kernel/linux.git/drivers/acpi/pptt.c, branch v5.10.257

ACPI: PPTT: Fix processor subtable walk

2025-06-04T12:36:57+00:00

commit adfab6b39202481bb43286fff94def4953793fdb upstream. The original PPTT code had a bug where the processor subtable length was not correctly validated when encountering a truncated acpi_pptt_processor node. Commit 7ab4f0e37a0f4 ("ACPI PPTT: Fix coding mistakes in a couple of sizeof() calls") attempted to fix this by validating the size is as large as the acpi_pptt_processor node structure. This introduced a regression where the last processor node in the PPTT table is ignored if it doesn't contain any private resources. That results errors like: ACPI PPTT: PPTT table found, but unable to locate core XX (XX) ACPI: SPE must be homogeneous Furthermore, it fails in a common case where the node length isn't equal to the acpi_pptt_processor structure size, leaving the original bug in a modified form. Correct the regression by adjusting the loop termination conditions as suggested by the bug reporters. An additional check performed after the subtable node type is detected, validates the acpi_pptt_processor node is fully contained in the PPTT table. Repeating the check in acpi_pptt_leaf_node() is largely redundant as the node is already known to be fully contained in the table. The case where a final truncated node's parent property is accepted, but the node itself is rejected should not be considered a bug. Fixes: 7ab4f0e37a0f4 ("ACPI PPTT: Fix coding mistakes in a couple of sizeof() calls") Reported-by: Maximilian Heyne Closes: https://lore.kernel.org/linux-acpi/20250506-draco-taped-15f475cd@mheyne-amazon/ Reported-by: Yicong Yang Closes: https://lore.kernel.org/linux-acpi/20250507035124.28071-1-yangyicong@huawei.com/ Signed-off-by: Jeremy Linton Tested-by: Yicong Yang Reviewed-by: Sudeep Holla Tested-by: Maximilian Heyne Cc: All applicable # 7ab4f0e37a0f4: ACPI PPTT: Fix coding mistakes ... Link: https://patch.msgid.link/20250508023025.1301030-1-jeremy.linton@arm.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

ACPI PPTT: Fix coding mistakes in a couple of sizeof() calls

2025-05-02T05:41:19+00:00

[ Upstream commit 7ab4f0e37a0f4207e742a8de69be03984db6ebf0 ] The end of table checks should be done with the structure size, but 2 of the 3 similar calls use the pointer size. Signed-off-by: Jean-Marc Eurin Link: https://patch.msgid.link/20250402001542.2600671-1-jmeurin@google.com [ rjw: Subject edits ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: PPTT: Consistently use unsigned int as parameter type

2020-01-07T10:46:36+00:00

The fourth parameter 'level' of function 'acpi_find_cache_level()' is a signed interger, but its caller 'acpi_find_cache_node()' passes that parameter an unsigned interger. Make the paramter type inconsistency go away. Signed-off-by: Tian Tao Signed-off-by: Xiongfeng Wang [ rjw: Subject/changelog ] Signed-off-by: Rafael J. Wysocki

ACPI/PPTT: Add support for ACPI 6.3 thread flag

2019-08-12T11:59:15+00:00

ACPI 6.3 adds a flag to the CPU node to indicate whether the given PE is a thread. Add a function to return that information for a given linux logical CPU. Signed-off-by: Jeremy Linton Reviewed-by: Sudeep Holla Reviewed-by: Robert Richter Acked-by: Rafael J. Wysocki Signed-off-by: Will Deacon

ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens

2019-06-27T15:53:18+00:00

ACPI 6.3 adds a flag to indicate that child nodes are all identical cores. This is useful to authoritatively determine if a set of (possibly offline) cores are identical or not. Since the flag doesn't give us a unique id we can generate one and use it to create bitmaps of sibling nodes, or simply in a loop to determine if a subset of cores are identical. Acked-by: Rafael J. Wysocki Tested-by: Hanjun Guo Reviewed-by: Sudeep Holla Signed-off-by: Jeremy Linton Signed-off-by: Will Deacon

ACPI/PPTT: Modify node flag detection to find last IDENTICAL

2019-06-27T15:52:13+00:00

The ACPI specification implies that the IDENTICAL flag should be set on all non leaf nodes where the children are identical. This means that we need to be searching for the last node with the identical flag set rather than the first one. Since this flag is also dependent on the table revision, we need to add a bit of extra code to verify the table revision, and the next node's state in the traversal. Since we want to avoid function pointers here, lets just special case the IDENTICAL flag. Acked-by: Rafael J. Wysocki Tested-by: Hanjun Guo Reviewed-by: Sudeep Holla Signed-off-by: Jeremy Linton Signed-off-by: Will Deacon

ACPI: Fix comment typos

2019-03-26T21:33:43+00:00

Fix some misspellings in comments. No functional change intended. Signed-off-by: Bjorn Helgaas Signed-off-by: Rafael J. Wysocki

ACPI: tables: Simplify PPTT leaf node detection

2019-03-11T11:14:57+00:00

ACPI 6.3 bumps the PPTT table revision and adds a LEAF_NODE flag. This allows us to avoid a second pass through the table to assure that the node in question is a leaf. Signed-off-by: Jeremy Linton Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki

ACPI/PPTT: Add acpi_pptt_warn_missing() to consolidate logs

2019-02-07T22:16:08+00:00

For a system using ACPI-based FW without a PPTT, we may get many warnings about the lack of a PPTT, as shown: root@(none)$ dmesg | grep -i pptt [ 0.010125] ACPI PPTT: No PPTT table found, cpu topology may be inaccurate [ 7.138339] ACPI PPTT: No PPTT table found, cache topology may be inaccurate [ 7.145368] ACPI PPTT: No PPTT table found, cache topology may be inaccurate These logs are generated with pr_warn_once(), so the intention was for a single log, but the logs overlap, so consolidate them. Signed-off-by: John Garry Reviewed-by: Jeremy Linton Signed-off-by: Rafael J. Wysocki

ACPI/PPTT: Handle architecturally unknown cache types

2018-10-04T21:02:17+00:00

The type of a cache might not be specified by architectural mechanisms (ie system registers), but its type might be specified in the PPTT. In this case, we should populate the type of the cache, rather than leave it undefined. This fixes the issue where the cacheinfo driver will not populate sysfs for such caches, resulting in the information missing from utilities like lstopo and lscpu, thus degrading the user experience. Fixes: 2bd00bcd73e5 (ACPI/PPTT: Add Processor Properties Topology Table parsing) Reported-by: Vijaya Kumar K Signed-off-by: Jeffrey Hugo Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki