<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/base, branch v5.1.13</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>PM / core: Propagate dev-&gt;power.wakeup_path when no callbacks</title>
<updated>2019-05-31T13:43:34+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2019-04-10T09:55:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=fdb3ecd0d65f9ac00a7b60da30e0031690e2821f'/>
<id>fdb3ecd0d65f9ac00a7b60da30e0031690e2821f</id>
<content type='text'>
[ Upstream commit dc351d4c5f4fe4d0f274d6d660227be0c3a03317 ]

The dev-&gt;power.direct_complete flag may become set in device_prepare() in
case the device don't have any PM callbacks (dev-&gt;power.no_pm_callbacks is
set). This leads to a broken behaviour, when there is child having wakeup
enabled and relies on its parent to be used in the wakeup path.

More precisely, when the direct complete path becomes selected for the
child in __device_suspend(), the propagation of the dev-&gt;power.wakeup_path
becomes skipped as well.

Let's address this problem, by checking if the device is a part the wakeup
path or has wakeup enabled, then prevent the direct complete path from
being used.

Reported-by: Loic Pallardy &lt;loic.pallardy@st.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
[ rjw: Comment cleanup ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit dc351d4c5f4fe4d0f274d6d660227be0c3a03317 ]

The dev-&gt;power.direct_complete flag may become set in device_prepare() in
case the device don't have any PM callbacks (dev-&gt;power.no_pm_callbacks is
set). This leads to a broken behaviour, when there is child having wakeup
enabled and relies on its parent to be used in the wakeup path.

More precisely, when the direct complete path becomes selected for the
child in __device_suspend(), the propagation of the dev-&gt;power.wakeup_path
becomes skipped as well.

Let's address this problem, by checking if the device is a part the wakeup
path or has wakeup enabled, then prevent the direct complete path from
being used.

Reported-by: Loic Pallardy &lt;loic.pallardy@st.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
[ rjw: Comment cleanup ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: Postpone DMA tear-down until after devres release for probe failure</title>
<updated>2019-05-25T16:16:48+00:00</updated>
<author>
<name>John Garry</name>
<email>john.garry@huawei.com</email>
</author>
<published>2019-03-28T10:08:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=04bdef8340c1477c5f55b96c17b8956d656c6411'/>
<id>04bdef8340c1477c5f55b96c17b8956d656c6411</id>
<content type='text'>
commit 0b777eee88d712256ba8232a9429edb17c4f9ceb upstream.

In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after
devres release"), we changed the ordering of tearing down the device DMA
ops and releasing all the device's resources; this was because the DMA ops
should be maintained until we release the device's managed DMA memories.

However, we have seen another crash on an arm64 system when a
device driver probe fails:

  hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
  scsi host1: hisi_sas_v3_hw
  BUG: Bad page state in process swapper/0  pfn:313f5
  page:ffff7e0000c4fd40 count:1 mapcount:0
  mapping:0000000000000000 index:0x0
  flags: 0xfffe00000001000(reserved)
  raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
0000000000000000
  raw: 0000000000000000 0000000000000000 00000001ffffffff
0000000000000000
  page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
  bad because of flags: 0x1000(reserved)
  Modules linked in:
  CPU: 49 PID: 1 Comm: swapper/0 Not tainted
5.1.0-rc1-43081-g22d97fd-dirty #1433
  Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
RC0 - V1.12.01 01/29/2019
  Call trace:
  dump_backtrace+0x0/0x118
  show_stack+0x14/0x1c
  dump_stack+0xa4/0xc8
  bad_page+0xe4/0x13c
  free_pages_check_bad+0x4c/0xc0
  __free_pages_ok+0x30c/0x340
  __free_pages+0x30/0x44
  __dma_direct_free_pages+0x30/0x38
  dma_direct_free+0x24/0x38
  dma_free_attrs+0x9c/0xd8
  dmam_release+0x20/0x28
  release_nodes+0x17c/0x220
  devres_release_all+0x34/0x54
  really_probe+0xc4/0x2c8
  driver_probe_device+0x58/0xfc
  device_driver_attach+0x68/0x70
  __driver_attach+0x94/0xdc
  bus_for_each_dev+0x5c/0xb4
  driver_attach+0x20/0x28
  bus_add_driver+0x14c/0x200
  driver_register+0x6c/0x124
  __pci_register_driver+0x48/0x50
  sas_v3_pci_driver_init+0x20/0x28
  do_one_initcall+0x40/0x25c
  kernel_init_freeable+0x2b8/0x3c0
  kernel_init+0x10/0x100
  ret_from_fork+0x10/0x18
  Disabling lock debugging due to kernel taint
  BUG: Bad page state in process swapper/0  pfn:313f6
  page:ffff7e0000c4fd80 count:1 mapcount:0
mapping:0000000000000000 index:0x0
[   89.322983] flags: 0xfffe00000001000(reserved)
  raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
0000000000000000
  raw: 0000000000000000 0000000000000000 00000001ffffffff
0000000000000000

The crash occurs for the same reason.

