Patch series "mm/memory_hotplug: "auto-movable" online policy and memory groups", v3.

I. Goal

The goal of this series is improving in-kernel auto-online support.  It
tackles the fundamental problems that:

 1) We can create zone imbalances when onlining all memory blindly to
    ZONE_MOVABLE, in the worst case crashing the system. We have to know
    upfront how much memory we are going to hotplug such that we can
    safely enable auto-onlining of all hotplugged memory to ZONE_MOVABLE
    via "online_movable". This is far from practical and only applicable in
    limited setups -- like inside VMs under the RHV/oVirt hypervisor which
    will never hotplug more than 3 times the boot memory (and the
    limitation is only in place due to the Linux limitation).

 2) We see more setups that implement dynamic VM resizing, hot(un)plugging
    memory to resize VM memory. In these setups, we might hotplug a lot of
    memory, but it might happen in various small steps in both directions
    (e.g., 2 GiB -> 8 GiB -> 4 GiB -> 16 GiB ...). virtio-mem is the
    primary driver of this upstream right now, performing such dynamic
    resizing NUMA-aware via multiple virtio-mem devices.

    Onlining all hotplugged memory to ZONE_NORMAL means we basically have
    no hotunplug guarantees. Onlining all to ZONE_MOVABLE means we can
    easily run into zone imbalances when growing a VM. We want a mixture,
    and we want as much memory as reasonable/configured in ZONE_MOVABLE.
    Details regarding zone imbalances can be found at [1].

 3) Memory devices consist of 1..X memory block devices, however, the
    kernel doesn't really track the relationship. Consequently, also user
    space has no idea. We want to make per-device decisions.

    As one example, for memory hotunplug it doesn't make sense to use a
    mixture of zones within a single DIMM: we want all MOVABLE if
    possible, otherwise all !MOVABLE, because any !MOVABLE part will easily
    block the whole DIMM from getting hotunplugged.

    As another example, virtio-mem operates on individual units that span
    1..X memory blocks. Similar to a DIMM, we want a unit to either be all
    MOVABLE or !MOVABLE. A "unit" can be thought of like a DIMM, however,
    all units of a virtio-mem device logically belong together and are
    managed (added/removed) by a single driver. We want as much memory of
    a virtio-mem device to be MOVABLE as possible.

 4) We want memory onlining to be done right from the kernel while adding
    memory, not triggered by user space via udev rules; for example, this
    is reqired for fast memory hotplug for drivers that add individual
    memory blocks, like virito-mem. We want a way to configure a policy in
    the kernel and avoid implementing advanced policies in user space.

The auto-onlining support we have in the kernel is not sufficient.  All we
have is a) online everything MOVABLE (online_movable) b) online everything
!MOVABLE (online_kernel) c) keep zones contiguous (online).  This series
allows configuring c) to mean instead "online movable if possible
according to the coniguration, driven by a maximum MOVABLE:KERNEL ratio"
-- a new onlining policy.

II. Approach

This series does 3 things:

 1) Introduces the "auto-movable" online policy that initially operates on
    individual memory blocks only. It uses a maximum MOVABLE:KERNEL ratio
    to make a decision whether a memory block will be onlined to
    ZONE_MOVABLE or not. However, in the basic form, hotplugged KERNEL
    memory does not allow for more MOVABLE memory (details in the
    patches). CMA memory is treated like MOVABLE memory.

 2) Introduces static (e.g., DIMM) and dynamic (e.g., virtio-mem) memory
    groups and uses group information to make decisions in the
    "auto-movable" online policy across memory blocks of a single memory
    device (modeled as memory group). More details can be found in patch
    #3 or in the DIMM example below.

 3) Maximizes ZONE_MOVABLE memory within dynamic memory groups, by
    allowing ZONE_NORMAL memory within a dynamic memory group to allow for
    more ZONE_MOVABLE memory within the same memory group. The target use
    case is dynamic VM resizing using virtio-mem. See the virtio-mem
    example below.

I remember that the basic idea of using a ratio to implement a policy in
the kernel was once mentioned by Vitaly Kuznetsov, but I might be wrong (I
lost the pointer to that discussion).

For me, the main use case is using it along with virtio-mem (and DIMMs /
ppc64 dlpar where necessary) for dynamic resizing of VMs, increasing the
amount of memory we can hotunplug reliably again if we might eventually
hotplug a lot of memory to a VM.

III. Target Usage

The target usage will be:

 1) Linux boots with "mhp_default_online_type=offline"

 2) User space (e.g., systemd unit) configures memory onlining (according
    to a config file and system properties), for example:
    * Setting memory_hotplug.online_policy=auto-movable
    * Setting memory_hotplug.auto_movable_ratio=301
    * Setting memory_hotplug.auto_movable_numa_aware=true

 3) User space enabled auto onlining via "echo online >
    /sys/devices/system/memory/auto_online_blocks"

 4) User space triggers manual onlining of all already-offline memory
    blocks (go over offline memory blocks and set them to "online")

IV. Example

For DIMMs, hotplugging 4 GiB DIMMs to a 4 GiB VM with a configured ratio of
301% results in the following layout:
	Memory block 0-15:    DMA32   (early)
	Memory block 32-47:   Normal  (early)
	Memory block 48-79:   Movable (DIMM 0)
	Memory block 80-111:  Movable (DIMM 1)
	Memory block 112-143: Movable (DIMM 2)
	Memory block 144-275: Normal  (DIMM 3)
	Memory block 176-207: Normal  (DIMM 4)
	... all Normal
	(-> hotplugged Normal memory does not allow for more Movable memory)

For virtio-mem, using a simple, single virtio-mem device with a 4 GiB VM
will result in the following layout:
	Memory block 0-15:    DMA32   (early)
	Memory block 32-47:   Normal  (early)
	Memory block 48-143:  Movable (virtio-mem, first 12 GiB)
	Memory block 144:     Normal  (virtio-mem, next 128 MiB)
	Memory block 145-147: Movable (virtio-mem, next 384 MiB)
	Memory block 148:     Normal  (virtio-mem, next 128 MiB)
	Memory block 149-151: Movable (virtio-mem, next 384 MiB)
	... Normal/Movable mixture as above
	(-> hotplugged Normal memory allows for more Movable memory within
	    the same device)

Which gives us maximum flexibility when dynamically growing/shrinking a
VM in smaller steps.

V. Doc Update

I'll update the memory-hotplug.rst documentation, once the overhaul [1] is
usptream. Until then, details can be found in patch #2.

VI. Future Work

 1) Use memory groups for ppc64 dlpar
 2) Being able to specify a portion of (early) kernel memory that will be
    excluded from the ratio. Like "128 MiB globally/per node" are excluded.

    This might be helpful when starting VMs with extremely small memory
    footprint (e.g., 128 MiB) and hotplugging memory later -- not wanting
    the first hotplugged units getting onlined to ZONE_MOVABLE. One
    alternative would be a trigger to not consider ZONE_DMA memory
    in the ratio. We'll have to see if this is really rrequired.
 3) Indicate to user space that MOVABLE might be a bad idea -- especially
    relevant when memory ballooning without support for balloon compaction
    is active.

This patch (of 9):

For implementing a new memory onlining policy, which determines when to
online memory blocks to ZONE_MOVABLE semi-automatically, we need the
number of present early (boot) pages -- present pages excluding hotplugged
pages.  Let's track these pages per zone.

Pass a page instead of the zone to adjust_present_page_count(), similar as
adjust_managed_page_count() and derive the zone from the page.

It's worth noting that a memory block to be offlined/onlined is either
completely "early" or "not early".  add_memory() and friends can only add
complete memory blocks and we only online/offline complete (individual)
memory blocks.

Link: https://lkml.kernel.org/r/20210806124715.17090-1-david@redhat.com
Link: https://lkml.kernel.org/r/20210806124715.17090-2-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Cc: Hui Zhu <teawater@gmail.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We allocate + initialize everything from scratch.  In case enabling the
device fails, we free all memory resourcs.

Link: https://lkml.kernel.org/r/20210712124052.26491-5-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jia He <justin.he@arm.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Cc: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is only a single user remaining.  We can simply lookup the nid only
used for node offlining purposes when walking our memory blocks.  We don't
expect to remove multi-nid ranges; and if we'd ever do, we most probably
don't care about removing multi-nid ranges that actually result in empty
nodes.

If ever required, we can detect the "multi-nid" scenario and simply try
offlining all online nodes.

Link: https://lkml.kernel.org/r/20210712124052.26491-4-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jia He <justin.he@arm.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@ionos.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The parameter is unused, let's remove it.

