[PATCH v2 00/11] zfcp: retrieve local RDP data, fix and cleanup

[PATCH v2 00/11] zfcp: retrieve local RDP data, fix and cleanup

[Benjamin Block]

Hello all,

this is the second version of my RDP patchset for zfcp, after I noticed
a memory-leak in the first version earlier this year. Here is the
original description, which remains valid:

    With FC-LS-3 Fibre Channel got support for the RDP Extended Link
    Service, which we can use to gather diagnostics data (health values
    from the optics and such). To gather those data from our local link,
    the FCP Channel firmware (for FCP and Ficon Express adapters) added
    some new fields in our Exchange Port Data firmware command
    (primarily SFP data).
        This patchset adds a new sysfs-directory below our
    adapter-object and several files in that to read those new fields.
        Additionally this also adds a file to read the buffer-to-buffer
    credit value from our local port (also something that can be
    gathered using the RDP ELS).
    
    The main purpose of the data from RDP requests (at least in my mind)
    are to catch some otherwise hard to track down errors, like dirt on
    the fibre and such (I would expect optics data to degraded with such
    conditions). These things are a pain to track down because it
    doesn't cause the link to go away, just some sporadic errors that
    can result in incomplete exchanges and such.
    
    The patchset is somewhat big because I don't want to issue a single
    Exchange Port/Config Data command for each read of those files,
    which would generate unnecessary traffic (and possibly inconsistent
    data) on our command-queue (we don't have an admin-queue or some
    such). So it also adds a (time-based) mechanism to cache data from
    Exchange Config/Port Data.
        We also want to prevent our adapter-structure from growing,
    which would further grow Scsi_Host, which is already too damn big,
    so these data are decoupled.
    
    More details are in the patches themselves.

Additionally to this, there are two more patches from Steffen that we
want to include, the first (patch 10) is just a cleanup for better
readability, the second (patch 11) is a fix/improvement for our
tracing-feature to make traces of failed FCP requests better. Even
though Steffen flagged the later as fix, I don't think we need extra
handling for it, if it goes in with the rest, thats fine - its nothing
pressing.

Reviews are highly welcome :-).

James, Martin, if there are no objections, it would be nice if you could
still include this in the merge for 5.5.

FYI: I also plan to/am in the middle of writing a simple command-line
     tool to send RDP to all/certain available remote/local FC-Ports in
     the System and present them in a sane format (sane to me ;-) ).
     This could be used for logging, or while gathering debug-data from
     a system.

     The RDP ELS' to remote ports will be send using BSG. Local data
     (for zFCP) would be read using this new interface.

     If anyone is interested, I can point it out on the list once I have
     something that has at least a minimum set of functionality.

Benjamin Block (9):
  zfcp: signal incomplete or error for sync exchange config/port data
  zfcp: diagnostics buffer caching and use for exchange port data
  zfcp: add diagnostics buffer for exchange config data
  zfcp: support retrieval of SFP Data via Exchange Port Data
  zfcp: introduce SysFS interface for diagnostics of local SFP
    transceiver
  zfcp: implicitly refresh port-data diagnostics when reading SysFS
  zfcp: introduce SysFS interface to read the local B2B-Credit
  zfcp: implicitly refresh config-data diagnostics when reading SysFS
  zfcp: move maximum age of diagnostic buffers into a per-adapter
    variable

Steffen Maier (2):
  zfcp: proper indentation to reduce confusion in zfcp_erp_required_act
  zfcp: trace channel log even for FCP command responses

 drivers/s390/scsi/Makefile     |   2 +-
 drivers/s390/scsi/zfcp_aux.c   |  12 +-
 drivers/s390/scsi/zfcp_dbf.c   |   8 +-
 drivers/s390/scsi/zfcp_def.h   |   4 +-
 drivers/s390/scsi/zfcp_diag.c  | 305 +++++++++++++++++++++++++++++++++
 drivers/s390/scsi/zfcp_diag.h  | 101 +++++++++++
 drivers/s390/scsi/zfcp_erp.c   |   4 +-
 drivers/s390/scsi/zfcp_ext.h   |   1 +
 drivers/s390/scsi/zfcp_fsf.c   |  73 +++++++-
 drivers/s390/scsi/zfcp_fsf.h   |  21 ++-
 drivers/s390/scsi/zfcp_scsi.c  |   4 +-
 drivers/s390/scsi/zfcp_sysfs.c | 170 +++++++++++++++++-
 12 files changed, 683 insertions(+), 22 deletions(-)
 create mode 100644 drivers/s390/scsi/zfcp_diag.c
 create mode 100644 drivers/s390/scsi/zfcp_diag.h

-- 
2.21.0

[PATCH v2 01/11] zfcp: signal incomplete or error for sync exchange config/port data

[Benjamin Block]

Adds a new FSF-Request status flag (ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE)
that signal that the data received using Exchange Config Data or
Exchange Port Data was incomplete. This new flags is set in the
respective handlers during the response path.

With this patch, only the synchronous FSF-functions for each command got
support for the new flag, otherwise it is transparent.

Together with this new flag and already existing status flags the
synchronous FSF-functions are extended to now detect whether the
received data is complete, incomplete or completely invalid (this
includes cases where a command ran into a timeout). This is now signaled
back to the caller, where previously only failures on the request path
would result in a bad return-code.

For complete data the return-code remains 0. For incomplete data a new
return-code -EAGAIN is added to the function-interface. For completely
invalid data the already existing return-code -EIO is reused - formerly
this was used to signal failures on the request path.

Existing callers of the FSF-functions are adjusted so that they
behave as before for return-code 0 and -EAGAIN, to not change the
user-interface. As -EIO existed all along, it was already exposed to the
user - and needed handling - and will now also be exposed in this new
special case.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_def.h   |  1 +
 drivers/s390/scsi/zfcp_fsf.c   | 46 ++++++++++++++++++++++++++++++----
 drivers/s390/scsi/zfcp_scsi.c  |  4 +--
 drivers/s390/scsi/zfcp_sysfs.c |  4 +--
 4 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 87d2f47a6990..f5acdb67442e 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -86,6 +86,7 @@
 #define ZFCP_STATUS_FSFREQ_ABORTNOTNEEDED       0x00000080
 #define ZFCP_STATUS_FSFREQ_TMFUNCFAILED         0x00000200
 #define ZFCP_STATUS_FSFREQ_DISMISSED            0x00001000
+#define ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE	0x00020000
 
 /************************* STRUCTURE DEFINITIONS *****************************/
 
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index cf63916814cc..d8f0e446fe13 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -585,6 +585,8 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
 				&adapter->status);
 		break;
 	case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE:
+		req->status |= ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE;
+
 		fc_host_node_name(shost) = 0;
 		fc_host_port_name(shost) = 0;
 		fc_host_port_id(shost) = 0;
@@ -663,6 +665,8 @@ static void zfcp_fsf_exchange_port_data_handler(struct zfcp_fsf_req *req)
 		zfcp_fsf_exchange_port_evaluate(req);
 		break;
 	case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE:
+		req->status |= ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE;
+
 		zfcp_fsf_exchange_port_evaluate(req);
 		zfcp_fsf_link_down_info_eval(req,
 			&qtcb->header.fsf_status_qual.link_down_info);
@@ -1278,6 +1282,19 @@ int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *erp_action)
 	return retval;
 }
 
+
+/**
+ * zfcp_fsf_exchange_config_data_sync() - Request information about FCP channel.
+ * @qdio: pointer to the QDIO-Queue to use for sending the command.
+ * @data: pointer to the QTCB-Bottom for storing the result of the command,
+ *	  might be %NULL.
+ *
+ * Returns:
+ * * 0		- Exchange Config Data was successful, @data is complete
+ * * -EIO	- Exchange Config Data was not successful, @data is invalid
+ * * -EAGAIN	- @data contains incomplete data
+ * * -ENOMEM	- Some memory allocation failed along the way
+ */
 int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *qdio,
 				       struct fsf_qtcb_bottom_config *data)
 {
@@ -1309,9 +1326,16 @@ int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *qdio,
 	zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
 	retval = zfcp_fsf_req_send(req);
 	spin_unlock_irq(&qdio->req_q_lock);
+
 	if (!retval) {
 		/* NOTE: ONLY TOUCH SYNC req AGAIN ON req->completion. */
 		wait_for_completion(&req->completion);
+
+		if (req->status &
+		    (ZFCP_STATUS_FSFREQ_ERROR | ZFCP_STATUS_FSFREQ_DISMISSED))
+			retval = -EIO;
+		else if (req->status & ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE)
+			retval = -EAGAIN;
 	}
 
 	zfcp_fsf_req_free(req);
@@ -1369,10 +1393,17 @@ int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *erp_action)
 }
 