In this case, on the really_probe() failure path, we are still clearing
the DMA ops prior to releasing the device's managed memories.

This patch fixes this issue by reordering the DMA ops teardown and the
call to devres_release_all() on the failure path.

Reported-by: Xiang Chen &lt;chenxiang66@hisilicon.com&gt;
Tested-by: Xiang Chen &lt;chenxiang66@hisilicon.com&gt;
Signed-off-by: John Garry &lt;john.garry@huawei.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0b777eee88d712256ba8232a9429edb17c4f9ceb upstream.

In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after
devres release"), we changed the ordering of tearing down the device DMA
ops and releasing all the device's resources; this was because the DMA ops
should be maintained until we release the device's managed DMA memories.

However, we have seen another crash on an arm64 system when a
device driver probe fails:

  hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2
  scsi host1: hisi_sas_v3_hw
  BUG: Bad page state in process swapper/0  pfn:313f5
  page:ffff7e0000c4fd40 count:1 mapcount:0
  mapping:0000000000000000 index:0x0
  flags: 0xfffe00000001000(reserved)
  raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48
0000000000000000
  raw: 0000000000000000 0000000000000000 00000001ffffffff
0000000000000000
  page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
  bad because of flags: 0x1000(reserved)
  Modules linked in:
  CPU: 49 PID: 1 Comm: swapper/0 Not tainted
5.1.0-rc1-43081-g22d97fd-dirty #1433
  Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI
RC0 - V1.12.01 01/29/2019
  Call trace:
  dump_backtrace+0x0/0x118
  show_stack+0x14/0x1c
  dump_stack+0xa4/0xc8
  bad_page+0xe4/0x13c
  free_pages_check_bad+0x4c/0xc0
  __free_pages_ok+0x30c/0x340
  __free_pages+0x30/0x44
  __dma_direct_free_pages+0x30/0x38
  dma_direct_free+0x24/0x38
  dma_free_attrs+0x9c/0xd8
  dmam_release+0x20/0x28
  release_nodes+0x17c/0x220
  devres_release_all+0x34/0x54
  really_probe+0xc4/0x2c8
  driver_probe_device+0x58/0xfc
  device_driver_attach+0x68/0x70
  __driver_attach+0x94/0xdc
  bus_for_each_dev+0x5c/0xb4
  driver_attach+0x20/0x28
  bus_add_driver+0x14c/0x200
  driver_register+0x6c/0x124
  __pci_register_driver+0x48/0x50
  sas_v3_pci_driver_init+0x20/0x28
  do_one_initcall+0x40/0x25c
  kernel_init_freeable+0x2b8/0x3c0
  kernel_init+0x10/0x100
  ret_from_fork+0x10/0x18
  Disabling lock debugging due to kernel taint
  BUG: Bad page state in process swapper/0  pfn:313f6
  page:ffff7e0000c4fd80 count:1 mapcount:0
mapping:0000000000000000 index:0x0
[   89.322983] flags: 0xfffe00000001000(reserved)
  raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88
0000000000000000
  raw: 0000000000000000 0000000000000000 00000001ffffffff
0000000000000000

The crash occurs for the same reason.

In this case, on the really_probe() failure path, we are still clearing
the DMA ops prior to releasing the device's managed memories.

This patch fixes this issue by reordering the DMA ops teardown and the
call to devres_release_all() on the failure path.

