<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/base, branch v5.18-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'devprop-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2022-03-29T18:30:12+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-29T18:30:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=13776ebb9964b2ea66ffb8c824c0762eed6da784'/>
<id>13776ebb9964b2ea66ffb8c824c0762eed6da784</id>
<content type='text'>
Pull device properties code update from Rafael Wysocki:
 "This is based on new i2c material for 5.18-rc1 and simply reorganizes
  the code on top of it so as to group similar functions together (Andy
  Shevchenko)"

* tag 'devprop-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  device property: Don't split fwnode_get_irq*() APIs in the code
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull device properties code update from Rafael Wysocki:
 "This is based on new i2c material for 5.18-rc1 and simply reorganizes
  the code on top of it so as to group similar functions together (Andy
  Shevchenko)"

* tag 'devprop-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  device property: Don't split fwnode_get_irq*() APIs in the code
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core</title>
<updated>2022-03-28T19:41:28+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-28T19:41:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=266d17a8c0d857a579813ad185cd1640b0d6ccac'/>
<id>266d17a8c0d857a579813ad185cd1640b0d6ccac</id>
<content type='text'>
Pull driver core updates from Greg KH:
 "Here is the set of driver core changes for 5.18-rc1.

  Not much here, primarily it was a bunch of cleanups and small updates:

   - kobj_type cleanups for default_groups

   - documentation updates

   - firmware loader minor changes

   - component common helper added and take advantage of it in many
     drivers (the largest part of this pull request).

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (54 commits)
  Documentation: update stable review cycle documentation
  drivers/base/dd.c : Remove the initial value of the global variable
  Documentation: update stable tree link
  Documentation: add link to stable release candidate tree
  devres: fix typos in comments
  Documentation: add note block surrounding security patch note
  samples/kobject: Use sysfs_emit instead of sprintf
  base: soc: Make soc_device_match() simpler and easier to read
  driver core: dd: fix return value of __setup handler
  driver core: Refactor sysfs and drv/bus remove hooks
  driver core: Refactor multiple copies of device cleanup
  scripts: get_abi.pl: Fix typo in help message
  kernfs: fix typos in comments
  kernfs: remove unneeded #if 0 guard
  ALSA: hda/realtek: Make use of the helper component_compare_dev_name
  video: omapfb: dss: Make use of the helper component_compare_dev
  power: supply: ab8500: Make use of the helper component_compare_dev
  ASoC: codecs: wcd938x: Make use of the helper component_compare/release_of
  iommu/mediatek: Make use of the helper component_compare/release_of
  drm: of: Make use of the helper component_release_of
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core updates from Greg KH:
 "Here is the set of driver core changes for 5.18-rc1.

  Not much here, primarily it was a bunch of cleanups and small updates:

   - kobj_type cleanups for default_groups

   - documentation updates

   - firmware loader minor changes

   - component common helper added and take advantage of it in many
     drivers (the largest part of this pull request).

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (54 commits)
  Documentation: update stable review cycle documentation
  drivers/base/dd.c : Remove the initial value of the global variable
  Documentation: update stable tree link
  Documentation: add link to stable release candidate tree
  devres: fix typos in comments
  Documentation: add note block surrounding security patch note
  samples/kobject: Use sysfs_emit instead of sprintf
  base: soc: Make soc_device_match() simpler and easier to read
  driver core: dd: fix return value of __setup handler
  driver core: Refactor sysfs and drv/bus remove hooks
  driver core: Refactor multiple copies of device cleanup
  scripts: get_abi.pl: Fix typo in help message
  kernfs: fix typos in comments
  kernfs: remove unneeded #if 0 guard
  ALSA: hda/realtek: Make use of the helper component_compare_dev_name
  video: omapfb: dss: Make use of the helper component_compare_dev
  power: supply: ab8500: Make use of the helper component_compare_dev
  ASoC: codecs: wcd938x: Make use of the helper component_compare/release_of
  iommu/mediatek: Make use of the helper component_compare/release_of
  drm: of: Make use of the helper component_release_of
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'i2c/for-mergewindow' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux</title>
<updated>2022-03-26T19:46:08+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-26T19:46:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5627ecb8374a00163d90bc92c33f829ac27895b2'/>
<id>5627ecb8374a00163d90bc92c33f829ac27895b2</id>
<content type='text'>
Pull i2c updates from Wolfram Sang:

 - tracepoints when Linux acts as an I2C client

 - added support for AMD PSP

 - whole subsystem now uses generic_handle_irq_safe()

 - piix4 driver gained MMIO access enabling so far missed controllers
   with AMD chipsets

 - a bulk of device driver updates, refactorization, and fixes.