 /**
- * zfcp_fsf_exchange_port_data_sync - request information about local port
- * @qdio: pointer to struct zfcp_qdio
- * @data: pointer to struct fsf_qtcb_bottom_port
- * Returns: 0 on success, error otherwise
+ * zfcp_fsf_exchange_port_data_sync() - Request information about local port.
+ * @qdio: pointer to the QDIO-Queue to use for sending the command.
+ * @data: pointer to the QTCB-Bottom for storing the result of the command,
+ *	  might be %NULL.
+ *
+ * Returns:
+ * * 0		- Exchange Port Data was successful, @data is complete
+ * * -EIO	- Exchange Port Data was not successful, @data is invalid
+ * * -EAGAIN	- @data contains incomplete data
+ * * -ENOMEM	- Some memory allocation failed along the way
+ * * -EOPNOTSUPP	- This operation is not supported
  */
 int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
 				     struct fsf_qtcb_bottom_port *data)
@@ -1408,10 +1439,15 @@ int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
 	if (!retval) {
 		/* NOTE: ONLY TOUCH SYNC req AGAIN ON req->completion. */
 		wait_for_completion(&req->completion);
+
+		if (req->status &
+		    (ZFCP_STATUS_FSFREQ_ERROR | ZFCP_STATUS_FSFREQ_DISMISSED))
+			retval = -EIO;
+		else if (req->status & ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE)
+			retval = -EAGAIN;
 	}
 
 	zfcp_fsf_req_free(req);
-
 	return retval;
 
 out_unlock:
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index e9ded2befa0d..3910d529c15a 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -605,7 +605,7 @@ zfcp_scsi_get_fc_host_stats(struct Scsi_Host *host)
 		return NULL;
 
 	ret = zfcp_fsf_exchange_port_data_sync(adapter->qdio, data);
-	if (ret) {
+	if (ret != 0 && ret != -EAGAIN) {
 		kfree(data);
 		return NULL;
 	}
@@ -634,7 +634,7 @@ static void zfcp_scsi_reset_fc_host_stats(struct Scsi_Host *shost)
 		return;
 
 	ret = zfcp_fsf_exchange_port_data_sync(adapter->qdio, data);
-	if (ret)
+	if (ret != 0 && ret != -EAGAIN)
 		kfree(data);
 	else {
 		adapter->stats_reset = jiffies/HZ;
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index af197e2b3e69..90d851d49410 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -577,7 +577,7 @@ static ssize_t zfcp_sysfs_adapter_util_show(struct device *dev,
 		return -ENOMEM;
 
 	retval = zfcp_fsf_exchange_port_data_sync(adapter->qdio, qtcb_port);
-	if (!retval)
+	if (retval == 0 || retval == -EAGAIN)
 		retval = sprintf(buf, "%u %u %u\n", qtcb_port->cp_util,
 				 qtcb_port->cb_util, qtcb_port->a_util);
 	kfree(qtcb_port);
@@ -603,7 +603,7 @@ static int zfcp_sysfs_adapter_ex_config(struct device *dev,
 		return -ENOMEM;
 
 	retval = zfcp_fsf_exchange_config_data_sync(adapter->qdio, qtcb_config);
-	if (!retval)
+	if (retval == 0 || retval == -EAGAIN)
 		*stat_inf = qtcb_config->stat_info;
 
 	kfree(qtcb_config);
-- 
2.21.0

[PATCH v2 02/11] zfcp: diagnostics buffer caching and use for exchange port data

[Benjamin Block]

The FCP channel exposes two central interfaces to receive information
about the local FCP-Adapter/-Port: Exchange Port and Exchange Config
Data. Using these commands can negatively impact the adapter if we allow
them to be sent at a very high rate.

The later parts of this patchset will introduce new user-interfaces to
receive more diagnostics from the adapter. To prevent any negative
impact from using those, this patch adds a simple caching-mechanism that
will prevent a malicious/faulty userspace-application from generating an
abnormal high amount of Exchange Port/Config Data traffic.

Relevant diagnostic data that is received via Exchange Config/Port Data
is cached in buffers associated with the corresponding adapter-struct.
Each buffer is associated with a timestamp that signals how old the data
is, and, added via a following patch in this series, lets
userspace-interfaces determine when the data is too old and needs to be
updated.

Buffer-updates are made during the normal response path of the
corresponding command. With this patch only the output of the Exchange
Port Data command is captured.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/Makefile    |  2 +-
 drivers/s390/scsi/zfcp_aux.c  |  8 ++-
 drivers/s390/scsi/zfcp_def.h  |  3 +-
 drivers/s390/scsi/zfcp_diag.c | 93 +++++++++++++++++++++++++++++++++++
 drivers/s390/scsi/zfcp_diag.h | 60 ++++++++++++++++++++++
 drivers/s390/scsi/zfcp_fsf.c  | 12 +++++
 6 files changed, 175 insertions(+), 3 deletions(-)
 create mode 100644 drivers/s390/scsi/zfcp_diag.c
 create mode 100644 drivers/s390/scsi/zfcp_diag.h

diff --git a/drivers/s390/scsi/Makefile b/drivers/s390/scsi/Makefile
index 9dda431ec8f3..352056eb0dd1 100644
--- a/drivers/s390/scsi/Makefile
+++ b/drivers/s390/scsi/Makefile
@@ -5,6 +5,6 @@
 
 zfcp-objs := zfcp_aux.o zfcp_ccw.o zfcp_dbf.o zfcp_erp.o \
 	     zfcp_fc.o zfcp_fsf.o zfcp_qdio.o zfcp_scsi.o zfcp_sysfs.o \
-	     zfcp_unit.o
+	     zfcp_unit.o zfcp_diag.o
 
 obj-$(CONFIG_ZFCP) += zfcp.o
diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index e390f8c6d5f3..a19189d7b3f3 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -4,7 +4,7 @@
  *
  * Module interface and handling of zfcp data structures.
  *
- * Copyright IBM Corp. 2002, 2017
+ * Copyright IBM Corp. 2002, 2018
  */
 
 /*
@@ -25,6 +25,7 @@
  *            Martin Petermann
  *            Sven Schuetz
  *            Steffen Maier
+ *	      Benjamin Block
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -36,6 +37,7 @@
 #include "zfcp_ext.h"
 #include "zfcp_fc.h"
 #include "zfcp_reqlist.h"
+#include "zfcp_diag.h"
 
 #define ZFCP_BUS_ID_SIZE	20
 
@@ -356,6 +358,9 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 
 	adapter->erp_action.adapter = adapter;
 
+	if (zfcp_diag_adapter_setup(adapter))
+		goto failed;
+
 	if (zfcp_qdio_setup(adapter))
 		goto failed;
 
@@ -449,6 +454,7 @@ void zfcp_adapter_release(struct kref *ref)
 	dev_set_drvdata(&adapter->ccw_device->dev, NULL);
 	zfcp_fc_gs_destroy(adapter);
 	zfcp_free_low_mem_buffers(adapter);
+	zfcp_diag_adapter_free(adapter);
 	kfree(adapter->req_list);
 	kfree(adapter->fc_stats);
 	kfree(adapter->stats_reset_data);
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index f5acdb67442e..8cc0eefe4ccc 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -4,7 +4,7 @@
  *
  * Global definitions for the zfcp device driver.
  *
- * Copyright IBM Corp. 2002, 2017
+ * Copyright IBM Corp. 2002, 2018
  */
 
 #ifndef ZFCP_DEF_H
@@ -198,6 +198,7 @@ struct zfcp_adapter {
 	struct device_dma_parameters dma_parms;
 	struct zfcp_fc_events events;
 	unsigned long		next_port_scan;
+	struct zfcp_diag_adapter	*diagnostics;
 };
 
