drivers/scsi/qla2xxx/qla_dbg.c:2542:7: warning: The scope of the variable 'pbuf'
can be reduced. [variableScope]
drivers/scsi/qla2xxx/qla_init.c:3615:6: warning: Variable 'rc' is assigned a
value that is never used. [unreadVariable]
drivers/scsi/qla2xxx/qla_isr.c:81:11-29: WARNING: dma_alloc_coherent use in
rsp_els already zeroes out memory, so memset is not needed
drivers/scsi/qla2xxx/qla_mbx.c:4889:15-33: WARNING: dma_alloc_coherent use in
els_cmd_map already zeroes out memory, so memset is not needed

[mkp: added newline after variable declaration]

Link: https://lore.kernel.org/r/20200403084018.30766-2-njavali@marvell.comReported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NNilesh Javali <njavali@marvell.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If SATA_HOST is n, build fails:

drivers/scsi/hisi_sas/hisi_sas_main.o: In function
`hisi_sas_fill_ata_reset_cmd': hisi_sas_main.c:(.text+0x2500): undefined
reference to `ata_tf_to_fis'

Select SATA_HOST to fix this.

Link: https://lore.kernel.org/r/20200402085812.32948-1-yuehaibing@huawei.com
Fixes: bd322af1 ("ata: make SATA_PMP option selectable only if any SATA host driver is enabled")
Reported-by: NHulk Robot <hulkci@huawei.com>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove dev_err() messages after platform_get_irq*() failures.
platform_get_irq() already prints an error.

Generated by: scripts/coccinelle/api/platform_get_irq.cocci

Fixes: 6c41ac96 ("dmaengine: tegra-apb: Support COMPILE_TEST")
Signed-off-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NJulia Lawall <julia.lawall@inria.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Acked-by: NThierry Reding <treding@nvidia.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2002271133450.2973@hadrienSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For security reasons I stopped using gmail account and kernel address is
now up-to-date alias to my personal address.

People periodically send me emails to address which they found in source
code of drivers, so this change reflects state where people can contact
me.

[ Added .mailmap entry as per Joe Perches  - Linus ]
Signed-off-by: NPali Rohár <pali@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200307104237.8199-1-pali@kernel.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are many places where all basic VMA access flags (read, write,
exec) are initialized or checked against as a group.  One such example
is during page fault.  Existing vma_is_accessible() wrapper already
creates the notion of VMA accessibility as a group access permissions.

Hence lets just create VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which
will not only reduce code duplication but also extend the VMA
accessibility concept in general.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Springer <rspringer@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/1583391014-8170-3-git-send-email-anshuman.khandual@arm.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With amdgpu and CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y, there are
errors like:
BUG: non-zero pgtables_bytes on freeing mm
and:
BUG: Bad rss-counter state
with TTM transparent huge-pages.
Until we've figured out what other TTM drivers do differently compared to
vmwgfx, disable the huge_fault() callback, eliminating transhuge
page-table entries.

Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: NThomas Hellstrom (VMware) <thomas_os@shipmail.org>
Reported-by: NAlex Xu (Hello71) <alex_y_xu@yahoo.ca>
Tested-by: NAlex Xu (Hello71) <alex_y_xu@yahoo.ca>
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200409164925.11912-1-thomas_os@shipmail.org

Intel Comet Lake should use the default LPM policy for mobile chipsets.
So, add the PCI ID to the driver list of supported devices.
Signed-off-by: NJian-Hong Pan <jian-hong@endlessm.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Analogix_dp driver acquires all its resources in the ->bind() callback,
what is a bit against the component driver based approach, where the
driver initialization is split into a probe(), where all resources are
gathered, and a bind(), where all objects are created and a compound
driver is initialized.

Extract all the resource related operations to analogix_dp_probe() and
analogix_dp_remove(), then call them before/after registration of the
device components from the main Exynos DP and Rockchip DP drivers. Also
move the plat_data initialization to the probe() to make it available for
the analogix_dp_probe() function.

This fixes the multiple calls to the bind() of the DRM compound driver
when the DP PHY driver is not yet loaded/probed:

[drm] Exynos DRM: using 14400000.fimd device for DMA mapping operations
exynos-drm exynos-drm: bound 14400000.fimd (ops fimd_component_ops [exynosdrm])
exynos-drm exynos-drm: bound 14450000.mixer (ops mixer_component_ops [exynosdrm])
exynos-dp 145b0000.dp-controller: no DP phy configured
exynos-drm exynos-drm: failed to bind 145b0000.dp-controller (ops exynos_dp_ops [exynosdrm]): -517
exynos-drm exynos-drm: master bind failed: -517
...
[drm] Exynos DRM: using 14400000.fimd device for DMA mapping operations
exynos-drm exynos-drm: bound 14400000.fimd (ops hdmi_enable [exynosdrm])
exynos-drm exynos-drm: bound 14450000.mixer (ops hdmi_enable [exynosdrm])
exynos-drm exynos-drm: bound 145b0000.dp-controller (ops hdmi_enable [exynosdrm])
exynos-drm exynos-drm: bound 14530000.hdmi (ops hdmi_enable [exynosdrm])
[drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
Console: switching to colour frame buffer device 170x48
exynos-drm exynos-drm: fb0: exynosdrmfb frame buffer device
[drm] Initialized exynos 1.1.0 20180330 for exynos-drm on minor 1
...
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Acked-by: NAndy Yan <andy.yan@rock-chips.com>
Reviewed-by: NAndrzej Hajda <a.hajda@samsung.com>
Signed-off-by: NAndrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200310103427.26048-1-m.szyprowski@samsung.com
(cherry picked from commit 83a19677)
Signed-off-by: NMaxime Ripard <maxime@cerno.tech>

fixes unused variable warning.
Reported-by: NEric Biggers <ebiggers@kernel.org>
Acked-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NMikita Lipski <mikita.lipski@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Make the fw_write_wait default case true since presumably all new
gfx9 asics will have updated firmware. That is using unique WAIT_REG_MEM
packet with opration=1.
Signed-off-by: NAaron Liu <aaron.liu@amd.com>
Tested-by: NAaron Liu <aaron.liu@amd.com>
Tested-by: NYuxian Dai <Yuxian.Dai@amd.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NHuang Rui <ray.huang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

For Arcturus, forcing clock to some specific level is not supported
with 54.18 and onwards SMU firmware. As according to firmware team,
they adopt new gfx dpm tuned parameters which can cover all the use
case in a much smooth way. Thus setting through driver interface
is not needed and maybe do a disservice.
Signed-off-by: NEvan Quan <evan.quan@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

The system will be hang up during S3 suspend because of SMU is pending
for GC not respose the register CP_HQD_ACTIVE access request.This issue
root cause of accessing the GC register under enter GFX CGGPG and can
be fixed by disable GFX CGPG before perform suspend.

v2: Use disable the GFX CGPG instead of RLC safe mode guard.
Signed-off-by: NPrike Liang <Prike.Liang@amd.com>
Tested-by: NMengbing Wang <Mengbing.Wang@amd.com>
Reviewed-by: NHuang Rui <ray.huang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

CONFIG_AS_MOVNTDQA was introduced by commit 0b1de5d5 ("drm/i915:
Use SSE4.1 movntdqa to accelerate reads from WC memory").

We raise the minimal supported binutils version from time to time.
The last bump was commit 1fb12b35 ("kbuild: Raise the minimum
required binutils version to 2.21").

I confirmed the code in $(call as-instr,...) can be assembled by the
binutils 2.21 assembler and also by LLVM integrated assembler.

Remove CONFIG_AS_MOVNTDQA, which is always defined.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NJason A. Donenfeld <Jason@zx2c4.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NJani Nikula <jani.nikula@intel.com>

Fix a spelling typo in cpuidle-haltpoll.c.
Signed-off-by: NYihao Wu <wuyihao@linux.alibaba.com>
[ rjw: Subject & changelog ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add a new sysfs attribute to show how many NVMe devices are remapped.