Reported-by: Xiang Chen &lt;chenxiang66@hisilicon.com&gt;
Tested-by: Xiang Chen &lt;chenxiang66@hisilicon.com&gt;
Signed-off-by: John Garry &lt;john.garry@huawei.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/speculation/mds: Add sysfs reporting for MDS</title>
<updated>2019-05-14T17:15:30+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-02-18T21:51:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=a287e16c15520d03050c988ed40c164716445da1'/>
<id>a287e16c15520d03050c988ed40c164716445da1</id>
<content type='text'>
commit 8a4b06d391b0a42a373808979b5028f5c84d9c6a upstream

Add the sysfs reporting file for MDS. It exposes the vulnerability and
mitigation state similar to the existing files for the other speculative
hardware vulnerabilities.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Jon Masters &lt;jcm@redhat.com&gt;
Tested-by: Jon Masters &lt;jcm@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8a4b06d391b0a42a373808979b5028f5c84d9c6a upstream

Add the sysfs reporting file for MDS. It exposes the vulnerability and
mitigation state similar to the existing files for the other speculative
hardware vulnerabilities.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Jon Masters &lt;jcm@redhat.com&gt;
Tested-by: Jon Masters &lt;jcm@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock</title>
<updated>2019-04-19T16:46:04+00:00</updated>
<author>
<name>zhong jiang</name>
<email>zhongjiang@huawei.com</email>
</author>
<published>2019-04-19T00:50:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=37803841c92d7b327147e0b1be3436423189e1cf'/>
<id>37803841c92d7b327147e0b1be3436423189e1cf</id>
<content type='text'>
When adding memory by probing a memory block in the sysfs interface,
there is an obvious issue where we will unlock the device_hotplug_lock
when we failed to takes it.

That issue was introduced in 8df1d0e4a265 ("mm/memory_hotplug: make
add_memory() take the device_hotplug_lock").

We should drop out in time when failing to take the device_hotplug_lock.

Link: http://lkml.kernel.org/r/1554696437-9593-1-git-send-email-zhongjiang@huawei.com
Fixes: 8df1d0e4a265 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")
Signed-off-by: zhong jiang &lt;zhongjiang@huawei.com&gt;
Reported-by: Yang yingliang &lt;yangyingliang@huawei.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: &lt;stable@vger.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>
When adding memory by probing a memory block in the sysfs interface,
there is an obvious issue where we will unlock the device_hotplug_lock
when we failed to takes it.

That issue was introduced in 8df1d0e4a265 ("mm/memory_hotplug: make
add_memory() take the device_hotplug_lock").

We should drop out in time when failing to take the device_hotplug_lock.

Link: http://lkml.kernel.org/r/1554696437-9593-1-git-send-email-zhongjiang@huawei.com
Fixes: 8df1d0e4a265 ("mm/memory_hotplug: make add_memory() take the device_hotplug_lock")
Signed-off-by: zhong jiang &lt;zhongjiang@huawei.com&gt;
Reported-by: Yang yingliang &lt;yangyingliang@huawei.com&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Reviewed-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: &lt;stable@vger.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>Merge tag 'devprop-5.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2019-03-22T19:08:52+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-22T19:08:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=e42091739f649b3caf43ddffa53f0416dc396fdd'/>
<id>e42091739f649b3caf43ddffa53f0416dc396fdd</id>
<content type='text'>
Pull device properties framework fix from Rafael Wysocki:
 "Add missing 'static' in two places (YueHaibing)"

* tag 'devprop-5.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  drivers: base: swnode: Make two functions static
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull device properties framework fix from Rafael Wysocki:
 "Add missing 'static' in two places (YueHaibing)"

* tag 'devprop-5.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  drivers: base: swnode: Make two functions static
</pre>
</div>
</content>
</entry>
<entry>
<title>PM / Domains: Avoid a potential deadlock</title>
<updated>2019-03-19T21:58:04+00:00</updated>
<author>
<name>Jiada Wang</name>
<email>jiada_wang@mentor.com</email>
</author>
<published>2019-03-12T06:51:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=2071ac985d37efe496782c34318dbead93beb02f'/>
<id>2071ac985d37efe496782c34318dbead93beb02f</id>
<content type='text'>
Lockdep warns that prepare_lock and genpd-&gt;mlock can cause a deadlock
the deadlock scenario is like following:
First thread is probing cs2000
cs2000_probe()
  clk_register()
    __clk_core_init()
      clk_prepare_lock()                            ----&gt; acquires prepare_lock
        cs2000_recalc_rate()
          i2c_smbus_read_byte_data()
            rcar_i2c_master_xfer()
              dma_request_chan()
                rcar_dmac_of_xlate()
                  rcar_dmac_alloc_chan_resources()
                    pm_runtime_get_sync()
                      __pm_runtime_resume()
                        rpm_resume()
                          rpm_callback()
                            genpd_runtime_resume()   ----&gt; acquires genpd-&gt;mlock

Second thread is attaching any device to the same PM domain
genpd_add_device()
  genpd_lock()                                       ----&gt; acquires genpd-&gt;mlock
    cpg_mssr_attach_dev()
      of_clk_get_from_provider()
        __of_clk_get_from_provider()
          __clk_create_clk()
            clk_prepare_lock()                       ----&gt; acquires prepare_lock

Since currently no PM provider access genpd's critical section
in .attach_dev, and .detach_dev callbacks, so there is no need to protect
these two callbacks with genpd-&gt;mlock.
This patch avoids a potential deadlock by moving out .attach_dev and .detach_dev
from genpd-&gt;mlock, so that genpd-&gt;mlock won't be held when prepare_lock is acquired
in .attach_dev and .detach_dev

Signed-off-by: Jiada Wang &lt;jiada_wang@mentor.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Lockdep warns that prepare_lock and genpd-&gt;mlock can cause a deadlock
the deadlock scenario is like following:
First thread is probing cs2000
cs2000_probe()
  clk_register()
    __clk_core_init()
      clk_prepare_lock()                            ----&gt; acquires prepare_lock
        cs2000_recalc_rate()
          i2c_smbus_read_byte_data()
            rcar_i2c_master_xfer()
              dma_request_chan()
                rcar_dmac_of_xlate()
                  rcar_dmac_alloc_chan_resources()
                    pm_runtime_get_sync()
                      __pm_runtime_resume()
                        rpm_resume()
                          rpm_callback()
                            genpd_runtime_resume()   ----&gt; acquires genpd-&gt;mlock

Second thread is attaching any device to the same PM domain
genpd_add_device()
  genpd_lock()                                       ----&gt; acquires genpd-&gt;mlock
    cpg_mssr_attach_dev()
      of_clk_get_from_provider()
        __of_clk_get_from_provider()
          __clk_create_clk()
            clk_prepare_lock()                       ----&gt; acquires prepare_lock

Since currently no PM provider access genpd's critical section
in .attach_dev, and .detach_dev callbacks, so there is no need to protect
these two callbacks with genpd-&gt;mlock.
This patch avoids a potential deadlock by moving out .attach_dev and .detach_dev
from genpd-&gt;mlock, so that genpd-&gt;mlock won't be held when prepare_lock is acquired
in .attach_dev and .detach_dev

Signed-off-by: Jiada Wang &lt;jiada_wang@mentor.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers: base: swnode: Make two functions static</title>
<updated>2019-03-19T15:37:56+00:00</updated>
<author>
<name>YueHaibing</name>
<email>yuehaibing@huawei.com</email>
</author>
<published>2019-03-19T15:20:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=0e3edd94448001a33ed7f8af2179cd4a280348a2'/>
<id>0e3edd94448001a33ed7f8af2179cd4a280348a2</id>
<content type='text'>
Fix sparse warning:

drivers/base/swnode.c:475:22: warning: symbol 'software_node_get_parent' was not declared. Should it be static?
drivers/base/swnode.c:484:22: warning: symbol 'software_node_get_next_child' was not declared. Should it be static?

Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix sparse warning:

drivers/base/swnode.c:475:22: warning: symbol 'software_node_get_parent' was not declared. Should it be static?
drivers/base/swnode.c:484:22: warning: symbol 'software_node_get_next_child' was not declared. Should it be static?

Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm</title>
<updated>2019-03-16T20:05:32+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-16T20:05:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f67e3fb4891287b8248ebb3320f794b9f5e782d4'/>
<id>f67e3fb4891287b8248ebb3320f794b9f5e782d4</id>
<content type='text'>
Pull device-dax updates from Dan Williams:
 "New device-dax infrastructure to allow persistent memory and other
  "reserved" / performance differentiated memories, to be assigned to
  the core-mm as "System RAM".

  Some users want to use persistent memory as additional volatile
  memory. They are willing to cope with potential performance
  differences, for example between DRAM and 3D Xpoint, and want to use
  typical Linux memory management apis rather than a userspace memory
  allocator layered over an mmap() of a dax file. The administration
  model is to decide how much Persistent Memory (pmem) to use as System
  RAM, create a device-dax-mode namespace of that size, and then assign
  it to the core-mm. The rationale for device-dax is that it is a
  generic memory-mapping driver that can be layered over any "special
  purpose" memory, not just pmem. On subsequent boots udev rules can be
  used to restore the memory assignment.

