(CONFIG_SCSI_UFS_EXYNOS) += ufs-exynos.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
>> -ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO) += ufshcd-crypto.o
>>  obj-$(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/ufs-debugfs.c b/drivers/scsi/ufs/ufs-
>> debugfs.c
>> new file mode 100644
>> index 000000000000..dee98dc72d29
>> --- /dev/null
>> +++ b/drivers/scsi/ufs/ufs-debugfs.c
>> @@ -0,0 +1,56 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Copyright (C) 2020 Intel Corporation
>> +
>> +#include <linux/debugfs.h>
>> +
>> +#include "ufs-debugfs.h"
>> +#include "ufshcd.h"
>> +
>> +static struct dentry *ufs_debugfs_root;
>> +
>> +void __init ufs_debugfs_init(void)
>> +{
>> +	ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
>> +}
>> +
>> +void __exit ufs_debugfs_exit(void)
>> +{
>> +	debugfs_remove_recursive(ufs_debugfs_root);
>> +}
>> +
>> +static int ufs_debugfs_stats_show(struct seq_file *s, void *data)
>> +{
>> +	struct ufs_hba *hba = s->private;
>> +	struct ufs_event_hist *e = hba->ufs_stats.event;
>> +
>> +#define PRT(fmt, typ) \
>> +	seq_printf(s, fmt, e[UFS_EVT_ ## typ].cnt)
>> +
>> +	PRT("PHY Adapter Layer errors (except LINERESET): %llu\n",
>> PA_ERR);
>> +	PRT("Data Link Layer errors: %llu\n", DL_ERR);
>> +	PRT("Network Layer errors: %llu\n", NL_ERR);
>> +	PRT("Transport Layer errors: %llu\n", TL_ERR);
>> +	PRT("Generic DME errors: %llu\n", DME_ERR);
>> +	PRT("Auto-hibernate errors: %llu\n", AUTO_HIBERN8_ERR);
>> +	PRT("IS Fatal errors (CEFES, SBFES, HCFES, DFES): %llu\n",
>> FATAL_ERR);
>> +	PRT("DME Link Startup errors: %llu\n", LINK_STARTUP_FAIL);
>> +	PRT("PM Resume errors: %llu\n", RESUME_ERR);
>> +	PRT("PM Suspend errors : %llu\n", SUSPEND_ERR);
>> +	PRT("Logical Unit Resets: %llu\n", DEV_RESET);
>> +	PRT("Host Resets: %llu\n", HOST_RESET);
>> +	PRT("SCSI command aborts: %llu\n", ABORT);
>> +#undef PRT
>> +	return 0;
>> +}
>> +DEFINE_SHOW_ATTRIBUTE(ufs_debugfs_stats);
>> +
>> +void ufs_debugfs_hba_init(struct ufs_hba *hba)
>> +{
> 
> I prefer adding:
> 	if (!ufs_debugfs_root)
> 		return;

I understand that you want to be careful, but it is not harmful if it is
NULL, so are you sure we should do this?

> 
>> +	hba->debugfs_root = debugfs_create_dir(dev_name(hba->dev),
>> ufs_debugfs_root);

It is OK to pass NULL or error codes as parent dentry to debugfs_create_...
functions.

If ufs_debugfs_root is NULL (which won't happen) then the directory will be
created in debugfs root i.e. /sys/kernel/debug, using the device name.

If ufs_debugfs_root is an error code, then debugfs_create_dir will return an
error code, and following debugfs_create_file() will return an error code.

> 
>> +	debugfs_create_file("stats", 0400, hba->debugfs_root, hba,
>> &ufs_debugfs_stats_fops);
> 
> 	if (!debugfs_create_file("stats", 0400, hba->debugfs_root, hba,
> 		&ufs_debugfs_stats_fops)) {
> 		debugfs_remove(hba->debugfs_root);
> 		return -ENOMEM;

Being without debugfs files is not a problem, so there is no reason to
return an error.  It is relatively rare in the kernel that code checks the
return value of debugfs_create_file().  We really don't want to fail probing
just because of debugfs.

