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Author SHA1 Message Date
Bart Van Assche 38c3159923 scsi_dh_alua: Fix a recently introduced deadlock
While retesting the SRP initiator I ran the command "rmmod mlx4_ib"
while I/O was in progress. That command triggers SCSI device removal
indirectly. Avoid that this action triggers the following deadlock:

=================================
[ INFO: inconsistent lock state ]
4.6.0-rc0-dbg+ #2 Tainted: G           O
---------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
multipathd/484 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (&(&pg->lock)->rlock){+.?...}, at: [<ffffffffa04f50a2>] alua_bus_detach+0x52/0xa0 [scsi_dh_alua]
{IN-SOFTIRQ-W} state was registered at:
  [<ffffffff810a64a9>] __lock_acquire+0x7e9/0x1ad0
  [<ffffffff810a7fd0>] lock_acquire+0x60/0x80
  [<ffffffff8159910e>] _raw_spin_lock_irqsave+0x3e/0x60
  [<ffffffffa04f5131>] alua_rtpg_queue+0x41/0x1d0 [scsi_dh_alua]
  [<ffffffffa04f5531>] alua_check+0xe1/0x220 [scsi_dh_alua]
  [<ffffffffa04f5709>] alua_check_sense+0x99/0xb0 [scsi_dh_alua]
  [<ffffffff813f0d01>] scsi_check_sense+0x71/0x3f0
  [<ffffffff813f2f8b>] scsi_decide_disposition+0x18b/0x1d0
  [<ffffffff813f6e52>] scsi_softirq_done+0x52/0x140
  [<ffffffff812a26f2>] blk_done_softirq+0x52/0x90
  [<ffffffff8105bc1f>] __do_softirq+0x10f/0x230
  [<ffffffff8105bec8>] irq_exit+0xa8/0xb0
  [<ffffffff8101a675>] do_IRQ+0x65/0x110
  [<ffffffff8159a2c9>] ret_from_intr+0x0/0x19
  [<ffffffff811732f1>] kmem_cache_alloc+0x151/0x190
  [<ffffffff8118e534>] create_object+0x34/0x2d0
  [<ffffffff8158eaa6>] kmemleak_alloc_percpu+0x56/0xd0
  [<ffffffff8113ab0d>] pcpu_alloc+0x38d/0x660
  [<ffffffff8113aded>] __alloc_percpu_gfp+0xd/0x10
  [<ffffffff812e56a5>] __percpu_counter_init+0x55/0xb0
  [<ffffffff812b4989>] blkg_alloc+0x79/0x230
  [<ffffffff812b6756>] blkcg_init_queue+0x26/0x1d0
  [<ffffffff81297eed>] blk_alloc_queue_node+0x27d/0x2e0
  [<ffffffffa017766c>] dm_create+0x20c/0x570 [dm_mod]
  [<ffffffffa017e356>] dev_create+0x56/0x2c0 [dm_mod]
  [<ffffffffa017dcae>] ctl_ioctl+0x26e/0x520 [dm_mod]
  [<ffffffffa017df6e>] dm_ctl_ioctl+0xe/0x20 [dm_mod]
  [<ffffffff811aa8ee>] do_vfs_ioctl+0x8e/0x660
  [<ffffffff811aaefc>] SyS_ioctl+0x3c/0x70
  [<ffffffff81599929>] entry_SYSCALL_64_fastpath+0x1c/0xac
irq event stamp: 4290931
hardirqs last  enabled at (4290931): [ 1662.892772]
[<ffffffff81599341>] _raw_spin_unlock_irqrestore+0x31/0x50
hardirqs last disabled at (4290930): [<ffffffff815990e7>] _raw_spin_lock_irqsave+0x17/0x60
softirqs last  enabled at (4290774): [<ffffffff8105bcdb>] __do_softirq+0x1cb/0x230
softirqs last disabled at (4289831): [<ffffffff8105bec8>] irq_exit+0xa8/0xb0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&pg->lock)->rlock);
  <Interrupt>
    lock(&(&pg->lock)->rlock);

 *** DEADLOCK ***

2 locks held by multipathd/484:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff811d1cc3>] __blkdev_put+0x33/0x360
 #1:  (sd_ref_mutex){+.+...}, at: [<ffffffff81400afc>] scsi_disk_put+0x1c/0x40

stack backtrace:
CPU: 6 PID: 484 Comm: multipathd Tainted: G           O    4.6.0-rc0-dbg+ #2
Call Trace:
 [<ffffffff812bd115>] dump_stack+0x67/0x92
 [<ffffffff810a5175>] print_usage_bug+0x215/0x240
 [<ffffffff810a56ea>] mark_lock+0x54a/0x610
 [<ffffffff810a6505>] __lock_acquire+0x845/0x1ad0
 [<ffffffff810a7fd0>] lock_acquire+0x60/0x80
 [<ffffffff81598f23>] _raw_spin_lock+0x33/0x50
 [<ffffffffa04f50a2>] alua_bus_detach+0x52/0xa0 [scsi_dh_alua]
 [<ffffffff813ff6f7>] scsi_dh_release_device+0x17/0x50
 [<ffffffff813fb8da>] scsi_device_dev_release_usercontext+0x2a/0x120
 [<ffffffff810701f0>] execute_in_process_context+0x80/0x90
 [<ffffffff813fb8a7>] scsi_device_dev_release+0x17/0x20
 [<ffffffff813c8cfd>] device_release+0x2d/0x90
 [<ffffffff812bfa8a>] kobject_release+0x7a/0x190
 [<ffffffff812bf946>] kobject_put+0x26/0x50
 [<ffffffff813c8ee2>] put_device+0x12/0x20
 [<ffffffff813edc86>] scsi_device_put+0x26/0x30
 [<ffffffff81400b0d>] scsi_disk_put+0x2d/0x40
 [<ffffffff81400b68>] sd_release+0x48/0xb0
 [<ffffffff811d1f2e>] __blkdev_put+0x29e/0x360
 [<ffffffff811d24b9>] blkdev_put+0x49/0x170
 [<ffffffff811d2600>] blkdev_close+0x20/0x30
 [<ffffffff81198f48>] __fput+0xe8/0x1f0
 [<ffffffff81199089>] ____fput+0x9/0x10
 [<ffffffff81075d9e>] task_work_run+0x6e/0xa0
 [<ffffffff81001119>] exit_to_usermode_loop+0xa9/0xb0
 [<ffffffff81001590>] syscall_return_slowpath+0xb0/0xc0
 [<ffffffff815999b7>] entry_SYSCALL_64_fastpath+0xaa/0xac

Fixes: cb0a168cb6 (scsi_dh_alua: update 'access_state' field)
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-29 20:32:02 -04:00
Bart Van Assche d78540dae7 scsi: Declare local symbols static
Avoid that building with W=1 causes gcc to report warnings about symbols
that have not been declared.

Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-29 20:29:55 -04:00
Manoj N. Kumar ea76543127 cxlflash: Move to exponential back-off when cmd_room is not available
While profiling the cxlflash_queuecommand() path under a heavy load it
was found that number of retries to find cmd_room was fairly high.

There are two problems with the current back-off:
a) It starts with a udelay of 0
b) It backs-off linearly

Tried several approaches (a higher multiple 10*n, 100*n, as well as n^2,
2^n) and found that the exponential back-off(2^n) approach had the least
overall cost. Cost as being defined as overall time spent waiting.

The fix is to change the linear back-off to an exponential back-off.
This solution also takes care of the problem with the initial
delay (starts with 1 usec).

Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-28 20:43:34 -04:00
Manoj N. Kumar 9526f36026 cxlflash: Fix regression issue with re-ordering patch
While running 'sg_reset -H' back to back the following exception was seen:

[  735.115695] Faulting instruction address: 0xd0000000098c0864
cpu 0x0: Vector: 300 (Data Access) at [c000000ffffafa80]
    pc: d0000000098c0864: cxlflash_async_err_irq+0x84/0x5c0 [cxlflash]
    lr: c00000000013aed0: handle_irq_event_percpu+0xa0/0x310
    sp: c000000ffffafd00
   msr: 9000000000009033
   dar: 2010000
 dsisr: 40000000
  current = 0xc000000001510880
  paca    = 0xc00000000fb80000   softe: 0        irq_happened: 0x01
    pid   = 0, comm = swapper/0

Linux version 4.5.0-491-26f710d+

enter ? for help
[c000000ffffafe10] c00000000013aed0 handle_irq_event_percpu+0xa0/0x310
[c000000ffffafed0] c00000000013b1a8 handle_irq_event+0x68/0xc0
[c000000ffffaff00] c0000000001404ec handle_fasteoi_irq+0xec/0x2a0
[c000000ffffaff30] c00000000013a084 generic_handle_irq+0x54/0x80
[c000000ffffaff60] c000000000011130 __do_irq+0x80/0x1d0
[c000000ffffaff90] c000000000024d40 call_do_irq+0x14/0x24
[c000000001573a20] c000000000011318 do_IRQ+0x98/0x140
[c000000001573a70] c000000000002594 hardware_interrupt_common+0x114/0x180

This exception is being hit because the async_err interrupt path performs
an MMIO to read the interrupt status register. The MMIO region in this
case is not available.

Commit 6ded8b3cbd ("cxlflash: Unmap problem state area before detaching
master context") re-ordered the sequence in which term_mc() and stop_afu()
are called. This introduces a window for interrupts to come in with the
problem space area unmapped, that did not exist previously.

The fix is to separate the disabling of all AFU interrupts to a distinct
function, term_intr() so that it is the first thing that is done in the
tear down process.

To keep the initialization process symmetric, separate the AFU interrupt
setup also to a distinct function: init_intr().

Fixes: 6ded8b3cbd ("cxlflash: Unmap problem state area before detaching master context")
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-28 20:43:17 -04:00
Calvin Owens 5ec8a1753b mpt3sas: Don't overreach ioc->reply_post[] during initialization
In _base_make_ioc_operational(), we walk ioc->reply_queue_list and pull
a pointer out of successive elements of ioc->reply_post[] for each entry
in that list if RDPQ is enabled.