Userspace like distro installer can use this info to ask user to change
the BIOS setting.
Signed-off-by: NKai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The use of `delay_usecs` in terminate_request() was replaced with the new
`delay` struct used by the SPI subsystem, however the unit was
set to SPI_DELAY_UNIT_NSECS instead of SPI_DELAY_UNIT_USECS. This fixes that.

Fixes: 7d3ca507 ("platform/chrome: cros_ec_spi: Use new structure for SPI transfer delays")
Signed-off-by: NBenson Leung <bleung@chromium.org>

The variable ret is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

During system resume from suspend, this can be observed on ASM1062 PMP
controller:

ata10.01: SATA link down (SStatus 0 SControl 330)
ata10.02: hard resetting link
ata10.02: SATA link down (SStatus 0 SControl 330)
ata10.00: configured for UDMA/133
Kernel panic - not syncing: stack-protector: Kernel
 in: sata_pmp_eh_recover+0xa2b/0xa40

CPU: 2 PID: 230 Comm: scsi_eh_9 Tainted: P OE
#49-Ubuntu
Hardware name: System manufacturer System Product
 1001 12/10/2017
Call Trace:
dump_stack+0x63/0x8b
panic+0xe4/0x244
? sata_pmp_eh_recover+0xa2b/0xa40
__stack_chk_fail+0x19/0x20
sata_pmp_eh_recover+0xa2b/0xa40
? ahci_do_softreset+0x260/0x260 [libahci]
? ahci_do_hardreset+0x140/0x140 [libahci]
? ata_phys_link_offline+0x60/0x60
? ahci_stop_engine+0xc0/0xc0 [libahci]
sata_pmp_error_handler+0x22/0x30
ahci_error_handler+0x45/0x80 [libahci]
ata_scsi_port_error_handler+0x29b/0x770
? ata_scsi_cmd_error_handler+0x101/0x140
ata_scsi_error+0x95/0xd0
? scsi_try_target_reset+0x90/0x90
scsi_error_handler+0xd0/0x5b0
kthread+0x121/0x140
? scsi_eh_get_sense+0x200/0x200
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x22/0x40
Kernel Offset: 0xcc00000 from 0xffffffff81000000
(relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Since sata_pmp_eh_recover_pmp() doens't set rc when ATA_DFLAG_DETACH is
set, sata_pmp_eh_recover() continues to run. During retry it triggers
the stack protector.

Set correct rc in sata_pmp_eh_recover_pmp() to let sata_pmp_eh_recover()
jump to pmp_fail directly.

BugLink: https://bugs.launchpad.net/bugs/1821434
Cc: stable@vger.kernel.org
Signed-off-by: NKai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

[WHY]
In cases where a clock table is malformed such that fclk entries have
frequencies but not voltages listed, we don't catch the error and set
clocks to 0 instead of using hardcoded values as we should.

[HOW]
Add check for clock tables fclk entry's voltage as well
Signed-off-by: NMichael Strauss <michael.strauss@amd.com>
Reviewed-by: NEric Yang <eric.yang2@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

[Why]
If dc->clk_mgr->funcs->are_clock_states_equal is set, then
wm_optimized_required is never checked. In that case, when going from a
higher mode to a lower mode, wm_optimized_required remains true until
the next mode change.

[How]
 - move from else-if to unconditional or
Signed-off-by: NJoshua Aberback <joshua.aberback@amd.com>
Reviewed-by: NJun Lei <Jun.Lei@amd.com>
Reviewed-by: NNicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Reviewed-by: NYongqiang Sun <yongqiang.sun@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
In some usecases, like tiled display, the stream and plane configuration
can be setup in a way where the caller expects DAL to perform the
clipping, eg:

P0:
src_rect(0, 0, w, h)
dst_rect(0, 0, w, h)

P1:
src_rect(w, 0, w, h)
dst_rect(0, 0, w, h)

Cursor is enabled on both streams with the same position.

This can result in double cursor on tiled display, even though this
behavior is technically correct from the DC interface point of view.

We need a mechanism to control this dynamically.

