We need to preserve the leading zeros in the vid and ssvid when generating
a unique NQN. Truncating these may lead to naming collisions.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

When nvme_init_identify() fails the ANA log buffer is deallocated
but _not_ set to NULL. This can cause double free oops when this
controller is deleted without ever being reconnected.
Signed-off-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Even if user-space sent it to us, it got it wrong so lets
help by disallowing it.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

For sure we are a fabric driver.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We should never touch the opal device from the transport driver.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

There is an out of bounds array access in nvme_cqe_peding().

When enable irq_thread for nvme interrupt, there is racing between the
nvmeq->cq_head updating and reading.

nvmeq->cq_head is updated in nvme_update_cq_head(), if nvmeq->cq_head
equals nvmeq->q_depth and before its value set to zero, nvme_cqe_pending()
uses its value as an array index, the index will be out of bounds.
Signed-off-by: NHongbo Yao <yaohongbo@huawei.com>
[hch: slight coding style update]
Signed-off-by: NChristoph Hellwig <hch@lst.de>

If the driver is unable to create a subset of IO queues for any reason,
the read/write and polled queue sets will not match the actual allocated
hardware contexts. This leaves gaps in the CPU affinity mappings and
causes the following kernel panic after blk_mq_map_queue_type() returns
a NULL hctx.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000198
  #PF error: [normal kernel read fault]
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP
  CPU: 64 PID: 1171 Comm: kworker/u259:1 Not tainted 4.20.0+ #241
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
  Workqueue: nvme-wq nvme_scan_work [nvme_core]
  RIP: 0010:blk_mq_init_allocated_queue+0x2d9/0x440
  RSP: 0018:ffffb1bf0abc3cd0 EFLAGS: 00010286
  RAX: 000000000000001f RBX: ffff8ea744cf0718 RCX: 0000000000000000
  RDX: 0000000000000002 RSI: 000000000000007c RDI: ffffffff9109a820
  RBP: ffff8ea7565f7008 R08: 000000000000001f R09: 000000000000003f
  R10: ffffb1bf0abc3c00 R11: 0000000000000000 R12: 000000000001d008
  R13: ffff8ea7565f7008 R14: 000000000000003f R15: 0000000000000001
  FS:  0000000000000000(0000) GS:ffff8ea757200000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000198 CR3: 0000000013058000 CR4: 00000000000006e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   blk_mq_init_queue+0x35/0x60
   nvme_validate_ns+0xc6/0x7c0 [nvme_core]
   ? nvme_identify_ctrl.isra.56+0x7e/0xc0 [nvme_core]
   nvme_scan_work+0xc8/0x340 [nvme_core]
   ? __wake_up_common+0x6d/0x120
   ? try_to_wake_up+0x55/0x410
   process_one_work+0x1e9/0x3d0
   worker_thread+0x2d/0x3d0
   ? process_one_work+0x3d0/0x3d0
   kthread+0x111/0x130
   ? kthread_park+0x90/0x90
   ret_from_fork+0x1f/0x30
  Modules linked in: nvme nvme_core serio_raw
  CR2: 0000000000000198

Fix by re-running the interrupt vector setup from scratch using a reduced
count that may be successful until the created queues matches the irq
affinity plus polling queue sets.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

When using HMB the PCIe host driver allocates host_mem_desc_bufs using
dma_alloc_attrs() but frees them using dma_free_coherent(). Use the
correct dma_free_attrs() function to free the buffers.
Signed-off-by: NLiviu Dudau <liviu@dudau.co.uk>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We only set the nr_maps to 3 if poll queues are supported.
Signed-off-by: NJianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

If the kernel is built without CONFIG_BLK_DEV_ZONED, a modprobe
of the null_blk driver with zoned=1 fails with 'Invalid argument'.
This can be confusing to users, prompting a search as to why the
parameter is invalid. To assist in that search, add a bit more
information to the failure, additionally adding to the documentation
that CONFIG_BLK_DEV_ZONED is needed for zoned=1.
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJohn Pittman <jpittman@redhat.com>

Added null_blk prefix to error message.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

vdc_blk_queue_start() may be called from irq context, so we can't run
queue via blk_mq_start_hw_queues() since we never allow to run queue
from irq context. Use blk_mq_start_stopped_hw_queues(q, true) to fix
this issue.

Fixes: fa182a1f ("sunvdc: convert to blk-mq")
Reported-by: NAnatoly Pugachev <matorola@gmail.com>
Tested-by: NAnatoly Pugachev <matorola@gmail.com>
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: sparclinux@vger.kernel.org
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

As of v4.20, the swim3 driver crashes when loaded on a PowerBook G3
(Wallstreet).

