The fw_event_work struct is concurrently referenced at shutdown. Add a
refcount to protect it and refactor the code to use it.

Additionally, refactor _scsih_fw_event_cleanup_queue() such that it no
longer iterates over the list without holding the lock since
_firmware_event_work() concurrently deletes items from the list.

This patch is ported from commit 008549f6

 ("mpt2sas: Refcount
fw_events and fix unsafe list usage"). These changes are also required
for mpt3sas.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

sas_device objects can be referenced concurrently throughout the driver.
We need a way to make sure threads can't delete them out from under each
other. This patch adds the refcount and refactors the code to use it.

Additionally, we cannot iterate over the sas_device_list without holding
the lock or we risk corrupting random memory if items are added or
deleted as we iterate. This patch refactors _scsih_probe_sas() to use
the sas_device_list in a safe way.

This patch is ported from the following mpt2sas driver commit
d224fe0d

 ("mpt2sas: Refcount sas_device objects and fix unsafe list
usage").

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

A new sysfs shost attribute called "BMR_status" is implemented to report
Backup Rail Monitor status.

This attribute is located in:

        /sys/class/scsi_host/host#/BMR_status

When reading this adapter attribute, the driver will output the state of
GPIO[24]. It returns "0" if BMR is healthy and "1" for failure.

If it returns an empty string then it means that there was an error
while obtaining the BMR status. Check dmesg for what error has occurred.

This sysfs shost attribute is mainly for WarpDrive controllers.

This commit is a port of 6c265660

 ("mpt2sas: Provide sysfs attribute
to report Backup Rail Monitor Status").

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Ported the following list of WarpDrive-specific patches:

1. commit 0bdccdb0 ("mpt2sas: WarpDrive
   New product SSS6200 support added")

2. commit 82a45258 ("mpt2sas: WarpDrive
   Infinite command retries due to wrong scsi command entry in MPI
   message")

3. commit ba96bd0b ("mpt2sas: Support
   for greater than 2TB capacity WarpDrive")

4. commit 4da7af94 ("mpt2sas: Do not
   retry a timed out direct IO for Warpdrive")

5. commit daeaa9df

 ("mpt2sas: Avoid type
   casting for direct I/O commands").

Also set the mpt2_ioctl_iocinfo adapter_type to:

1. MPT3_IOCTL_INTERFACE_SAS3 for Gen3 HBAs

2. MPT2_IOCTL_INTERFACE_SAS2_SSS6200 for Warp Drive

3. MPT2_IOCTL_INTERFACE_SAS2  for other Gen2 HBAs

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This patch stops the driver to invoke kthread (which remove the dead
ioc) for some time while EEH recovery has started.

This patch is a port of commit b4730fb6

 ("mpt2sas: fix for driver
fails EEH, recovery from injected pci bus error")'.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1. Do not enable MSI-X vectors for SAS2008 B0 controllers

2. Enable a single MSI-X vector for the following controller:

   a. SAS2004
   b. SAS2008
   c. SAS2008_1
   d. SAS2008_2
   e. SAS2008_3
   f. SAS2116_1
   g. SAS2116_2

3. Enable Combined Reply Post Queue Support (i.e. 96 MSI-X vectors)
   for Gen3 Invader/Fury C0 and above revision HBAs

4. Enable Combined Reply Post Queue Support (i.e. 96 MSI-X vectors)
   for all Intruder and Cutlass HBAs

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Avoid sending PHYDISK_HIDDEN RAID action requests to SAS2 controllers
since they don't support it.

Also enable fast_path only for SAS3 HBAs.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Gen2 HBAs use MPI scatter-gather lists whereas Gen3 HBAs use IEEE
scatter-gather lists. Modify the common code part in such a way that it
will build IEEE SGL tables for Gen3 HBAs and MPI SGL tables for Gen2
HBAs.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Currently there is a logging level option provided for each of our
drivers in the kernel configuration utility. Users can enable this
option to get more verbose information. By default it is enabled.

