<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/base/cacheinfo.c, branch v6.3-rc1</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>cacheinfo: Initialize variables in fetch_cache_info()</title>
<updated>2023-01-31T15:02:02+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-01-24T15:40:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ecaef469920fd6d2c7687f19081946f47684a423'/>
<id>ecaef469920fd6d2c7687f19081946f47684a423</id>
<content type='text'>
Set potentially uninitialized variables to 0. This is particularly
relevant when CONFIG_ACPI_PPTT is not set.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Link: https://lore.kernel.org/all/202301052307.JYt1GWaJ-lkp@intel.com/
Reported-by: Dan Carpenter &lt;error27@gmail.com&gt;
Link: https://lore.kernel.org/all/Y86iruJPuwNN7rZw@kili/
Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230124154053.355376-2-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Set potentially uninitialized variables to 0. This is particularly
relevant when CONFIG_ACPI_PPTT is not set.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Link: https://lore.kernel.org/all/202301052307.JYt1GWaJ-lkp@intel.com/
Reported-by: Dan Carpenter &lt;error27@gmail.com&gt;
Link: https://lore.kernel.org/all/Y86iruJPuwNN7rZw@kili/
Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230124154053.355376-2-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Fix shared_cpu_map to handle shared caches at different levels</title>
<updated>2023-01-18T09:58:40+00:00</updated>
<author>
<name>Yong-Xuan Wang</name>
<email>yongxuan.wang@sifive.com</email>
</author>
<published>2023-01-17T10:51:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=198102c9103fc78d8478495971947af77edb05c1'/>
<id>198102c9103fc78d8478495971947af77edb05c1</id>
<content type='text'>
The cacheinfo sets up the shared_cpu_map by checking whether the caches
with the same index are shared between CPUs. However, this will trigger
slab-out-of-bounds access if the CPUs do not have the same cache hierarchy.
Another problem is the mismatched shared_cpu_map when the shared cache does
not have the same index between CPUs.

CPU0	I	D	L3
index	0	1	2	x
	^	^	^	^
index	0	1	2	3
CPU1	I	D	L2	L3

This patch checks each cache is shared with all caches on other CPUs.

Reviewed-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Signed-off-by: Yong-Xuan Wang &lt;yongxuan.wang@sifive.com&gt;
Link: https://lore.kernel.org/r/20230117105133.4445-2-yongxuan.wang@sifive.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The cacheinfo sets up the shared_cpu_map by checking whether the caches
with the same index are shared between CPUs. However, this will trigger
slab-out-of-bounds access if the CPUs do not have the same cache hierarchy.
Another problem is the mismatched shared_cpu_map when the shared cache does
not have the same index between CPUs.

CPU0	I	D	L3
index	0	1	2	x
	^	^	^	^
index	0	1	2	3
CPU1	I	D	L2	L3

This patch checks each cache is shared with all caches on other CPUs.

Reviewed-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Signed-off-by: Yong-Xuan Wang &lt;yongxuan.wang@sifive.com&gt;
Link: https://lore.kernel.org/r/20230117105133.4445-2-yongxuan.wang@sifive.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch_topology: Build cacheinfo from primary CPU</title>
<updated>2023-01-18T09:58:40+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-01-04T18:30:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5944ce092b97caed5d86d961e963b883b5c44ee2'/>
<id>5944ce092b97caed5d86d961e963b883b5c44ee2</id>
<content type='text'>
commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection
in the CPU hotplug path")
adds a call to detect_cache_attributes() to populate the cacheinfo
before updating the siblings mask. detect_cache_attributes() allocates
memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT
kernels, on secondary CPUs, this triggers a:
  'BUG: sleeping function called from invalid context' [1]
as the code is executed with preemption and interrupts disabled.

The primary CPU was previously storing the cache information using
the now removed (struct cpu_topology).llc_id:
commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from
the CPU topology")

allocate_cache_info() tries to build the cacheinfo from the primary
CPU prior secondary CPUs boot, if the DT/ACPI description
contains cache information.
If allocate_cache_info() fails, then fallback to the current state
for the cacheinfo allocation. [1] will be triggered in such case.

When unplugging a CPU, the cacheinfo memory cannot be freed. If it
was, then the memory would be allocated early by the re-plugged
CPU and would trigger [1].

Note that populate_cache_leaves() might be called multiple times
due to populate_leaves being moved up. This is required since
detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu)
being allocated but not populated.

[1]:
 | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111
 | preempt_count: 1, expected: 0
 | RCU nest depth: 1, expected: 1
 | 3 locks held by swapper/111/0:
 |  #0:  (&amp;pcp-&gt;lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8
 |  #1:  (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0
 |  #2:  (&amp;zone-&gt;lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80
 | irq event stamp: 0
 | hardirqs last  enabled at (0):  0x0
 | hardirqs last disabled at (0):  copy_process+0x5dc/0x1ab8
 | softirqs last  enabled at (0):  copy_process+0x5dc/0x1ab8
 | softirqs last disabled at (0):  0x0
 | Preemption disabled at:
 |  migrate_enable+0x30/0x130
 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G        W          6.0.0-rc4-rt6-[...]
 | Call trace:
 |  __kmalloc+0xbc/0x1e8
 |  detect_cache_attributes+0x2d4/0x5f0
 |  update_siblings_masks+0x30/0x368
 |  store_cpu_topology+0x78/0xb8
 |  secondary_start_kernel+0xd0/0x198
 |  __secondary_switched+0xb0/0xb4

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Acked-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection
in the CPU hotplug path")
adds a call to detect_cache_attributes() to populate the cacheinfo
before updating the siblings mask. detect_cache_attributes() allocates
memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT
kernels, on secondary CPUs, this triggers a:
  'BUG: sleeping function called from invalid context' [1]
as the code is executed with preemption and interrupts disabled.

The primary CPU was previously storing the cache information using
the now removed (struct cpu_topology).llc_id:
commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from
the CPU topology")

allocate_cache_info() tries to build the cacheinfo from the primary
CPU prior secondary CPUs boot, if the DT/ACPI description
contains cache information.
If allocate_cache_info() fails, then fallback to the current state
for the cacheinfo allocation. [1] will be triggered in such case.

When unplugging a CPU, the cacheinfo memory cannot be freed. If it
was, then the memory would be allocated early by the re-plugged
CPU and would trigger [1].

Note that populate_cache_leaves() might be called multiple times
due to populate_leaves being moved up. This is required since
detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu)
being allocated but not populated.

[1]:
 | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111
 | preempt_count: 1, expected: 0
 | RCU nest depth: 1, expected: 1
 | 3 locks held by swapper/111/0:
 |  #0:  (&amp;pcp-&gt;lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8
 |  #1:  (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0
 |  #2:  (&amp;zone-&gt;lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80
 | irq event stamp: 0
 | hardirqs last  enabled at (0):  0x0
 | hardirqs last disabled at (0):  copy_process+0x5dc/0x1ab8
 | softirqs last  enabled at (0):  copy_process+0x5dc/0x1ab8
 | softirqs last disabled at (0):  0x0
 | Preemption disabled at:
 |  migrate_enable+0x30/0x130
 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G        W          6.0.0-rc4-rt6-[...]
 | Call trace:
 |  __kmalloc+0xbc/0x1e8
 |  detect_cache_attributes+0x2d4/0x5f0
 |  update_siblings_masks+0x30/0x368
 |  store_cpu_topology+0x78/0xb8
 |  secondary_start_kernel+0xd0/0x198
 |  __secondary_switched+0xb0/0xb4

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Acked-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Check 'cache-unified' property to count cache leaves</title>
<updated>2023-01-18T09:58:31+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-01-04T18:30:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=de0df442ee49cb1f6ee58f3fec5dcb5e5eb70aab'/>
<id>de0df442ee49cb1f6ee58f3fec5dcb5e5eb70aab</id>
<content type='text'>
The DeviceTree Specification v0.3 specifies that the cache node
'[d-|i-|]cache-size' property is required. The 'cache-unified'
property is specifies whether the cache level is separate
or unified.

If the cache-size property is missing, no cache leaves is accounted.
This can lead to a 'BUG: KASAN: slab-out-of-bounds' [1] bug.

Check 'cache-unified' property and always account for at least
one cache leaf when parsing the device tree.

[1] https://lore.kernel.org/all/0f19cb3f-d6cf-4032-66d2-dedc9d09a0e3@linaro.org/

Reported-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Tested-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Link: https://lore.kernel.org/r/20230104183033.755668-4-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The DeviceTree Specification v0.3 specifies that the cache node
'[d-|i-|]cache-size' property is required. The 'cache-unified'
property is specifies whether the cache level is separate
or unified.

If the cache-size property is missing, no cache leaves is accounted.
This can lead to a 'BUG: KASAN: slab-out-of-bounds' [1] bug.

Check 'cache-unified' property and always account for at least
one cache leaf when parsing the device tree.

[1] https://lore.kernel.org/all/0f19cb3f-d6cf-4032-66d2-dedc9d09a0e3@linaro.org/

Reported-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Tested-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Link: https://lore.kernel.org/r/20230104183033.755668-4-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Return error code in init_of_cache_level()</title>
<updated>2023-01-17T22:00:06+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-01-04T18:30:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8844c3df001bc1d8397fddea341308da63855d53'/>
<id>8844c3df001bc1d8397fddea341308da63855d53</id>
<content type='text'>
Make init_of_cache_level() return an error code when the cache
information parsing fails to help detecting missing information.

init_of_cache_level() is only called for riscv. Returning an error
code instead of 0 will prevent detect_cache_attributes() to allocate
memory if an incomplete DT is parsed.