 struct zfcp_port {
diff --git a/drivers/s390/scsi/zfcp_diag.c b/drivers/s390/scsi/zfcp_diag.c
new file mode 100644
index 000000000000..fa1b25f3ec3c
--- /dev/null
+++ b/drivers/s390/scsi/zfcp_diag.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * zfcp device driver
+ *
+ * Functions to handle diagnostics.
+ *
+ * Copyright IBM Corp. 2018
+ */
+
+#include <linux/spinlock.h>
+#include <linux/jiffies.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+
+#include "zfcp_diag.h"
+#include "zfcp_ext.h"
+#include "zfcp_def.h"
+
+/* Max age of data in a diagnostics buffer before it needs a refresh (in ms). */
+#define ZFCP_DIAG_MAX_AGE (5 * 1000)
+
+/**
+ * zfcp_diag_adapter_setup() - Setup storage for adapter diagnostics.
+ * @adapter: the adapter to setup diagnostics for.
+ *
+ * Creates the data-structures to store the diagnostics for an adapter. This
+ * overwrites whatever was stored before at &zfcp_adapter->diagnostics!
+ *
+ * Return:
+ * * 0	     - Everyting is OK
+ * * -ENOMEM - Could not allocate all/parts of the data-structures;
+ *	       &zfcp_adapter->diagnostics remains unchanged
+ */
+int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter)
+{
+	struct zfcp_diag_adapter *diag;
+	struct zfcp_diag_header *hdr;
+
+	diag = kzalloc(sizeof(*diag), GFP_KERNEL);
+	if (diag == NULL)
+		return -ENOMEM;
+
+	/* setup header for port_data */
+	hdr = &diag->port_data.header;
+
+	spin_lock_init(&hdr->access_lock);
+	hdr->buffer = &diag->port_data.data;
+	hdr->buffer_size = sizeof(diag->port_data.data);
+	/* set the timestamp so that the first test on age will always fail */
+	hdr->timestamp = jiffies - msecs_to_jiffies(ZFCP_DIAG_MAX_AGE);
+
+	adapter->diagnostics = diag;
+	return 0;
+}
+
+/**
+ * zfcp_diag_adapter_free() - Frees all adapter diagnostics allocations.
+ * @adapter: the adapter whose diagnostic structures should be freed.
+ *
+ * Frees all data-structures in the given adapter that store diagnostics
+ * information. Can savely be called with partially setup diagnostics.
+ */
+void zfcp_diag_adapter_free(struct zfcp_adapter *const adapter)
+{
+	kfree(adapter->diagnostics);
+	adapter->diagnostics = NULL;
+}
+
+/**
+ * zfcp_diag_update_xdata() - Update a diagnostics buffer.
+ * @hdr: the meta data to update.
+ * @data: data to use for the update.
+ * @incomplete: flag stating whether the data in @data is incomplete.
+ */
+void zfcp_diag_update_xdata(struct zfcp_diag_header *const hdr,
+			    const void *const data, const bool incomplete)
+{
+	const unsigned long capture_timestamp = jiffies;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hdr->access_lock, flags);
+
+	/* make sure we never go into the past with an update */
+	if (!time_after_eq(capture_timestamp, hdr->timestamp))
+		goto out;
+
+	hdr->timestamp = capture_timestamp;
+	hdr->incomplete = incomplete;
+	memcpy(hdr->buffer, data, hdr->buffer_size);
+out:
+	spin_unlock_irqrestore(&hdr->access_lock, flags);
+}
diff --git a/drivers/s390/scsi/zfcp_diag.h b/drivers/s390/scsi/zfcp_diag.h
new file mode 100644
index 000000000000..2a933326b6e4
--- /dev/null
+++ b/drivers/s390/scsi/zfcp_diag.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * zfcp device driver
+ *
+ * Definitions for handling diagnostics in the the zfcp device driver.
+ *
+ * Copyright IBM Corp. 2018
+ */
+
+#ifndef ZFCP_DIAG_H
+#define ZFCP_DIAG_H
+
+#include <linux/spinlock.h>
+
+#include "zfcp_fsf.h"
+#include "zfcp_def.h"
+
+/**
+ * struct zfcp_diag_header - general part of a diagnostic buffer.
+ * @access_lock: lock protecting all the data in this buffer.
+ * @updating: flag showing that an update for this buffer is currently running.
+ * @incomplete: flag showing that the data in @buffer is incomplete.
+ * @timestamp: time in jiffies when the data of this buffer was last captured.
+ * @buffer: implementation-depending data of this buffer
+ * @buffer_size: size of @buffer
+ */
+struct zfcp_diag_header {
+	spinlock_t	access_lock;
+
+	/* Flags */
+	u64		updating	:1;
+	u64		incomplete	:1;
+
+	unsigned long	timestamp;
+
+	void		*buffer;
+	size_t		buffer_size;
+};
+
+/**
+ * struct zfcp_diag_adapter - central storage for all diagnostics concerning an
+ *			      adapter.
+ * @port_data: data retrieved using exchange port data.
+ * @port_data.header: header with metadata for the cache in @port_data.data.
+ * @port_data.data: cached QTCB Bottom of command exchange port data.
+ */
+struct zfcp_diag_adapter {
+	struct {
+		struct zfcp_diag_header		header;
+		struct fsf_qtcb_bottom_port	data;
+	} port_data;
+};
+
+int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter);
+void zfcp_diag_adapter_free(struct zfcp_adapter *const adapter);
+
+void zfcp_diag_update_xdata(struct zfcp_diag_header *const hdr,
+			    const void *const data, const bool incomplete);
+
+#endif /* ZFCP_DIAG_H */
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index d8f0e446fe13..883bbfd67a62 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -11,6 +11,7 @@
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/blktrace_api.h>
+#include <linux/jiffies.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <scsi/fc/fc_els.h>
@@ -19,6 +20,7 @@
 #include "zfcp_dbf.h"
 #include "zfcp_qdio.h"
 #include "zfcp_reqlist.h"
+#include "zfcp_diag.h"
 
 /* timeout for FSF requests sent during scsi_eh: abort or FCP TMF */
 #define ZFCP_FSF_SCSI_ER_TIMEOUT (10*HZ)
@@ -655,16 +657,26 @@ static void zfcp_fsf_exchange_port_evaluate(struct zfcp_fsf_req *req)
 
 static void zfcp_fsf_exchange_port_data_handler(struct zfcp_fsf_req *req)
 {
+	struct zfcp_diag_header *const diag_hdr =
+		&req->adapter->diagnostics->port_data.header;
 	struct fsf_qtcb *qtcb = req->qtcb;
+	struct fsf_qtcb_bottom_port *bottom = &qtcb->bottom.port;
 
 	if (req->status & ZFCP_STATUS_FSFREQ_ERROR)
 		return;
 
 	switch (qtcb->header.fsf_status) {
 	case FSF_GOOD:
+		/*
+		 * usually we wait with an update till the cache is too old,
+		 * but because we have the data available, update it anyway
+		 */
+		zfcp_diag_update_xdata(diag_hdr, bottom, false);
+
 		zfcp_fsf_exchange_port_evaluate(req);
 		break;
 	case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE:
+		zfcp_diag_update_xdata(diag_hdr, bottom, true);
 		req->status |= ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE;
 
 		zfcp_fsf_exchange_port_evaluate(req);
-- 
2.21.0

[PATCH v2 03/11] zfcp: add diagnostics buffer for exchange config data

[Benjamin Block]

In the same vein as the previous patch, add diagnostic data capture for
the Exchange Config Data command.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_diag.c | 14 ++++++++++++--
 drivers/s390/scsi/zfcp_diag.h |  7 +++++++
 drivers/s390/scsi/zfcp_fsf.c  |  9 +++++++++
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_diag.c b/drivers/s390/scsi/zfcp_diag.c
index fa1b25f3ec3c..d7d2db85b32e 100644
--- a/drivers/s390/scsi/zfcp_diag.c
+++ b/drivers/s390/scsi/zfcp_diag.c
@@ -34,6 +34,9 @@
  */
 int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter)
 {
+	/* set the timestamp so that the first test on age will always fail */
+	const unsigned long initial_timestamp =
+		jiffies - msecs_to_jiffies(ZFCP_DIAG_MAX_AGE);
 	struct zfcp_diag_adapter *diag;
 	struct zfcp_diag_header *hdr;
 
@@ -47,8 +50,15 @@ int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter)
 	spin_lock_init(&hdr->access_lock);
 	hdr->buffer = &diag->port_data.data;
 	hdr->buffer_size = sizeof(diag->port_data.data);
-	/* set the timestamp so that the first test on age will always fail */
-	hdr->timestamp = jiffies - msecs_to_jiffies(ZFCP_DIAG_MAX_AGE);
+	hdr->timestamp = initial_timestamp;
+
+	/* setup header for config_data */
+	hdr = &diag->config_data.header;
+
+	spin_lock_init(&hdr->access_lock);
+	hdr->buffer = &diag->config_data.data;
+	hdr->buffer_size = sizeof(diag->config_data.data);
+	hdr->timestamp = initial_timestamp;
 
 	adapter->diagnostics = diag;
 	return 0;
diff --git a/drivers/s390/scsi/zfcp_diag.h b/drivers/s390/scsi/zfcp_diag.h
index 2a933326b6e4..a3eb21cc201d 100644
--- a/drivers/s390/scsi/zfcp_diag.h
+++ b/drivers/s390/scsi/zfcp_diag.h
@@ -43,12 +43,19 @@ struct zfcp_diag_header {
  * @port_data: data retrieved using exchange port data.
  * @port_data.header: header with metadata for the cache in @port_data.data.
  * @port_data.data: cached QTCB Bottom of command exchange port data.
+ * @config_data: data retrieved using exchange config data.
+ * @config_data.header: header with metadata for the cache in @config_data.data.
+ * @config_data.data: cached QTCB Bottom of command exchange config data.
  */
 struct zfcp_diag_adapter {
 	struct {
 		struct zfcp_diag_header		header;
 		struct fsf_qtcb_bottom_port	data;
 	} port_data;
+	struct {
+		struct zfcp_diag_header		header;
+		struct fsf_qtcb_bottom_config	data;
+	} config_data;
 };
 
 int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter);
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 883bbfd67a62..0fff060de5ac 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -556,6 +556,8 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req)
 static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
 {
 	struct zfcp_adapter *adapter = req->adapter;
+	struct zfcp_diag_header *const diag_hdr =
+		&adapter->diagnostics->config_data.header;
 	struct fsf_qtcb *qtcb = req->qtcb;
 	struct fsf_qtcb_bottom_config *bottom = &qtcb->bottom.config;
 	struct Scsi_Host *shost = adapter->scsi_host;
@@ -572,6 +574,12 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
 
 	switch (qtcb->header.fsf_status) {
 	case FSF_GOOD:
+		/*
+		 * usually we wait with an update till the cache is too old,
+		 * but because we have the data available, update it anyway
+		 */
+		zfcp_diag_update_xdata(diag_hdr, bottom, false);
+
 		if (zfcp_fsf_exchange_config_evaluate(req))
 			return;
 