  One implication of using pmem as RAM is that mlock() no longer keeps
  data off persistent media. For this reason it is recommended to enable
  NVDIMM Security (previously merged for 5.0) to encrypt pmem contents
  at rest. We considered making this recommendation an actively enforced
  requirement, but in the end decided to leave it as a distribution /
  administrator policy to allow for emulation and test environments that
  lack security capable NVDIMMs.

  Summary:

   - Replace the /sys/class/dax device model with /sys/bus/dax, and
     include a compat driver so distributions can opt-in to the new ABI.

   - Allow for an alternative driver for the device-dax address-range

   - Introduce the 'kmem' driver to hotplug / assign a device-dax
     address-range to the core-mm.

   - Arrange for the device-dax target-node to be onlined so that the
     newly added memory range can be uniquely referenced by numa apis"

NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because
we currently have special - and very annoying rules in the kernel about
accessing PMEM only with the "MC safe" accessors, because machine checks
inside the regular repeat string copy functions can be fatal in some
(not described) circumstances.

And apparently the PMEM modules can cause that a lot more than regular
RAM.  The argument is that this happens because PMEM doesn't necessarily
get scrubbed at boot like RAM does, but that is planned to be added for
the user space tooling.

Quoting Dan from another email:
 "The exposure can be reduced in the volatile-RAM case by scanning for
  and clearing errors before it is onlined as RAM. The userspace tooling
  for that can be in place before v5.1-final. There's also runtime
  notifications of errors via acpi_nfit_uc_error_notify() from
  background scrubbers on the DIMM devices. With that mechanism the
  kernel could proactively clear newly discovered poison in the volatile
  case, but that would be additional development more suitable for v5.2.

  I understand the concern, and the need to highlight this issue by
  tapping the brakes on feature development, but I don't see PMEM as RAM
  making the situation worse when the exposure is also there via DAX in
  the PMEM case. Volatile-RAM is arguably a safer use case since it's
  possible to repair pages where the persistent case needs active
  application coordination"

* tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: "Hotplug" persistent memory for use like normal RAM
  mm/resource: Let walk_system_ram_range() search child resources
  mm/memory-hotplug: Allow memory resources to be children
  mm/resource: Move HMM pr_debug() deeper into resource code
  mm/resource: Return real error codes from walk failures
  device-dax: Add a 'modalias' attribute to DAX 'bus' devices
  device-dax: Add a 'target_node' attribute
  device-dax: Auto-bind device after successful new_id
  acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node
  device-dax: Add /sys/class/dax backwards compatibility
  device-dax: Add support for a dax override driver
  device-dax: Move resource pinning+mapping into the common driver
  device-dax: Introduce bus + driver model
  device-dax: Start defining a dax bus model
  device-dax: Remove multi-resource infrastructure
  device-dax: Kill dax_region base
  device-dax: Kill dax_region ida
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull device-dax updates from Dan Williams:
 "New device-dax infrastructure to allow persistent memory and other
  "reserved" / performance differentiated memories, to be assigned to
  the core-mm as "System RAM".

  Some users want to use persistent memory as additional volatile
  memory. They are willing to cope with potential performance
  differences, for example between DRAM and 3D Xpoint, and want to use
  typical Linux memory management apis rather than a userspace memory
  allocator layered over an mmap() of a dax file. The administration
  model is to decide how much Persistent Memory (pmem) to use as System
  RAM, create a device-dax-mode namespace of that size, and then assign
  it to the core-mm. The rationale for device-dax is that it is a
  generic memory-mapping driver that can be layered over any "special
  purpose" memory, not just pmem. On subsequent boots udev rules can be
  used to restore the memory assignment.

  One implication of using pmem as RAM is that mlock() no longer keeps
  data off persistent media. For this reason it is recommended to enable
  NVDIMM Security (previously merged for 5.0) to encrypt pmem contents
  at rest. We considered making this recommendation an actively enforced
  requirement, but in the end decided to leave it as a distribution /
  administrator policy to allow for emulation and test environments that
  lack security capable NVDIMMs.

  Summary:

   - Replace the /sys/class/dax device model with /sys/bus/dax, and
     include a compat driver so distributions can opt-in to the new ABI.

   - Allow for an alternative driver for the device-dax address-range

   - Introduce the 'kmem' driver to hotplug / assign a device-dax
     address-range to the core-mm.

   - Arrange for the device-dax target-node to be onlined so that the
     newly added memory range can be uniquely referenced by numa apis"

NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because
we currently have special - and very annoying rules in the kernel about
accessing PMEM only with the "MC safe" accessors, because machine checks
inside the regular repeat string copy functions can be fatal in some
(not described) circumstances.

And apparently the PMEM modules can cause that a lot more than regular
RAM.  The argument is that this happens because PMEM doesn't necessarily
get scrubbed at boot like RAM does, but that is planned to be added for
the user space tooling.

Quoting Dan from another email:
 "The exposure can be reduced in the volatile-RAM case by scanning for
  and clearing errors before it is onlined as RAM. The userspace tooling
  for that can be in place before v5.1-final. There's also runtime
  notifications of errors via acpi_nfit_uc_error_notify() from
  background scrubbers on the DIMM devices. With that mechanism the
  kernel could proactively clear newly discovered poison in the volatile
  case, but that would be additional development more suitable for v5.2.

  I understand the concern, and the need to highlight this issue by
  tapping the brakes on feature development, but I don't see PMEM as RAM
  making the situation worse when the exposure is also there via DAX in
  the PMEM case. Volatile-RAM is arguably a safer use case since it's
  possible to repair pages where the persistent case needs active
  application coordination"

* tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: "Hotplug" persistent memory for use like normal RAM
  mm/resource: Let walk_system_ram_range() search child resources
  mm/memory-hotplug: Allow memory resources to be children
  mm/resource: Move HMM pr_debug() deeper into resource code
  mm/resource: Return real error codes from walk failures
  device-dax: Add a 'modalias' attribute to DAX 'bus' devices
  device-dax: Add a 'target_node' attribute
  device-dax: Auto-bind device after successful new_id
  acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node
  device-dax: Add /sys/class/dax backwards compatibility
  device-dax: Add support for a dax override driver
  device-dax: Move resource pinning+mapping into the common driver
  device-dax: Introduce bus + driver model
  device-dax: Start defining a dax bus model
  device-dax: Remove multi-resource infrastructure
  device-dax: Kill dax_region base
  device-dax: Kill dax_region ida
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2019-03-14T17:30:06+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-03-14T17:30:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=9352ca585b2ac7b67d2119b9386573b2a4c0ef4b'/>
<id>9352ca585b2ac7b67d2119b9386573b2a4c0ef4b</id>
<content type='text'>
Pull more power management updates from Rafael Wysocki:
 "These are mostly fixes and cleanups on top of the previously merged
  power management material for 5.1-rc1 with one cpupower utility update
  that wasn't pushed earlier due to unfortunate timing.

  Specifics:

   - Fix registration of new cpuidle governors partially broken during
     the 5.0 development cycle by mistake (Rafael Wysocki).

   - Avoid integer overflows in the menu cpuidle governor by making it
     discard the overflowing data points upfront (Rafael Wysocki).

   - Fix minor mistake in the recent update of the iowait boost
     computation in the intel_pstate driver (Rafael Wysocki).

   - Drop incorrect __init annotation from one function in the pxa2xx
     cpufreq driver (Arnd Bergmann).

   - Fix the operating performance points (OPP) framework initialization
     for devices in multiple power domains if only one of them is
     scalable (Rajendra Nayak).

   - Fix mistake in dev_pm_opp_set_rate() which causes it to skip
     updating the performance state if the new frequency is the same as
     the old one (Viresh Kumar).

   - Rework the cancellation of wakeup source timers to avoid potential
     issues with it and do some cleanups unlocked by that change (Viresh
     Kumar, Rafael Wysocki).

   - Clean up the code computing the active/suspended time of devices in
     the PM-runtime framework after recent changes (Ulf Hansson).

   - Make the power management infrastructure code use pr_fmt()
     consistently (Joe Perches).

   - Clean up the generic power domains (genpd) framework somewhat
     (Aisheng Dong).

   - Improve kerneldoc comments for two functions in the cpufreq core
     (Rafael Wysocki).

   - Fix typo in a PM QoS file description comment (Aisheng Dong).