Link: https://lkml.kernel.org/r/20210712124052.26491-3-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Acked-by: Heiko Carstens <hca@linux.ibm.com>	[s390]
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Joe Perches <joe@perches.com>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Jia He <justin.he@arm.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/memory_hotplug: preparatory patches for new online policy and memory"

These are all cleanups and one fix previously sent as part of [1]:
[PATCH v1 00/12] mm/memory_hotplug: "auto-movable" online policy and memory
groups.

These patches make sense even without the other series, therefore I pulled
them out to make the other series easier to digest.

[1] https://lkml.kernel.org/r/20210607195430.48228-1-david@redhat.com

This patch (of 4):

Checkpatch complained on a follow-up patch that we are using "unsigned"
here, which defaults to "unsigned int" and checkpatch is correct.

As we will search for a fitting zone using the wrong pfn, we might end
up onlining memory to one of the special kernel zones, such as ZONE_DMA,
which can end badly as the onlined memory does not satisfy properties of
these zones.

Use "unsigned long" instead, just as we do in other places when handling
PFNs.  This can bite us once we have physical addresses in the range of
multiple TB.

Link: https://lkml.kernel.org/r/20210712124052.26491-2-david@redhat.com
Fixes: e5e68930 ("mm, memory_hotplug: display allowed zones in the preferred ordering")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: virtualization@lists.linux-foundation.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jia He <justin.he@arm.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Cc: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When test_pages_in_a_zone() used pfn_valid_within() is has some logic
surrounding pfn_valid_within() checks.

Since pfn_valid_within() is gone, this logic can be removed.

Link: https://lkml.kernel.org/r/20210713080035.7464-3-rppt@kernel.orgSigned-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE".

After recent updates to freeing unused parts of the memory map, no
architecture can have holes in the memory map within a pageblock.  This
makes pfn_valid_within() check and CONFIG_HOLES_IN_ZONE configuration
option redundant.

The first patch removes them both in a mechanical way and the second patch
simplifies memory_hotplug::test_pages_in_a_zone() that had
pfn_valid_within() surrounded by more logic than simple if.

This patch (of 2):

After recent changes in freeing of the unused parts of the memory map and
rework of pfn_valid() in arm and arm64 there are no architectures that can
have holes in the memory map within a pageblock and so nothing can enable
CONFIG_HOLES_IN_ZONE which guards non trivial implementation of
pfn_valid_within().

With that, pfn_valid_within() is always hardwired to 1 and can be
completely removed.

Remove calls to pfn_valid_within() and CONFIG_HOLES_IN_ZONE.

Link: https://lkml.kernel.org/r/20210713080035.7464-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20210713080035.7464-2-rppt@kernel.orgSigned-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The memory hot(un)plug documentation is outdated and incomplete.  Most of
the content dates back to 2007, so it's time for a major overhaul.

Let's rewrite, reorganize and update most parts of the documentation.  In
addition to memory hot(un)plug, also add some details regarding
ZONE_MOVABLE, with memory hotunplug being one of its main consumers.

Drop the file history, that information can more reliably be had from the
git log.

The style of the document is also properly fixed that e.g., "restview"
renders it cleanly now.

In the future, we might add some more details about virt users like
virtio-mem, the XEN balloon, the Hyper-V balloon and ppc64 dlpar.

Link: https://lkml.kernel.org/r/20210707073205.3835-3-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "memory-hotplug.rst: complete admin-guide overhaul", v3.

This patch (of 2):

We have the same content at Documentation/core-api/memory-hotplug.rst and
it doesn't fit into the admin-guide.  The documentation was accidentially
duplicated when merging.

Link: https://lkml.kernel.org/r/20210707073205.3835-1-david@redhat.com
Link: https://lkml.kernel.org/r/20210707073205.3835-2-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull clk fix from Stephen Boyd:
 "One hotfix for a NULL pointer deref in the Renesas usb clk driver"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: renesas: rcar-usb2-clock-sel: Fix kernel NULL pointer dereference

Pull scheduler fixes from Borislav Petkov:

 - Have get_push_task() check whether current has migration disabled and
   thus avoid useless invocations of the migration thread

 - Rework initialization flow so that all rq->core's are initialized,
   even of CPUs which have not been onlined yet, so that iterating over
   them all works as expected

* tag 'sched_urgent_for_v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix get_push_task() vs migrate_disable()
  sched: Fix Core-wide rq->lock for uninitialized CPUs

Pull irq fix from Borislav Petkov:

 - Have msix_mask_all() check a global control which says whether MSI-X
   masking should be done and thus make it usable on Xen-PV too

