Thanks to work done by Broadcom explaining their USB 3.0 PHY details we
know it's attached to the MDIO bus. Use this knowledge to update the
binding: make it a subnode to the MDIO bus and rework way of specifying
required registers. This will describe hardware more precisely and will
allow to support (describe) more devices attached to the MDIO.

While compatibility strings remain the same there isn't a direct
conflict (compatibility breakage) for the binding. Originally it wasn't
supposed to be used for MDIO subnode so this change should be safe
unless some operating system was probing MDIO subnodes as standalone
devices.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

When we finally start using MDIO layer then bus initialization will be
handled in a separated driver. It means our code handling this has to be
used for the platform driver only.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Our current writing function accesses PHY directly bypassing MDIO layer.

The aim is to extend this module to also behave as MDIO driver. This
will require using different writing function which can be handled
cleanly by having an extra pointer like this.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Move MDIO specific code to the writing helper function. This makes init
code a bit more generic and doesn't require it to track what happens
after every write.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

This patch adds support for stingray SATA phy in the
SATA BRCM phy driver.
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Update BRCM SATA phy dt-binding documentation for stingray.
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Rob Herring <rob@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Commit 8ae904e3c236 ("phy: cpcap-usb: Add CPCAP PMIC USB support")
is missing return statement as noted by Colin Ian King
<colin.king@canonical.com>. If the optional pins are not configured,
we just want to return early and not attempt to configure the pins.

Fixes: 8ae904e3c236 ("phy: cpcap-usb: Add CPCAP PMIC USB support")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

This is driver for USB DRD PHY used in Broadcom's Northstar2
SoC. The phy can be configured to be in Device mode or Host
mode based on the type of cable connected to the port. The
driver registers to  extcon framework to get appropriate
connect events for Host/Device cables connect/disconnect
states based on VBUS and ID interrupts.
Signed-off-by: Raviteja Garimella <raviteja.garimella@broadcom.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

This patch adds DT bindings documentation for NS2 DRD PHY driver.
Signed-off-by: Raviteja Garimella <raviteja.garimella@broadcom.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

When MUSB is a loadable module, we get a link error for a built-in
CPCAP driver:

drivers/phy/built-in.o: In function `cpcap_usb_phy_remove':
phy-cpcap-usb.c:(.text+0xed9): undefined reference to `musb_mailbox'

This adds a Kconfig dependency to prevent this broken configuration,
enforcing that CPCAP can only be a module when MUSB is also a module.

Fixes: 68a1f7c9d470 ("phy: cpcap-usb: Add CPCAP PMIC USB support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

->set_mode() can be used to tell PHY to prepare itself to enter USB
Host/Peripheral mode and that's very important for DRD
configurations.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

TUSB1211 is software compatible with TUSB1210 and as such we don't
need an entire new driver to control it. Let's add its product ID to
the existing TUSB1210 driver instead.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

The USB 3.0 PHY modules of R-Car Gen3 SoCs have:
 - Spread spectrum clock (ssc).
 - Using USB 2.0 EXTAL clock instead of USB 3.0 clock.
 - Enabling VBUS detection for usb3.0 peripheral.

So, this driver supports these features.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

This adds support usb2-phy for rk3228 SoCs and amend phy Documentation.
Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

At the current rockchip-inno-usb2 phy driver framework, it can
only support usb2-phy which comprises with one otg-port and one
host-port.

However, some Rockchip SoCs' (e.g RK3228, RK3229) usb2-phy comprises
with two host-ports, so we use index of otg id for one host-port
configuration, and make it work the same as otg-port host mode.
Signed-off-by: William Wu <william.wu@rock-chips.com>
Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

In rockchip-inno-usb2 phy driver, we use otg_sm_work to
dynamically manage power consumption for phy otg-port.
If the otg-port works as peripheral mode and does not
communicate with usb host, we will suspend phy.

But once suspend phy, the phy no longer has any internal
clock running, include the utmi_clk which supplied for
usb controller. So if we suspend phy before usb controller
init, it will cause usb controller fail to initialize.

Specifically, without this patch, the observed order is:
 1. unplug usb cable
 2. start system, do dwc2 controller probe
 3. dwc2_lowlevel_hw_enable()
    - phy_init()
     - rockchip_usb2phy_init()
      - schedule otg_sm_work after 2s
        put phy in suspend, and close utmi_clk
 4. dwc2_hsotg_udc_start() - fail to initialize the usb core

Generally, dwc2_hsotg_udc_start() can be called within 5s
after start system on Rockchip platform, so we increase the
the first schedule delay time to 6s for otg_sm_work afer usb
controller calls phy_init(), this can make sure that the usb
controller completes initialization before phy enter suspend.
Signed-off-by: William Wu <william.wu@rock-chips.com>
Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

When resume phy, it need about 1.5 ~ 2ms to wait for
utmi_clk which used for USB controller to become stable.
Signed-off-by: William Wu <william.wu@rock-chips.com>
Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Some Motorola phones like droid 4 use a custom CPCAP PMIC that has a
multiplexing USB PHY.

This USB PHY can operate at least in four modes using pin multiplexing
and two control GPIOS:

- Pass through companion PHY for the SoC USB PHY
- ULPI PHY for the SoC
- Pass through USB for the modem
- UART debug console for the SoC

This patch adds support for droid 4 USB PHY and debug UART modes,
support for other modes can be added later on as needed.

Both peripheral and host mode are working for the USB. The
host mode depends on the cpcap-charger driver for VBUS.

VBUS and ID pin detection are done using cpcap-adc IIO ADC
driver.

Cc: devicetree@vger.kernel.org
Cc: Marcel Partap <mpartap@gmx.net>
Cc: Michael Scott <michael.scott@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Meson8 uses the same USB PHY as found on the Meson8b and GXBB SoCs. Add
a new of_device_id to indicate this. Also update the Kconfig option and
MODULE_DESCRIPTION accordingly.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Meson8 uses the same USB PHY as found on the Meson8b and GXBB SoCs. This
adds a new compatible string to indicate that this binding also supports
the Meson8 SoCs.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

This adds a new driver for the USB2 PHYs found on Meson GXL and GXM SoCs
(both SoCs are using the same USB PHY register layout).

The USB2 PHY is a simple PHY which only has a few registers to configure
the mode (host/device) and a reset register (to enable/disable the PHY).

Unfortunately there are no datasheets available for this PHY. The driver
was written by reading the code from Amlogic's GPL kernel sources and
by analyzing the registers on an actual GXL and GXM device running the
kernel that was shipped on the boards I have.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

This adds the DT binding documentation for the USB2 PHY(s) found in the
Meson GXL and GXM SoCs.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Adding vendor specific directories in phy to group
phy drivers under their respective vendor umbrella.

Also updated the MAINTAINERS file to reflect the correct
directory structure for phy drivers.
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Although ULPI phy is currently being used by tusb1210,
there can be other consumers too in future. So move this
to the includes path for phy.
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Ulpi phy header is not used for anything. Remove the same
from qcom-hs and qcom-hsic phy drivers.
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Suggested-by: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/qualcomm/phy-qcom-qmp.c:847:37-43: ERROR: application of sizeof to pointer

 sizeof when applied to a pointer typed expression gives the size of
 the pointer

Generated by: scripts/coccinelle/misc/noderef.cocci

CC: Vivek Gautam <vivek.gautam@codeaurora.org>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

In case of error, the function of_iomap() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should
be replaced with NULL test.

Fixes: e78f3d15 ("phy: qcom-qmp: new qmp phy driver for qcom-chipsets")
Reviewed-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Pull some more input subsystem updates from Dmitry Torokhov:
 "An updated xpad driver with a few more recognized device IDs, and a
  new psxpad-spi driver, allowing connecting Playstation 1 and 2 joypads
  via SPI bus"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: cros_ec_keyb - remove extraneous 'const'
  Input: add support for PlayStation 1/2 joypads connected via SPI
  Input: xpad - add USB IDs for Mad Catz Brawlstick and Razer Sabertooth
  Input: xpad - sync supported devices with xboxdrv
  Input: xpad - sort supported devices by USB ID

Pull UBI/UBIFS updates from Richard Weinberger:

 - new config option CONFIG_UBIFS_FS_SECURITY

 - minor improvements

 - random fixes

* tag 'upstream-4.12-rc1' of git://git.infradead.org/linux-ubifs:
  ubi: Add debugfs file for tracking PEB state
  ubifs: Fix a typo in comment of ioctl2ubifs & ubifs2ioctl
  ubifs: Remove unnecessary assignment
  ubifs: Fix cut and paste error on sb type comparisons
  ubi: fastmap: Fix slab corruption
  ubifs: Add CONFIG_UBIFS_FS_SECURITY to disable/enable security labels
  ubi: Make mtd parameter readable
  ubi: Fix section mismatch

Pull UML fixes from Richard Weinberger:
 "No new stuff, just fixes"

* 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Add missing NR_CPUS include
  um: Fix to call read_initrd after init_bootmem
  um: Include kbuild.h instead of duplicating its macros
  um: Fix PTRACE_POKEUSER on x86_64
  um: Set number of CPUs
  um: Fix _print_addr()

Merge misc fixes from Andrew Morton:
 "15 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, docs: update memory.stat description with workingset* entries
  mm: vmscan: scan until it finds eligible pages
  mm, thp: copying user pages must schedule on collapse
  dax: fix PMD data corruption when fault races with write
  dax: fix data corruption when fault races with write
  ext4: return to starting transaction in ext4_dax_huge_fault()
  mm: fix data corruption due to stale mmap reads
  dax: prevent invalidation of mapped DAX entries
  Tigran has moved
  mm, vmalloc: fix vmalloc users tracking properly
  mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin
  gcov: support GCC 7.1
  mm, vmstat: Remove spurious WARN() during zoneinfo print
  time: delete current_fs_time()
  hwpoison, memcg: forcibly uncharge LRU pages

Commit 4b4cea91691d ("mm: vmscan: fix IO/refault regression in cache
workingset transition") introduced three new entries in memory stat
file:

 - workingset_refault
 - workingset_activate
 - workingset_nodereclaim

This commit adds a corresponding description to the cgroup v2 docs.

Link: http://lkml.kernel.org/r/1494530293-31236-1-git-send-email-guro@fb.comSigned-off-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Although there are a ton of free swap and anonymous LRU page in elgible
zones, OOM happened.

  balloon invoked oom-killer: gfp_mask=0x17080c0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_NOTRACK), nodemask=(null),  order=0, oom_score_adj=0
  CPU: 7 PID: 1138 Comm: balloon Not tainted 4.11.0-rc6-mm1-zram-00289-ge228d67e9677-dirty #17
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
  Call Trace:
   oom_kill_process+0x21d/0x3f0
   out_of_memory+0xd8/0x390
   __alloc_pages_slowpath+0xbc1/0xc50
   __alloc_pages_nodemask+0x1a5/0x1c0
   pte_alloc_one+0x20/0x50
   __pte_alloc+0x1e/0x110
   __handle_mm_fault+0x919/0x960
   handle_mm_fault+0x77/0x120
   __do_page_fault+0x27a/0x550
   trace_do_page_fault+0x43/0x150
   do_async_page_fault+0x2c/0x90
   async_page_fault+0x28/0x30
  Mem-Info:
  active_anon:424716 inactive_anon:65314 isolated_anon:0
   active_file:52 inactive_file:46 isolated_file:0
   unevictable:0 dirty:27 writeback:0 unstable:0
   slab_reclaimable:3967 slab_unreclaimable:4125
   mapped:133 shmem:43 pagetables:1674 bounce:0
   free:4637 free_pcp:225 free_cma:0
  Node 0 active_anon:1698864kB inactive_anon:261256kB active_file:208kB inactive_file:184kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:532kB dirty:108kB writeback:0kB shmem:172kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no
  DMA free:7316kB min:32kB low:44kB high:56kB active_anon:8064kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB slab_reclaimable:464kB slab_unreclaimable:40kB kernel_stack:0kB pagetables:24kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
  lowmem_reserve[]: 0 992 992 1952
  DMA32 free:9088kB min:2048kB low:3064kB high:4080kB active_anon:952176kB inactive_anon:0kB active_file:36kB inactive_file:0kB unevictable:0kB writepending:88kB present:1032192kB managed:1019388kB mlocked:0kB slab_reclaimable:13532kB slab_unreclaimable:16460kB kernel_stack:3552kB pagetables:6672kB bounce:0kB free_pcp:56kB local_pcp:24kB free_cma:0kB
  lowmem_reserve[]: 0 0 0 959
  Movable free:3644kB min:1980kB low:2960kB high:3940kB active_anon:738560kB inactive_anon:261340kB active_file:188kB inactive_file:640kB unevictable:0kB writepending:20kB present:1048444kB managed:1010816kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:832kB local_pcp:60kB free_cma:0kB
  lowmem_reserve[]: 0 0 0 0
  DMA: 1*4kB (E) 0*8kB 18*16kB (E) 10*32kB (E) 10*64kB (E) 9*128kB (ME) 8*256kB (E) 2*512kB (E) 2*1024kB (E) 0*2048kB 0*4096kB = 7524kB
  DMA32: 417*4kB (UMEH) 181*8kB (UMEH) 68*16kB (UMEH) 48*32kB (UMEH) 14*64kB (MH) 3*128kB (M) 1*256kB (H) 1*512kB (M) 2*1024kB (M) 0*2048kB 0*4096kB = 9836kB
  Movable: 1*4kB (M) 1*8kB (M) 1*16kB (M) 1*32kB (M) 0*64kB 1*128kB (M) 2*256kB (M) 4*512kB (M) 1*1024kB (M) 0*2048kB 0*4096kB = 3772kB
  378 total pagecache pages
  17 pages in swap cache
  Swap cache stats: add 17325, delete 17302, find 0/27
  Free swap  = 978940kB
  Total swap = 1048572kB
  524157 pages RAM
  0 pages HighMem/MovableOnly
  12629 pages reserved
  0 pages cma reserved
  0 pages hwpoisoned
  [ pid ]   uid  tgid total_vm      rss nr_ptes nr_pmds swapents oom_score_adj name
  [  433]     0   433     4904        5      14       3       82             0 upstart-udev-br
  [  438]     0   438    12371        5      27       3      191         -1000 systemd-udevd

With investigation, skipping page of isolate_lru_pages makes reclaim
void because it returns zero nr_taken easily so LRU shrinking is
effectively nothing and just increases priority aggressively.  Finally,
OOM happens.

The problem is that get_scan_count determines nr_to_scan with eligible
zones so although priority drops to zero, it couldn't reclaim any pages
if the LRU contains mostly ineligible pages.

get_scan_count:

        size = lruvec_lru_size(lruvec, lru, sc->reclaim_idx);
	size = size >> sc->priority;

Assumes sc->priority is 0 and LRU list is as follows.

	N-N-N-N-H-H-H-H-H-H-H-H-H-H-H-H-H-H-H-H

(Ie, small eligible pages are in the head of LRU but others are
 almost ineligible pages)

In that case, size becomes 4 so VM want to scan 4 pages but 4 pages from
tail of the LRU are not eligible pages.  If get_scan_count counts
skipped pages, it doesn't reclaim any pages remained after scanning 4
pages so it ends up OOM happening.

This patch makes isolate_lru_pages try to scan pages until it encounters
eligible zones's pages.

[akpm@linux-foundation.org: clean up mind-bending `for' statement.  Tweak comment text]
Fixes: 3db65812 ("Revert "mm, vmscan: account for skipped pages as a partial scan"")
Link: http://lkml.kernel.org/r/1494457232-27401-1-git-send-email-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We have encountered need_resched warnings in __collapse_huge_page_copy()
while doing {clear,copy}_user_highpage() over HPAGE_PMD_NR source pages.

mm->mmap_sem is held for write, but the iteration is well bounded.

Reschedule as needed.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705101426380.109808@chino.kir.corp.google.comSigned-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is based on a patch from Jan Kara that fixed the equivalent race in
the DAX PTE fault path.

Currently DAX PMD read fault can race with write(2) in the following
way:

CPU1 - write(2)                 CPU2 - read fault
                                dax_iomap_pmd_fault()
                                  ->iomap_begin() - sees hole

dax_iomap_rw()
  iomap_apply()
    ->iomap_begin - allocates blocks
    dax_iomap_actor()
      invalidate_inode_pages2_range()
        - there's nothing to invalidate

                                  grab_mapping_entry()
				  - we add huge zero page to the radix tree
				    and map it to page tables

The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.