MacIO PCI driver attached to Gatwick chipset
MacIO PCI driver attached to Heathrow chipset
swim3 0.00015000:floppy: [fd0] SWIM3 floppy controller in media bay
0.00013020:ch-a: ttyS0 at MMIO 0xf3013020 (irq = 16, base_baud = 230400) is a Z85c30 ESCC - Serial port
0.00013000:ch-b: ttyS1 at MMIO 0xf3013000 (irq = 17, base_baud = 230400) is a Z85c30 ESCC - Infrared port
macio: fixed media-bay irq on gatwick
macio: fixed left floppy irqs
swim3 1.00015000:floppy: [fd1] Couldn't request interrupt
Unable to handle kernel paging request for data at address 0x00000024
Faulting instruction address: 0xc02652f8
Oops: Kernel access of bad area, sig: 11 [#1]
BE SMP NR_CPUS=2 PowerMac
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0 #2
NIP:  c02652f8 LR: c026915c CTR: c0276d1c
REGS: df43ba10 TRAP: 0300   Not tainted  (4.20.0)
MSR:  00009032 <EE,ME,IR,DR,RI>  CR: 28228288  XER: 00000100
DAR: 00000024 DSISR: 40000000
GPR00: c026915c df43bac0 df439060 c0731524 df494700 00000000 c06e1c08 00000001
GPR08: 00000001 00000000 df5ff220 00001032 28228282 00000000 c0004ca4 00000000
GPR16: 00000000 00000000 00000000 c073144c dfffe064 c0731524 00000120 c0586108
GPR24: c073132c c073143c c073143c 00000000 c0731524 df67cd70 df494700 00000001
NIP [c02652f8] blk_mq_free_rqs+0x28/0xf8
LR [c026915c] blk_mq_sched_tags_teardown+0x58/0x84
Call Trace:
[df43bac0] [c0045f50] flush_workqueue_prep_pwqs+0x178/0x1c4 (unreliable)
[df43bae0] [c026915c] blk_mq_sched_tags_teardown+0x58/0x84
[df43bb00] [c02697f0] blk_mq_exit_sched+0x9c/0xb8
[df43bb20] [c0252794] elevator_exit+0x84/0xa4
[df43bb40] [c0256538] blk_exit_queue+0x30/0x50
[df43bb50] [c0256640] blk_cleanup_queue+0xe8/0x184
[df43bb70] [c034732c] swim3_attach+0x330/0x5f0
[df43bbb0] [c034fb24] macio_device_probe+0x58/0xec
[df43bbd0] [c032ba88] really_probe+0x1e4/0x2f4
[df43bc00] [c032bd28] driver_probe_device+0x64/0x204
[df43bc20] [c0329ac4] bus_for_each_drv+0x60/0xac
[df43bc50] [c032b824] __device_attach+0xe8/0x160
[df43bc80] [c032ab38] bus_probe_device+0xa0/0xbc
[df43bca0] [c0327338] device_add+0x3d8/0x630
[df43bcf0] [c0350848] macio_add_one_device+0x444/0x48c
[df43bd50] [c03509f8] macio_pci_add_devices+0x168/0x1bc
[df43bd90] [c03500ec] macio_pci_probe+0xc0/0x10c
[df43bda0] [c02ad884] pci_device_probe+0xd4/0x184
[df43bdd0] [c032ba88] really_probe+0x1e4/0x2f4
[df43be00] [c032bd28] driver_probe_device+0x64/0x204
[df43be20] [c032bfcc] __driver_attach+0x104/0x108
[df43be40] [c0329a00] bus_for_each_dev+0x64/0xb4
[df43be70] [c032add8] bus_add_driver+0x154/0x238
[df43be90] [c032ca24] driver_register+0x84/0x148
[df43bea0] [c0004aa0] do_one_initcall+0x40/0x188
[df43bf00] [c0690100] kernel_init_freeable+0x138/0x1d4
[df43bf30] [c0004cbc] kernel_init+0x18/0x10c
[df43bf40] [c00121e4] ret_from_kernel_thread+0x14/0x1c
Instruction dump:
5484d97e 4bfff4f4 9421ffe0 7c0802a6 bf410008 7c9e2378 90010024 8124005c
2f890000 419e0078 81230004 7c7c1b78 <81290024> 2f890000 419e0064 81440000
---[ end trace 12025ab921a9784c ]---

Reverting commit 8ccb8cb1 ("swim3: convert to blk-mq") resolves the
problem.