   - Update the handling of CPU boost frequencies in the cpupower
     utility (Abhishek Goel)"

* tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: governor: Add new governors to cpuidle_governors again
  cpufreq: intel_pstate: Fix up iowait_boost computation
  PM / OPP: Update performance state when freq == old_freq
  PM / wakeup: Drop wakeup_source_drop()
  PM / wakeup: Rework wakeup source timer cancellation
  PM / domains: Remove one unnecessary blank line
  PM / Domains: Return early for all errors in _genpd_power_off()
  PM / Domains: Improve warn for multiple states but no governor
  OPP: Fix handling of multiple power domains
  PM / QoS: Fix typo in file description
  cpufreq: pxa2xx: remove incorrect __init annotation
  PM-runtime: Call pm_runtime_active|suspended_time() from sysfs
  PM-runtime: Consolidate code to get active/suspended time
  PM: Add and use pr_fmt()
  cpufreq: Improve kerneldoc comments for cpufreq_cpu_get/put()
  cpuidle: menu: Avoid overflows when computing variance
  tools/power/cpupower: Display boost frequency separately
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more power management updates from Rafael Wysocki:
 "These are mostly fixes and cleanups on top of the previously merged
  power management material for 5.1-rc1 with one cpupower utility update
  that wasn't pushed earlier due to unfortunate timing.

  Specifics:

   - Fix registration of new cpuidle governors partially broken during
     the 5.0 development cycle by mistake (Rafael Wysocki).

   - Avoid integer overflows in the menu cpuidle governor by making it
     discard the overflowing data points upfront (Rafael Wysocki).

   - Fix minor mistake in the recent update of the iowait boost
     computation in the intel_pstate driver (Rafael Wysocki).

   - Drop incorrect __init annotation from one function in the pxa2xx
     cpufreq driver (Arnd Bergmann).

   - Fix the operating performance points (OPP) framework initialization
     for devices in multiple power domains if only one of them is
     scalable (Rajendra Nayak).

   - Fix mistake in dev_pm_opp_set_rate() which causes it to skip
     updating the performance state if the new frequency is the same as
     the old one (Viresh Kumar).

   - Rework the cancellation of wakeup source timers to avoid potential
     issues with it and do some cleanups unlocked by that change (Viresh
     Kumar, Rafael Wysocki).

   - Clean up the code computing the active/suspended time of devices in
     the PM-runtime framework after recent changes (Ulf Hansson).

   - Make the power management infrastructure code use pr_fmt()
     consistently (Joe Perches).

   - Clean up the generic power domains (genpd) framework somewhat
     (Aisheng Dong).

   - Improve kerneldoc comments for two functions in the cpufreq core
     (Rafael Wysocki).

   - Fix typo in a PM QoS file description comment (Aisheng Dong).

   - Update the handling of CPU boost frequencies in the cpupower
     utility (Abhishek Goel)"

* tag 'pm-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: governor: Add new governors to cpuidle_governors again
  cpufreq: intel_pstate: Fix up iowait_boost computation
  PM / OPP: Update performance state when freq == old_freq
  PM / wakeup: Drop wakeup_source_drop()
  PM / wakeup: Rework wakeup source timer cancellation
  PM / domains: Remove one unnecessary blank line
  PM / Domains: Return early for all errors in _genpd_power_off()
  PM / Domains: Improve warn for multiple states but no governor
  OPP: Fix handling of multiple power domains
  PM / QoS: Fix typo in file description
  cpufreq: pxa2xx: remove incorrect __init annotation
  PM-runtime: Call pm_runtime_active|suspended_time() from sysfs
  PM-runtime: Consolidate code to get active/suspended time
  PM: Add and use pr_fmt()
  cpufreq: Improve kerneldoc comments for cpufreq_cpu_get/put()
  cpuidle: menu: Avoid overflows when computing variance
  tools/power/cpupower: Display boost frequency separately
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'pm-domains'</title>
<updated>2019-03-14T09:53:08+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-03-14T09:53:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=75f3e2395430ad6416a7d35e892db7ff60e012e1'/>
<id>75f3e2395430ad6416a7d35e892db7ff60e012e1</id>
<content type='text'>
* pm-domains:
  PM / domains: Remove one unnecessary blank line
  PM / Domains: Return early for all errors in _genpd_power_off()
  PM / Domains: Improve warn for multiple states but no governor
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* pm-domains:
  PM / domains: Remove one unnecessary blank line
  PM / Domains: Return early for all errors in _genpd_power_off()
  PM / Domains: Improve warn for multiple states but no governor
</pre>
</div>
</content>
</entry>
</feed>