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Acked-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20230104183033.755668-3-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make init_of_cache_level() return an error code when the cache
information parsing fails to help detecting missing information.

init_of_cache_level() is only called for riscv. Returning an error
code instead of 0 will prevent detect_cache_attributes() to allocate
memory if an incomplete DT is parsed.

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Acked-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20230104183033.755668-3-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Use RISC-V's init_cache_level() as generic OF implementation</title>
<updated>2023-01-17T21:59:52+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-01-04T18:30:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c3719bd9eeb2edf84bd263d662e36ca0ba262a23'/>
<id>c3719bd9eeb2edf84bd263d662e36ca0ba262a23</id>
<content type='text'>
RISC-V's implementation of init_of_cache_level() is following
the Devicetree Specification v0.3 regarding caches, cf.:
- s3.7.3 'Internal (L1) Cache Properties'
- s3.8 'Multi-level and Shared Cache Nodes'

Allow reusing the implementation by moving it.

Also make 'levels', 'leaves' and 'level' unsigned int.

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Acked-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20230104183033.755668-2-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
RISC-V's implementation of init_of_cache_level() is following
the Devicetree Specification v0.3 regarding caches, cf.:
- s3.7.3 'Internal (L1) Cache Properties'
- s3.8 'Multi-level and Shared Cache Nodes'

Allow reusing the implementation by moving it.

Also make 'levels', 'leaves' and 'level' unsigned int.

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Acked-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20230104183033.755668-2-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Remove of_node_put() for fw_token</title>
<updated>2022-11-23T19:03:51+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2022-11-16T09:49:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2613cc29c5723881ca603b1a3b50f0107010d5d6'/>
<id>2613cc29c5723881ca603b1a3b50f0107010d5d6</id>
<content type='text'>
fw_token is used for DT/ACPI systems to identify CPUs sharing caches.
For DT based systems, fw_token is set to a pointer to a DT node.

commit 3da72e18371c ("cacheinfo: Decrement refcount in
cache_setup_of_node()")
doesn't increment the refcount of fw_token anymore in
cache_setup_of_node(). fw_token is indeed used as a token and not
as a (struct device_node*), so no reference to fw_token should be
kept.

However, [1] is triggered when hotplugging a CPU multiple times
since cache_shared_cpu_map_remove() decrements the refcount to
fw_token at each CPU unplugging, eventually reaching 0.

Remove of_node_put() for fw_token in cache_shared_cpu_map_remove().

[1]
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 4 PID: 32 at lib/refcount.c:22 refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
Modules linked in:
CPU: 4 PID: 32 Comm: cpuhp/4 Tainted: G        W          6.1.0-rc1-14091-g9fdf2ca7b9c8 #76
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Oct 31 2022
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
lr : refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
[...]
Call trace:
[...]
of_node_release (drivers/of/dynamic.c:335)
kobject_put (lib/kobject.c:677 lib/kobject.c:704 ./include/linux/kref.h:65 lib/kobject.c:721)
of_node_put (drivers/of/dynamic.c:49)
free_cache_attributes.part.0 (drivers/base/cacheinfo.c:712)
cacheinfo_cpu_pre_down (drivers/base/cacheinfo.c:718)
cpuhp_invoke_callback (kernel/cpu.c:247 (discriminator 4))
cpuhp_thread_fun (kernel/cpu.c:785)
smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3))
kthread (kernel/kthread.c:376)
ret_from_fork (arch/arm64/kernel/entry.S:861)
---[ end trace 0000000000000000 ]---

Fixes: 3da72e18371c ("cacheinfo: Decrement refcount in cache_setup_of_node()")
Reported-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Reported-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Tested-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Tested-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Link: https://lore.kernel.org/r/20221116094958.2141072-1-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
fw_token is used for DT/ACPI systems to identify CPUs sharing caches.
For DT based systems, fw_token is set to a pointer to a DT node.

commit 3da72e18371c ("cacheinfo: Decrement refcount in
cache_setup_of_node()")
doesn't increment the refcount of fw_token anymore in
cache_setup_of_node(). fw_token is indeed used as a token and not
as a (struct device_node*), so no reference to fw_token should be
kept.

However, [1] is triggered when hotplugging a CPU multiple times
since cache_shared_cpu_map_remove() decrements the refcount to
fw_token at each CPU unplugging, eventually reaching 0.

Remove of_node_put() for fw_token in cache_shared_cpu_map_remove().