That commit added a struct blk_mq_tag_set to struct floppy_state and
initialized it with a blk_mq_init_sq_queue() call. Unfortunately, there
is a memset() in swim3_add_device() that subsequently clears the
floppy_state struct. That means fs->tag_set->ops is a NULL pointer, and
it gets dereferenced by blk_mq_free_rqs() which gets called in the
request_irq() error path. Move the memset() to fix this bug.

BTW, the request_irq() failure for the left mediabay floppy (fd1) is not
a regression. I don't know why it happens. The right media bay floppy
(fd0) works fine however.
Reported-and-tested-by: NStan Johnson <userm57@yahoo.com>
Fixes: 8ccb8cb1 ("swim3: convert to blk-mq")
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When the block device is opened with FMODE_EXCL, ref_count is set to -1.
This value doesn't get reset when the device is closed which means the
device cannot be opened again. Fix this by checking for refcount <= 0
in the release method.
Reported-and-tested-by: NStan Johnson <userm57@yahoo.com>
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Cc: linux-m68k@lists.linux-m68k.org
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Rename core files so there is a clearer separation between the RTC core and
the RTC drivers.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>

In cas of probe failure, devres may free the memory allocated for
rtc->nvram before devm_rtc_release_device() is called. This leads to
rtc_nvram_unregister using it after being freed which may lead to a crash.

This has been shown to happen after commit 461e557b ("rtc: nvmem: use
devm_nvmem_register()")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>

In probe_gdrom(), the buffer pointed by 'gd.cd_info' is allocated through
kzalloc() and is used to hold the information of the gdrom device. To
register and unregister the device, the pointer 'gd.cd_info' is passed to
the functions register_cdrom() and unregister_cdrom(), respectively.
However, this buffer is not freed after it is used, which can cause a
memory leak bug.

This patch simply frees the buffer 'gd.cd_info' in exit_gdrom() to fix the
above issue.
Signed-off-by: NWenwen Wang <wang6495@umn.edu>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This adds ELAN0501 to the ACPI table to support Elan touchpad found in ASUS
Aspire F5-573G.
Signed-off-by: NPatrick Dreyer <Patrick.Dreyer@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

If the user attempts to update Atmel device with an invalid configuration
cfg file, error handling code is trying to free cfg file memory which is
not allocated yet hence results into kernel crash.

This patch fixes the order of memory free operations.
Signed-off-by: NSanjeev Chugh <sanjeev_chugh@mentor.com>
Fixes: a4891f10 ("Input: atmel_mxt_ts - zero terminate config firmware file")
Cc: stable@vger.kernel.org
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

pages_correctly_probed is missing new lines which means that the line is
not printed rightaway but it rather waits for additional printks.

Add \n to all three messages in pages_correctly_probed.

Link: http://lkml.kernel.org/r/20181218162307.10518-1-mhocko@kernel.org
Fixes: b77eab70 ("mm/memory_hotplug: optimize probe routine")
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NWei Yang <richard.weiyang@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mmu notifier contextual informations", v2.

This patchset adds contextual information, why an invalidation is
happening, to mmu notifier callback.  This is necessary for user of mmu
notifier that wish to maintains their own data structure without having to
add new fields to struct vm_area_struct (vma).

For instance device can have they own page table that mirror the process
address space.  When a vma is unmap (munmap() syscall) the device driver
can free the device page table for the range.

Today we do not have any information on why a mmu notifier call back is
happening and thus device driver have to assume that it is always an
munmap().  This is inefficient at it means that it needs to re-allocate
device page table on next page fault and rebuild the whole device driver
data structure for the range.

Other use case beside munmap() also exist, for instance it is pointless
for device driver to invalidate the device page table when the
invalidation is for the soft dirtyness tracking.  Or device driver can
optimize away mprotect() that change the page table permission access for
the range.

This patchset enables all this optimizations for device drivers.  I do not
include any of those in this series but another patchset I am posting will
leverage this.

The patchset is pretty simple from a code point of view.  The first two
patches consolidate all mmu notifier arguments into a struct so that it is
easier to add/change arguments.  The last patch adds the contextual
information (munmap, protection, soft dirty, clear, ...).

This patch (of 3):

To avoid having to change many callback definition everytime we want to
add a parameter use a structure to group all parameters for the
mmu_notifier invalidate_range_start/end callback.  No functional changes
with this patch.