Only when this option is enabled will the functions which display the
required information get compiled in.

As we are merging the both drivers we can no longer provide this
configuration option. Remove the SCSI_MPTXSAS_LOGGING entry from Kconfig
and unconditionally enable logging (by removing the #ifdef
CONFIG_SCSI_MPT3SAS_LOGGING preprocessor check conditions) so that all
functions which are defined to display more verbose information get
compiled in.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1. Use 'hba_mpi_version_belonged' IOC varable to uniquely identify each
individual generation driver functionality at runtime.

2. Declare global variable 'driver_name' and use this variable while
reserving PCI regions and while allocating the IRQs.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Remove .c and .h files which are no longer needed from mpt2sas
driver. We are reusing this code from mpt3sas.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1. Create a mpt2sas_module.c file for mpt2sas where GEN2 HBA devices
register with PCI, SML, IOCTL subsystems.

2. Updated the Makefile to use the object files from mpt3sas folder.

3. Defined a compilation flag SCSI_MPT2SAS which can be used to not
include those sections of code from mpt3sas driver which are not
required for mpt2sas driver.

4. Inherited automatic diag buffer feature from mpt3sas driver.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Created a mpt3sas_module.c file for mpt3sas driver where it can register
SAS3 HBA devices with PCI, SML, IOCTL subsystems. Also removed the
corresponding interfaces from mpt3sas_scsih.c file.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1. Added mpt2sas driver related macros in mpt3sas header files

2. Made scsi host's, raid class', pci's, ioctl's callback functions
global so that both drivers can use them.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Use a single set of the hardware description headers instead of having
them in the source tree twice.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@avagotech.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Previously, when this module was unloaded via 'rmmod' with at least one
drive attached, the SCSI error handler thread would become stuck in an
infinite recovery loop and lockup the system, necessitating a reboot.

Once the SAS layer is detached, the driver will fail any subsequent
commands since the target devices are removed.  However, removing the
SCSI host generates a SYNCHRONIZE CACHE (10) command, which was failed
and left the error handler no method of recovery.

This patch simply removes the SCSI host first so that no more commands
can come down, prior to cleaning up the SAS layer.  Note that the stack
is built up with the SCSI host first, and then the SAS layer.  Perhaps
it should be reversed for symmetry, so that commands cannot be sent to
the pm80xx driver prior to attaching the SAS layer?

What was really strange about this bug was that it was introduced at
commit cff549e4 ("[SCSI]: proper state checking and module refcount
handling in scsi_device_get").  This commit appears to tinker with how
the reference counting is performed for SCSI device objects.  My theory
is that prior to this commit, the refcount for a device object was
blindly incremented at some point during the teardown process which
coincidentially made the device stick around during the procedure, which
also coincidentially made any commands sent to the driver not fail
(since the device was technically still "there").  After this commit was
applied, my theory is the refcount for the device object is not being
incremented at a specific point anymore, which makes the device go away,
and thus made the pm80xx driver fail any subsequent commands.

You may also want to see the following for more details:

[1] http://www.spinics.net/lists/linux-scsi/msg37208.html
[2] http://marc.info/?l=linux-scsi&m=144416476406993&w=2



Signed-off-by: Benjamin Rood <brood@attotech.com>
Acked-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

commit cff549e4 ("scsi: proper state checking and module refcount
handling in scsi_device_get") the reference count of scsi device was
changed, which could lead to when rmmod with at least on drive attached,
SCSI error handle will run into infinite loop, and lockup the system.

Fix it by remove scsi host first, this way scsi core will not send
commands down after detaching SAS transport.

This is a follow up fix for Benjamin's fix for pm80xx.