[1]
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 4 PID: 32 at lib/refcount.c:22 refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
Modules linked in:
CPU: 4 PID: 32 Comm: cpuhp/4 Tainted: G        W          6.1.0-rc1-14091-g9fdf2ca7b9c8 #76
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Oct 31 2022
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
lr : refcount_warn_saturate (lib/refcount.c:22 (discriminator 3))
[...]
Call trace:
[...]
of_node_release (drivers/of/dynamic.c:335)
kobject_put (lib/kobject.c:677 lib/kobject.c:704 ./include/linux/kref.h:65 lib/kobject.c:721)
of_node_put (drivers/of/dynamic.c:49)
free_cache_attributes.part.0 (drivers/base/cacheinfo.c:712)
cacheinfo_cpu_pre_down (drivers/base/cacheinfo.c:718)
cpuhp_invoke_callback (kernel/cpu.c:247 (discriminator 4))
cpuhp_thread_fun (kernel/cpu.c:785)
smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3))
kthread (kernel/kthread.c:376)
ret_from_fork (arch/arm64/kernel/entry.S:861)
---[ end trace 0000000000000000 ]---

Fixes: 3da72e18371c ("cacheinfo: Decrement refcount in cache_setup_of_node()")
Reported-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Reported-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Tested-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Tested-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Link: https://lore.kernel.org/r/20221116094958.2141072-1-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Decrement refcount in cache_setup_of_node()</title>
<updated>2022-11-10T17:33:28+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2022-10-26T18:59:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3da72e18371c41a6f6f96b594854b178168c7757'/>
<id>3da72e18371c41a6f6f96b594854b178168c7757</id>
<content type='text'>
Refcounts to DT nodes are only incremented in the function
and never decremented. Decrease the refcounts when necessary.

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Link: https://lore.kernel.org/r/20221026185954.991547-1-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Refcounts to DT nodes are only incremented in the function
and never decremented. Decrease the refcounts when necessary.

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Link: https://lore.kernel.org/r/20221026185954.991547-1-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Use atomic allocation for percpu cache attributes</title>
<updated>2022-07-22T08:04:42+00:00</updated>
<author>
<name>Sudeep Holla</name>
<email>sudeep.holla@arm.com</email>
</author>
<published>2022-07-20T12:55:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=11969d698f8cda31bd176ec346833ef97ea7c67e'/>
<id>11969d698f8cda31bd176ec346833ef97ea7c67e</id>
<content type='text'>
On couple of architectures like RISC-V and ARM64, we need to detect
cache attribues quite early during the boot when the secondary CPUs
start. So we will call detect_cache_attributes in the atomic context
and since use of normal allocation can sleep, we will end up getting
"sleeping in the atomic context" bug splat.

In order avoid that, move the allocation to use atomic version in
preparation to move the actual detection of cache attributes in the
CPU hotplug path which is atomic.

Cc: Ionela Voinescu &lt;ionela.voinescu@arm.com&gt;
Tested-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Link: https://lore.kernel.org/r/20220720-arch_topo_fixes-v3-1-43d696288e84@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On couple of architectures like RISC-V and ARM64, we need to detect
cache attribues quite early during the boot when the secondary CPUs
start. So we will call detect_cache_attributes in the atomic context
and since use of normal allocation can sleep, we will end up getting
"sleeping in the atomic context" bug splat.

In order avoid that, move the allocation to use atomic version in
preparation to move the actual detection of cache attributes in the
CPU hotplug path which is atomic.

Cc: Ionela Voinescu &lt;ionela.voinescu@arm.com&gt;
Tested-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Link: https://lore.kernel.org/r/20220720-arch_topo_fixes-v3-1-43d696288e84@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Align checks in cache_shared_cpu_map_{setup,remove} for readability</title>
<updated>2022-07-04T15:22:28+00:00</updated>
<author>
<name>Sudeep Holla</name>
<email>sudeep.holla@arm.com</email>
</author>
<published>2022-07-04T10:15:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=521103134a0d07774c8b17f25ff0ef70cbd56c9d'/>
<id>521103134a0d07774c8b17f25ff0ef70cbd56c9d</id>
<content type='text'>
The checks to skip the CPU itself or no cacheinfo case are implemented
bit differently though the effect is exactly same. Just align the
implementation in both cache_shared_cpu_map_{setup,remove} just for
improved readability. No functional change.

Link: https://lore.kernel.org/r/20220704101605.1318280-9-sudeep.holla@arm.com
Tested-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The checks to skip the CPU itself or no cacheinfo case are implemented
bit differently though the effect is exactly same. Just align the
implementation in both cache_shared_cpu_map_{setup,remove} just for
improved readability. No functional change.

Link: https://lore.kernel.org/r/20220704101605.1318280-9-sudeep.holla@arm.com
Tested-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