[akpm@linux-foundation.org: fix drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c kerneldoc]
Link: http://lkml.kernel.org/r/20181205053628.3210-2-jglisse@redhat.comSigned-off-by: NJérôme Glisse <jglisse@redhat.com>
Acked-by: NJan Kara <jack@suse.cz>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>	[infiniband]
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If there are lots of write IO with flash device, it could have a
wearout problem of storage. To overcome the problem, admin needs
to design write limitation to guarantee flash health
for entire product life.

This patch creates a new knob "writeback_limit" for zram.

writeback_limit's default value is 0 so that it doesn't limit
any writeback. If admin want to measure writeback count in a
certain period, he could know it via /sys/block/zram0/bd_stat's
3rd column.

If admin want to limit writeback as per-day 400M, he could do it
like below.

	MB_SHIFT=20
	4K_SHIFT=12
	echo $((400<<MB_SHIFT>>4K_SHIFT)) > \
		/sys/block/zram0/writeback_limit.

If admin want to allow further write again, he could do it like below

	echo 0 > /sys/block/zram0/writeback_limit

If admin want to see remaining writeback budget,

	cat /sys/block/zram0/writeback_limit

The writeback_limit count will reset whenever you reset zram (e.g., system
reboot, echo 1 > /sys/block/zramX/reset) so keeping how many of writeback
happened until you reset the zram to allocate extra writeback budget in
next setting is user's job.

[minchan@kernel.org: v4]
  Link: http://lkml.kernel.org/r/20181203024045.153534-8-minchan@kernel.org
Link: http://lkml.kernel.org/r/20181127055429.251614-8-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Joey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bd_stat represents things that happened in the backing device.  Currently
it supports bd_counts, bd_reads and bd_writes which are helpful to
understand wearout of flash and memory saving.

[minchan@kernel.org: v4]
  Link: http://lkml.kernel.org/r/20181203024045.153534-7-minchan@kernel.org
Link: http://lkml.kernel.org/r/20181127055429.251614-7-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Joey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a new feature "zram idle/huge page writeback".  In the zram-swap use
case, zram usually has many idle/huge swap pages.  It's pointless to keep
them in memory (ie, zram).

To solve this problem, this feature introduces idle/huge page writeback to
the backing device so the goal is to save more memory space on embedded
systems.

Normal sequence to use idle/huge page writeback feature is as follows,

while (1) {
        # mark allocated zram slot to idle
        echo all > /sys/block/zram0/idle
        # leave system working for several hours
        # Unless there is no access for some blocks on zram,
	# they are still IDLE marked pages.

        echo "idle" > /sys/block/zram0/writeback
	or/and
	echo "huge" > /sys/block/zram0/writeback
        # write the IDLE or/and huge marked slot into backing device
	# and free the memory.
}

Per the discussion at
https://lore.kernel.org/lkml/20181122065926.GG3441@jagdpanzerIV/T/#u,

This patch removes direct incommpressibe page writeback feature
(d2afd25114f4 ("zram: write incompressible pages to backing device")).

Below concerns from Sergey:
== &< ==

"IDLE writeback" is superior to "incompressible writeback".

"incompressible writeback" is completely unpredictable and uncontrollable;
it depens on data patterns and compression algorithms.  While "IDLE
writeback" is predictable.

I even suspect, that, *ideally*, we can remove "incompressible writeback".
"IDLE pages" is a super set which also includes "incompressible" pages.
So, technically, we still can do "incompressible writeback" from "IDLE
writeback" path; but a much more reasonable one, based on a page idling
period.

I understand that you want to keep "direct incompressible writeback"
around.  ZRAM is especially popular on devices which do suffer from flash
wearout, so I can see "incompressible writeback" path becoming a dead
code, long term.

== &< ==

Below concerns from Minchan:
== &< ==

My concern is if we enable CONFIG_ZRAM_WRITEBACK in this implementation,
both hugepage/idlepage writeck will turn on.  However someuser want to
enable only idlepage writeback so we need to introduce turn on/off knob
for hugepage or new CONFIG_ZRAM_IDLEPAGE_WRITEBACK for those usecase.  I
don't want to make it complicated *if possible*.

Long term, I imagine we need to make VM aware of new swap hierarchy a
little bit different with as-is.  For example, first high priority swap
can return -EIO or -ENOCOMP, swap try to fallback to next lower priority
swap device.  With that, hugepage writeback will work tranparently.