[How]
This is something that should live in the DM layer based on detection
of the specified configuration but it's not something that we really
have enough information to deal with today.

Add a flag to the cursor position state that specifies whether we
want DC to do the translation or not and make it opt-in and let
the DM decide when to do it.
Signed-off-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: NTony Cheng <Tony.Cheng@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
If a plane isn't being actively enabled or disabled then DC won't
always recalculate scaling rects and ratios for the primary plane.

This results in only a partial or corrupted rect being displayed on
the screen instead of scaling to fit the screen.

[How]
Add back the logic to recalculate the scaling rects into
dc_commit_updates_for_stream since this is the expected place to
do it in DC.

This was previously removed a few years ago to fix an underscan issue
but underscan is still functional now with this change - and it should
be, since this is only updating to the latest plane state getting passed
in.
Signed-off-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: NAric Cyr <Aric.Cyr@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
For medium updates that change nothing but the source rect position
the viewport doesn't change on DCN20.

We're missing the check for the position update bit that was there in
the DCN10 hardware sequencer.

[How]
Check the position bit along with the scaling bit like we were doing
with DCN20.

We shouldn't actually hit a case where context != current_state in
our programming/commit model but guard against it anyway since it was
guarded for the other bits.
Signed-off-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: NZhan Liu <Zhan.Liu@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
Cursor pos is correctly adjusted from DC side for source rect offset
on DCN ASIC, but only on the overlay.

This is because DM places offsets the cursor for primary planes only
to workaround missing code in DCE for the adjustment we're now correctly
doing in DC for DCN ASIC.

[How]
Drop the adjustment for source rect from the DM side of things and put
the code where it actually belongs - in DC on the pipe level.

This matches what we do for DCN now.
Signed-off-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: NZhan Liu <Zhan.Liu@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
Changing policy to dynamic will allow 4k multi display configs
to be supported at DPM0
Signed-off-by: NEric Yang <Eric.Yang2@amd.com>
Reviewed-by: NTony Cheng <Tony.Cheng@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
Cursor is drawn as part of the framebuffer for a plane on AMD hardware.
The cursor position on the framebuffer does not change even if the
source rect viewport for the cursor does. This causes the cursor to be
clipped.

The following IGT tests fail as a result of this issue:

- kms_plane_cursor@pipe-*-viewport-size-*

[How]
Offset cursor position by plane source rect viewport. If the viewport
is unscaled then the cursor is now correctly positioned on any
plane - primary or overlay.

There is still a hardware limitation for dealing with the cursor size
being incorrectly scaled but that's not something we can address.

Add some documentation explaining some of this in the code while we're
at it.
Signed-off-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: NZhan Liu <Zhan.Liu@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
After v_total_min and max are updated in vrr structure, the changes are
not reflected in stream adjust. When these values are read from stream
adjust it does not reflect the actual state of the system.

[How]
Set stream adjust values equal to vrr adjust values after vrr adjust
values are updated.
Signed-off-by: NIsabel Zhang <isabel.zhang@amd.com>
Reviewed-by: NAlvin Lee <Alvin.Lee2@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
Prop are created at boot stage, and not allowed to create new prop
after device registration.

[How]
Reuse the connector property from SST if exist.
Signed-off-by: NJerry (Fangzhi) Zuo <Jerry.Zuo@amd.com>
Reviewed-by: NHersen Wu <hersenxs.wu@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Replace dev_warn() with dev_info() and note that they are
optional to avoid confusing users.