Since the code pulls the pointer for the next iteration at the bottom of
the loop, it triggers the a KASAN dump on the final iteration:

    BUG: KASAN: slab-out-of-bounds in _base_make_ioc_operational+0x47b7/0x47e0 [mpt3sas] at addr ffff880754816ab0
    Read of size 8 by task modprobe/305
    <snip>
    Call Trace:
     [<ffffffff81dfc591>] dump_stack+0x4d/0x6c
     [<ffffffff814c9689>] print_trailer+0xf9/0x150
     [<ffffffff814ceda4>] object_err+0x34/0x40
     [<ffffffff814d1231>] kasan_report_error+0x221/0x530
     [<ffffffff814d1673>] __asan_report_load8_noabort+0x43/0x50
     [<ffffffffa0043637>] _base_make_ioc_operational+0x47b7/0x47e0 [mpt3sas]
     [<ffffffffa0049a51>] mpt3sas_base_attach+0x1991/0x2120 [mpt3sas]
     [<ffffffffa0053c93>] _scsih_probe+0xeb3/0x16b0 [mpt3sas]
     [<ffffffff81ebd047>] local_pci_probe+0xc7/0x170
     [<ffffffff81ebf2cf>] pci_device_probe+0x20f/0x290
     [<ffffffff820d50cd>] really_probe+0x17d/0x600
     [<ffffffff820d56a3>] __driver_attach+0x153/0x190
     [<ffffffff820cffac>] bus_for_each_dev+0x11c/0x1a0
     [<ffffffff820d421d>] driver_attach+0x3d/0x50
     [<ffffffff820d378a>] bus_add_driver+0x44a/0x5f0
     [<ffffffff820d666c>] driver_register+0x18c/0x3b0
     [<ffffffff81ebcb76>] __pci_register_driver+0x156/0x200
     [<ffffffffa00c8135>] _mpt3sas_init+0x135/0x1000 [mpt3sas]
     [<ffffffff81000423>] do_one_initcall+0x113/0x2b0
     [<ffffffff813caa5a>] do_init_module+0x1d0/0x4d8
     [<ffffffff81273909>] load_module+0x6729/0x8dc0
     [<ffffffff81276123>] SYSC_init_module+0x183/0x1a0
     [<ffffffff8127625e>] SyS_init_module+0xe/0x10
     [<ffffffff828fe7d7>] entry_SYSCALL_64_fastpath+0x12/0x6a

Fix this by pulling the value at the beginning of the loop.

Signed-off-by: Calvin Owens <calvinowens@fb.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Jens Axboe <axboe@fb.com>
Acked-by: Chaitra Basappa <chaitra.basappa@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-23 16:33:09 -04:00
Arnd Bergmann 548f0e65a3 aacraid: add missing curly braces
gcc-6 warns about obviously wrong indentation for newly added code in
aac_slave_configure():

drivers/scsi/aacraid/linit.c: In function 'aac_slave_configure':
drivers/scsi/aacraid/linit.c:458:3: warning: statement is indented as if it were guarded by... [-Wmisleading-indentation]
   sdev->tagged_supported = 1;
   ^~~~
drivers/scsi/aacraid/linit.c:455:4: note: ...this 'else' clause, but it is not

gcc is correct, and evidently this was meant to be within the curly
braces that should have been there to start with. This patch adds them,
which avoids the warning and makes it clear what was intended here.

Nothing changes in behavior because in the 'if' block, the
sdev->tagged_supported flag is known to be set already.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 6bf3b630d0 ("aacraid: SCSI blk tag support")
Reviewed-by: Raghava Aditya Renukunta <raghavaaditya.renukunta@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-21 20:25:31 -04:00
Hannes Reinecke ba08311647 scsi_common: do not clobber fixed sense information
For fixed sense the information field is 32 bits, to we need to truncate
the information field to avoid clobbering the sense code.

Fixes: a1524f226a ("libata-eh: Set 'information' field for autosense")
Cc: <stable@vger.kernel.org> #v4.1+
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-18 15:49:44 -04:00
Arnd Bergmann c80fa12e6d scsi: ufs: select CONFIG_NLS
A recent change to ufshcd introduced a call to utf16s_to_utf8s, a
function that is provided by the NLS module, so we get a link error when
that is not present:

drivers/scsi/built-in.o: In function `ufshcd_read_string_desc':
:(.text+0x124d0): undefined reference to `utf16s_to_utf8s'

This adds a Kconfig 'select' statement to avoid the build error.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b573d484e4 ("scsi: ufs: add support to read device and string descriptors")
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-18 15:35:23 -04:00
Arnd Bergmann ef3fb2422f scsi: fc: use get/put_unaligned64 for wwn access
A bug in the gcc-6.0 prerelease version caused at least one
driver (lpfc) to have excessive stack usage when dealing with
wwn data, on the ARM architecture.

lpfc_scsi.c: In function 'lpfc_find_next_oas_lun':
lpfc_scsi.c:117:1: warning: the frame size of 1152 bytes is larger than 1024 bytes [-Wframe-larger-than=]

I have reported this as a gcc regression in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70232

However, using a better implementation of wwn_to_u64() not only
helps with the particular gcc problem but also leads to better
object code for any version or architecture.

The kernel already provides get_unaligned_be64() and
put_unaligned_be64() helper functions that provide an
optimized implementation with the desired semantics.

The lpfc_find_next_oas_lun() function in the example that
grew from 1146 bytes to 5144 bytes when moving from gcc-5.3
to gcc-6.0 is now 804 bytes, as the optimized
get_unaligned_be64() load can be done in three instructions.
The stack usage is now down to 28 bytes from 128 bytes with
gcc-5.3 before.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-18 15:29:58 -04:00
Maurizio Lombardi 14cee5b4de fnic: move printk()s outside of the critical code section.
This patch moves a printk() outside of the code section where interrupt
are disabled. In some cases a flood of error messages may cause a kernel
panic.  It also removes one of the printk()s because the same error
message was printed twice.

[709686.317197] Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 12
[709686.317200] CPU: 12 PID: 1963 Comm: systemd-journal Tainted: GF          O--------------   3.10.0-229.el7.x86_64 #1
[709686.317201] Hardware name: Cisco Systems Inc UCSB-B200-M3/UCSB-B200-M3, BIOS B200M3.2.2.3.6.030620151309 03/06/2015
[709686.317206]  ffffffff8182b2e8 00000000392722ba ffff88046fcc5c48 ffffffff81603f36
[709686.317209]  ffff88046fcc5cc8 ffffffff815fd7da 0000000000000010 ffff88046fcc5cd8
[709686.317211]  ffff88046fcc5c78 00000000392722ba ffff88046fcc5c88 000000000000000c
[709686.317212] Call Trace:
[709686.317221]  <NMI>  [<ffffffff81603f36>] dump_stack+0x19/0x1b
[709686.317223]  [<ffffffff815fd7da>] panic+0xd8/0x1e7
[709686.317227]  [<ffffffff8110a760>] ? watchdog_enable_all_cpus.part.2+0x40/0x40
[709686.317229]  [<ffffffff8110a822>] watchdog_overflow_callback+0xc2/0xd0
[709686.317233]  [<ffffffff8114c901>] __perf_event_overflow+0xa1/0x250
[709686.317235]  [<ffffffff8114d404>] perf_event_overflow+0x14/0x20
[709686.317239]  [<ffffffff810301fd>] intel_pmu_handle_irq+0x1fd/0x410
[709686.317242]  [<ffffffff811908d1>] ? unmap_kernel_range_noflush+0x11/0x20
[709686.317246]  [<ffffffff81373574>] ? ghes_copy_tofrom_phys+0x124/0x210
[709686.317249]  [<ffffffff8160cfcb>] perf_event_nmi_handler+0x2b/0x50
[709686.317251]  [<ffffffff8160c719>] nmi_handle.isra.0+0x69/0xb0
[709686.317252]  [<ffffffff8160c830>] do_nmi+0xd0/0x340
[709686.317256]  [<ffffffff8160bb71>] end_repeat_nmi+0x1e/0x2e
[709686.317260]  [<ffffffff812e24fd>] ? memcpy+0xd/0x110
[709686.317263]  [<ffffffff812e24fd>] ? memcpy+0xd/0x110
[709686.317265]  [<ffffffff812e24fd>] ? memcpy+0xd/0x110
[709686.317269]  <<EOE>>  [<ffffffff8132c297>] ? vgacon_scroll+0x2d7/0x330
[709686.317273]  [<ffffffff813a086c>] scrup+0xfc/0x110
[709686.317275]  [<ffffffff813a0920>] lf+0xa0/0xb0
[709686.317278]  [<ffffffff813a1b32>] vt_console_print+0x2d2/0x420
[709686.317283]  [<ffffffff8106f4a1>] call_console_drivers.constprop.15+0x91/0xf0
[709686.317287]  [<ffffffff8107069f>] console_unlock+0x3bf/0x400
[709686.317291]  [<ffffffff81070996>] vprintk_emit+0x2b6/0x530
[709686.317294]  [<ffffffff815fd961>] printk_emit+0x44/0x5b
[709686.317297]  [<ffffffff81070d98>] devkmsg_writev+0x158/0x1d0
[709686.317303]  [<ffffffff811c5ef9>] do_sync_readv_writev+0x79/0xd0
[709686.317307]  [<ffffffff811c73ee>] do_readv_writev+0xce/0x260
[709686.317310]  [<ffffffff811c8d18>] ? __sb_start_write+0x58/0x110
[709686.317314]  [<ffffffff811c7615>] vfs_writev+0x35/0x60
[709686.317318]  [<ffffffff811c776c>] SyS_writev+0x5c/0xd0
[709686.317322]  [<ffffffff81613da9>] system_call_fastpath+0x16/0x1b

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-18 15:28:17 -04:00
Arnd Bergmann bc7095a926 qla2xxx: avoid maybe_uninitialized warning
The qlt_check_reserve_free_req() function produces an incorrect warning
when CONFIG_PROFILE_ANNOTATED_BRANCHES is set:

drivers/scsi/qla2xxx/qla_target.c: In function 'qlt_check_reserve_free_req':
drivers/scsi/qla2xxx/qla_target.c:1887:3: error: 'cnt_in' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   ql_dbg(ql_dbg_io, vha, 0x305a,
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       "qla_target(%d): There is no room in the request ring: vha->req->ring_index=%d, vha->req->cnt=%d, req_cnt=%d Req-out=%d Req-in=%d Req-Length=%d\n",
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       vha->vp_idx, vha->req->ring_index,
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       vha->req->cnt, req_cnt, cnt, cnt_in, vha->req->length);
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/qla2xxx/qla_target.c:1887:3: error: 'cnt' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The problem is that gcc fails to track the state of the condition across
an annotated branch.