Fix the problem by locking exception entry before mapping blocks for the
fault.  That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).

Fixes: 9f141d6e ("dax: Call ->iomap_begin without entry lock during dax fault")
Link: http://lkml.kernel.org/r/20170510172700.18991-1-ross.zwisler@linux.intel.comSigned-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently DAX read fault can race with write(2) in the following way:

CPU1 - write(2)			CPU2 - read fault
				dax_iomap_pte_fault()
				  ->iomap_begin() - sees hole
dax_iomap_rw()
  iomap_apply()
    ->iomap_begin - allocates blocks
    dax_iomap_actor()
      invalidate_inode_pages2_range()
        - there's nothing to invalidate
				  grab_mapping_entry()
				  - we add zero page in the radix tree
				    and map it to page tables

The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.

Fix the problem by locking exception entry before mapping blocks for the
fault.  That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).

Fixes: 9f141d6e
Link: http://lkml.kernel.org/r/20170510085419.27601-5-jack@suse.czSigned-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

DAX will return to locking exceptional entry before mapping blocks for a
page fault to fix possible races with concurrent writes.  To avoid lock
inversion between exceptional entry lock and transaction start, start
the transaction already in ext4_dax_huge_fault().

Fixes: 9f141d6e
Link: http://lkml.kernel.org/r/20170510085419.27601-4-jack@suse.czSigned-off-by: Jan Kara <jack@suse.cz>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently, we didn't invalidate page tables during invalidate_inode_pages2()
for DAX.  That could result in e.g. 2MiB zero page being mapped into
page tables while there were already underlying blocks allocated and
thus data seen through mmap were different from data seen by read(2).
The following sequence reproduces the problem:

 - open an mmap over a 2MiB hole

 - read from a 2MiB hole, faulting in a 2MiB zero page

 - write to the hole with write(3p). The write succeeds but we
   incorrectly leave the 2MiB zero page mapping intact.

 - via the mmap, read the data that was just written. Since the zero
   page mapping is still intact we read back zeroes instead of the new
   data.

Fix the problem by unconditionally calling invalidate_inode_pages2_range()
in dax_iomap_actor() for new block allocations and by properly
invalidating page tables in invalidate_inode_pages2_range() for DAX
mappings.

Fixes: c6dcf52c
Link: http://lkml.kernel.org/r/20170510085419.27601-3-jack@suse.czSigned-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "mm,dax: Fix data corruption due to mmap inconsistency",
v4.

This series fixes data corruption that can happen for DAX mounts when
page faults race with write(2) and as a result page tables get out of
sync with block mappings in the filesystem and thus data seen through
mmap is different from data seen through read(2).

The series passes testing with t_mmap_stale test program from Ross and
also other mmap related tests on DAX filesystem.

This patch (of 4):

dax_invalidate_mapping_entry() currently removes DAX exceptional entries
only if they are clean and unlocked.  This is done via:

  invalidate_mapping_pages()
    invalidate_exceptional_entry()
      dax_invalidate_mapping_entry()

However, for page cache pages removed in invalidate_mapping_pages()
there is an additional criteria which is that the page must not be
mapped.  This is noted in the comments above invalidate_mapping_pages()
and is checked in invalidate_inode_page().

For DAX entries this means that we can can end up in a situation where a
DAX exceptional entry, either a huge zero page or a regular DAX entry,
could end up mapped but without an associated radix tree entry.  This is
inconsistent with the rest of the DAX code and with what happens in the
page cache case.

We aren't able to unmap the DAX exceptional entry because according to
its comments invalidate_mapping_pages() isn't allowed to block, and
unmap_mapping_range() takes a write lock on the mapping->i_mmap_rwsem.

Since we essentially never have unmapped DAX entries to evict from the
radix tree, just remove dax_invalidate_mapping_entry().

Fixes: c6dcf52c ("mm: Invalidate DAX radix tree entries only if appropriate")
Link: http://lkml.kernel.org/r/20170510085419.27601-2-jack@suse.czSigned-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>    [4.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>