So we could regard it as regression because incompressible pages doesn't
go to backing storage automatically.  Instead, user should do it via "echo
huge" > /sys/block/zram/writeback" manually.

== &< ==

Link: http://lkml.kernel.org/r/20181127055429.251614-6-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NJoey Pabalinas <joeypabalinas@gmail.com>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To support idle page writeback with upcoming patches, this patch
introduces a new ZRAM_IDLE flag.

Userspace can mark zram slots as "idle" via
	"echo all > /sys/block/zramX/idle"
which marks every allocated zram slot as ZRAM_IDLE.
User could see it by /sys/kernel/debug/zram/zram0/block_state.

          300    75.033841 ...i
          301    63.806904 s..i
          302    63.806919 ..hi

Once there is IO for the slot, the mark will be disappeared.

	  300    75.033841 ...
          301    63.806904 s..i
          302    63.806919 ..hi

Therefore, 300th block is idle zpage. With this feature,
user can how many zram has idle pages which are waste of memory.

Link: http://lkml.kernel.org/r/20181127055429.251614-5-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: NJoey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename some variables and restructure some code for better readability in
writeback and zs_free_page.

Link: http://lkml.kernel.org/r/20181127055429.251614-4-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: NJoey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If blkdev_get fails, we shouldn't do blkdev_put.  Otherwise, kernel emits
below log.  This patch fixes it.

  WARNING: CPU: 0 PID: 1893 at fs/block_dev.c:1828 blkdev_put+0x105/0x120
  Modules linked in:
  CPU: 0 PID: 1893 Comm: swapoff Not tainted 4.19.0+ #453
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
  RIP: 0010:blkdev_put+0x105/0x120
  Call Trace:
    __x64_sys_swapoff+0x46d/0x490
    do_syscall_64+0x5a/0x190
    entry_SYSCALL_64_after_hwframe+0x49/0xbe
  irq event stamp: 4466
  hardirqs last  enabled at (4465):  __free_pages_ok+0x1e3/0x490
  hardirqs last disabled at (4466):  trace_hardirqs_off_thunk+0x1a/0x1c
  softirqs last  enabled at (3420):  __do_softirq+0x333/0x446
  softirqs last disabled at (3407):  irq_exit+0xd1/0xe0

Link: http://lkml.kernel.org/r/20181127055429.251614-3-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: NJoey Pabalinas <joeypabalinas@gmail.com>
Cc: <stable@vger.kernel.org>	[4.14+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "zram idle page writeback", v3.

Inherently, swap device has many idle pages which are rare touched since
it was allocated.  It is never problem if we use storage device as swap.
However, it's just waste for zram-swap.

This patchset supports zram idle page writeback feature.

* Admin can define what is idle page "no access since X time ago"
* Admin can define when zram should writeback them
* Admin can define when zram should stop writeback to prevent wearout

Details are in each patch's description.

This patch (of 7):

  ================================
  WARNING: inconsistent lock state
  4.19.0+ #390 Not tainted
  --------------------------------
  inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
  zram_verify/2095 [HC0[0]:SC1[1]:HE1:SE0] takes:
  00000000b1828693 (&(&zram->bitmap_lock)->rlock){+.?.}, at: put_entry_bdev+0x1e/0x50
  {SOFTIRQ-ON-W} state was registered at:
    _raw_spin_lock+0x2c/0x40
    zram_make_request+0x755/0xdc9
    generic_make_request+0x373/0x6a0
    submit_bio+0x6c/0x140
    __swap_writepage+0x3a8/0x480
    shrink_page_list+0x1102/0x1a60
    shrink_inactive_list+0x21b/0x3f0
    shrink_node_memcg.constprop.99+0x4f8/0x7e0
    shrink_node+0x7d/0x2f0
    do_try_to_free_pages+0xe0/0x300
    try_to_free_pages+0x116/0x2b0
    __alloc_pages_slowpath+0x3f4/0xf80
    __alloc_pages_nodemask+0x2a2/0x2f0
    __handle_mm_fault+0x42e/0xb50
    handle_mm_fault+0x55/0xb0
    __do_page_fault+0x235/0x4b0
    page_fault+0x1e/0x30
  irq event stamp: 228412
  hardirqs last  enabled at (228412): [<ffffffff98245846>] __slab_free+0x3e6/0x600
  hardirqs last disabled at (228411): [<ffffffff98245625>] __slab_free+0x1c5/0x600
  softirqs last  enabled at (228396): [<ffffffff98e0031e>] __do_softirq+0x31e/0x427
  softirqs last disabled at (228403): [<ffffffff98072051>] irq_exit+0xd1/0xe0