@@ -587,6 +595,7 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
 				&adapter->status);
 		break;
 	case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE:
+		zfcp_diag_update_xdata(diag_hdr, bottom, true);
 		req->status |= ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE;
 
 		fc_host_node_name(shost) = 0;
-- 
2.21.0

[PATCH v2 04/11] zfcp: support retrieval of SFP Data via Exchange Port Data

[Benjamin Block]

A new FCP channel feature allows us to read the diagnostics from our
local SFP transceivers. To make use of that add a flag
(FSF_FEATURE_REQUEST_SFP_DATA) to the feature-set we request from the
FCP channel. Whether the channel actually implements this can be
determined via an other new flag (FSF_FEATURE_REPORT_SFP_DATA), that is
set in the adapter_features field of the adapter structure after
Exchange Config Data finished.

Also add the corresponding definitions in the QTCB Bottom for Exchange
Port Data. These new definitions are only valid, if
FSF_FEATURE_REPORT_SFP_DATA is set.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_fsf.c |  6 ++++--
 drivers/s390/scsi/zfcp_fsf.h | 21 ++++++++++++++++++++-
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 0fff060de5ac..223a805f0b0b 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -1286,7 +1286,8 @@ int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *erp_action)
 
 	req->qtcb->bottom.config.feature_selection =
 			FSF_FEATURE_NOTIFICATION_LOST |
-			FSF_FEATURE_UPDATE_ALERT;
+			FSF_FEATURE_UPDATE_ALERT |
+			FSF_FEATURE_REQUEST_SFP_DATA;
 	req->erp_action = erp_action;
 	req->handler = zfcp_fsf_exchange_config_data_handler;
 	erp_action->fsf_req_id = req->req_id;
@@ -1339,7 +1340,8 @@ int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *qdio,
 
 	req->qtcb->bottom.config.feature_selection =
 			FSF_FEATURE_NOTIFICATION_LOST |
-			FSF_FEATURE_UPDATE_ALERT;
+			FSF_FEATURE_UPDATE_ALERT |
+			FSF_FEATURE_REQUEST_SFP_DATA;
 
 	if (data)
 		req->data = data;
diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index 2c658b66318c..2b1e4da1944f 100644
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -163,6 +163,8 @@
 #define FSF_FEATURE_ELS_CT_CHAINED_SBALS	0x00000020
 #define FSF_FEATURE_UPDATE_ALERT		0x00000100
 #define FSF_FEATURE_MEASUREMENT_DATA		0x00000200
+#define FSF_FEATURE_REQUEST_SFP_DATA		0x00000200
+#define FSF_FEATURE_REPORT_SFP_DATA		0x00000800
 #define FSF_FEATURE_DIF_PROT_TYPE1		0x00010000
 #define FSF_FEATURE_DIX_PROT_TCPIP		0x00020000
 
@@ -407,7 +409,24 @@ struct fsf_qtcb_bottom_port {
 	u8 cp_util;
 	u8 cb_util;
 	u8 a_util;
-	u8 res2[253];
+	u8 res2;
+	u16 temperature;
+	u16 vcc;
+	u16 tx_bias;
+	u16 tx_power;
+	u16 rx_power;
+	union {
+		u16 raw;
+		struct {
+			u16 fec_active		:1;
+			u16:7;
+			u16 connector_type	:2;
+			u16 sfp_invalid		:1;
+			u16 optical_port	:1;
+			u16 port_tx_type	:4;
+		};
+	} sfp_flags;
+	u8 res3[240];
 } __attribute__ ((packed));
 
 union fsf_qtcb_bottom {
-- 
2.21.0

[PATCH v2 05/11] zfcp: introduce SysFS interface for diagnostics of local SFP transceiver

[Benjamin Block]

This adds an interface to read the diagnostics of the local SFP
transceiver of an FCP-Channel from userspace. This comes in the form of
new SysFS entries that are attached to the CCW device representing the
FCP device. Each type of data gets its own SysFS entry; the whole
collection of entries is pooled into a new child-directory of the CCW
device node: "diagnostics".

Adds SysFS entries for:
 * sfp_invalid:    boolean value evaluating to whether the following 5
                   fields are invalid; {0, 1}; 1 - invalid
 * temperature:    transceiver temp.; unit 1/256°C;
                   range [-128°C, +128°C]
 * vcc:            supply voltage; unit 100μV; range [0, 6.55V]
 * tx_bias:        transmitter laser bias current; unit 2μA;
                   range [0, 131mA]
 * tx_power:       coupled TX output power; unit 0.1μW; range [0, 6.5mW]
 * rx_power:       received optical power; unit 0.1μW; range [0, 6.5mW]

 * optical_port:   boolean value evaluating to whether the FCP-Channel has
                   an optical port; {0, 1}; 1 - optical
 * fec_active:     boolean value evaluating to whether 16G FEC is active;
                   {0, 1}; 1 - active
 * port_tx_type:   nibble describing the port type; {0, 1, 2, 3};
                   0 - unknown,             1 - short wave,
                   2 - long wave LC 1310nm, 3 - long wave LL 1550nm
 * connector_type: two bits describing the connector type; {0, 1};
                   0 - unknown,             1 - SFP+

This is only supported if the FCP-Channel in turn supports reporting the
SFP Diagnostic Data, otherwise read() on these new entries will return
EOPNOTSUPP (this affects only adapters older than FICON Express8S, on
Mainframe generations older than z14). Other possible errors for read()
include ENOLINK, ENODEV and ENOMEM.

With this patch the userspace-interface will only read data stored in
the corresponding "diagnostic buffer" (that was stored during completion
of an previous Exchange Port Data command). Implicit updating will
follow later in this series.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_aux.c   |  4 ++
 drivers/s390/scsi/zfcp_diag.c  | 42 ++++++++++++++++++++
 drivers/s390/scsi/zfcp_diag.h  | 18 +++++++++
 drivers/s390/scsi/zfcp_ext.h   |  1 +
 drivers/s390/scsi/zfcp_sysfs.c | 71 ++++++++++++++++++++++++++++++++++
 5 files changed, 136 insertions(+)

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index a19189d7b3f3..09ec846fe01d 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -407,6 +407,9 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 			       &zfcp_sysfs_adapter_attrs))
 		goto failed;
 
+	if (zfcp_diag_sysfs_setup(adapter))
+		goto failed;
+
 	/* report size limit per scatter-gather segment */
 	adapter->ccw_device->dev.dma_parms = &adapter->dma_parms;
 
@@ -431,6 +434,7 @@ void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
 
 	zfcp_fc_wka_ports_force_offline(adapter->gs);
 	zfcp_scsi_adapter_unregister(adapter);
+	zfcp_diag_sysfs_destroy(adapter);
 	sysfs_remove_group(&cdev->dev.kobj, &zfcp_sysfs_adapter_attrs);
 
 	zfcp_erp_thread_kill(adapter);
diff --git a/drivers/s390/scsi/zfcp_diag.c b/drivers/s390/scsi/zfcp_diag.c
index d7d2db85b32e..8df3ace6135d 100644
--- a/drivers/s390/scsi/zfcp_diag.c
+++ b/drivers/s390/scsi/zfcp_diag.c
@@ -10,6 +10,8 @@
 #include <linux/spinlock.h>
 #include <linux/jiffies.h>
 #include <linux/string.h>
+#include <linux/kernfs.h>
+#include <linux/sysfs.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 
@@ -77,6 +79,46 @@ void zfcp_diag_adapter_free(struct zfcp_adapter *const adapter)
 	adapter->diagnostics = NULL;
 }
 