The RAS TAs only exist on server boards and the HDCP and DTM
TAs only exist on client boards.  They are optional either way.
Acked-by: NNirmoy Das <nirmoy.das@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

prefix RAS error related dmesg print with pci device info
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: NJohn Clements <john.clements@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

upon receiving uncorrectable error, query every GPU node for ras errors
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: NJohn Clements <john.clements@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Incorrect CG sequence will cause gfx timedout,
if we keep switching power profile mode
(enter profile mod such as PEAK will disable CG,
exit profile mode EXIT will enable CG)
when run Vulkan test case(case used for test: vkexample).
Signed-off-by: NChengming Gui <Jack.Gui@amd.com>
Reviewed-by: NKenneth Feng <kenneth.feng@amd.com>
Acked-by: NEvan Quan <evan.quan@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Adds LKDTM tests for arithmetic overflow (both signed and unsigned), as
well as array bounds checking.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Elena Petrova <lenaptr@google.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Link: http://lkml.kernel.org/r/20200227193516.32566-4-keescook@chromium.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For now, distributions implement advanced udev rules to essentially
- Don't online any hotplugged memory (s390x)
- Online all memory to ZONE_NORMAL (e.g., most virt environments like
  hyperv)
- Online all memory to ZONE_MOVABLE in case the zone imbalance is taken
  care of (e.g., bare metal, special virt environments)

In summary: All memory is usually onlined the same way, however, the
kernel always has to ask user space to come up with the same answer.
E.g., Hyper-V always waits for a memory block to get onlined before
continuing, otherwise it might end up adding memory faster than
onlining it, which can result in strange OOM situations.  This waiting
slows down adding of a bigger amount of memory.

Let's allow to specify a default online_type, not just "online" and
"offline".  This allows distributions to configure the default online_type
when booting up and be done with it.

We can now specify "offline", "online", "online_movable" and
"online_kernel" via
- "memhp_default_state=" on the kernel cmdline
- /sys/devices/system/memory/auto_online_blocks
just like we are able to specify for a single memory block via
/sys/devices/system/memory/memoryX/state
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NWei Yang <richard.weiyang@gmail.com>
Reviewed-by: NBaoquan He <bhe@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Yumei Huang <yuhuang@redhat.com>
Link: http://lkml.kernel.org/r/20200317104942.11178-9-david@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

...  and rename it to memhp_default_online_type.  This is a preparation
for more detailed default online behavior.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NWei Yang <richard.weiyang@gmail.com>
Reviewed-by: NBaoquan He <bhe@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Yumei Huang <yuhuang@redhat.com>
Link: http://lkml.kernel.org/r/20200317104942.11178-8-david@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We get the MEM_ONLINE notifier call if memory is added right from the
kernel via add_memory() or later from user space.

Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt
mechanism (->done) for that.  Initialize the wait event only once and
reinitialize before adding memory.  Unconditionally call complete() and
wait_for_completion_timeout().

If there are no waiters, complete() will only increment ->done - which
will be reset by reinit_completion().  If complete() has already been
called, wait_for_completion_timeout() will not wait.

There is still the chance for a small race between concurrent
reinit_completion() and complete().  If complete() wins, we would not wait
- which is tolerable (and the race exists in current code as well).

Note: We only wait for "some" memory to get onlined, which seems to be
      good enough for now.

[akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David]
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NBaoquan He <bhe@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Yumei Huang <yuhuang@redhat.com>
Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Let's use a simple array which we can reuse soon.  While at it, move the
string->mmop conversion out of the device hotplug lock.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NWei Yang <richard.weiyang@gmail.com>
Reviewed-by: NBaoquan He <bhe@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Yumei Huang <yuhuang@redhat.com>
Link: http://lkml.kernel.org/r/20200317104942.11178-4-david@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Historically, we used the value -1.  Just treat 0 as the special case now.
Clarify a comment (which was wrong, when we come via device_online() the
first time, the online_type would have been 0 / MEM_ONLINE).  The default
is now always MMOP_OFFLINE.  This removes the last user of the manual
"-1", which didn't use the enum value.

This is a preparation to use the online_type as an array index.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NWei Yang <richard.weiyang@gmail.com>
Reviewed-by: NBaoquan He <bhe@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Yumei Huang <yuhuang@redhat.com>
Link: http://lkml.kernel.org/r/20200317104942.11178-3-david@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/memory_hotplug: allow to specify a default online_type", v3.

Distributions nowadays use udev rules ([1] [2]) to specify if and how to
online hotplugged memory.  The rules seem to get more complex with many
special cases.  Due to the various special cases,
CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE cannot be used.  All memory hotplug
is handled via udev rules.