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

         CPU0
         ----
    lock(&(&zram->bitmap_lock)->rlock);
    <Interrupt>
      lock(&(&zram->bitmap_lock)->rlock);

   *** DEADLOCK ***

  no locks held by zram_verify/2095.

  stack backtrace:
  CPU: 5 PID: 2095 Comm: zram_verify Not tainted 4.19.0+ #390
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
  Call Trace:
   <IRQ>
   dump_stack+0x67/0x9b
   print_usage_bug+0x1bd/0x1d3
   mark_lock+0x4aa/0x540
   __lock_acquire+0x51d/0x1300
   lock_acquire+0x90/0x180
   _raw_spin_lock+0x2c/0x40
   put_entry_bdev+0x1e/0x50
   zram_free_page+0xf6/0x110
   zram_slot_free_notify+0x42/0xa0
   end_swap_bio_read+0x5b/0x170
   blk_update_request+0x8f/0x340
   scsi_end_request+0x2c/0x1e0
   scsi_io_completion+0x98/0x650
   blk_done_softirq+0x9e/0xd0
   __do_softirq+0xcc/0x427
   irq_exit+0xd1/0xe0
   do_IRQ+0x93/0x120
   common_interrupt+0xf/0xf
   </IRQ>

With writeback feature, zram_slot_free_notify could be called in softirq
context by end_swap_bio_read.  However, bitmap_lock is not aware of that
so lockdep yell out:

  get_entry_bdev
  spin_lock(bitmap->lock);
  irq
  softirq
  end_swap_bio_read
  zram_slot_free_notify
  zram_slot_lock <-- deadlock prone
  zram_free_page
  put_entry_bdev
  spin_lock(bitmap->lock); <-- deadlock prone

With akpm's suggestion (i.e.  bitmap operation is already atomic), we
could remove bitmap lock.  It might fail to find a empty slot if serious
contention happens.  However, it's not severe problem because huge page
writeback has already possiblity to fail if there is severe memory
pressure.  Worst case is just keeping the incompressible in memory, not
storage.

The other problem is zram_slot_lock in zram_slot_slot_free_notify.  To
make it safe is this patch introduces zram_slot_trylock where
zram_slot_free_notify uses it.  Although it's rare to be contented, this
patch adds new debug stat "miss_free" to keep monitoring how often it
happens.

Link: http://lkml.kernel.org/r/20181127055429.251614-2-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: NJoey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Userspace should always be in charge of how to online memory and if memory
should be onlined automatically in the kernel.  Let's drop the parameter
to overwrite this - XEN passes memhp_auto_online, just like add_memory(),
so we can directly use that instead internally.

Link: http://lkml.kernel.org/r/20181123123740.27652-1-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Acked-by: NJuergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In cb5e39b8 ("drivers: base: refactor add_memory_section() to
add_memory_block()"), add_memory_block() is introduced, which is only
invoked in memory_dev_init().

When combining these two loops in memory_dev_init() and
add_memory_block(), they looks like this:

    for (i = 0; i < NR_MEM_SECTIONS; i += sections_per_block)
        for (j = i;
	    (j < i + sections_per_block) && j < NR_MEM_SECTIONS;
	    j++)

Since it is sure the (i < NR_MEM_SECTIONS) and j sits in its own memory
block, the check of (j < NR_MEM_SECTIONS) is not necessary.

This patch just removes this check.

Link: http://lkml.kernel.org/r/20181123222811.18216-1-richard.weiyang@gmail.comSigned-off-by: NWei Yang <richard.weiyang@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Seth Jennings <sjenning@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

At Maintainer Summit, Greg brought up a topic I proposed around
EXPORT_SYMBOL_GPL usage.  The motivation was considerations for when
EXPORT_SYMBOL_GPL is warranted and the criteria for taking the exceptional
step of reclassifying an existing export.  Specifically, I wanted to make
the case that although the line is fuzzy and hard to specify in abstract
terms, it is nonetheless clear that devm_memremap_pages() and HMM
(Heterogeneous Memory Management) have crossed it.  The
devm_memremap_pages() facility should have been EXPORT_SYMBOL_GPL from the
beginning, and HMM as a derivative of that functionality should have
naturally picked up that designation as well.

Contrary to typical rules, the HMM infrastructure was merged upstream with
zero in-tree consumers.  There was a promise at the time that those users
would be merged "soon", but it has been over a year with no drivers
arriving.  While the Nouveau driver is about to belatedly make good on
that promise it is clear that HMM was targeted first and foremost at an
out-of-tree consumer.

HMM is derived from devm_memremap_pages(), a facility Christoph and I
spearheaded to support persistent memory.  It combines a device lifetime
model with a dynamically created 'struct page' / memmap array for any
physical address range.  It enables coordination and control of the many
code paths in the kernel built to interact with memory via 'struct page'
objects.  With HMM the integration goes even deeper by allowing device
drivers to hook and manipulate page fault and page free events.

One interpretation of when EXPORT_SYMBOL is suitable is when it is
exporting stable and generic leaf functionality.  The
devm_memremap_pages() facility continues to see expanding use cases,
peer-to-peer DMA being the most recent, with no clear end date when it
will stop attracting reworks and semantic changes.  It is not suitable to
export devm_memremap_pages() as a stable 3rd party driver API due to the
fact that it is still changing and manipulates core behavior.  Moreover,
it is not in the best interest of the long term development of the core
memory management subsystem to permit any external driver to effectively
define its own system-wide memory management policies with no
encouragement to engage with upstream.

I am also concerned that HMM was designed in a way to minimize further
engagement with the core-MM.  That, with these hooks in place,
device-drivers are free to implement their own policies without much
consideration for whether and how the core-MM could grow to meet that
need.  Going forward not only should HMM be EXPORT_SYMBOL_GPL, but the
core-MM should be allowed the opportunity and stimulus to change and
address these new use cases as first class functionality.

Original changelog:

hmm_devmem_add(), and hmm_devmem_add_resource() duplicated
devm_memremap_pages() and are now simple now wrappers around the core
facility to inject a dev_pagemap instance into the global pgmap_radix and
hook page-idle events.  The devm_memremap_pages() interface is base
infrastructure for HMM.  HMM has more and deeper ties into the kernel
memory management implementation than base ZONE_DEVICE which is itself a
EXPORT_SYMBOL_GPL facility.

Originally, the HMM page structure creation routines copied the
devm_memremap_pages() code and reused ZONE_DEVICE.  A cleanup to unify the
implementations was discussed during the initial review:
http://lkml.iu.edu/hypermail/linux/kernel/1701.2/00812.html Recent work to
extend devm_memremap_pages() for the peer-to-peer-DMA facility enabled
this cleanup to move forward.

In addition to the integration with devm_memremap_pages() HMM depends on
other GPL-only symbols:

    mmu_notifier_unregister_no_release
    percpu_ref
    region_intersects
    __class_create

It goes further to consume / indirectly expose functionality that is not
exported to any other driver:

    alloc_pages_vma
    walk_page_range

HMM is derived from devm_memremap_pages(), and extends deep core-kernel
fundamentals. Similar to devm_memremap_pages(), mark its entry points
EXPORT_SYMBOL_GPL().

[logang@deltatee.com: PCI/P2PDMA: match interface changes to devm_memremap_pages()]
  Link: http://lkml.kernel.org/r/20181130225911.2900-1-logang@deltatee.com
Link: http://lkml.kernel.org/r/154275560565.76910.15919297436557795278.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>,
Cc: Michal Hocko <mhocko@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The last step before devm_memremap_pages() returns success is to allocate
a release action, devm_memremap_pages_release(), to tear the entire setup
down.  However, the result from devm_add_action() is not checked.

Checking the error from devm_add_action() is not enough.  The api
currently relies on the fact that the percpu_ref it is using is killed by
the time the devm_memremap_pages_release() is run.  Rather than continue
this awkward situation, offload the responsibility of killing the
percpu_ref to devm_memremap_pages_release() directly.  This allows
devm_memremap_pages() to do the right thing relative to init failures and
shutdown.

Without this change we could fail to register the teardown of
devm_memremap_pages().  The likelihood of hitting this failure is tiny as
small memory allocations almost always succeed.  However, the impact of
the failure is large given any future reconfiguration, or disable/enable,
of an nvdimm namespace will fail forever as subsequent calls to
devm_memremap_pages() will fail to setup the pgmap_radix since there will
be stale entries for the physical address range.

An argument could be made to require that the ->kill() operation be set in
the @pgmap arg rather than passed in separately.  However, it helps code
readability, tracking the lifetime of a given instance, to be able to grep
the kill routine directly at the devm_memremap_pages() call site.