* 'i2c/for-mergewindow' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (61 commits)
  i2c: mux: demux-pinctrl: do not deactivate a master that is not active
  i2c: meson: Fix wrong speed use from probe
  i2c: add tracepoints for I2C slave events
  i2c: designware: Remove code duplication
  i2c: cros-ec-tunnel: Fix syntax errors in comments
  MAINTAINERS: adjust XLP9XX I2C DRIVER after removing the devicetree binding
  i2c: designware: Mark dw_i2c_plat_{suspend,resume}() as __maybe_unused
  i2c: mediatek: Add i2c compatible for Mediatek MT8168
  dt-bindings: i2c: update bindings for MT8168 SoC
  i2c: mt65xx: Simplify with clk-bulk
  i2c: i801: Drop two outdated comments
  i2c: xiic: Make bus names unique
  i2c: i801: Add support for the Process Call command
  i2c: i801: Drop useless masking in i801_access
  i2c: tegra: Add SMBus block read function
  i2c: designware: Use the i2c_mark_adapter_suspended/resumed() helpers
  i2c: designware: Lock the adapter while setting the suspended flag
  i2c: mediatek: remove redundant null check
  i2c: mediatek: modify bus speed calculation formula
  i2c: designware: Fix improper usage of readl
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull i2c updates from Wolfram Sang:

 - tracepoints when Linux acts as an I2C client

 - added support for AMD PSP

 - whole subsystem now uses generic_handle_irq_safe()

 - piix4 driver gained MMIO access enabling so far missed controllers
   with AMD chipsets

 - a bulk of device driver updates, refactorization, and fixes.

* 'i2c/for-mergewindow' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (61 commits)
  i2c: mux: demux-pinctrl: do not deactivate a master that is not active
  i2c: meson: Fix wrong speed use from probe
  i2c: add tracepoints for I2C slave events
  i2c: designware: Remove code duplication
  i2c: cros-ec-tunnel: Fix syntax errors in comments
  MAINTAINERS: adjust XLP9XX I2C DRIVER after removing the devicetree binding
  i2c: designware: Mark dw_i2c_plat_{suspend,resume}() as __maybe_unused
  i2c: mediatek: Add i2c compatible for Mediatek MT8168
  dt-bindings: i2c: update bindings for MT8168 SoC
  i2c: mt65xx: Simplify with clk-bulk
  i2c: i801: Drop two outdated comments
  i2c: xiic: Make bus names unique
  i2c: i801: Add support for the Process Call command
  i2c: i801: Drop useless masking in i801_access
  i2c: tegra: Add SMBus block read function
  i2c: designware: Use the i2c_mark_adapter_suspended/resumed() helpers
  i2c: designware: Lock the adapter while setting the suspended flag
  i2c: mediatek: remove redundant null check
  i2c: mediatek: modify bus speed calculation formula
  i2c: designware: Fix improper usage of readl
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2022-03-22T23:11:53+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-22T23:11:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3bf03b9a0839c9fb06927ae53ebd0f960b19d408'/>
<id>3bf03b9a0839c9fb06927ae53ebd0f960b19d408</id>
<content type='text'>
Merge updates from Andrew Morton:

 - A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs

 - Most the MM patches which precede the patches in Willy's tree: kasan,
   pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
   sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb,
   userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp,
   cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap,
   zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon.

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (227 commits)
  mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release()
  Docs/ABI/testing: add DAMON sysfs interface ABI document
  Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface
  selftests/damon: add a test for DAMON sysfs interface
  mm/damon/sysfs: support DAMOS stats
  mm/damon/sysfs: support DAMOS watermarks
  mm/damon/sysfs: support schemes prioritization
  mm/damon/sysfs: support DAMOS quotas
  mm/damon/sysfs: support DAMON-based Operation Schemes
  mm/damon/sysfs: support the physical address space monitoring
  mm/damon/sysfs: link DAMON for virtual address spaces monitoring
  mm/damon: implement a minimal stub for sysfs-based DAMON interface
  mm/damon/core: add number of each enum type values
  mm/damon/core: allow non-exclusive DAMON start/stop
  Docs/damon: update outdated term 'regions update interval'
  Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling
  Docs/vm/damon: call low level monitoring primitives the operations
  mm/damon: remove unnecessary CONFIG_DAMON option
  mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}()
  mm/damon/dbgfs-test: fix is_target_id() change
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge updates from Andrew Morton:

 - A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs

 - Most the MM patches which precede the patches in Willy's tree: kasan,
   pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
   sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb,
   userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp,
   cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap,
   zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon.