Every time we hotplug memory, the udev rule will come to the same
conclusion.  Especially Hyper-V (but also soon virtio-mem) add a lot of
memory in separate memory blocks and wait for memory to get onlined by
user space before continuing to add more memory blocks (to not add memory
faster than it is getting onlined).  This of course slows down the whole
memory hotplug process.

To make the job of distributions easier and to avoid udev rules that get
more and more complicated, let's extend the mechanism provided by
- /sys/devices/system/memory/auto_online_blocks
- "memhp_default_state=" on the kernel cmdline
to be able to specify also "online_movable" as well as "online_kernel"

=== Example /usr/libexec/config-memhotplug ===

#!/bin/bash

VIRT=`systemd-detect-virt --vm`
ARCH=`uname -p`

sense_virtio_mem() {
  if [ -d "/sys/bus/virtio/drivers/virtio_mem/" ]; then
    DEVICES=`find /sys/bus/virtio/drivers/virtio_mem/ -maxdepth 1 -type l | wc -l`
    if [ $DEVICES != "0" ]; then
        return 0
    fi
  fi
  return 1
}

if [ ! -e "/sys/devices/system/memory/auto_online_blocks" ]; then
  echo "Memory hotplug configuration support missing in the kernel"
  exit 1
fi

if grep "memhp_default_state=" /proc/cmdline > /dev/null; then
  echo "Memory hotplug configuration overridden in kernel cmdline (memhp_default_state=)"
  exit 1
fi

if [ $VIRT == "microsoft" ]; then
  echo "Detected Hyper-V on $ARCH"
  # Hyper-V wants all memory in ZONE_NORMAL
  ONLINE_TYPE="online_kernel"
elif sense_virtio_mem; then
  echo "Detected virtio-mem on $ARCH"
  # virtio-mem wants all memory in ZONE_NORMAL
  ONLINE_TYPE="online_kernel"
elif [ $ARCH == "s390x" ] || [ $ARCH == "s390" ]; then
  echo "Detected $ARCH"
  # standby memory should not be onlined automatically
  ONLINE_TYPE="offline"
elif [ $ARCH == "ppc64" ] || [ $ARCH == "ppc64le" ]; then
  echo "Detected" $ARCH
  # PPC64 onlines all hotplugged memory right from the kernel
  ONLINE_TYPE="offline"
elif [ $VIRT == "none" ]; then
  echo "Detected bare-metal on $ARCH"
  # Bare metal users expect hotplugged memory to be unpluggable. We assume
  # that ZONE imbalances on such enterpise servers cannot happen and is
  # properly documented
  ONLINE_TYPE="online_movable"
else
  # TODO: Hypervisors that want to unplug DIMMs and can guarantee that ZONE
  # imbalances won't happen
  echo "Detected $VIRT on $ARCH"
  # Usually, ballooning is used in virtual environments, so memory should go to
  # ZONE_NORMAL. However, sometimes "movable_node" is relevant.
  ONLINE_TYPE="online"
fi

echo "Selected online_type:" $ONLINE_TYPE

# Configure what to do with memory that will be hotplugged in the future
echo $ONLINE_TYPE 2>/dev/null > /sys/devices/system/memory/auto_online_blocks
if [ $? != "0" ]; then
  echo "Memory hotplug cannot be configured (e.g., old kernel or missing permissions)"
  # A backup udev rule should handle old kernels if necessary
  exit 1
fi

# Process all already pluggedd blocks (e.g., DIMMs, but also Hyper-V or virtio-mem)
if [ $ONLINE_TYPE != "offline" ]; then
  for MEMORY in /sys/devices/system/memory/memory*; do
    STATE=`cat $MEMORY/state`
    if [ $STATE == "offline" ]; then
        echo $ONLINE_TYPE > $MEMORY/state
    fi
  done
fi

=== Example /usr/lib/systemd/system/config-memhotplug.service ===

[Unit]
Description=Configure memory hotplug behavior
DefaultDependencies=no
Conflicts=shutdown.target
Before=sysinit.target shutdown.target
After=systemd-modules-load.service
ConditionPathExists=|/sys/devices/system/memory/auto_online_blocks