* tag 'irq_urgent_for_v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  PCI/MSI: Skip masking MSI-X on Xen PV

Pull perf fixes from Borislav Petkov:

 - Prevent the amd/power module from being removed while in use

 - Mark AMD IBS as not supporting content exclusion

 - Add a workaround for AMD erratum #1197 where IBS registers might not
   be restored properly after exiting CC6 state

 - Fix a potential truncation of a 32-bit variable due to shifting

 - Read the correct bits describing the number of configurable address
   ranges on Intel PT

* tag 'perf_urgent_for_v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/power: Assign pmu.module
  perf/x86/amd/ibs: Extend PERF_PMU_CAP_NO_EXCLUDE to IBS Op
  perf/x86/amd/ibs: Work around erratum #1197
  perf/x86/intel/uncore: Fix integer overflow on 23 bit left shift of a u32
  perf/x86/intel/pt: Fix mask of num_address_ranges

Pull x86 fixes from Borislav Petkov:

 - Fix build error on RHEL where -Werror=maybe-uninitialized is set.

 - Restore the firmware's IDT when calling EFI boot services and before
   ExitBootServices() has been called. This fixes a boot failure on what
   appears to be a tablet with 32-bit UEFI running a 64-bit kernel.

* tag 'x86_urgent_for_v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/resctrl: Fix a maybe-uninitialized build warning treated as error
  x86/efi: Restore Firmware IDT before calling ExitBootServices()

This reverts commit 83af58f8.

It turns out that at least the assembly implementation for strncpy() was
buggy.  Revert the whole commit and return back to the default coding.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.4+
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The probe was manually passing NULL instead of dev to devm_clk_hw_register.
This caused a Unable to handle kernel NULL pointer dereference error.
Fix this by passing 'dev'.
Signed-off-by: Adam Ford <aford173@gmail.com>
Fixes: a20a40a8 ("clk: renesas: rcar-usb2-clock-sel: Fix error handling in .probe()")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Pull SCSI fix from James Bottomley:
 "A single fix for a race introduced by a fix that went into 5.14-rc5"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: core: Fix hang of freezing queue between blocking and running device

Pull USB fixes from Greg KH:
 "Here are a few tiny USB fixes for reported issues with some USB
  drivers.

  These fixes include:

   - gadget driver fixes for regressions

   - tcpm driver fix

   - dwc3 driver fixes

   - xhci renesas firmware loading fix, again.

   - usb serial option driver device id addition

   - usb serial ch341 revert for regression

  All all of these have been in linux-next with no reported problems"

* tag 'usb-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: gadget: u_audio: fix race condition on endpoint stop
  usb: gadget: f_uac2: fixup feedback endpoint stop
  usb: typec: tcpm: Raise vdm_sm_running flag only when VDM SM is running
  usb: renesas-xhci: Prefer firmware loading on unknown ROM state
  usb: dwc3: gadget: Stop EP0 transfers during pullup disable
  usb: dwc3: gadget: Fix dwc3_calc_trbs_left()
  Revert "USB: serial: ch341: fix character loss at high transfer rates"
  USB: serial: option: add new VID/PID to support Fibocom FG150

Pull powerpc fixes from Michael Ellerman:

 - Fix scv implicit soft-mask table for relocated (eg. kdump) kernels

 - Re-enable ARCH_ENABLE_SPLIT_PMD_PTLOCK, which was disabled due to a
   typo

Thanks to Lukas Bulwahn, Nicholas Piggin, and Daniel Axtens.

* tag 'powerpc-5.14-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Fix scv implicit soft-mask table for relocated kernels
  powerpc: Re-enable ARCH_ENABLE_SPLIT_PMD_PTLOCK

Pull block fixes from Jens Axboe:

 - Revert the mq-deadline priority handling, it's causing serious
   performance regressions. While experimental patches exists to fix
   this up, it's too late to do so now. Revert it and re-do it properly
   for 5.15 instead.

 - Fix a NULL vs IS_ERR() regression in this release (Dan)

 - Fix a mq-deadline accounting regression in this release (Bart)

 - Mark cryptoloop as deprecated. It's broken and dm-crypt fully
   supports it, and it's actively intefering with loop. Plan on removal
   for 5.16 (Christoph)

* tag 'block-5.14-2021-08-27' of git://git.kernel.dk/linux-block:
  cryptoloop: add a deprecation warning
  pd: fix a NULL vs IS_ERR() check
  Revert "block/mq-deadline: Prioritize high-priority requests"
  mq-deadline: Fix request accounting

Pull ARM SoC fixes from Arnd Bergmann:
 "Just two trivial fixes from the reset driver tree, nothing else came
  up since the last soc fixes"

* tag 'soc-fixes-5.14-4' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  reset: reset-zynqmp: Fixed the argument data type
  reset: RESET_MCHP_SPARX5 should depend on ARCH_SPARX5

Pull ACPI fix from Rafael Wysocki:
 "Fix a regression introduced during this cycle that has been partially
  addressed by an earlier commit (Andy Shevchenko)"

* tag 'acpi-5.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  media: ipu3-cio2: Drop reference on error path in cio2_bridge_connect_sensor()

Pull power management fixes from Rafael Wysocki:
 "These fix two issues introduced during this cycle, one of which is a
  regression and the other one affects new code.

  Specifics:

   - Prevent the operating performance points (OPP) code from crashing
     when some entries in the table of required OPPs are set to error
     pointer values (Marijn Suijten)

   - Prevent the generic power domains (genpd) framework from
     incorrectly overriding the performance state of a device set by its
     driver while it is runtime-suspended or when runtime PM of it is
     disabled (Dmitry Osipenko)"

* tag 'pm-5.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: domains: Improve runtime PM performance state handling
  opp: core: Check for pending links before reading required_opp pointers

virtio_mem_set_fake_offline() might sleep now, and we call it under
rcu_read_lock(). To fix it, simply move the rcu_read_unlock() further
up, as we're done with the device.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 6cc26d77: "virtio-mem: use page_offline_(start|end) when setting PageOffline()
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* pm-opp:
  opp: core: Check for pending links before reading required_opp pointers

Pull RISC-V fixes from Palmer Dabbelt:

 - device tree updates for the Microsemi Polarfire development kit that
   fix some mismatches between the u-boot and Linux enternet entries

 - ensure that the F register state is correctly reflected in core dumps

* tag 'riscv-for-linus-5.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: dts: microchip: Add ethernet0 to the aliases node
  riscv: dts: microchip: Use 'local-mac-address' for emac1
  riscv: Ensure the value of FP registers in the core dump file is up to date

Pull MMC host fix from Ulf Hansson:

 - sdhci-iproc: Fix clock error for ACPI rpi's

* tag 'mmc-v5.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  Revert "mmc: sdhci-iproc: Set SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN on BCM2711"

Support for cryptoloop has been officially marked broken and deprecated
in favor of dm-crypt (which supports the same broken algorithms if
needed) in Linux 2.6.4 (released in March 2004), and support for it has
been entirely removed from losetup in util-linux 2.23 (released in April
2013).  Add a warning and a deprecation schedule.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210827163250.255325-1-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull ARM fix from Russell King:
 "Resolve a Keystone 2 kernel mapping regression"

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 9104/2: Fix Keystone 2 kernel mapping regression

This reverts commit 419dd626.

It turned out that the change from the reverted commit breaks the ACPI
based rpi's because it causes the 100Mhz max clock to be overridden to the
return from sdhci_iproc_get_max_clock(), which is 0 because there isn't a
OF/DT based clock device.
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Fixes: 419dd626 ("mmc: sdhci-iproc: Set SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN on BCM2711")
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

If the endpoint completion callback is call right after the ep_enabled flag
is cleared and before usb_ep_dequeue() is call, we could do a double free
on the request and the associated buffer.

Fix this by clearing ep_enabled after all the endpoint requests have been
dequeued.

Fixes: 7de8681b ("usb: gadget: u_audio: Free requests only after callback")
Cc: stable <stable@vger.kernel.org>
Reported-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20210827092927.366482-1-jbrunet@baylibre.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When the uac2 function is stopped, there seems to be an issue reported on
some platforms (Intel Merrifield at least)

BUG: kernel NULL pointer dereference, address: 0000000000000008
...
RIP: 0010:dwc3_gadget_del_and_unmap_request+0x19/0xe0
...
Call Trace:
 dwc3_remove_requests.constprop.0+0x12f/0x170
 __dwc3_gadget_ep_disable+0x7a/0x160
 dwc3_gadget_ep_disable+0x3d/0xd0
 usb_ep_disable+0x1c/0x70
 u_audio_stop_capture+0x79/0x120 [u_audio]
 afunc_set_alt+0x73/0x80 [usb_f_uac2]
 composite_setup+0x224/0x1b90 [libcomposite]

The issue happens only when the gadget is using the sync type "async", not
"adaptive". This indicates that problem is coming from the feedback
endpoint, which is only used with async synchronization mode.

