printk: Fix rq->lock vs logbuf_lock unlock lock inversion

commit 07354eb1a74d1 ("locking printk: Annotate logbuf_lock as raw")
reintroduced a lock inversion problem which was fixed in commit
0b5e1c5255 ("printk: Release console_sem after logbuf_lock"). This
happened probably when fixing up patch rejects.

Restore the ordering and unlock logbuf_lock before releasing
console_sem.

Signed-off-by: ybu <ybu@qti.qualcomm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
ARM: OMAP4: PM: Avoid expensive cpu_suspend() path for all CPU power states except off

Current CPU PM code code make use of common cpu_suspend() path for all the
CPU power states which is not optimal. In fact cpu_suspend() path is needed
only when we put CPU power domain to off state where the CPU context is lost.

Update the code accordingly so that the expensive cpu_suspend() path
can be avoided for the shallow CPU power states like CPU PD INA/CSWR.

The patch has been tested on OMAP4430 and OMAP5430(with few out of tree patches)
devices for suspend and CPUidle.

Cc: Kevin Hilman <khilman@deeprootsystems.com>

Reported-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
ARM: OMAP4+: PM: Consolidate MPU subsystem PM code for re-use

OMAP5 and future OMAP based SOCs has backward compatible MPUSS
IP block with OMAP4. It's programming model is mostly similar.
Hence consolidate the OMAP MPUSS code so that it can be re-used
on OMAP5 and future SOCs.

No functional change.

Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
ARM: OMAP4+: Make secondary_startup function name more consistent

Current code has rather inconsistent function names for 'secondary_startup'
routines. Update it to make it more consistent.

Suggested by Kevin Hilman as part of OMAP5 PM patch review.

Cc: Kevin Hilman <khilman@deeprootsystems.com>

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
ARM: OMAP4+: PM: Consolidate OMAP4 PM code to re-use it for OMAP5

OMAP5 has backward compatible PRCM block and it's programming
model is mostly similar to OMAP4. Same is going to be maintained
for future OMAP4 based SOCs. Hence consolidate the OMAP4 power
management code so that it can be re-used on OMAP5 and later devices.

While at it, update the kernel-doc for omap4_pm_init().

Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
xen-blkback: print stats about persistent grants

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-blkback: use balloon pages for all mappings

Using balloon pages for all granted pages allows us to simplify the
logic in blkback, especially in the xen_blkbk_map function, since now
we can decide if we want to map a grant persistently or not after we
have actually mapped it. This could not be done before because
persistent grants used ballooned pages, whereas non-persistent grants
used pages from the kernel.

This patch also introduces several changes, the first one is that the
list of free pages is no longer global, now each blkback instance has
it's own list of free pages that can be used to map grants. Also, a
run time parameter (max_buffer_pages) has been added in order to tune
the maximum number of free pages each blkback instance will keep in
it's buffer.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-blkback: implement LRU mechanism for persistent grants

This mechanism allows blkback to change the number of grants
persistently mapped at run time.

The algorithm uses a simple LRU mechanism that removes (if needed) the
persistent grants that have not been used since the last LRU run, or
if all grants have been used it removes the first grants in the list
(that are not in use).

The algorithm allows the user to change the maximum number of
persistent grants, by changing max_persistent_grants in sysfs.

Since we are storing the persistent grants used inside the request
struct (to be able to mark them as "unused" when unmapping), we no
longer need the bitmap (unmap_seg).

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-blkback: move pending handles list from blkbk to pending_req

Moving grant ref handles from blkbk to pending_req will allow us to
get rid of the shared blkbk structure.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-blkback: make the queue of free requests per backend

Remove the last dependency from blkbk by moving the list of free
requests to blkif. This change reduces the contention on the list of
available requests.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-blkback: expand map/unmap functions

Preparatory change for implementing indirect descriptors. Change
xen_blkbk_{map/unmap} in order to be able to map/unmap a random amount
of grants (previously it was limited to
BLKIF_MAX_SEGMENTS_PER_REQUEST). Also, remove the usage of pending_req
in the map/unmap functions, so we can map/unmap grants without needing
to pass a pending_req.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-block: implement indirect descriptors

Indirect descriptors introduce a new block operation
(BLKIF_OP_INDIRECT) that passes grant references instead of segments
in the request. This grant references are filled with arrays of
blkif_request_segment_aligned, this way we can send more segments in a
request.

The proposed implementation sets the maximum number of indirect grefs
(frames filled with blkif_request_segment_aligned) to 256 in the
backend and 32 in the frontend. The value in the frontend has been
chosen experimentally, and the backend value has been set to a sane
value that allows expanding the maximum number of indirect descriptors
in the frontend if needed.

The migration code has changed from the previous implementation, in
which we simply remapped the segments on the shared ring. Now the
maximum number of segments allowed in a request can change depending
on the backend, so we have to requeue all the requests in the ring and
in the queue and split the bios in them if they are bigger than the
new maximum number of segments.

[v2: Fixed minor comments by Konrad.
[v1: Added padding to make the indirect request 64bit aligned.
 Added some BUGs, comments; fixed number of indirect pages in
 blkif_get_x86_{32/64}_req. Added description about the indirect operation
 in blkif.h]
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
[v3: Fixed spaces and tabs mix ups]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
sched: Factor out load calculation code from sched/core.c --> sched/proc.c

This large chunk of load calculation code can be easily divorced
from the main core.c scheduler file, with only a couple
prototypes and externs added to a kernel/sched header.