See also:
http://www.spinics.net/lists/linux-scsi/msg90088.html



Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

commit cff549e4 ("scsi: proper state checking and module refcount
handling in scsi_device_get") the reference count of scsi device was
changed, which could lead to when rmmod with at least on drive attached,
SCSI error handle will run into infinite loop, and lockup the system.

Fix it by remove scsi host first, this way scsi core will not send
commands down after detaching SAS transport.

This is a follow up fix for Benjamin's fix for pm80xx.

See also:
http://www.spinics.net/lists/linux-scsi/msg90088.html



Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

commit cff549e4 ("scsi: proper state checking and module refcount
handling in scsi_device_get") , the reference count of scsi device was
changed, which could lead to when rmmod with at least on drive attached,
SCSI error handle will run into infinite loop, and lockup the system.

Fix it by remove scsi host first, this way scsi core will not send
commands down after detaching SAS transport.

This is a follow up fix for Benjamin's fix for pm80xx.

See also:
http://www.spinics.net/lists/linux-scsi/msg90088.html



Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Some new adapters require a special Configure Cache Parameters command
to enable the adapter write cache, so send this during the adapter
initialization if the adapter requires it.

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add an IOA Inquiry command for Page 0xC4 during IOA initialization to
collect cache capabilities, particularly to check if Sync IOA Write
Cache is supported.

Inquiry will happen right after Cap Inquiry on page 0xD0; and will
execute only if the "Supported Pages" field in Inquiry Page 0x0 shows
support for Page 0xC4.  Otherwise, assume Sync IOA Write Cache is
not supported.

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

According to the IPR specification, Inhibit Underlength Checking bit
must be disabled when issuing commands to vsets.  Enabling it in this
case might cause SCSI commands to fail with an Illegal Request, so make
sure we keep this bit cleared when resource is a vset.

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add a holding pattern prior to collecting dump data, to wait for the IOA
indication that the Mailbox register is stable and won't change without
an explicit reset.  This ensures we'll be collecting meaningful dump
data, even when dumping right after an adapter reset.

In the event of a timeout, we still force the dump, since a partial dump
still might be useful.

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

New revisions of UFS host controller supports the new UniPro
hardware controller (referred as QUniPro). This patch adds
the support to enable this new UniPro controller hardware.

This change also adds power optimization for bus scaling feature,
as well as support for HS-G3 power mode.

Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Adds support for configuring and reading the test bus and debug
registers. This change also adds another vops in order to print the
debug registers.

Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This change turns the UFS variant (SCSI_UFS_QCOM) into a UFS
a platform device.
In order to do so a few additional changes are required:
1. The ufshcd-pltfrm is no longer serves as a platform device.
   Now it only serves as a group of platform APIs such as PM APIs
   (runtime suspend/resume, system suspend/resume etc), parsers of
   clocks, regulators and pm_levels from DT.
2. What used to be the old platform "probe" is now "only"
   a pltfrm_init() routine, that does exactly the same, but only
   being called by the new probe function of the UFS variant.

Reviewed-by: Rob Herring <robherring2@gmail.com>
Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

In order to simplify the code a set of wrapper functions is created
to test and call each of the variant operations.

Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This patch adds ufshcd_get_variant() and ufshcd_set_variant()
routines in order to get/set the variant specific data.

Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This change is required in order to be able to build the component
as a module.

Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This change fixes a compilation warning that happens if SCSI_UFS_QCOM is
compiled as a module.  Also this patch fixes an error happens when
insmod the module: "ufs_qcom: module license 'unspecified' taints
kernel."

Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Export the following functions in order to avoid build errors
when the component PHY_QCOM_UFS is compiled as a module:

ERROR: "ufs_qcom_phy_disable_ref_clk"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_enable_ref_clk"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_is_pcs_ready"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_disable_iface_clk"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_start_serdes"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_calibrate_phy"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_enable_dev_ref_clk"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_set_tx_lane_enable"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_disable_dev_ref_clk"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_save_controller_version"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
ERROR: "ufs_qcom_phy_enable_iface_clk"
	[drivers/scsi/ufs/ufs-qcom.ko] undefined!
make[1]: *** [__modpost] Error 1

Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This patch fixes a 'general protection fault' issue by
moving the attribute to where it was likely meant.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Gerry Morong <gerry.morong.pmcs.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

path_info_show() seems to be broken in multiple ways.