[Service]
ExecStart=/usr/libexec/config-memhotplug
Type=oneshot
TimeoutSec=0
RemainAfterExit=yes

[Install]
WantedBy=sysinit.target

=== Example modification to the 40-redhat.rules [2] ===

: diff --git a/40-redhat.rules b/40-redhat.rules-new
: index 2c690e5..168fd03 100644
: --- a/40-redhat.rules
: +++ b/40-redhat.rules-new
: @@ -6,6 +6,9 @@ SUBSYSTEM=="cpu", ACTION=="add", TEST=="online", ATTR{online}=="0", ATTR{online}
:  # Memory hotadd request
:  SUBSYSTEM!="memory", GOTO="memory_hotplug_end"
:  ACTION!="add", GOTO="memory_hotplug_end"
: +# memory hotplug behavior configured
: +PROGRAM=="grep online /sys/devices/system/memory/auto_online_blocks", GOTO="memory_hotplug_end"
: +
:  PROGRAM="/bin/uname -p", RESULT=="s390*", GOTO="memory_hotplug_end"
:
:  ENV{.state}="online"

===

[1] https://github.com/lnykryn/systemd-rhel/pull/281
[2] https://github.com/lnykryn/systemd-rhel/blob/staging/rules/40-redhat.rules

This patch (of 8):

The name is misleading and it's not really clear what is "kept".  Let's
just name it like the online_type name we expose to user space ("online").

Add some documentation to the types.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NWei Yang <richard.weiyang@gmail.com>
Reviewed-by: NBaoquan He <bhe@redhat.com>
Acked-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Yumei Huang <yuhuang@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Link: http://lkml.kernel.org/r/20200319131221.14044-1-david@redhat.com
Link: http://lkml.kernel.org/r/20200317104942.11178-2-david@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pages_correctly_probed() is a leftover from ancient times.  It dates back
to commit 3947be19 ("[PATCH] memory hotplug: sysfs and add/remove
functions"), where Pg_reserved checks were added as a sfety net:

	/*
	 * The probe routines leave the pages reserved, just
	 * as the bootmem code does.  Make sure they're still
	 * that way.
	 */

The checks were refactored quite a bit over the years, especially in
commit b77eab70 ("mm/memory_hotplug: optimize probe routine"), where
checks for present, valid, and online sections were added.

Hotplugged memory is added via add_memory(), which will create the full
memmap for the hotplugged memory, and mark all sections valid and present.

Only full memory blocks are onlined/offlined, so we also cannot have an
inconsistency in that regard (especially, memory blocks with some sections
being online and some being offline).

1. Boot memory always starts online.  Since commit c5e79ef5
   ("mm/memory_hotplug.c: don't allow to online/offline memory blocks with
   holes") we disallow to offline any memory with holes.  Therefore, we
   never online memory with holes.  Present and validity checks are
   superfluous.

2. Only complete memory blocks are onlined/offlined (and especially,
   the state - online or offline - is stored for whole memory blocks).
   Besides the core, only arch/powerpc/platforms/powernv/memtrace.c
   manually calls offline_pages() and fiddels with memory block states.
   But it also only offlines complete memory blocks.

3. To make any of these conditions trigger, something would have to be
   terribly messed up in the core.  (e.g., online/offline only some
   sections of a memory block).

4. Memory unplug properly makes sure that all sysfs attributes were
   removed (and therefore, that all threads left the sysfs handlers).  We
   don't have to worry about zombie devices at this point.

5. The valid_section_nr(section_nr) check is actually dead code, as it
   would never have been reached due to the WARN_ON_ONCE(!pfn_valid(pfn)).

No wonder we haven't seen any of these errors in a long time (or even
   ever, according to my search).  Let's just get rid of them.  Now, all
   checks that could hinder onlining and offlining are completely
   contained in online_pages()/offline_pages().
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Link: http://lkml.kernel.org/r/20200127110424.5757-3-david@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>