Some recent commits expanded the code and the documentation of
it, making it large enough to warrant separation.  For example,
see:

  556061b, "sched/nohz: Fix rq->cpu_load[] calculations"
  5aaa0b7, "sched/nohz: Fix rq->cpu_load calculations some more"
  5167e8d, "sched/nohz: Rewrite and fix load-avg computation -- again"

More importantly, it helps reduce the size of the main
sched/core.c by yet another significant amount (~600 lines).

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1366398650-31599-2-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched: Move update_load_*() methods from sched.h to fair.c

These inlines are only used by kernel/sched/fair.c so they do
not need to be present in the main kernel/sched/sched.h file.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1366398650-31599-3-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
xen-blkback: allocate list of pending reqs in small chunks

Allocate pending requests in smaller chunks instead of allocating them
all at the same time.

This change also removes the global array of pending_reqs, it is no
longer necessay.

Variables related to the grant mapping have been grouped into a struct
called "grant_page", this allows to allocate them in smaller chunks,
and also improves memory locality.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Tested-by: Sander Eikelenboom <linux@eikelenboom.it>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-blkfront: use a different scatterlist for each request

In blkif_queue_request blkfront iterates over the scatterlist in order
to set the segments of the request, and in blkif_completion blkfront
iterates over the raw request, which makes it hard to know the exact
position of the source and destination memory positions.

This can be solved by allocating a scatterlist for each request, that
will be keep until the request is finished, allowing us to copy the
data back to the original memory without having to iterate over the
raw request.

Oracle-Bug: 16660413 - LARGE ASYNCHRONOUS READS APPEAR BROKEN ON 2.6.39-400
CC: stable@vger.kernel.org
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reported-and-Tested-by: Anne Milicia <anne.milicia@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
sched: Use this_rq() helper

It is a few instructions more efficent to and slightly more
readable to use this_rq()-> instead of cpu_rq(smp_processor_id())-> .

Size comparison of kernel/sched/fair.o:

   text    data     bss     dec     hex filename
  27972     122      26   28120    6dd8 fair.o.before
  27956     122      26   28104    6dc8 fair.o.after

Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1368116643-87971-1-git-send-email-nzimmer@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
libfcoe: Fix Conflicting FCFs issue in the fabric

When multiple FCFs in use, and first FIP Advertisement received is
with "Available for Login" i.e A bit set to 0, FCF selection will fail.
The fix is to remove the assumption in the code that first FCF is only
allowed selectable FCF.
Consider the scenario fip->fcfs contains FCF1(fabricname X, marked A=0)
FCF2(fabricname Y, marked A=1). list_first_entry(first) points to FCF1
and 1st iteration we ignore the FCF and on 2nd iteration we compare
FCF1 & FCF2 fabric name and we fails to perform FCF selection.

Signed-off-by: Krishna Mohan <krmohan@cisco.com>
Reviewed-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
libfc: Correct check for initiator role

The service_params field is being checked against the symbol
FC_RPORT_ROLE_FCP_INITIATOR where it really should be checked
against FCP_SPPF_INIT_FCN.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Jack Morgan <jack.morgan@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
libfc: extend ex_lock to protect all of fc_seq_send

This warning was reported recently:

WARNING: at drivers/scsi/libfc/fc_exch.c:478 fc_seq_send+0x14f/0x160 [libfc]()
(Not tainted)
Hardware name: ProLiant DL120 G7
Modules linked in: tcm_fc target_core_iblock target_core_file target_core_pscsi
target_core_mod configfs dm_round_robin dm_multipath 8021q garp stp llc bnx2fc
cnic uio fcoe libfcoe libfc scsi_transport_fc scsi_tgt autofs4 sunrpc
pcc_cpufreq ipv6 hpilo hpwdt e1000e microcode iTCO_wdt iTCO_vendor_support
serio_raw shpchp ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif pata_acpi
ata_generic ata_piix hpsa dm_mirror dm_region_hash dm_log dm_mod [last unloaded:
scsi_wait_scan]
Pid: 5464, comm: target_completi Not tainted 2.6.32-272.el6.x86_64 #1
Call Trace:
 [<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0
 [<ffffffff8106b79a>] ? warn_slowpath_null+0x1a/0x20
 [<ffffffffa025f7df>] ? fc_seq_send+0x14f/0x160 [libfc]
 [<ffffffffa035cbce>] ? ft_queue_status+0x16e/0x210 [tcm_fc]
 [<ffffffffa030a660>] ? target_complete_ok_work+0x0/0x4b0 [target_core_mod]
 [<ffffffffa030a766>] ? target_complete_ok_work+0x106/0x4b0 [target_core_mod]
 [<ffffffffa030a660>] ? target_complete_ok_work+0x0/0x4b0 [target_core_mod]
 [<ffffffff8108c760>] ? worker_thread+0x170/0x2a0
 [<ffffffff810920d0>] ? autoremove_wake_function+0x0/0x40
 [<ffffffff8108c5f0>] ? worker_thread+0x0/0x2a0
 [<ffffffff81091d66>] ? kthread+0x96/0xa0
 [<ffffffff8100c14a>] ? child_rip+0xa/0x20
 [<ffffffff81091cd0>] ? kthread+0x0/0xa0
 [<ffffffff8100c140>] ? child_rip+0x0/0x20

It occurs because fc_seq_send can have multiple contexts executing within it at
the same time, and fc_seq_send doesn't consistently use the ep->ex_lock that
protects this structure.  Because of that, its possible for one context to clear
the INIT bit in the ep->esb_state field while another checks it, leading to the
above stack trace generated by the WARN_ON in the function.

We should probably undertake the effort to convert access to the fc_exch
structures to use rcu, but that a larger work item.  To just fix this specific
issue, we can just extend the ex_lock protection through the entire fc_seq_send
path

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Gris Ge <fge@redhat.com>
CC: Robert Love <robert.w.love@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>