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (227 commits)
  mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release()
  Docs/ABI/testing: add DAMON sysfs interface ABI document
  Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface
  selftests/damon: add a test for DAMON sysfs interface
  mm/damon/sysfs: support DAMOS stats
  mm/damon/sysfs: support DAMOS watermarks
  mm/damon/sysfs: support schemes prioritization
  mm/damon/sysfs: support DAMOS quotas
  mm/damon/sysfs: support DAMON-based Operation Schemes
  mm/damon/sysfs: support the physical address space monitoring
  mm/damon/sysfs: link DAMON for virtual address spaces monitoring
  mm/damon: implement a minimal stub for sysfs-based DAMON interface
  mm/damon/core: add number of each enum type values
  mm/damon/core: allow non-exclusive DAMON start/stop
  Docs/damon: update outdated term 'regions update interval'
  Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling
  Docs/vm/damon: call low level monitoring primitives the operations
  mm/damon: remove unnecessary CONFIG_DAMON option
  mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}()
  mm/damon/dbgfs-test: fix is_target_id() change
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/base/memory: clarify adding and removing of memory blocks</title>
<updated>2022-03-22T22:57:10+00:00</updated>
<author>
<name>David Hildenbrand</name>
<email>david@redhat.com</email>
</author>
<published>2022-03-22T21:47:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2aa065f7afb28aabb475cc27f24cb18c5141173d'/>
<id>2aa065f7afb28aabb475cc27f24cb18c5141173d</id>
<content type='text'>
Let's make it clearer at which places we actually add and remove memory
blocks -- streamlining the terminology -- and highlight which memory block
start out online and which start out as offline.

 * rename add_memory_block -&gt; add_boot_memory_block
 * rename init_memory_block -&gt; add_memory_block
 * rename unregister_memory -&gt; remove_memory_block
 * rename register_memory -&gt; __add_memory_block
 * add add_hotplug_memory_block
 * mark add_boot_memory_block with __init (suggested by Oscar)

__add_memory_block() is  a pure helper for add_memory_block(), remove
the somewhat obvious comment.

Link: https://lkml.kernel.org/r/20220221154531.11382-1-david@redhat.com
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Let's make it clearer at which places we actually add and remove memory
blocks -- streamlining the terminology -- and highlight which memory block
start out online and which start out as offline.

 * rename add_memory_block -&gt; add_boot_memory_block
 * rename init_memory_block -&gt; add_memory_block
 * rename unregister_memory -&gt; remove_memory_block
 * rename register_memory -&gt; __add_memory_block
 * add add_hotplug_memory_block
 * mark add_boot_memory_block with __init (suggested by Oscar)

__add_memory_block() is  a pure helper for add_memory_block(), remove
the somewhat obvious comment.

Link: https://lkml.kernel.org/r/20220221154531.11382-1-david@redhat.com
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/base/memory: determine and store zone for single-zone memory blocks</title>
<updated>2022-03-22T22:57:10+00:00</updated>
<author>
<name>David Hildenbrand</name>
<email>david@redhat.com</email>
</author>
<published>2022-03-22T21:47:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=395f6081bad49f9c54abafebab49ee23aa985bbd'/>
<id>395f6081bad49f9c54abafebab49ee23aa985bbd</id>
<content type='text'>
test_pages_in_a_zone() is just another nasty PFN walker that can easily
stumble over ZONE_DEVICE memory ranges falling into the same memory block
as ordinary system RAM: the memmap of parts of these ranges might possibly
be uninitialized.  In fact, we observed (on an older kernel) with UBSAN:

  UBSAN: Undefined behaviour in ./include/linux/mm.h:1133:50
  index 7 is out of range for type 'zone [5]'
  CPU: 121 PID: 35603 Comm: read_all Kdump: loaded Tainted: [...]
  Hardware name: Dell Inc. PowerEdge R7425/08V001, BIOS 1.12.2 11/15/2019
  Call Trace:
   dump_stack+0x9a/0xf0
   ubsan_epilogue+0x9/0x7a
   __ubsan_handle_out_of_bounds+0x13a/0x181
   test_pages_in_a_zone+0x3c4/0x500
   show_valid_zones+0x1fa/0x380
   dev_attr_show+0x43/0xb0
   sysfs_kf_seq_show+0x1c5/0x440
   seq_read+0x49d/0x1190
   vfs_read+0xff/0x300
   ksys_read+0xb8/0x170
   do_syscall_64+0xa5/0x4b0
   entry_SYSCALL_64_after_hwframe+0x6a/0xdf
  RIP: 0033:0x7f01f4439b52

We seem to stumble over a memmap that contains a garbage zone id.  While
we could try inserting pfn_to_online_page() calls, it will just make
memory offlining slower, because we use test_pages_in_a_zone() to make
sure we're offlining pages that all belong to the same zone.

Let's just get rid of this PFN walker and determine the single zone of a
memory block -- if any -- for early memory blocks during boot.  For memory
onlining, we know the single zone already.  Let's avoid any additional
memmap scanning and just rely on the zone information available during
boot.

For memory hot(un)plug, we only really care about memory blocks that:
* span a single zone (and, thereby, a single node)
* are completely System RAM (IOW, no holes, no ZONE_DEVICE)
If one of these conditions is not met, we reject memory offlining.
Hotplugged memory blocks (starting out offline), always meet both
conditions.

There are three scenarios to handle:

(1) Memory hot(un)plug

A memory block with zone == NULL cannot be offlined, corresponding to
our previous test_pages_in_a_zone() check.

After successful memory onlining/offlining, we simply set the zone
accordingly.
* Memory onlining: set the zone we just used for onlining
* Memory offlining: set zone = NULL

So a hotplugged memory block starts with zone = NULL. Once memory
onlining is done, we set the proper zone.

(2) Boot memory with !CONFIG_NUMA

We know that there is just a single pgdat, so we simply scan all zones
of that pgdat for an intersection with our memory block PFN range when
adding the memory block. If more than one zone intersects (e.g., DMA and
DMA32 on x86 for the first memory block) we set zone = NULL and
consequently mimic what test_pages_in_a_zone() used to do.

(3) Boot memory with CONFIG_NUMA

At the point in time we create the memory block devices during boot, we
don't know yet which nodes *actually* span a memory block. While we could
scan all zones of all nodes for intersections, overlapping nodes complicate
the situation and scanning all nodes is possibly expensive. But that
problem has already been solved by the code that sets the node of a memory
block and creates the link in the sysfs --
do_register_memory_block_under_node().

So, we hook into the code that sets the node id for a memory block. If
we already have a different node id set for the memory block, we know
that multiple nodes *actually* have PFNs falling into our memory block:
we set zone = NULL and consequently mimic what test_pages_in_a_zone() used
to do. If there is no node id set, we do the same as (2) for the given
node.

Note that the call order in driver_init() is:
-&gt; memory_dev_init(): create memory block devices
-&gt; node_dev_init(): link memory block devices to the node and set the
		    node id

So in summary, we detect if there is a single zone responsible for this
memory block and we consequently store the zone in that case in the
memory block, updating it during memory onlining/offlining.

Link: https://lkml.kernel.org/r/20220210184359.235565-3-david@redhat.com
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Reported-by: Rafael Parra &lt;rparrazo@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Rafael Parra &lt;rparrazo@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
test_pages_in_a_zone() is just another nasty PFN walker that can easily
stumble over ZONE_DEVICE memory ranges falling into the same memory block
as ordinary system RAM: the memmap of parts of these ranges might possibly
be uninitialized.  In fact, we observed (on an older kernel) with UBSAN:

  UBSAN: Undefined behaviour in ./include/linux/mm.h:1133:50
  index 7 is out of range for type 'zone [5]'
  CPU: 121 PID: 35603 Comm: read_all Kdump: loaded Tainted: [...]
  Hardware name: Dell Inc. PowerEdge R7425/08V001, BIOS 1.12.2 11/15/2019
  Call Trace:
   dump_stack+0x9a/0xf0
   ubsan_epilogue+0x9/0x7a
   __ubsan_handle_out_of_bounds+0x13a/0x181
   test_pages_in_a_zone+0x3c4/0x500
   show_valid_zones+0x1fa/0x380
   dev_attr_show+0x43/0xb0
   sysfs_kf_seq_show+0x1c5/0x440
   seq_read+0x49d/0x1190
   vfs_read+0xff/0x300
   ksys_read+0xb8/0x170
   do_syscall_64+0xa5/0x4b0
   entry_SYSCALL_64_after_hwframe+0x6a/0xdf
  RIP: 0033:0x7f01f4439b52

We seem to stumble over a memmap that contains a garbage zone id.  While
we could try inserting pfn_to_online_page() calls, it will just make
memory offlining slower, because we use test_pages_in_a_zone() to make
sure we're offlining pages that all belong to the same zone.