The problem is that request is freed regardless of usb_ep_dequeue(), which
ends up badly if the request is not actually dequeued yet.

Update the feedback endpoint free function to release the endpoint the same
way it is done for the data endpoint, which takes care of the problem.

Fixes: 24f779da ("usb: gadget: f_uac2/u_audio: add feedback endpoint support")
Reported-by: Ferry Toth <ftoth@exalondelft.nl>
Tested-by: Ferry Toth <ftoth@exalondelft.nl>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20210827075853.266912-1-jbrunet@baylibre.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

blk_mq_alloc_disk() returns error pointers, it doesn't return NULL
so correct the check.

Fixes: 262d431f ("pd: use blk_mq_alloc_disk and blk_cleanup_disk")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20210827100023.GB9449@kiliSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull drm fixes from Dave Airlie:
 "Last set of fixes for 5.14, nothing major a couple of i915, couple of
  imx and a few amdgpu. All pretty small.

  i915:
   - Fix syncmap memory leak
   - Drop redundant display port debug print

  amdgpu:
   - Fix for pinning display buffers multiple times
   - Fix delayed work handling for GFXOFF
   - Fix build when CONFIG_SUSPEND is not set

  imx:
   - fix planar offset calculations
   - fix accidental partial revert"

* tag 'drm-fixes-2021-08-27' of git://anongit.freedesktop.org/drm/drm:
  drm/i915/dp: Drop redundant debug print
  drm/i915: Fix syncmap memory leak
  drm/amdgpu: Fix build with missing pm_suspend_target_state module export
  drm/amdgpu: Cancel delayed work when GFXOFF is disabled
  drm/amdgpu: use the preferred pin domain after the check
  drm/imx: ipuv3-plane: fix accidental partial revert of 8 pixel alignment fix
  gpu: ipu-v3: Fix i.MX IPU-v3 offset calculations for (semi)planar U/V formats

drm/imx: imx-drm alignment and plane offset fixes

Fix an accidental partial revert of commit 94dfec48 ("drm/imx: Add 8
pixel alignment fix") and plane offset calculations for capture of
non-aligned resolutions.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/85a41af99beb2c9e7d6020435a135bf9f205a5ff.camel@pengutronix.de

Merge tag 'amd-drm-fixes-5.14-2021-08-25' of https://gitlab.freedesktop.org/agd5f/linux into drm-fixes

amd-drm-fixes-5.14-2021-08-25:

amdgpu:
- Fix for pinning display buffers multiple times
- Fix delayed work handling for GFXOFF
- Fix build when CONFIG_SUSPEND is not set
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210826032658.4068-1-alexander.deucher@amd.com

Merge tag 'drm-intel-fixes-2021-08-26' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

- Fix syncmap memory leak
- Drop redundant display port debug print
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/YSfSeHbyS5wBZtNJ@intel.com

When running as Xen PV guest, masking MSI-X is a responsibility of the
hypervisor. The guest has no write access to the relevant BAR at all - when
it tries to, it results in a crash like this:

    BUG: unable to handle page fault for address: ffffc9004069100c
    #PF: supervisor write access in kernel mode
    #PF: error_code(0x0003) - permissions violation
    RIP: e030:__pci_enable_msix_range.part.0+0x26b/0x5f0
     e1000e_set_interrupt_capability+0xbf/0xd0 [e1000e]
     e1000_probe+0x41f/0xdb0 [e1000e]
     local_pci_probe+0x42/0x80
    (...)

The recently introduced function msix_mask_all() does not check the global
variable pci_msi_ignore_mask which is set by XEN PV to bypass the masking
of MSI[-X] interrupts.

Add the check to make this function XEN PV compatible.

Fixes: 7d5ec3d3 ("PCI/MSI: Mask all unused MSI-X entries")
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210826170342.135172-1-marmarek@invisiblethingslab.com

Pull nfsd fix from Bruce Fields:
 "This is a one-liner fix for a serious bug that can cause the server to
  become unresponsive to a client, so I think it's worth the last-minute
  inclusion for 5.14"

* tag 'nfsd-5.14-1' of git://linux-nfs.org/~bfields/linux:
  SUNRPC: Fix XPT_BUSY flag leakage in svc_handle_xprt()...