This slightly rearranges the code to move the second if() block
into the first one, to avoid the warning while retaining the
behavior of the code.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-By: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-18 15:25:07 -04:00
Arnd Bergmann 3deb9438d3 megaraid_sas: add missing curly braces in ioctl handler
gcc-6 found a dubious indentation in the megasas_mgmt_fw_ioctl
function:

drivers/scsi/megaraid/megaraid_sas_base.c: In function 'megasas_mgmt_fw_ioctl':
drivers/scsi/megaraid/megaraid_sas_base.c:6658:4: warning: statement is indented as if it were guarded by... [-Wmisleading-indentation]
    kbuff_arr[i] = NULL;
    ^~~~~~~~~
drivers/scsi/megaraid/megaraid_sas_base.c:6653:3: note: ...this 'if' clause, but it is not
   if (kbuff_arr[i])
   ^~

The code is actually correct, as there is no downside in clearing a NULL
pointer again.

This clarifies the code and avoids the warning by adding extra curly
braces.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 90dc9d98f0 ("megaraid_sas : MFI MPT linked list corruption fix")
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-18 15:22:55 -04:00
Arnd Bergmann aeb6641f8e lpfc: fix misleading indentation
gcc-6 complains about the indentation of the lpfc_destroy_vport_work_array()
call in lpfc_online(), which clearly doesn't look right:

drivers/scsi/lpfc/lpfc_init.c: In function 'lpfc_online':
drivers/scsi/lpfc/lpfc_init.c:2880:3: warning: statement is indented as if it were guarded by... [-Wmisleading-indentation]
   lpfc_destroy_vport_work_array(phba, vports);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/lpfc/lpfc_init.c:2863:2: note: ...this 'if' clause, but it is not
  if (vports != NULL)
  ^~

Looking at the patch that introduced this code, it's clear that the
behavior is correct and the indentation is wrong.

This fixes the indentation and adds curly braces around the previous
if() block for clarity, as that is most likely what caused the code
to be misindented in the first place.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 549e55cd2a ("[SCSI] lpfc 8.2.2 : Fix locking around HBA's port_list")
Reviewed-by: Sebastian Herbszt <herbszt@gmx.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-18 15:21:23 -04:00
Hannes Reinecke cdc43ae34c scsi_transport_sas: add 'scsi_target_id' sysfs attribute
There is no way to detect the scsi_target_id for any given SAS remote
port, so add a new sysfs attribute 'scsi_target_id'.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:05:04 -04:00
Dan Carpenter 100bcb851b scsi_dh_alua: uninitialized variable in alua_check_vpd()
The pg_updated variable is support to be set to false at the start but
it is uninitialized.

Fixes: cb0a168cb6 ('scsi_dh_alua: update 'access_state' field')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:59 -04:00
Yaniv Gardi eba5ed3539 scsi: ufs-qcom: add printouts of testbus debug registers
This change adds printouts of testbus and debug registers.

Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi f37aabcf58 scsi: ufs-qcom: enable/disable the device ref clock
This change enables the device ref clock before changing to HS mode
and disables it if entered to PWM mode.

Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi 4b9ad0b88c scsi: ufs-qcom: set PA_Local_TX_LCC_Enable before link startup
Some UFS devices (and may be host) have issues if LCC is
enabled. So we are setting PA_Local_TX_LCC_Enable to 0
before link startup which will make sure that both host
and device TX LCC are disabled once link startup is
completed.

Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi b799fdf754 scsi: ufs: add device quirk delay before putting UFS rails in LPM
We put the UFS device in sleep state & UFS link in hibern8 state during
runtime suspend. After this we put all the UFS rails in low power
modes immediately but it seems some devices may still draw more than
sleep current from UFS rails (especially from VCCQ rail) at-least for
500us.
To avoid this situation, this change adds 2ms delay before putting
these UFS rails in LPM mode.

Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi f3099fbd9b scsi: ufs: fix leakage during link off state
Currently when we try to put the link in off/disabled state during
suspend, it seems link is not being kept in low power mode.
This patch fixes the issue by putting the link in hibern8 first
(so device also puts the link in low power mode) and then stop the
host controller.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi 371131065d scsi: ufs: tune UniPro parameters to optimize hibern8 exit time
Optimal values of local UniPro parameters like PA_Hibern8Time &
PA_TActivate can help reduce the hibern8 exit latency. If both host and
device supports UniPro ver1.6 or later, these parameters will be
automatically tuned during link startup itself. But if either host or
device doesn't support UniPro ver 1.6 or later, we have to manually
tune them. But to keep manual tuning logic simple, we will only do
manual tuning if local unipro version doesn't support ver1.6 or later.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi afdfff59a0 scsi: ufs: handle non spec compliant bkops behaviour by device
We are seeing that some devices are raising the urgent bkops exception
events even when BKOPS status doesn't indicate performace impacted or
critical. Handle these device by determining their urgent bkops status
at runtime.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi a70e91b8bb scsi: ufs: add retry for query descriptors
Query commands have 100ms timeout and it may timeout if they are
issued in parallel to ongoing read/write SCSI commands, this change
adds the retry (max: 10) in case command timeouts.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi 583fa62d08 scsi: ufs: add error recovery after DL NAC error
Some vendor's UFS device sends back to back NACs for the DL data frames
causing the host controller to raise the DFES error status. Sometimes
such UFS devices send back to back NAC without waiting for new
retransmitted DL frame from the host and in such cases it might be
possible the Host UniPro goes into bad state without raising the DFES
error interrupt. If this happens then all the pending commands would
timeout only after respective SW command (which is generally too
large).

This change workarounds such device behaviour like this:
- As soon as SW sees the DL NAC error, it would schedule the error
  handler
- Error handler would sleep for 50ms to see if there any fatal errors
  raised by UFS controller.
   - If there are fatal errors then SW does normal error recovery.
   - If there are no fatal errors then SW sends the NOP command to
     device to check if link is alive.
       - If NOP command times out, SW does normal error recovery
       - If NOP command succeed, skip the error handling.

If DL NAC error is seen multiple times with some vendor's UFS devices
then enable this quirk to initiate quick error recovery and also
silence related error logs to reduce spamming of kernel logs.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi 9a47ec7c39 scsi: ufs: make error handling bit faster
UFS driver's error handler forcefully tries to clear all the pending
requests. For each pending request in the queue, it waits 1 sec for it
to get cleared. If we have multiple requests in the queue then it's
possible that we might end up waiting for those many seconds before
resetting the host. But note that resetting host would any way clear
all the pending requests from the hardware. Hence this change skips
the forceful clear of the pending requests if we are anyway going to
reset the host (for fatal errors).

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi 60f0187031 scsi: ufs: disable vccq if it's not needed by UFS device
Some UFS devices don't require VCCQ rail for device operations hence
this change adds support to recognize such devices and remove vote for
the unused VCCQ rail.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi c58ab7aab7 scsi: ufs: separate device and host quirks
Currently we use the host quirks mechanism in order to
handle both device and host controller quirks.
In order to support various of UFS devices we should separate
handling the device quirks from the host controller's.

Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi b573d484e4 scsi: ufs: add support to read device and string descriptors
This change adds support to read device descriptor and string descriptor
from a UFS device

Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi 596585a285 scsi: ufs: verify hba controller hce reg value
Sometimes due to hw issues it takes some time to the
host controller register to update. In order to verify the register
has updated, a polling is done until its value is set.

In addition the functions ufshcd_hba_stop() and
ufshcd_wait_for_register() was updated with an additional input
parameter, indicating the timeout between reads will
be done by sleeping or spinning the cpu.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi f550c65b54 scsi: ufs: implement scsi host timeout handler
A race condition exists between request requeueing and scsi layer
error handling:
When UFS driver queuecommand returns a busy status for a request,
it will be requeued and its tag will be freed and set to -1.
At the same time it is possible that the request will timeout and
scsi layer will start error handling for it. The scsi layer reuses
the request and its tag to send error related commands to the device,
however its tag is no longer valid.
As this request was never really sent to the device, there is no
point to start error handling with the device.
Implement the scsi error handling timeout callback and bypass SCSI
error handling for request that were not actually sent to the device.
For such requests simply reset the block layer timer. Otherwise, let
SCSI layer perform the usual error handling.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi 199ef13cac scsi: ufs: avoid spurious UFS host controller interrupts
When control reaches to Linux UFS driver during UFS boot mode, UFS host
controller interrupt status/enable registers may have left over
settings.
In order to avoid any spurious interrupts due to these left overs,
it's important to clear these interrupt status/enable registers before
enabling UFS interrupt handling.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Yaniv Gardi 54b879b76e scsi: ufs-qcom: add number of lanes per direction
Different platform may have different number of lanes
for the UFS link.
Add parameter to device tree specifying how many lanes
should be configured for the UFS link.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 21:04:45 -04:00
Douglas Gilbert f6a695cf7a sg: fix dxferp in from_to case
One of the strange things that the original sg driver did was let the
user provide both a data-out buffer (it followed the sg_header+cdb)
_and_ specify a reply length greater than zero. What happened was that
the user data-out buffer was copied into some kernel buffers and then
the mid level was told a read type operation would take place with the
data from the device overwriting the same kernel buffers. The user would
then read those kernel buffers back into the user space.

From what I can tell, the above action was broken by commit fad7f01e61
("sg: set dxferp to NULL for READ with the older SG interface") in 2008
and syzkaller found that out recently.