+/**
+ * zfcp_diag_sysfs_setup() - Setup the sysfs-group for adapter-diagnostics.
+ * @adapter: target adapter to which the group should be added.
+ *
+ * Return: 0 on success; Something else otherwise (see sysfs_create_group()).
+ */
+int zfcp_diag_sysfs_setup(struct zfcp_adapter *const adapter)
+{
+	int rc = sysfs_create_group(&adapter->ccw_device->dev.kobj,
+				    &zfcp_sysfs_diag_attr_group);
+	if (rc == 0)
+		adapter->diagnostics->sysfs_established = 1;
+
+	return rc;
+}
+
+/**
+ * zfcp_diag_sysfs_destroy() - Remove the sysfs-group for adapter-diagnostics.
+ * @adapter: target adapter from which the group should be removed.
+ */
+void zfcp_diag_sysfs_destroy(struct zfcp_adapter *const adapter)
+{
+	if (adapter->diagnostics == NULL ||
+	    !adapter->diagnostics->sysfs_established)
+		return;
+
+	/*
+	 * We need this state-handling so we can prevent warnings being printed
+	 * on the kernel-console in case we have to abort a halfway done
+	 * zfcp_adapter_enqueue(), in which the sysfs-group was not yet
+	 * established. sysfs_remove_group() does this checking as well, but
+	 * still prints a warning in case we try to remove a group that has not
+	 * been established before
+	 */
+	adapter->diagnostics->sysfs_established = 0;
+	sysfs_remove_group(&adapter->ccw_device->dev.kobj,
+			   &zfcp_sysfs_diag_attr_group);
+}
+
+
 /**
  * zfcp_diag_update_xdata() - Update a diagnostics buffer.
  * @hdr: the meta data to update.
diff --git a/drivers/s390/scsi/zfcp_diag.h b/drivers/s390/scsi/zfcp_diag.h
index a3eb21cc201d..2deebccda17d 100644
--- a/drivers/s390/scsi/zfcp_diag.h
+++ b/drivers/s390/scsi/zfcp_diag.h
@@ -40,6 +40,8 @@ struct zfcp_diag_header {
 /**
  * struct zfcp_diag_adapter - central storage for all diagnostics concerning an
  *			      adapter.
+ * @sysfs_established: flag showing that the associated sysfs-group was created
+ *		       during run of zfcp_adapter_enqueue().
  * @port_data: data retrieved using exchange port data.
  * @port_data.header: header with metadata for the cache in @port_data.data.
  * @port_data.data: cached QTCB Bottom of command exchange port data.
@@ -48,6 +50,8 @@ struct zfcp_diag_header {
  * @config_data.data: cached QTCB Bottom of command exchange config data.
  */
 struct zfcp_diag_adapter {
+	u64	sysfs_established	:1;
+
 	struct {
 		struct zfcp_diag_header		header;
 		struct fsf_qtcb_bottom_port	data;
@@ -61,7 +65,21 @@ struct zfcp_diag_adapter {
 int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter);
 void zfcp_diag_adapter_free(struct zfcp_adapter *const adapter);
 
+int zfcp_diag_sysfs_setup(struct zfcp_adapter *const adapter);
+void zfcp_diag_sysfs_destroy(struct zfcp_adapter *const adapter);
+
 void zfcp_diag_update_xdata(struct zfcp_diag_header *const hdr,
 			    const void *const data, const bool incomplete);
 
+/**
+ * zfcp_diag_support_sfp() - Return %true if the @adapter supports reporting
+ *			     SFP Data.
+ * @adapter: adapter to test the availability of SFP Data reporting for.
+ */
+static inline bool
+zfcp_diag_support_sfp(const struct zfcp_adapter *const adapter)
+{
+	return !!(adapter->adapter_features & FSF_FEATURE_REPORT_SFP_DATA);
+}
+
 #endif /* ZFCP_DIAG_H */
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 31e8a7240fd7..c8556787cfdc 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -167,6 +167,7 @@ extern const struct attribute_group *zfcp_port_attr_groups[];
 extern struct mutex zfcp_sysfs_port_units_mutex;
 extern struct device_attribute *zfcp_sysfs_sdev_attrs[];
 extern struct device_attribute *zfcp_sysfs_shost_attrs[];
+extern const struct attribute_group zfcp_sysfs_diag_attr_group;
 bool zfcp_sysfs_port_is_removing(const struct zfcp_port *const port);
 
 /* zfcp_unit.c */
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 90d851d49410..6c0cea71ae5d 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -11,6 +11,7 @@
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/slab.h>
+#include "zfcp_diag.h"
 #include "zfcp_ext.h"
 
 #define ZFCP_DEV_ATTR(_feat, _name, _mode, _show, _store) \
@@ -664,3 +665,73 @@ struct device_attribute *zfcp_sysfs_shost_attrs[] = {
 	&dev_attr_queue_full,
 	NULL
 };
+
+#define ZFCP_DEFINE_DIAG_SFP_ATTR(_name, _qtcb_member, _prtsize, _prtfmt)      \
+	static ssize_t zfcp_sysfs_adapter_diag_sfp_##_name##_show(	       \
+		struct device *dev, struct device_attribute *attr, char *buf)  \
+	{								       \
+		struct zfcp_adapter *const adapter =			       \
+			zfcp_ccw_adapter_by_cdev(to_ccwdev(dev));	       \
+		struct zfcp_diag_header *diag_hdr;			       \
+		ssize_t rc = -ENOLINK;					       \
+		unsigned long flags;					       \
+		unsigned int status;					       \
+									       \
+		if (!adapter)						       \
+			return -ENODEV;					       \
+									       \
+		status = atomic_read(&adapter->status);			       \
+		if (0 == (status & ZFCP_STATUS_COMMON_OPEN) ||		       \
+		    0 == (status & ZFCP_STATUS_COMMON_UNBLOCKED) ||	       \
+		    0 != (status & ZFCP_STATUS_COMMON_ERP_FAILED))	       \
+			goto out;					       \
+									       \
+		if (!zfcp_diag_support_sfp(adapter)) {			       \
+			rc = -EOPNOTSUPP;				       \
+			goto out;					       \
+		}							       \
+									       \
+		diag_hdr = &adapter->diagnostics->port_data.header;	       \
+									       \
+		spin_lock_irqsave(&diag_hdr->access_lock, flags);	       \
+		rc = scnprintf(						       \
+			buf, (_prtsize) + 2, _prtfmt "\n",		       \
+			adapter->diagnostics->port_data.data._qtcb_member);    \
+		spin_unlock_irqrestore(&diag_hdr->access_lock, flags);	       \
+									       \
+	out:								       \
+		zfcp_ccw_adapter_put(adapter);				       \
+		return rc;						       \
+	}								       \
+	static ZFCP_DEV_ATTR(adapter_diag_sfp, _name, 0400,		       \
+			     zfcp_sysfs_adapter_diag_sfp_##_name##_show, NULL)
+
+ZFCP_DEFINE_DIAG_SFP_ATTR(temperature, temperature, 5, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(vcc, vcc, 5, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(tx_bias, tx_bias, 5, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(tx_power, tx_power, 5, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(rx_power, rx_power, 5, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(port_tx_type, sfp_flags.port_tx_type, 2, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(optical_port, sfp_flags.optical_port, 1, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(sfp_invalid, sfp_flags.sfp_invalid, 1, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(connector_type, sfp_flags.connector_type, 1, "%hu");
+ZFCP_DEFINE_DIAG_SFP_ATTR(fec_active, sfp_flags.fec_active, 1, "%hu");
+
+static struct attribute *zfcp_sysfs_diag_attrs[] = {
+	&dev_attr_adapter_diag_sfp_temperature.attr,
+	&dev_attr_adapter_diag_sfp_vcc.attr,
+	&dev_attr_adapter_diag_sfp_tx_bias.attr,
+	&dev_attr_adapter_diag_sfp_tx_power.attr,
+	&dev_attr_adapter_diag_sfp_rx_power.attr,
+	&dev_attr_adapter_diag_sfp_port_tx_type.attr,
+	&dev_attr_adapter_diag_sfp_optical_port.attr,
+	&dev_attr_adapter_diag_sfp_sfp_invalid.attr,
+	&dev_attr_adapter_diag_sfp_connector_type.attr,
+	&dev_attr_adapter_diag_sfp_fec_active.attr,
+	NULL,
+};
+
+const struct attribute_group zfcp_sysfs_diag_attr_group = {
+	.name = "diagnostics",
+	.attrs = zfcp_sysfs_diag_attrs,
+};
-- 
2.21.0

[PATCH v2 06/11] zfcp: implicitly refresh port-data diagnostics when reading SysFS

[Benjamin Block]

This patch adds implicit updates to the SysFS entries that read the
diagnostic data stored in the "caching buffer" for Exchange Port Data.

An update is triggered once the buffer is older than ZFCP_DIAG_MAX_AGE
milliseconds (5s). This entails sending an Exchange Port Data command to
the FCP-Channel, and during its ingress path updating the cached data
and the timestamp. To prevent multiple concurrent userspace-applications
from triggering this update in parallel we synchronize all of them using
a wait-queue (waiting threads are interruptible; the updating thread is
not).