Let's just get rid of this PFN walker and determine the single zone of a
memory block -- if any -- for early memory blocks during boot.  For memory
onlining, we know the single zone already.  Let's avoid any additional
memmap scanning and just rely on the zone information available during
boot.

For memory hot(un)plug, we only really care about memory blocks that:
* span a single zone (and, thereby, a single node)
* are completely System RAM (IOW, no holes, no ZONE_DEVICE)
If one of these conditions is not met, we reject memory offlining.
Hotplugged memory blocks (starting out offline), always meet both
conditions.

There are three scenarios to handle:

(1) Memory hot(un)plug

A memory block with zone == NULL cannot be offlined, corresponding to
our previous test_pages_in_a_zone() check.

After successful memory onlining/offlining, we simply set the zone
accordingly.
* Memory onlining: set the zone we just used for onlining
* Memory offlining: set zone = NULL

So a hotplugged memory block starts with zone = NULL. Once memory
onlining is done, we set the proper zone.

(2) Boot memory with !CONFIG_NUMA

We know that there is just a single pgdat, so we simply scan all zones
of that pgdat for an intersection with our memory block PFN range when
adding the memory block. If more than one zone intersects (e.g., DMA and
DMA32 on x86 for the first memory block) we set zone = NULL and
consequently mimic what test_pages_in_a_zone() used to do.

(3) Boot memory with CONFIG_NUMA

At the point in time we create the memory block devices during boot, we
don't know yet which nodes *actually* span a memory block. While we could
scan all zones of all nodes for intersections, overlapping nodes complicate
the situation and scanning all nodes is possibly expensive. But that
problem has already been solved by the code that sets the node of a memory
block and creates the link in the sysfs --
do_register_memory_block_under_node().

So, we hook into the code that sets the node id for a memory block. If
we already have a different node id set for the memory block, we know
that multiple nodes *actually* have PFNs falling into our memory block:
we set zone = NULL and consequently mimic what test_pages_in_a_zone() used
to do. If there is no node id set, we do the same as (2) for the given
node.

Note that the call order in driver_init() is:
-&gt; memory_dev_init(): create memory block devices
-&gt; node_dev_init(): link memory block devices to the node and set the
		    node id

So in summary, we detect if there is a single zone responsible for this
memory block and we consequently store the zone in that case in the
memory block, updating it during memory onlining/offlining.

Link: https://lkml.kernel.org/r/20220210184359.235565-3-david@redhat.com
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Reported-by: Rafael Parra &lt;rparrazo@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Rafael Parra &lt;rparrazo@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/base/node: rename link_mem_sections() to register_memory_block_under_node()</title>
<updated>2022-03-22T22:57:10+00:00</updated>
<author>
<name>David Hildenbrand</name>
<email>david@redhat.com</email>
</author>
<published>2022-03-22T21:47:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cc6515591b25f08ce199e9379844a964f52a27f2'/>
<id>cc6515591b25f08ce199e9379844a964f52a27f2</id>
<content type='text'>
Patch series "drivers/base/memory: determine and store zone for single-zone memory blocks", v2.

I remember talking to Michal in the past about removing
test_pages_in_a_zone(), which we use for:
* verifying that a memory block we intend to offline is really only managed
  by a single zone. We don't support offlining of memory blocks that are
  managed by multiple zones (e.g., multiple nodes, DMA and DMA32)
* exposing that zone to user space via
  /sys/devices/system/memory/memory*/valid_zones

Now that I identified some more cases where test_pages_in_a_zone() might
go wrong, and we received an UBSAN report (see patch #3), let's get rid of
this PFN walker.

So instead of detecting the zone at runtime with test_pages_in_a_zone() by
scanning the memmap, let's determine and remember for each memory block if
it's managed by a single zone.  The stored zone can then be used for the
above two cases, avoiding a manual lookup using test_pages_in_a_zone().