However, because debugfs' only real resource is a small amount of memory, it
is extremely unlikely it will fail in that sense.  Although you can force it
to fail by adding the kernel command line parameter debugfs=off
Bean Huo Dec. 18, 2020, 6:57 p.m. UTC | #3
On Fri, 2020-12-18 at 20:34 +0200, Adrian Hunter wrote:
> It is OK to pass NULL or error codes as parent dentry to
> debugfs_create_...
> functions.
> 
> If ufs_debugfs_root is NULL (which won't happen) then the directory
> will be
> created in debugfs root i.e. /sys/kernel/debug, using the device
> name.
> 
> If ufs_debugfs_root is an error code, then debugfs_create_dir will
> return an
> error code, and following debugfs_create_file() will return an error
> code.
> 
> > 
> > > +    debugfs_create_file("stats", 0400, hba->debugfs_root, hba,
> > > &ufs_debugfs_stats_fops);
> > 
> >        if (!debugfs_create_file("stats", 0400, hba->debugfs_root,
> > hba,
> >                &ufs_debugfs_stats_fops)) {
> >                debugfs_remove(hba->debugfs_root);
> >                return -ENOMEM;
> 
> Being without debugfs files is not a problem, so there is no reason
> to
> return an error.  It is relatively rare in the kernel that code
> checks the
> return value of debugfs_create_file().  We really don't want to fail
> probing
> just because of debugfs.
> 
> However, because debugfs' only real resource is a small amount of
> memory, it
> is extremely unlikely it will fail in that sense.  Although you can
> force it
> to fail by adding the kernel command line parameter debugfs=off

Adrian
Sounds your choice is correct. thanks.

Reviewed-by: Bean Huo <beanhuo@micron.com>

Patch
diff mbox series

diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index 4679af1b564e..06f3a3fe4a44 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -1,5 +1,14 @@ 
 # SPDX-License-Identifier: GPL-2.0
 # UFSHCD makefile
+
+# The link order is important here. ufshcd-core must initialize
+# before vendor drivers.
+obj-$(CONFIG_SCSI_UFSHCD)		+= ufshcd-core.o
+ufshcd-core-y				+= ufshcd.o ufs-sysfs.o
+ufshcd-core-$(CONFIG_DEBUG_FS)		+= ufs-debugfs.o
+ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
+ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO)	+= ufshcd-crypto.o
+
 obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210.o
 obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o
 obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
@@ -7,10 +16,6 @@  obj-$(CONFIG_SCSI_UFS_QCOM) += ufs_qcom.o
 ufs_qcom-y += ufs-qcom.o
 ufs_qcom-$(CONFIG_SCSI_UFS_CRYPTO) += ufs-qcom-ice.o
 obj-$(CONFIG_SCSI_UFS_EXYNOS) += ufs-exynos.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
-ufshcd-core-$(CONFIG_SCSI_UFS_CRYPTO) += ufshcd-crypto.o
 obj-$(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/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
new file mode 100644
index 000000000000..dee98dc72d29
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-debugfs.c
@@ -0,0 +1,56 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 Intel Corporation
+
+#include <linux/debugfs.h>
+
+#include "ufs-debugfs.h"
+#include "ufshcd.h"
+
+static struct dentry *ufs_debugfs_root;
+
+void __init ufs_debugfs_init(void)
+{
+	ufs_debugfs_root = debugfs_create_dir("ufshcd", NULL);
+}
+
+void __exit ufs_debugfs_exit(void)
+{
+	debugfs_remove_recursive(ufs_debugfs_root);
+}
+
+static int ufs_debugfs_stats_show(struct seq_file *s, void *data)
+{
+	struct ufs_hba *hba = s->private;
+	struct ufs_event_hist *e = hba->ufs_stats.event;
+
+#define PRT(fmt, typ) \
+	seq_printf(s, fmt, e[UFS_EVT_ ## typ].cnt)
+
+	PRT("PHY Adapter Layer errors (except LINERESET): %llu\n", PA_ERR);
+	PRT("Data Link Layer errors: %llu\n", DL_ERR);
+	PRT("Network Layer errors: %llu\n", NL_ERR);
+	PRT("Transport Layer errors: %llu\n", TL_ERR);
+	PRT("Generic DME errors: %llu\n", DME_ERR);
+	PRT("Auto-hibernate errors: %llu\n", AUTO_HIBERN8_ERR);
+	PRT("IS Fatal errors (CEFES, SBFES, HCFES, DFES): %llu\n", FATAL_ERR);
+	PRT("DME Link Startup errors: %llu\n", LINK_STARTUP_FAIL);
+	PRT("PM Resume errors: %llu\n", RESUME_ERR);
+	PRT("PM Suspend errors : %llu\n", SUSPEND_ERR);
+	PRT("Logical Unit Resets: %llu\n", DEV_RESET);
+	PRT("Host Resets: %llu\n", HOST_RESET);
+	PRT("SCSI command aborts: %llu\n", ABORT);
+#undef PRT
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(ufs_debugfs_stats);
+
+void ufs_debugfs_hba_init(struct ufs_hba *hba)
+{
+	hba->debugfs_root = debugfs_create_dir(dev_name(hba->dev), ufs_debugfs_root);
+	debugfs_create_file("stats", 0400, hba->debugfs_root, hba, &ufs_debugfs_stats_fops);
+}
+
+void ufs_debugfs_hba_exit(struct ufs_hba *hba)
+{
+	debugfs_remove_recursive(hba->debugfs_root);
+}
diff --git a/drivers/scsi/ufs/ufs-debugfs.h b/drivers/scsi/ufs/ufs-debugfs.h
new file mode 100644
index 000000000000..f35b39c4b4f5
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-debugfs.h
@@ -0,0 +1,22 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2020 Intel Corporation
+ */
+
+#ifndef __UFS_DEBUGFS_H__
+#define __UFS_DEBUGFS_H__
+
+struct ufs_hba;
+
+#ifdef CONFIG_DEBUG_FS
+void __init ufs_debugfs_init(void);
+void __exit ufs_debugfs_exit(void);
+void ufs_debugfs_hba_init(struct ufs_hba *hba);
+void ufs_debugfs_hba_exit(struct ufs_hba *hba);
+#else
+static inline void ufs_debugfs_init(void) {}
+static inline void ufs_debugfs_exit(void) {}
+static inline void ufs_debugfs_hba_init(struct ufs_hba *hba) {}
+static inline void ufs_debugfs_hba_exit(struct ufs_hba *hba) {}
+#endif
+
+#endif
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 82ad31781bc9..d8a3cf0cd6d5 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -20,6 +20,7 @@ 
 #include "ufs_quirks.h"
 #include "unipro.h"
 #include "ufs-sysfs.h"
+#include "ufs-debugfs.h"
 #include "ufs_bsg.h"
 #include "ufshcd-crypto.h"
 #include <asm/unaligned.h>
@@ -4540,6 +4541,7 @@  void ufshcd_update_evt_hist(struct ufs_hba *hba, u32 id, u32 val)
 	e = &hba->ufs_stats.event[id];
 	e->val[e->pos] = val;
 	e->tstamp[e->pos] = ktime_get();
+	e->cnt += 1;
 	e->pos = (e->pos + 1) % UFS_EVENT_HIST_LENGTH;
 