Link: http://lkml.kernel.org/r/154275558526.76910.7535251937849268605.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>
Fixes: e8d51348 ("memremap: change devm_memremap_pages interface...")
Reviewed-by: N"Jérôme Glisse" <jglisse@redhat.com>
Reported-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

totalram_pages and totalhigh_pages are made static inline function.

Main motivation was that managed_page_count_lock handling was complicating
things.  It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.

[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.orgSigned-off-by: NArun KS <arunks@codeaurora.org>
Suggested-by: NMichal Hocko <mhocko@suse.com>
Suggested-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

totalram_pages, zone->managed_pages and totalhigh_pages updates are
protected by managed_page_count_lock, but readers never care about it.
Convert these variables to atomic to avoid readers potentially seeing a
store tear.

This patch converts zone->managed_pages.  Subsequent patches will convert
totalram_panges, totalhigh_pages and eventually managed_page_count_lock
will be removed.

Main motivation was that managed_page_count_lock handling was complicating
things.  It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.

Link: http://lkml.kernel.org/r/1542090790-21750-3-git-send-email-arunks@codeaurora.orgSigned-off-by: NArun KS <arunks@codeaurora.org>
Suggested-by: NMichal Hocko <mhocko@suse.com>
Suggested-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: convert totalram_pages, totalhigh_pages and managed
pages to atomic", v5.

This series converts totalram_pages, totalhigh_pages and
zone->managed_pages to atomic variables.

totalram_pages, zone->managed_pages and totalhigh_pages updates are
protected by managed_page_count_lock, but readers never care about it.
Convert these variables to atomic to avoid readers potentially seeing a
store tear.

Main motivation was that managed_page_count_lock handling was complicating
things.  It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better
to remove the lock and convert variables to atomic.  With the change,
preventing poteintial store-to-read tearing comes as a bonus.

This patch (of 4):

This is in preparation to a later patch which converts totalram_pages and
zone->managed_pages to atomic variables.  Please note that re-reading the
value might lead to a different value and as such it could lead to
unexpected behavior.  There are no known bugs as a result of the current
code but it is better to prevent from them in principle.

Link: http://lkml.kernel.org/r/1542090790-21750-2-git-send-email-arunks@codeaurora.orgSigned-off-by: NArun KS <arunks@codeaurora.org>
Reviewed-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

SCU clock can be used in a similar way by IMX8QXP and IMX8QM SoCs.
Let's make the name of clock ID generic to allow other SoCs to reuse
the common part.

This patch only changes the clock id name and file name, so no
functional change.

Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: NDong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: NFabio Estevam <festevam@gmail.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NStephen Boyd <sboyd@kernel.org>

The CONFIG_SOC_IMX8MQ will go away, so the dependency can be based on
ARCH_MXC && ARM64.
Signed-off-by: NAbel Vesa <abel.vesa@nxp.com>
Acked-by: NDong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: NFabio Estevam <festevam@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Otherwise building fails with only PINCTRL_IMX_SCU selected:

    aarch64-linux-gnu-ld: drivers/pinctrl/freescale/pinctrl-scu.o: in function `imx_pinctrl_sc_ipc_init':
    pinctrl-scu.c:(.text+0x10): undefined reference to `imx_scu_get_handle'
    aarch64-linux-gnu-ld: pinctrl-scu.c:(.text+0x10): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `imx_scu_get_handle'
    aarch64-linux-gnu-ld: drivers/pinctrl/freescale/pinctrl-scu.o: in function `imx_pinconf_get_scu':
    pinctrl-scu.c:(.text+0x64): undefined reference to `imx_scu_call_rpc'
    aarch64-linux-gnu-ld: pinctrl-scu.c:(.text+0x64): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `imx_scu_call_rpc'
    aarch64-linux-gnu-ld: drivers/pinctrl/freescale/pinctrl-scu.o: in function `imx_pinconf_set_scu':
    pinctrl-scu.c:(.text+0x104): undefined reference to `imx_scu_call_rpc'
    aarch64-linux-gnu-ld: pinctrl-scu.c:(.text+0x104): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `imx_scu_call_rpc'
    make: *** [Makefile:1038: vmlinux] Error 1
Signed-off-by: NGuido Günther <agx@sigxcpu.or>
Reviewed-by: NFabio Estevam <festevam@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The to_software_mode() macro can potentially return NULL, so also add
a NULL check on swnode before dereferencing it to avoid any NULL
pointer dereferences.

Detected by CoverityScan, CID#1476052 ("Explicit null dereferenced")

Fixes: 59abd836 (drivers: base: Introducing software nodes to the firmware node framework)
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>