This avoids eventually stumbling over uninitialized memmaps in corner
cases, especially when ZONE_DEVICE ranges partly fall into memory block
(that are responsible for managing System RAM).

Handling memory onlining is easy, because we online to exactly one zone.
Handling boot memory is more tricky, because we want to avoid scanning all
zones of all nodes to detect possible zones that overlap with the physical
memory region of interest.  Fortunately, we already have code that
determines the applicable nodes for a memory block, to create sysfs links
-- we'll hook into that.

Patch #1 is a simple cleanup I had laying around for a longer time.
Patch #2 contains the main logic to remove test_pages_in_a_zone() and
further details.

[1] https://lkml.kernel.org/r/20220128144540.153902-1-david@redhat.com
[2] https://lkml.kernel.org/r/20220203105212.30385-1-david@redhat.com

This patch (of 2):

Let's adjust the stale terminology, making it match
unregister_memory_block_under_nodes() and
do_register_memory_block_under_node().  We're dealing with memory block
devices, which span 1..X memory sections.

Link: https://lkml.kernel.org/r/20220210184359.235565-1-david@redhat.com
Link: https://lkml.kernel.org/r/20220210184359.235565-2-david@redhat.com
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Rafael Parra &lt;rparrazo@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Patch series "drivers/base/memory: determine and store zone for single-zone memory blocks", v2.

I remember talking to Michal in the past about removing
test_pages_in_a_zone(), which we use for:
* verifying that a memory block we intend to offline is really only managed
  by a single zone. We don't support offlining of memory blocks that are
  managed by multiple zones (e.g., multiple nodes, DMA and DMA32)
* exposing that zone to user space via
  /sys/devices/system/memory/memory*/valid_zones

Now that I identified some more cases where test_pages_in_a_zone() might
go wrong, and we received an UBSAN report (see patch #3), let's get rid of
this PFN walker.

So instead of detecting the zone at runtime with test_pages_in_a_zone() by
scanning the memmap, let's determine and remember for each memory block if
it's managed by a single zone.  The stored zone can then be used for the
above two cases, avoiding a manual lookup using test_pages_in_a_zone().

This avoids eventually stumbling over uninitialized memmaps in corner
cases, especially when ZONE_DEVICE ranges partly fall into memory block
(that are responsible for managing System RAM).

Handling memory onlining is easy, because we online to exactly one zone.
Handling boot memory is more tricky, because we want to avoid scanning all
zones of all nodes to detect possible zones that overlap with the physical
memory region of interest.  Fortunately, we already have code that
determines the applicable nodes for a memory block, to create sysfs links
-- we'll hook into that.

Patch #1 is a simple cleanup I had laying around for a longer time.
Patch #2 contains the main logic to remove test_pages_in_a_zone() and
further details.

[1] https://lkml.kernel.org/r/20220128144540.153902-1-david@redhat.com
[2] https://lkml.kernel.org/r/20220203105212.30385-1-david@redhat.com

This patch (of 2):

Let's adjust the stale terminology, making it match
unregister_memory_block_under_nodes() and
do_register_memory_block_under_node().  We're dealing with memory block
devices, which span 1..X memory sections.

Link: https://lkml.kernel.org/r/20220210184359.235565-1-david@redhat.com
Link: https://lkml.kernel.org/r/20220210184359.235565-2-david@redhat.com
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Rafael Parra &lt;rparrazo@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/base/node: consolidate node device subsystem initialization in node_dev_init()</title>
<updated>2022-03-22T22:57:10+00:00</updated>
<author>
<name>David Hildenbrand</name>
<email>david@redhat.com</email>
</author>
<published>2022-03-22T21:47:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2848a28b0a6052a4c8450397d2647d7d8e3f6f06'/>
<id>2848a28b0a6052a4c8450397d2647d7d8e3f6f06</id>
<content type='text'>
...  and call node_dev_init() after memory_dev_init() from driver_init(),
so before any of the existing arch/subsys calls.  All online nodes should
be known at that point: early during boot, arch code determines node and
zone ranges and sets the relevant nodes online; usually this happens in
setup_arch().

This is in line with memory_dev_init(), which initializes the memory
device subsystem and creates all memory block devices.

Similar to memory_dev_init(), panic() if anything goes wrong, we don't
want to continue with such basic initialization errors.