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_diag.c  | 129 +++++++++++++++++++++++++++++++++
 drivers/s390/scsi/zfcp_diag.h  |  11 +++
 drivers/s390/scsi/zfcp_sysfs.c |   5 ++
 3 files changed, 145 insertions(+)

diff --git a/drivers/s390/scsi/zfcp_diag.c b/drivers/s390/scsi/zfcp_diag.c
index 8df3ace6135d..9c5a0f3431ca 100644
--- a/drivers/s390/scsi/zfcp_diag.c
+++ b/drivers/s390/scsi/zfcp_diag.c
@@ -22,6 +22,8 @@
 /* Max age of data in a diagnostics buffer before it needs a refresh (in ms). */
 #define ZFCP_DIAG_MAX_AGE (5 * 1000)
 
+static DECLARE_WAIT_QUEUE_HEAD(__zfcp_diag_publish_wait);
+
 /**
  * zfcp_diag_adapter_setup() - Setup storage for adapter diagnostics.
  * @adapter: the adapter to setup diagnostics for.
@@ -143,3 +145,130 @@ void zfcp_diag_update_xdata(struct zfcp_diag_header *const hdr,
 out:
 	spin_unlock_irqrestore(&hdr->access_lock, flags);
 }
+
+/**
+ * zfcp_diag_update_port_data_buffer() - Implementation of
+ *					 &typedef zfcp_diag_update_buffer_func
+ *					 to collect and update Port Data.
+ * @adapter: Adapter to collect Port Data from.
+ *
+ * This call is SYNCHRONOUS ! It blocks till the respective command has
+ * finished completely, or has failed in some way.
+ *
+ * Return:
+ * * 0		- Successfully retrieved new Diagnostics and Updated the buffer;
+ *		  this also includes cases where data was retrieved, but
+ *		  incomplete; you'll have to check the flag ``incomplete``
+ *		  of &struct zfcp_diag_header.
+ * * see zfcp_fsf_exchange_port_data_sync() for possible error-codes (
+ *   excluding -EAGAIN)
+ */
+int zfcp_diag_update_port_data_buffer(struct zfcp_adapter *const adapter)
+{
+	int rc;
+
+	rc = zfcp_fsf_exchange_port_data_sync(adapter->qdio, NULL);
+	if (rc == -EAGAIN)
+		rc = 0; /* signaling incomplete via struct zfcp_diag_header */
+
+	/* buffer-data was updated in zfcp_fsf_exchange_port_data_handler() */
+
+	return rc;
+}
+
+static int __zfcp_diag_update_buffer(struct zfcp_adapter *const adapter,
+				     struct zfcp_diag_header *const hdr,
+				     zfcp_diag_update_buffer_func buffer_update,
+				     unsigned long *const flags)
+	__must_hold(hdr->access_lock)
+{
+	int rc;
+
+	if (hdr->updating == 1) {
+		rc = wait_event_interruptible_lock_irq(__zfcp_diag_publish_wait,
+						       hdr->updating == 0,
+						       hdr->access_lock);
+		rc = (rc == 0 ? -EAGAIN : -EINTR);
+	} else {
+		hdr->updating = 1;
+		spin_unlock_irqrestore(&hdr->access_lock, *flags);
+
+		/* unlocked, because update function sleeps */
+		rc = buffer_update(adapter);
+
+		spin_lock_irqsave(&hdr->access_lock, *flags);
+		hdr->updating = 0;
+
+		/*
+		 * every thread waiting here went via an interruptible wait,
+		 * so its fine to only wake those
+		 */
+		wake_up_interruptible_all(&__zfcp_diag_publish_wait);
+	}
+
+	return rc;
+}
+
+static bool
+__zfcp_diag_test_buffer_age_isfresh(const struct zfcp_diag_header *const hdr)
+	__must_hold(hdr->access_lock)
+{
+	const unsigned long now = jiffies;
+
+	/*
+	 * Should not happen (data is from the future).. if it does, still
+	 * signal that it needs refresh
+	 */
+	if (!time_after_eq(now, hdr->timestamp))
+		return false;
+
+	if (jiffies_to_msecs(now - hdr->timestamp) >= ZFCP_DIAG_MAX_AGE)
+		return false;
+
+	return true;
+}
+
+/**
+ * zfcp_diag_update_buffer_limited() - Collect diagnostics and update a
+ *				       diagnostics buffer rate limited.
+ * @adapter: Adapter to collect the diagnostics from.
+ * @hdr: buffer-header for which to update with the collected diagnostics.
+ * @buffer_update: Specific implementation for collecting and updating.
+ *
+ * This function will cause an update of the given @hdr by calling the also
+ * given @buffer_update function. If called by multiple sources at the same
+ * time, it will synchornize the update by only allowing one source to call
+ * @buffer_update and the others to wait for that source to complete instead
+ * (the wait is interruptible).
+ *
+ * Additionally this version is rate-limited and will only exit if either the
+ * buffer is fresh enough (within the limit) - it will do nothing if the buffer
+ * is fresh enough to begin with -, or if the source/thread that started this
+ * update is the one that made the update (to prevent endless loops).
+ *
+ * Return:
+ * * 0		- If the update was successfully published and/or the buffer is
+ *		  fresh enough
+ * * -EINTR	- If the thread went into the wait-state and was interrupted
+ * * whatever @buffer_update returns
+ */
+int zfcp_diag_update_buffer_limited(struct zfcp_adapter *const adapter,
+				    struct zfcp_diag_header *const hdr,
+				    zfcp_diag_update_buffer_func buffer_update)
+{
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(&hdr->access_lock, flags);
+
+	for (rc = 0; !__zfcp_diag_test_buffer_age_isfresh(hdr); rc = 0) {
+		rc = __zfcp_diag_update_buffer(adapter, hdr, buffer_update,
+					       &flags);
+		if (rc != -EAGAIN)
+			break;
+	}
+
+	spin_unlock_irqrestore(&hdr->access_lock, flags);
+
+	return rc;
+}
diff --git a/drivers/s390/scsi/zfcp_diag.h b/drivers/s390/scsi/zfcp_diag.h
index 2deebccda17d..7ff8fb0bb735 100644
--- a/drivers/s390/scsi/zfcp_diag.h
+++ b/drivers/s390/scsi/zfcp_diag.h
@@ -71,6 +71,17 @@ void zfcp_diag_sysfs_destroy(struct zfcp_adapter *const adapter);
 void zfcp_diag_update_xdata(struct zfcp_diag_header *const hdr,
 			    const void *const data, const bool incomplete);
 
+/*
+ * Function-Type used in zfcp_diag_update_buffer_limited() for the function
+ * that does the buffer-implementation dependent work.
+ */
+typedef int (*zfcp_diag_update_buffer_func)(struct zfcp_adapter *const adapter);
+
+int zfcp_diag_update_port_data_buffer(struct zfcp_adapter *const adapter);
+int zfcp_diag_update_buffer_limited(struct zfcp_adapter *const adapter,
+				    struct zfcp_diag_header *const hdr,
+				    zfcp_diag_update_buffer_func buffer_update);
+
 /**
  * zfcp_diag_support_sfp() - Return %true if the @adapter supports reporting
  *			     SFP Data.
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 6c0cea71ae5d..a2fa3db5695d 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -693,6 +693,11 @@ struct device_attribute *zfcp_sysfs_shost_attrs[] = {
 									       \
 		diag_hdr = &adapter->diagnostics->port_data.header;	       \
 									       \
+		rc = zfcp_diag_update_buffer_limited(			       \
+			adapter, diag_hdr, zfcp_diag_update_port_data_buffer); \
+		if (rc != 0)						       \
+			goto out;					       \
+									       \
 		spin_lock_irqsave(&diag_hdr->access_lock, flags);	       \
 		rc = scnprintf(						       \
 			buf, (_prtsize) + 2, _prtfmt "\n",		       \
-- 
2.21.0

[PATCH v2 07/11] zfcp: introduce SysFS interface to read the local B2B-Credit

[Benjamin Block]

In addition to the diagnostic data from the local SFP transceiver this
patch adds an interface to read the advertised buffer-to-buffer credit
from the local FC_Port.

With this patch the userspace-interface will only read data stored in
the corresponding "diagnostic buffer" (that was stored during completion
of a previous Exchange Config Data command). Implicit updating will
follow later in this series.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_sysfs.c | 40 ++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index a2fa3db5695d..376d76b9f337 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -666,6 +666,45 @@ struct device_attribute *zfcp_sysfs_shost_attrs[] = {
 	NULL
 };
 
