lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20180425233121.13270-10-jeremy.linton@arm.com> Date: Wed, 25 Apr 2018 18:31:17 -0500 From: Jeremy Linton <jeremy.linton@....com> To: linux-acpi@...r.kernel.org Cc: Sudeep.Holla@....com, linux-arm-kernel@...ts.infradead.org, Lorenzo.Pieralisi@....com, hanjun.guo@...aro.org, rjw@...ysocki.net, Will.Deacon@....com, Catalin.Marinas@....com, gregkh@...uxfoundation.org, Mark.Rutland@....com, linux-kernel@...r.kernel.org, linux-riscv@...ts.infradead.org, wangxiongfeng2@...wei.com, vkilari@...eaurora.org, ahs3@...hat.com, Dietmar.Eggemann@....com, Morten.Rasmussen@....com, palmer@...ive.com, lenb@...nel.org, john.garry@...wei.com, austinwc@...eaurora.org, tnowicki@...iumnetworks.com, jhugo@....qualcomm.com, timur@....qualcomm.com, ard.biesheuvel@...aro.org, Jeremy Linton <jeremy.linton@....com> Subject: [PATCH v8 09/13] ACPI/PPTT: Add topology parsing code The PPTT can be used to determine the groupings of CPU's at given levels in the system. Lets add a few routines to the PPTT parsing code to return a unique id for each unique level in the processor hierarchy. This can then be matched to build thread/core/cluster/die/package/etc mappings for each processing element in the system. Signed-off-by: Jeremy Linton <jeremy.linton@....com> --- drivers/acpi/pptt.c | 160 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 4 ++ 2 files changed, 164 insertions(+) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index cced71ef851a..0fc4b2654665 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -453,6 +453,86 @@ static void cache_setup_acpi_cpu(struct acpi_table_header *table, } } +/* Passing level values greater than this will result in search termination */ +#define PPTT_ABORT_PACKAGE 0xFF + +/** + * acpi_find_processor_package_id() - Locate the processor structure for a cpu + * + * Given an acpi_pptt_processor node, walk up until we identify the + * package that the node is associated with, or we run out of levels + * to request or the search is terminated with a flag match + * The level parameter also serves to limit possible loops within the tree. + * + * Return: acpi_pptt_processor* describing the passed core or NULL + */ +static struct acpi_pptt_processor *acpi_find_processor_package_id(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *cpu, + int level, int flag) +{ + struct acpi_pptt_processor *prev_node; + + while (cpu && level) { + if (cpu->flags & flag) + break; + pr_debug("level %d\n", level); + prev_node = fetch_pptt_node(table_hdr, cpu->parent); + if (prev_node == NULL) + break; + cpu = prev_node; + level--; + } + return cpu; +} + +/** + * topology_get_acpi_cpu_tag() - Find a unique topology value for a feature + * + * Get a unique value given a cpu, and a topology level, that can be + * matched to determine which cpus share common topological features + * at that level. + * + * Return: Unique value, or -ENOENT if unable to locate cpu + */ +static int topology_get_acpi_cpu_tag(struct acpi_table_header *table, + unsigned int cpu, int level, int flag) +{ + struct acpi_pptt_processor *cpu_node; + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); + + cpu_node = acpi_find_processor_node(table, acpi_cpu_id); + if (cpu_node) { + cpu_node = acpi_find_processor_package_id(table, cpu_node, + level, flag); + /* Only the first level has a guaranteed id */ + if (level == 0) + return cpu_node->acpi_processor_id; + return ACPI_PTR_DIFF(cpu_node, table); + } + pr_warn_once("PPTT table found, but unable to locate core %d (%d)\n", + cpu, acpi_cpu_id); + return -ENOENT; +} + +static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag) +{ + struct acpi_table_header *table; + acpi_status status; + int retval; + + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + pr_warn_once("No PPTT table found, cpu topology may be inaccurate\n"); + return -ENOENT; + } + retval = topology_get_acpi_cpu_tag(table, cpu, level, flag); + pr_debug("Topology Setup ACPI cpu %d, level %d ret = %d\n", + cpu, level, retval); + acpi_put_table(table); + + return retval; +} + /** * acpi_find_last_cache_level() - Determines the number of cache levels for a PE * @cpu: Kernel logical cpu number @@ -516,3 +596,83 @@ int cache_setup_acpi(unsigned int cpu) return status; } + +/** + * find_acpi_cpu_topology() - Determine a unique topology value for a given cpu + * @cpu: Kernel logical cpu number + * @level: The topological level for which we would like a unique ID + * + * Determine a topology unique ID for each thread/core/cluster/mc_grouping + * /socket/etc. This ID can then be used to group peers, which will have + * matching ids. + * + * The search terminates when either the requested level is found or + * we reach a root node. Levels beyond the termination point will return the + * same unique ID. The unique id for level 0 is the acpi processor id. All + * other levels beyond this use a generated value to uniquely identify + * a topological feature. + * + * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found. + * Otherwise returns a value which represents a unique topological feature. + */ +int find_acpi_cpu_topology(unsigned int cpu, int level) +{ + return find_acpi_cpu_topology_tag(cpu, level, 0); +} + +/** + * find_acpi_cpu_cache_topology() - Determine a unique cache topology value + * @cpu: Kernel logical cpu number + * @level: The cache level for which we would like a unique ID + * + * Determine a unique ID for each unified cache in the system + * + * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found. + * Otherwise returns a value which represents a unique topological feature. + */ +int find_acpi_cpu_cache_topology(unsigned int cpu, int level) +{ + struct acpi_table_header *table; + struct acpi_pptt_cache *found_cache; + acpi_status status; + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); + struct acpi_pptt_processor *cpu_node = NULL; + int ret = -1; + + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + pr_warn_once("No PPTT table found, topology may be inaccurate\n"); + return -ENOENT; + } + + found_cache = acpi_find_cache_node(table, acpi_cpu_id, + CACHE_TYPE_UNIFIED, + level, + &cpu_node); + if (found_cache) + ret = ACPI_PTR_DIFF(cpu_node, table); + + acpi_put_table(table); + + return ret; +} + + +/** + * find_acpi_cpu_topology_package() - Determine a unique cpu package value + * @cpu: Kernel logical cpu number + * + * Determine a topology unique package ID for the given cpu. + * This ID can then be used to group peers, which will have matching ids. + * + * The search terminates when either a level is found with the PHYSICAL_PACKAGE + * flag set or we reach a root node. + * + * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found. + * Otherwise returns a value which represents the package for this cpu. + */ +int find_acpi_cpu_topology_package(unsigned int cpu) +{ + return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, + ACPI_PPTT_PHYSICAL_PACKAGE); +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 15bfb15c2fa5..032e12a2fdc2 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1297,4 +1297,8 @@ static inline int lpit_read_residency_count_address(u64 *address) } #endif +int find_acpi_cpu_topology(unsigned int cpu, int level); +int find_acpi_cpu_topology_package(unsigned int cpu); +int find_acpi_cpu_cache_topology(unsigned int cpu, int level); + #endif /*_LINUX_ACPI_H*/ -- 2.13.6
Powered by blists - more mailing lists