Make sure that a user space pointer is passed through when data follows
the sg_header structure and command.  Fix the abnormal case when a
non-zero reply_len is also given.

Fixes: fad7f01e61
Cc: <stable@vger.kernel.org> #v2.6.28+
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 15:50:25 -04:00
Vitaly Kuznetsov bb017d031a scsi: storvsc: fix SRB_STATUS_ABORTED handling
Commit 3209f9d780 ("scsi: storvsc: Fix a bug in the handling of SRB
status flags") filtered SRB_STATUS_AUTOSENSE_VALID out effectively making
the (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID) case a dead code. The
logic from this branch (e.g. storvsc_device_scan() call) is still required,
fix the check.

Cc: <stable@vger.kernel.org> #v4.4+
Fixes: 3209f9d780 ("scsi: storvsc: Fix a bug in the handling of SRB status flags")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 15:50:16 -04:00
Maurizio Lombardi a41b2efb13 be2iscsi: set the boot_kset pointer to NULL in case of failure
In beiscsi_setup_boot_info(), the boot_kset pointer should be set to
NULL in case of failure otherwise an invalid pointer dereference may
occur later.

Cc: <stable@vger.kernel.org>
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Jitendra Bhivare <jitendra.bhivare@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-14 15:50:11 -04:00
Martin K. Petersen f4327a95dd sd: Fix discard granularity when LBPRZ=1
Commit 397737223c ("sd: Make discard granularity match logical block
size when LBPRZ=1") accidentally set the granularity to one byte instead
of one logical block on devices that provide deterministic zeroes after
UNMAP.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Fixes: 397737223c
Cc: <stable@vger.kernel.org> #v4.4+
2016-03-14 15:50:06 -04:00
Hannes Reinecke 688875826f scsi_sysfs: Fix typo in is_bin_visible()
The test for the existence vpd_pg83 is inverted.

Fixes: 7e47976bcf ("scsi_sysfs: add 'is_bin_visible' callback")
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reported-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Laurence Oberman loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-10 20:29:54 -05:00
Sumit Saxena 3084558658 megaraid_sas: Don't issue kill adapter for MFI controllers in case of PD list DCMD failure
There are few MFI adapters which do not support MR_DCMD_PD_LIST_QUERY so
if MFI adapters fail this DCMD, it should not be considered as FATAL and
driver should not issue kill adapter and set per controller's instance
variable- pd_list_not_supported so that same variable can be used inside
functions- slave_alloc and slave_configure to allow firmware scan.

Killing adapter because of DCMD failure when this DCMD is not supported
causes driver's probe getting failed. This issue got introduced by
commit 6d40afbc7d ("megaraid_sas: MFI IO timeout handling").

Killing adapter in case of this DCMD failure should be limited to Fusion
adapters only. Per controller's instance variable allow_fw_scan is
removed as pd_list_not_supported better reflect the purpose.

Fixes: 6d40afbc7d
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-10 20:25:31 -05:00
Lars-Peter Clausen 7f8b8f3fba mpt3sas: Remove unnecessary synchronize_irq() before free_irq()
Calling synchronize_irq() right before free_irq() is quite useless. On
one hand the IRQ can easily fire again before free_irq() is entered, on
the other hand free_irq() itself calls synchronize_irq() internally (in
a race condition free way), before any state associated with the IRQ is
freed.

Patch was generated using the following semantic patch:
// <smpl>
@@
expression irq;
@@
-synchronize_irq(irq);
 free_irq(irq, ...);
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-09 20:42:47 -05:00
Manoj N. Kumar 83430833b4 cxlflash: Increase cmd_per_lun for better throughput
With the current value of cmd_per_lun at 16, the throughput
over a single adapter is limited to around 150kIOPS.

Increase the value of cmd_per_lun to 256 to improve
throughput. With this change a single adapter is able to
attain close to the maximum throughput (380kIOPS).
Also change the number of RRQ entries that can be queued.

Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08 21:17:33 -05:00
Manoj N. Kumar 603ecce95f cxlflash: Fix to avoid unnecessary scan with internal LUNs
When switching to the internal LUN defined on the
IBM CXL flash adapter, there is an unnecessary
scan occurring on the second port. This scan leads
to the following extra lines in the log:

Dec 17 10:09:00 tul83p1 kernel: [ 3708.561134] cxlflash 0008:00:00.0: cxlflash_queuecommand: (scp=c0000000fc1f0f00) 11/1/0/0 cdb=(A0000000-00000000-10000000-00000000)
Dec 17 10:09:00 tul83p1 kernel: [ 3708.561147] process_cmd_err: cmd failed afu_rc=32 scsi_rc=0 fc_rc=0 afu_extra=0xE, scsi_extra=0x0, fc_extra=0x0

By definition, both of the internal LUNs are on the first port/channel.

When the lun_mode is switched to internal LUN the
same value for host->max_channel is retained. This
causes an unnecessary scan over the second port/channel.

This fix alters the host->max_channel to 0 (1 port), if internal
LUNs are configured and switches it back to 1 (2 ports) while
going back to external LUNs.

Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08 21:17:33 -05:00
Uma Krishnan 5d1952acd0 cxlflash: Reorder user context initialization
In order to support cxlflash in the PowerVM environment, underlying
hypervisor APIs have imposed a kernel API ordering change.

For the superpipe access to LUN, user applications need a context.
The cxlflash module creates this context by making a sequence of
cxl calls. In the current code, a context is initialized via
cxl_dev_context_init() followed by cxl_process_element(), a function
that obtains the process element id. Finally, cxl_start_work()
is called to attach the process element.

In the PowerVM environment, a process element id cannot be obtained
from the hypervisor until the process element is attached. The
cxlflash module is unable to create contexts without a valid
process element id.

To fix this problem, cxl_start_work() is called before obtaining
the process element id.

Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08 21:17:33 -05:00
Matthew R. Ochs 8a96b52af5 cxlflash: Simplify attach path error cleanup
The cxlflash_disk_attach() routine currently uses a cascading error
gate strategy for its error cleanup path. While this strategy is
commonly used to handle cleanup scenarios, it is too restrictive when
function callouts need to be restructured. Problems range from
inserting error path bugs in previously 'good' code to the cleanup
path imposing design changes to how the normal path is structured.
A less restrictive approach is needed to support ordering changes
that come about when operating in different environments.

To overcome this restriction, the error cleanup path is modified to
have a single entrypoint and use conditional logic to cleanup where
necessary. Entities that require multiple cleanup steps must be
carefully vetted to ensure their APIs support state. In cases where
they do not (none as of this commit) additional local variables can
be used to maintain state on their behalf.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08 21:17:33 -05:00
Matthew R. Ochs 5e6632d19e cxlflash: Split out context initialization
Presently, context information structures are allocated and
initialized in the same routine, create_context(). This imposes
an ordering restriction such that all pieces of information needed
to initialize a context must be known before the context is even
allocated.

This design point is not flexible when the order of context
creation needs to be modified. Specifically, this can lead to
problems when members of the context information structure are
a part of an ordering dependency (i.e. - the 'work' structure
embedded within the context).

To remedy, the allocation is left as-is, inside of the existing
create_context() routine and the initialization is transitioned
to a new void routine, init_context(). At the same time, in
anticipation of these routines not being called in sequence, a
state boolean is added to the context information structure to
track when the context has been initilized. The context teardown
routine, destroy_context(), is modified to support being called
with a non-initialized context.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08 21:17:33 -05:00
Uma Krishnan 6ded8b3cbd cxlflash: Unmap problem state area before detaching master context
When operating in the PowerVM environment, the cxlflash module can
receive an error from the hypervisor indicating that there are
existing mappings in the page table for the process MMIO space.

This issue exists because term_afu() currently invokes term_mc()
before stop_afu(), allowing for the master context to be detached
first and the problem state area to be unmapped second.

To resolve this issue, stop_afu() should be called before term_mc().

Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08 21:17:33 -05:00
Manoj N. Kumar 961487e46a cxlflash: Simplify PCI registration
The calls to pci_request_regions(), pci_resource_start(),
pci_set_dma_mask(), pci_set_master() and pci_save_state() are all
unnecessary for the IBM CXL flash adapter since data buffers
are not required to be mapped to the device's memory.

The use of services such as pci_set_dma_mask() are problematic on
hypervisor managed systems as the IBM CXL flash adapter is operating
under a virtual PCI Host Bridge (virtual PHB) which does not support
these services.

cxlflash 0001:00:00.0: init_pci: Failed to set PCI DMA mask rc=-5

The resolution is to simplify init_pci(), to a point where it does the
bare minimum (pci_enable_device). Similarly, remove the call the
pci_release_regions() from cxlflash_remove().

Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08 21:17:33 -05:00
Lars-Peter Clausen e729b50307 be2iscsi: Remove unnecessary synchronize_irq() before free_irq()
Calling synchronize_irq() right before free_irq() is quite useless. On one
hand the IRQ can easily fire again before free_irq() is entered, on the
other hand free_irq() itself calls synchronize_irq() internally (in a race
condition free way), before any state associated with the IRQ is freed.

Patch was generated using the following semantic patch:
// <smpl>
@@
expression irq;
@@
-synchronize_irq(irq);
 free_irq(irq, ...);
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jitendra Bhivare <jitendra.bhivare@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-07 21:07:50 -05:00
Hannes Reinecke 4cd2459c06 scsi_sysfs: call 'device_add' after attaching device handler
'device_add' will be evaluating the 'is_visible' callback when creating
the sysfs attributes. As by this time the device handler has not been
attached the 'access_state' attribute will never be visible.

This patch moves the code around so that the device handler is present
by the time 'is_visible' is evaluated to correctly display the
'access_state' attribute.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-05 17:21:41 -05:00
Hannes Reinecke 0323375c8b scsi_dh_emc: update 'access_state' field
Update the 'access_state' field of the SCSI device whenever the path
state changes.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-05 17:20:33 -05:00
Hannes Reinecke 1a5dc166cd scsi_dh_rdac: update 'access_state' field
Track attached SCSI devices and update the 'access_state' whenever the
path state of the device changes.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-05 17:18:28 -05:00