 	ufshcd_vops_event_notify(hba, id, &val);
@@ -8334,6 +8336,8 @@  static int ufshcd_hba_init(struct ufs_hba *hba)
 	if (err)
 		goto out_disable_vreg;
 
+	ufs_debugfs_hba_init(hba);
+
 	hba->is_powered = true;
 	goto out;
 
@@ -8350,6 +8354,7 @@  static int ufshcd_hba_init(struct ufs_hba *hba)
 static void ufshcd_hba_exit(struct ufs_hba *hba)
 {
 	if (hba->is_powered) {
+		ufs_debugfs_hba_exit(hba);
 		ufshcd_variant_hba_exit(hba);
 		ufshcd_setup_vreg(hba, false);
 		ufshcd_suspend_clkscaling(hba);
@@ -9436,6 +9441,20 @@  int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 }
 EXPORT_SYMBOL_GPL(ufshcd_init);
 
+static int __init ufshcd_core_init(void)
+{
+	ufs_debugfs_init();
+	return 0;
+}
+
+static void __exit ufshcd_core_exit(void)
+{
+	ufs_debugfs_exit();
+}
+
+module_init(ufshcd_core_init);
+module_exit(ufshcd_core_exit);
+
 MODULE_AUTHOR("Santosh Yaragnavi <santosh.sy@samsung.com>");
 MODULE_AUTHOR("Vinayak Holikatti <h.vinayak@samsung.com>");
 MODULE_DESCRIPTION("Generic UFS host controller driver Core");
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index aa9ea3552323..8c51ce01517e 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -445,11 +445,13 @@  struct ufs_clk_scaling {
  * @pos: index to indicate cyclic buffer position
  * @reg: cyclic buffer for registers value
  * @tstamp: cyclic buffer for time stamp
+ * @cnt: error counter
  */
 struct ufs_event_hist {
 	int pos;
 	u32 val[UFS_EVENT_HIST_LENGTH];
 	ktime_t tstamp[UFS_EVENT_HIST_LENGTH];
+	unsigned long long cnt;
 };
 
 /**
@@ -817,6 +819,9 @@  struct ufs_hba {
 	u32 crypto_cfg_register;
 	struct blk_keyslot_manager ksm;
 #endif
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs_root;
+#endif
 };
 
 /* Returns true if clocks can be gated. Otherwise false */