The important part is that node_dev_init() gets called after
memory_dev_init() and after cpu_dev_init(), but before any of the relevant
archs call register_cpu() to register the new cpu device under the node
device.  The latter should be the case for the current users of
topology_init().

Link: https://lkml.kernel.org/r/20220203105212.30385-1-david@redhat.com
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Tested-by: Anatoly Pugachev &lt;matorola@gmail.com&gt; (sparc64)
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
...  and call node_dev_init() after memory_dev_init() from driver_init(),
so before any of the existing arch/subsys calls.  All online nodes should
be known at that point: early during boot, arch code determines node and
zone ranges and sets the relevant nodes online; usually this happens in
setup_arch().

This is in line with memory_dev_init(), which initializes the memory
device subsystem and creates all memory block devices.

Similar to memory_dev_init(), panic() if anything goes wrong, we don't
want to continue with such basic initialization errors.

The important part is that node_dev_init() gets called after
memory_dev_init() and after cpu_dev_init(), but before any of the relevant
archs call register_cpu() to register the new cpu device under the node
device.  The latter should be the case for the current users of
topology_init().

Link: https://lkml.kernel.org/r/20220203105212.30385-1-david@redhat.com
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Tested-by: Anatoly Pugachev &lt;matorola@gmail.com&gt; (sparc64)
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/base/memory: add memory block to memory group after registration succeeded</title>
<updated>2022-03-22T22:57:10+00:00</updated>
<author>
<name>David Hildenbrand</name>
<email>david@redhat.com</email>
</author>
<published>2022-03-22T21:47:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7ea0d2d79da09d1f7d71c96a9c9bc1b5229360b5'/>
<id>7ea0d2d79da09d1f7d71c96a9c9bc1b5229360b5</id>
<content type='text'>
If register_memory() fails, we freed the memory block but already added
the memory block to the group list, not good.  Let's defer adding the
block to the memory group to after registering the memory block device.

We do handle it properly during unregister_memory(), but that's not
called when the registration fails.

Link: https://lkml.kernel.org/r/20220128144540.153902-1-david@redhat.com
Fixes: 028fc57a1c36 ("drivers/base/memory: introduce "memory groups" to logically group memory blocks")
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If register_memory() fails, we freed the memory block but already added
the memory block to the group list, not good.  Let's defer adding the
block to the memory group to after registering the memory block device.

We do handle it properly during unregister_memory(), but that's not
called when the registration fails.

Link: https://lkml.kernel.org/r/20220128144540.153902-1-david@redhat.com
Fixes: 028fc57a1c36 ("drivers/base/memory: introduce "memory groups" to logically group memory blocks")
Signed-off-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/hwpoison: avoid the impact of hwpoison_filter() return value on mce handler</title>
<updated>2022-03-22T22:57:07+00:00</updated>
<author>
<name>luofei</name>
<email>luofei@unicloud.com</email>
</author>
<published>2022-03-22T21:44:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d1fe111fb62a1cf0446a2919f5effbb33ad0702c'/>
<id>d1fe111fb62a1cf0446a2919f5effbb33ad0702c</id>
<content type='text'>
When the hwpoison page meets the filter conditions, it should not be
regarded as successful memory_failure() processing for mce handler, but
should return a distinct value, otherwise mce handler regards the error
page has been identified and isolated, which may lead to calling
set_mce_nospec() to change page attribute, etc.

Here memory_failure() return -EOPNOTSUPP to indicate that the error
event is filtered, mce handler should not take any action for this
situation and hwpoison injector should treat as correct.

Link: https://lkml.kernel.org/r/20220223082135.2769649-1-luofei@unicloud.com
Signed-off-by: luofei &lt;luofei@unicloud.com&gt;
Acked-by: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Naoya Horiguchi &lt;naoya.horiguchi@nec.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the hwpoison page meets the filter conditions, it should not be
regarded as successful memory_failure() processing for mce handler, but
should return a distinct value, otherwise mce handler regards the error
page has been identified and isolated, which may lead to calling
set_mce_nospec() to change page attribute, etc.

Here memory_failure() return -EOPNOTSUPP to indicate that the error
event is filtered, mce handler should not take any action for this
situation and hwpoison injector should treat as correct.

Link: https://lkml.kernel.org/r/20220223082135.2769649-1-luofei@unicloud.com
Signed-off-by: luofei &lt;luofei@unicloud.com&gt;
Acked-by: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Naoya Horiguchi &lt;naoya.horiguchi@nec.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