+static ssize_t zfcp_sysfs_adapter_diag_b2b_credit_show(
+	struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(to_ccwdev(dev));
+	struct zfcp_diag_header *diag_hdr;
+	struct fc_els_flogi *nsp;
+	ssize_t rc = -ENOLINK;
+	unsigned long flags;
+	unsigned int status;
+
+	if (!adapter)
+		return -ENODEV;
+
+	status = atomic_read(&adapter->status);
+	if (0 == (status & ZFCP_STATUS_COMMON_OPEN) ||
+	    0 == (status & ZFCP_STATUS_COMMON_UNBLOCKED) ||
+	    0 != (status & ZFCP_STATUS_COMMON_ERP_FAILED))
+		goto out;
+
+	diag_hdr = &adapter->diagnostics->config_data.header;
+
+	spin_lock_irqsave(&diag_hdr->access_lock, flags);
+	/* nport_serv_param doesn't contain the ELS_Command code */
+	nsp = (struct fc_els_flogi *)((unsigned long)
+					      adapter->diagnostics->config_data
+						      .data.nport_serv_param -
+				      sizeof(u32));
+
+	rc = scnprintf(buf, 5 + 2, "%hu\n",
+		       be16_to_cpu(nsp->fl_csp.sp_bb_cred));
+	spin_unlock_irqrestore(&diag_hdr->access_lock, flags);
+
+out:
+	zfcp_ccw_adapter_put(adapter);
+	return rc;
+}
+static ZFCP_DEV_ATTR(adapter_diag, b2b_credit, 0400,
+		     zfcp_sysfs_adapter_diag_b2b_credit_show, NULL);
+
 #define ZFCP_DEFINE_DIAG_SFP_ATTR(_name, _qtcb_member, _prtsize, _prtfmt)      \
 	static ssize_t zfcp_sysfs_adapter_diag_sfp_##_name##_show(	       \
 		struct device *dev, struct device_attribute *attr, char *buf)  \
@@ -733,6 +772,7 @@ static struct attribute *zfcp_sysfs_diag_attrs[] = {
 	&dev_attr_adapter_diag_sfp_sfp_invalid.attr,
 	&dev_attr_adapter_diag_sfp_connector_type.attr,
 	&dev_attr_adapter_diag_sfp_fec_active.attr,
+	&dev_attr_adapter_diag_b2b_credit.attr,
 	NULL,
 };
 
-- 
2.21.0

[PATCH v2 08/11] zfcp: implicitly refresh config-data diagnostics when reading SysFS

[Benjamin Block]

Adds implicit updates of cached diagnostics via Exchange Config Data
when reading SysFS attributes interfacing them. Right now this only
affects the new B2B-Credit diagnostic attribute.

This uses the same mechanism previously also used for cached diagnostics
of Exchange Port Data.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_diag.c  | 30 ++++++++++++++++++++++++++++++
 drivers/s390/scsi/zfcp_diag.h  |  1 +
 drivers/s390/scsi/zfcp_sysfs.c |  5 +++++
 3 files changed, 36 insertions(+)

diff --git a/drivers/s390/scsi/zfcp_diag.c b/drivers/s390/scsi/zfcp_diag.c
index 9c5a0f3431ca..5ef7b3288c6f 100644
--- a/drivers/s390/scsi/zfcp_diag.c
+++ b/drivers/s390/scsi/zfcp_diag.c
@@ -176,6 +176,36 @@ int zfcp_diag_update_port_data_buffer(struct zfcp_adapter *const adapter)
 	return rc;
 }
 
+/**
+ * zfcp_diag_update_config_data_buffer() - Implementation of
+ *					   &typedef zfcp_diag_update_buffer_func
+ *					   to collect and update Config Data.
+ * @adapter: Adapter to collect Config Data from.
+ *
+ * This call is SYNCHRONOUS ! It blocks till the respective command has
+ * finished completely, or has failed in some way.
+ *
+ * Return:
+ * * 0		- Successfully retrieved new Diagnostics and Updated the buffer;
+ *		  this also includes cases where data was retrieved, but
+ *		  incomplete; you'll have to check the flag ``incomplete``
+ *		  of &struct zfcp_diag_header.
+ * * see zfcp_fsf_exchange_config_data_sync() for possible error-codes (
+ *   excluding -EAGAIN)
+ */
+int zfcp_diag_update_config_data_buffer(struct zfcp_adapter *const adapter)
+{
+	int rc;
+
+	rc = zfcp_fsf_exchange_config_data_sync(adapter->qdio, NULL);
+	if (rc == -EAGAIN)
+		rc = 0; /* signaling incomplete via struct zfcp_diag_header */
+
+	/* buffer-data was updated in zfcp_fsf_exchange_config_data_handler() */
+
+	return rc;
+}
+
 static int __zfcp_diag_update_buffer(struct zfcp_adapter *const adapter,
 				     struct zfcp_diag_header *const hdr,
 				     zfcp_diag_update_buffer_func buffer_update,
diff --git a/drivers/s390/scsi/zfcp_diag.h b/drivers/s390/scsi/zfcp_diag.h
index 7ff8fb0bb735..cf2947cd8c8f 100644
--- a/drivers/s390/scsi/zfcp_diag.h
+++ b/drivers/s390/scsi/zfcp_diag.h
@@ -77,6 +77,7 @@ void zfcp_diag_update_xdata(struct zfcp_diag_header *const hdr,
  */
 typedef int (*zfcp_diag_update_buffer_func)(struct zfcp_adapter *const adapter);
 
+int zfcp_diag_update_config_data_buffer(struct zfcp_adapter *const adapter);
 int zfcp_diag_update_port_data_buffer(struct zfcp_adapter *const adapter);
 int zfcp_diag_update_buffer_limited(struct zfcp_adapter *const adapter,
 				    struct zfcp_diag_header *const hdr,
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 376d76b9f337..ae8e9137f448 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -687,6 +687,11 @@ static ssize_t zfcp_sysfs_adapter_diag_b2b_credit_show(
 
 	diag_hdr = &adapter->diagnostics->config_data.header;
 
+	rc = zfcp_diag_update_buffer_limited(
+		adapter, diag_hdr, zfcp_diag_update_config_data_buffer);
+	if (rc != 0)
+		goto out;
+
 	spin_lock_irqsave(&diag_hdr->access_lock, flags);
 	/* nport_serv_param doesn't contain the ELS_Command code */
 	nsp = (struct fc_els_flogi *)((unsigned long)
-- 
2.21.0

[PATCH v2 09/11] zfcp: move maximum age of diagnostic buffers into a per-adapter variable

[Benjamin Block]

Replace the static define (ZFCP_DIAG_MAX_AGE) with a per-adapter
variable (${adapter}->diagnostics->max_age). This new variable is
exported via SysFS, along with other, already existing adapter
variables, and can both be read and written. This way users can choose
how much time should pass between refreshes of diagnostic buffers. The
default value for the age remains to be five seconds.

By setting this new variable to 0, the caching of diagnostic buffers for
userspace accesses can also be completely removed.

All diagnostic buffers of a given adapter are subject to this setting in
the same way.

Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_diag.c  | 23 ++++++++---------
 drivers/s390/scsi/zfcp_diag.h  |  4 +++
 drivers/s390/scsi/zfcp_sysfs.c | 45 ++++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+), 11 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_diag.c b/drivers/s390/scsi/zfcp_diag.c
index 5ef7b3288c6f..67a8f4e57db1 100644
--- a/drivers/s390/scsi/zfcp_diag.c
+++ b/drivers/s390/scsi/zfcp_diag.c
@@ -19,9 +19,6 @@
 #include "zfcp_ext.h"
 #include "zfcp_def.h"
 
-/* Max age of data in a diagnostics buffer before it needs a refresh (in ms). */
-#define ZFCP_DIAG_MAX_AGE (5 * 1000)
-
 static DECLARE_WAIT_QUEUE_HEAD(__zfcp_diag_publish_wait);
 
 /**
@@ -38,9 +35,6 @@ static DECLARE_WAIT_QUEUE_HEAD(__zfcp_diag_publish_wait);
  */
 int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter)
 {
-	/* set the timestamp so that the first test on age will always fail */
-	const unsigned long initial_timestamp =
-		jiffies - msecs_to_jiffies(ZFCP_DIAG_MAX_AGE);
 	struct zfcp_diag_adapter *diag;
 	struct zfcp_diag_header *hdr;
 
@@ -48,13 +42,16 @@ int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter)
 	if (diag == NULL)
 		return -ENOMEM;
 
+	diag->max_age = (5 * 1000); /* default value: 5 s */
+
 	/* setup header for port_data */
 	hdr = &diag->port_data.header;
 
 	spin_lock_init(&hdr->access_lock);
 	hdr->buffer = &diag->port_data.data;
 	hdr->buffer_size = sizeof(diag->port_data.data);
-	hdr->timestamp = initial_timestamp;
+	/* set the timestamp so that the first test on age will always fail */
+	hdr->timestamp = jiffies - msecs_to_jiffies(diag->max_age);
 
 	/* setup header for config_data */
 	hdr = &diag->config_data.header;
@@ -62,7 +59,8 @@ int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter)
 	spin_lock_init(&hdr->access_lock);
 	hdr->buffer = &diag->config_data.data;
 	hdr->buffer_size = sizeof(diag->config_data.data);
-	hdr->timestamp = initial_timestamp;
+	/* set the timestamp so that the first test on age will always fail */
+	hdr->timestamp = jiffies - msecs_to_jiffies(diag->max_age);
 
 	adapter->diagnostics = diag;
 	return 0;
@@ -240,7 +238,8 @@ static int __zfcp_diag_update_buffer(struct zfcp_adapter *const adapter,
 }
 
 static bool
-__zfcp_diag_test_buffer_age_isfresh(const struct zfcp_diag_header *const hdr)
+__zfcp_diag_test_buffer_age_isfresh(const struct zfcp_diag_adapter *const diag,
+				    const struct zfcp_diag_header *const hdr)
 	__must_hold(hdr->access_lock)
 {
 	const unsigned long now = jiffies;
@@ -252,7 +251,7 @@ __zfcp_diag_test_buffer_age_isfresh(const struct zfcp_diag_header *const hdr)
 	if (!time_after_eq(now, hdr->timestamp))
 		return false;
 
-	if (jiffies_to_msecs(now - hdr->timestamp) >= ZFCP_DIAG_MAX_AGE)
+	if (jiffies_to_msecs(now - hdr->timestamp) >= diag->max_age)
 		return false;
 
 	return true;
@@ -291,7 +290,9 @@ int zfcp_diag_update_buffer_limited(struct zfcp_adapter *const adapter,
 
 	spin_lock_irqsave(&hdr->access_lock, flags);
 
-	for (rc = 0; !__zfcp_diag_test_buffer_age_isfresh(hdr); rc = 0) {
+	for (rc = 0;
+	     !__zfcp_diag_test_buffer_age_isfresh(adapter->diagnostics, hdr);
+	     rc = 0) {
 		rc = __zfcp_diag_update_buffer(adapter, hdr, buffer_update,
 					       &flags);
 		if (rc != -EAGAIN)
diff --git a/drivers/s390/scsi/zfcp_diag.h b/drivers/s390/scsi/zfcp_diag.h
index cf2947cd8c8f..b9c93d15f67c 100644
--- a/drivers/s390/scsi/zfcp_diag.h
+++ b/drivers/s390/scsi/zfcp_diag.h
@@ -42,6 +42,8 @@ struct zfcp_diag_header {
  *			      adapter.
  * @sysfs_established: flag showing that the associated sysfs-group was created
  *		       during run of zfcp_adapter_enqueue().
+ * @max_age: maximum age of data in diagnostic buffers before they need to be
+ *	     refreshed (in ms).
  * @port_data: data retrieved using exchange port data.
  * @port_data.header: header with metadata for the cache in @port_data.data.
  * @port_data.data: cached QTCB Bottom of command exchange port data.
@@ -52,6 +54,8 @@ struct zfcp_diag_header {
 struct zfcp_diag_adapter {
 	u64	sysfs_established	:1;
 
+	unsigned long	max_age;
+
 	struct {
 		struct zfcp_diag_header		header;
 		struct fsf_qtcb_bottom_port	data;
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index ae8e9137f448..494b9fe9cc94 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -326,6 +326,50 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
 static ZFCP_DEV_ATTR(adapter, port_remove, S_IWUSR, NULL,
 		     zfcp_sysfs_port_remove_store);
 
+static ssize_t
+zfcp_sysfs_adapter_diag_max_age_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(to_ccwdev(dev));
+	ssize_t rc;
+
+	if (!adapter)
+		return -ENODEV;
+
+	/* ceil(log(2^64 - 1) / log(10)) = 20 */
+	rc = scnprintf(buf, 20 + 2, "%lu\n", adapter->diagnostics->max_age);
+
+	zfcp_ccw_adapter_put(adapter);
+	return rc;
+}
+
+static ssize_t
+zfcp_sysfs_adapter_diag_max_age_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(to_ccwdev(dev));
+	unsigned long max_age;
+	ssize_t rc;
+
+	if (!adapter)
+		return -ENODEV;
+
+	rc = kstrtoul(buf, 10, &max_age);
+	if (rc != 0)
+		goto out;
+
+	adapter->diagnostics->max_age = max_age;
+
+	rc = count;
+out:
+	zfcp_ccw_adapter_put(adapter);
+	return rc;
+}
+static ZFCP_DEV_ATTR(adapter, diag_max_age, 0644,
+		     zfcp_sysfs_adapter_diag_max_age_show,
+		     zfcp_sysfs_adapter_diag_max_age_store);
+
 static struct attribute *zfcp_adapter_attrs[] = {
 	&dev_attr_adapter_failed.attr,
 	&dev_attr_adapter_in_recovery.attr,
@@ -338,6 +382,7 @@ static struct attribute *zfcp_adapter_attrs[] = {
 	&dev_attr_adapter_lic_version.attr,
 	&dev_attr_adapter_status.attr,
 	&dev_attr_adapter_hardware_version.attr,
+	&dev_attr_adapter_diag_max_age.attr,
 	NULL
 };
 
-- 
2.21.0

[PATCH v2 10/11] zfcp: proper indentation to reduce confusion in zfcp_erp_required_act

[Benjamin Block]

From: Steffen Maier <maier@linux.ibm.com>

No functional change.

The unary not operator only applies to the sub expression before
the logical or. So we return early if (not running) or failed.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_erp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index 96f0d34e9459..93655b85b73f 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -174,7 +174,7 @@ static enum zfcp_erp_act_type zfcp_erp_required_act(enum zfcp_erp_act_type want,
 			return 0;
 		p_status = atomic_read(&port->status);
 		if (!(p_status & ZFCP_STATUS_COMMON_RUNNING) ||
-		      p_status & ZFCP_STATUS_COMMON_ERP_FAILED)
+		    p_status & ZFCP_STATUS_COMMON_ERP_FAILED)
 			return 0;
 		if (!(p_status & ZFCP_STATUS_COMMON_UNBLOCKED))
 			need = ZFCP_ERP_ACTION_REOPEN_PORT;
@@ -190,7 +190,7 @@ static enum zfcp_erp_act_type zfcp_erp_required_act(enum zfcp_erp_act_type want,
 			return 0;
 		a_status = atomic_read(&adapter->status);
 		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) ||
-		      a_status & ZFCP_STATUS_COMMON_ERP_FAILED)
+		    a_status & ZFCP_STATUS_COMMON_ERP_FAILED)
 			return 0;
 		if (p_status & ZFCP_STATUS_COMMON_NOESC)
 			return need;
-- 
2.21.0

[PATCH v2 11/11] zfcp: trace channel log even for FCP command responses

[Benjamin Block]

From: Steffen Maier <maier@linux.ibm.com>

While v2.6.26 commit b75db73159cc
("[SCSI] zfcp: Add qtcb dump to hba debug trace")
is right that we don't want to flood the (payload) trace ring buffer,
we don't trace successful FCP command responses by default.
So we can include the channel log for problem determination
with failed responses of any FSF request type.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Fixes: b75db73159cc ("[SCSI] zfcp: Add qtcb dump to hba debug trace")
Fixes: a54ca0f62f95 ("[SCSI] zfcp: Redesign of the debug tracing for HBA records.")
Cc: <stable@vger.kernel.org> #2.6.38+
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
---
 drivers/s390/scsi/zfcp_dbf.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c
index dccdb41bed8c..1234294700c4 100644
--- a/drivers/s390/scsi/zfcp_dbf.c
+++ b/drivers/s390/scsi/zfcp_dbf.c
@@ -95,11 +95,9 @@ void zfcp_dbf_hba_fsf_res(char *tag, int level, struct zfcp_fsf_req *req)
 	memcpy(rec->u.res.fsf_status_qual, &q_head->fsf_status_qual,
 	       FSF_STATUS_QUALIFIER_SIZE);
 
-	if (q_head->fsf_command != FSF_QTCB_FCP_CMND) {
-		rec->pl_len = q_head->log_length;
-		zfcp_dbf_pl_write(dbf, (char *)q_pref + q_head->log_start,
-				  rec->pl_len, "fsf_res", req->req_id);
-	}
+	rec->pl_len = q_head->log_length;
+	zfcp_dbf_pl_write(dbf, (char *)q_pref + q_head->log_start,
+			  rec->pl_len, "fsf_res", req->req_id);
 
 	debug_event(dbf->hba, level, rec, sizeof(*rec));
 	spin_unlock_irqrestore(&dbf->hba_lock, flags);
-- 
2.21.0

Re: [PATCH v2 00/11] zfcp: retrieve local RDP data, fix and cleanup

[Martin K. Petersen]

Benjamin,

> this is the second version of my RDP patchset for zfcp, after I
> noticed a memory-leak in the first version earlier this year. Here is
> the original description, which remains valid:

Applied to 5.5/scsi-queue, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH v2 00/11] zfcp: retrieve local RDP data, fix and cleanup

[Benjamin Block]

On Mon, Oct 28, 2019 at 10:16:44PM -0400, Martin K. Petersen wrote:
> 
> Benjamin,
> 
> > this is the second version of my RDP patchset for zfcp, after I
> > noticed a memory-leak in the first version earlier this year. Here is
> > the original description, which remains valid:
> 
> Applied to 5.5/scsi-queue, thanks!
> 

Thanks, Martin.

-- 
With Best Regards, Benjamin Block      /      Linux on IBM Z Kernel Development
IBM Systems & Technology Group   /  IBM Deutschland Research & Development GmbH
Vorsitz. AufsR.: Matthias Hartmann       /      Geschäftsführung: Dirk Wittkopp
Sitz der Gesellschaft: Böblingen / Registergericht: AmtsG Stuttgart, HRB 243294