First, there's

  817 return snprintf(buf, output_len+1, "%s%s%s%s%s%s%s%s",
  818       path[0], path[1], path[2], path[3],
  819       path[4], path[5], path[6], path[7]);

so hopefully output_len contains the combined length of the eight
strings. Otherwise, snprintf will stop copying to the output
buffer, but still end up reporting that combined length - which
in turn would result in user-space getting a bunch of useless nul
bytes (thankfully the upper sysfs layer seems to clear the output
buffer before passing it to the various ->show routines). But we have

  767      output_len = snprintf(path[i],
  768                       PATH_STRING_LEN, "[%d:%d:%d:%d] %20.20s ",
  769                       h->scsi_host->host_no,
  770                       hdev->bus, hdev->target, hdev->lun,
  771                       scsi_device_type(hdev->devtype));

so output_len at best contains the length of the last string printed.

Inside the loop, we then otherwise add to output_len. By magic,
we still have PATH_STRING_LEN available every time... This
wouldn't really be a problem if the bean-counting has been done
properly and each line actually does fit in 50 bytes, and maybe
it does, but I don't immediately see why. Suppose we end up
taking this branch:

  802                  output_len += snprintf(path[i] + output_len,
  803                          PATH_STRING_LEN,
  804                          "BOX: %hhu BAY: %hhu %s\n",
  805                          box, bay, active);

An optimistic estimate says this uses strlen("BOX: 1 BAY: 2
Active\n") which is 21. Now add the 20 bytes guaranteed by the
%20.20s and then some for the rest of that format string, and
we're easily over 50 bytes. I don't think we can get over 100
bytes even being pessimistic, so this just means we'll scribble
into the next path[i+1] and maybe get that overwritten later,
leading to some garbled output (in fact, since we'd overwrite the
previous string's 0-terminator, we could end up with one very
long string and then print various suffixes of that, leading to
much more than 400 bytes of output). Except of course when we're
filling path[7], where overrunning it means writing random stuff
to the kernel stack, which is usually a lot of fun.

We can fix all of that and get rid of the 400 byte stack buffer by
simply writing directly to the given output buffer, which the upper
layer guarantees is at least PAGE_SIZE. s[c]nprintf doesn't care where
it is writing to, so this doesn't make the spin lock hold time any
longer. Using scnprintf ensures that output_len always represents the
number of bytes actually written to the buffer, so we'll report the
proper amount to the upper layer.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

When external target arrays are present, disable the firmware's
normal behavior of returning a cached copy of the report lun data,
and force it to collect new data each time we request a report luns.

This is necessary for external arrays, since there may be no
reliable signal from the external array to the smart array when
lun configuration changes, and thus when driver requests
report luns, it may be stale data.

Use diag options to turn off RPL data caching.

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

There are problems with getting configuration change notification
in pass-through RAID environments.  So, activate flag
h->discovery_polling when one of these devices is detected in
update_scsi_devices.

After discovery_polling is set, execute a report luns from
rescan_controller_worker (every 30 seconds).

If the data from report_luns is different than last
time (binary compare), execute a full rescan via update_scsi_devices.

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

We don't need to create fake enclosure devices at Lun0
in external target array configurations anymore.
This was done to support Pre-SCSI rev 5 controllers
that didn't suppoprt report luns commands, so the
SCSI layer had to scan targets. If there was no
LUN at LUN 0, then the target scan would stop, and
move to the next target.  Lun0 enclosure device
was added to prevent sparsely-numbered LUNs from
being missed.

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>