From: Jeremy Linton <jeremy.linton@arm.com> To: linux-arm-kernel@lists.infradead.org Cc: mark.rutland@arm.com, lorenzo.pieralisi@arm.com, will.deacon@arm.com, sudeep.holla@arm.com, rjw@rjwysocki.net, linuxarm@huawei.com, Jeremy Linton <jeremy.linton@arm.com>, linux-acpi@vger.kernel.org, catalin.marinas@arm.com, john.garry@huawei.com, lenb@kernel.org Subject: [PATCH v3 2/5] ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens Date: Fri, 3 May 2019 18:24:04 -0500 [thread overview] Message-ID: <20190503232407.37195-3-jeremy.linton@arm.com> (raw) In-Reply-To: <20190503232407.37195-1-jeremy.linton@arm.com> 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. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> --- drivers/acpi/pptt.c | 26 ++++++++++++++++++++++++++ include/linux/acpi.h | 5 +++++ 2 files changed, 31 insertions(+) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 83a026765faa..1865515297ca 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -660,3 +660,29 @@ int find_acpi_cpu_topology_package(unsigned int cpu) return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, ACPI_PPTT_PHYSICAL_PACKAGE); } + +/** + * find_acpi_cpu_topology_hetero_id() - Get a core architecture tag + * @cpu: Kernel logical CPU number + * + * Determine a unique heterogeneous tag for the given CPU. CPUs with the same + * implementation should have matching tags. + * + * The returned tag can be used to group peers with identical implementation. + * + * The search terminates when a level is found with the identical implementation + * flag set or we reach a root node. + * + * Due to limitations in the PPTT data structure, there may be rare situations + * where two cores in a heterogeneous machine may be identical, but won't have + * the same tag. + * + * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found. + * Otherwise returns a value which represents a group of identical cores + * similar to this CPU. + */ +int find_acpi_cpu_topology_hetero_id(unsigned int cpu) +{ + return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, + ACPI_PPTT_ACPI_IDENTICAL); +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index d5dcebd7aad3..1444fb042898 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1309,6 +1309,7 @@ static inline int lpit_read_residency_count_address(u64 *address) #ifdef CONFIG_ACPI_PPTT int find_acpi_cpu_topology(unsigned int cpu, int level); int find_acpi_cpu_topology_package(unsigned int cpu); +int find_acpi_cpu_topology_hetero_id(unsigned int cpu); int find_acpi_cpu_cache_topology(unsigned int cpu, int level); #else static inline int find_acpi_cpu_topology(unsigned int cpu, int level) @@ -1319,6 +1320,10 @@ static inline int find_acpi_cpu_topology_package(unsigned int cpu) { return -EINVAL; } +static int find_acpi_cpu_topology_hetero_id(unsigned int cpu) +{ + return -EINVAL; +} static inline int find_acpi_cpu_cache_topology(unsigned int cpu, int level) { return -EINVAL; -- 2.21.0
WARNING: multiple messages have this Message-ID (diff)
From: Jeremy Linton <jeremy.linton@arm.com> To: linux-arm-kernel@lists.infradead.org Cc: linux-acpi@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, sudeep.holla@arm.com, linuxarm@huawei.com, john.garry@huawei.com, Jeremy Linton <jeremy.linton@arm.com> Subject: [PATCH v3 2/5] ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens Date: Fri, 3 May 2019 18:24:04 -0500 [thread overview] Message-ID: <20190503232407.37195-3-jeremy.linton@arm.com> (raw) Message-ID: <20190503232404.q-NI-A2JP-gB5HjJkcnTeVO_K192G8AAEZR3KuC7rAI@z> (raw) In-Reply-To: <20190503232407.37195-1-jeremy.linton@arm.com> 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. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> --- drivers/acpi/pptt.c | 26 ++++++++++++++++++++++++++ include/linux/acpi.h | 5 +++++ 2 files changed, 31 insertions(+) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 83a026765faa..1865515297ca 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -660,3 +660,29 @@ int find_acpi_cpu_topology_package(unsigned int cpu) return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, ACPI_PPTT_PHYSICAL_PACKAGE); } + +/** + * find_acpi_cpu_topology_hetero_id() - Get a core architecture tag + * @cpu: Kernel logical CPU number + * + * Determine a unique heterogeneous tag for the given CPU. CPUs with the same + * implementation should have matching tags. + * + * The returned tag can be used to group peers with identical implementation. + * + * The search terminates when a level is found with the identical implementation + * flag set or we reach a root node. + * + * Due to limitations in the PPTT data structure, there may be rare situations + * where two cores in a heterogeneous machine may be identical, but won't have + * the same tag. + * + * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found. + * Otherwise returns a value which represents a group of identical cores + * similar to this CPU. + */ +int find_acpi_cpu_topology_hetero_id(unsigned int cpu) +{ + return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, + ACPI_PPTT_ACPI_IDENTICAL); +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index d5dcebd7aad3..1444fb042898 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1309,6 +1309,7 @@ static inline int lpit_read_residency_count_address(u64 *address) #ifdef CONFIG_ACPI_PPTT int find_acpi_cpu_topology(unsigned int cpu, int level); int find_acpi_cpu_topology_package(unsigned int cpu); +int find_acpi_cpu_topology_hetero_id(unsigned int cpu); int find_acpi_cpu_cache_topology(unsigned int cpu, int level); #else static inline int find_acpi_cpu_topology(unsigned int cpu, int level) @@ -1319,6 +1320,10 @@ static inline int find_acpi_cpu_topology_package(unsigned int cpu) { return -EINVAL; } +static int find_acpi_cpu_topology_hetero_id(unsigned int cpu) +{ + return -EINVAL; +} static inline int find_acpi_cpu_cache_topology(unsigned int cpu, int level) { return -EINVAL; -- 2.21.0
next prev parent reply other threads:[~2019-05-03 23:24 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-03 23:24 [PATCH v3 0/5] arm64: SPE ACPI enablement Jeremy Linton 2019-05-03 23:24 ` Jeremy Linton 2019-05-03 23:24 ` [PATCH v3 1/5] ACPI/PPTT: Trivial, change the capitalization of CPU Jeremy Linton 2019-05-03 23:24 ` Jeremy Linton 2019-05-07 18:12 ` Jeremy Linton 2019-05-07 18:12 ` Jeremy Linton 2019-05-03 23:24 ` Jeremy Linton [this message] 2019-05-03 23:24 ` [PATCH v3 2/5] ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens Jeremy Linton 2019-05-05 7:09 ` Kefeng Wang 2019-05-05 7:09 ` Kefeng Wang 2019-05-07 18:26 ` Jeremy Linton 2019-05-07 18:26 ` Jeremy Linton 2019-06-07 9:49 ` Sudeep Holla 2019-05-03 23:24 ` [PATCH v3 3/5] ACPI/PPTT: Modify node flag detection to find last IDENTICAL Jeremy Linton 2019-05-03 23:24 ` Jeremy Linton 2019-06-07 9:53 ` Sudeep Holla 2019-06-07 13:15 ` Jeremy Linton 2019-06-07 13:47 ` Sudeep Holla 2019-05-03 23:24 ` [PATCH v3 4/5] arm_pmu: acpi: spe: Add initial MADT/SPE probing Jeremy Linton 2019-05-03 23:24 ` Jeremy Linton 2019-05-08 11:18 ` John Garry 2019-05-08 20:04 ` Jeremy Linton 2019-06-07 9:57 ` Sudeep Holla 2019-06-07 13:28 ` Jeremy Linton 2019-06-07 13:37 ` Sudeep Holla 2019-05-03 23:24 ` [PATCH v3 5/5] perf: arm_spe: Enable ACPI/Platform automatic module loading Jeremy Linton 2019-05-03 23:24 ` Jeremy Linton 2019-05-04 11:06 ` [PATCH v3 0/5] arm64: SPE ACPI enablement Hanjun Guo 2019-05-04 11:06 ` Hanjun Guo 2019-05-07 17:58 ` Jeremy Linton 2019-05-07 17:58 ` Jeremy Linton 2019-05-08 9:35 ` Hanjun Guo 2019-05-08 16:51 ` Sudeep Holla 2019-05-09 9:28 ` Will Deacon 2019-05-09 10:35 ` Sudeep Holla 2019-05-09 14:13 ` Sudeep Holla 2019-05-13 10:56 ` Will Deacon 2019-05-13 11:31 ` Sudeep Holla 2019-05-13 11:10 ` Hanjun Guo 2019-05-08 16:45 ` Sudeep Holla
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