| Message ID | 20190523224015.56270-2-jeremy.linton@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64/PPTT ACPI 6.3 thread flag support | expand |
On Thu, May 23, 2019 at 05:40:14PM -0500, Jeremy Linton wrote: > 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 <jeremy.linton@arm.com> > --- > drivers/acpi/pptt.c | 53 +++++++++++++++++++++++++++++++++++++++++++- > include/linux/acpi.h | 5 +++++ > 2 files changed, 57 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c > index b72e6afaa8fb..6f43a0c05f61 100644 > --- a/drivers/acpi/pptt.c > +++ b/drivers/acpi/pptt.c > @@ -517,6 +517,43 @@ static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag) > return retval; > } > > +/** > + * check_acpi_cpu_flag() - Determine if CPU node has a flag set > + * @cpu: Kernel logical CPU number > + * @rev: The PPTT revision defining the flag > + * @flag: The flag itself > + * > + * Check the node representing a CPU for a given flag. > + * > + * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or > + * the table revision isn't new enough. > + * Otherwise returns flag value > + */ > +static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag) Initially, I thought we already have similar function, but I was wrong. > +{ > + struct acpi_table_header *table; > + acpi_status status; > + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); > + struct acpi_pptt_processor *cpu_node = NULL; > + int ret = -ENONET; Unfortunately even ENONET is defined and will silently compile fine, but I assume you need ENOENT as mentioned in the comment/doc. > + > + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); > + if (ACPI_FAILURE(status)) { > + acpi_pptt_warn_missing(); > + return ret; > + } > + > + if (table->revision >= rev) > + cpu_node = acpi_find_processor_node(table, acpi_cpu_id); > + > + if (cpu_node) > + ret = cpu_node->flags & flag; > + > + acpi_put_table(table); > + > + return ret; > +} > + > /** > * acpi_find_last_cache_level() - Determines the number of cache levels for a PE > * @cpu: Kernel logical CPU number > @@ -581,6 +618,21 @@ int cache_setup_acpi(unsigned int cpu) > return status; > } > > +/** > + * acpi_pptt_cpu_is_thread() - Determine if logical CPU is a thread > + * @cpu: Kernel logical CPU number > + * > + * > + * Return: 1, a thread > + * 0, not a thread > + * -ENOENT if the PPTT doesn't exist, the CPU cannot be found or > + * the table revision isn't new enough. > + */ > +int acpi_pptt_cpu_is_thread(unsigned int cpu) > +{ > + return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD); > +} > + > /** > * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU > * @cpu: Kernel logical CPU number > @@ -641,7 +693,6 @@ int find_acpi_cpu_cache_topology(unsigned int cpu, int level) > return ret; > } > > - Spurious ? > /** > * find_acpi_cpu_topology_package() - Determine a unique CPU package value > * @cpu: Kernel logical CPU number > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 98440df7fe42..513833233c65 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -1314,10 +1314,15 @@ static inline int lpit_read_residency_count_address(u64 *address) > #endif > > #ifdef CONFIG_ACPI_PPTT > +int acpi_pptt_cpu_is_thread(unsigned int cpu); > 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); > #else > +static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) > +{ > + return -EINVAL; > +} > static inline int find_acpi_cpu_topology(unsigned int cpu, int level) > { > return -EINVAL; > -- > 2.21.0 >
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index b72e6afaa8fb..6f43a0c05f61 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -517,6 +517,43 @@ static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag) return retval; } +/** + * check_acpi_cpu_flag() - Determine if CPU node has a flag set + * @cpu: Kernel logical CPU number + * @rev: The PPTT revision defining the flag + * @flag: The flag itself + * + * Check the node representing a CPU for a given flag. + * + * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or + * the table revision isn't new enough. + * Otherwise returns flag value + */ +static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag) +{ + struct acpi_table_header *table; + acpi_status status; + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); + struct acpi_pptt_processor *cpu_node = NULL; + int ret = -ENONET; + + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + acpi_pptt_warn_missing(); + return ret; + } + + if (table->revision >= rev) + cpu_node = acpi_find_processor_node(table, acpi_cpu_id); + + if (cpu_node) + ret = cpu_node->flags & flag; + + acpi_put_table(table); + + return ret; +} + /** * acpi_find_last_cache_level() - Determines the number of cache levels for a PE * @cpu: Kernel logical CPU number @@ -581,6 +618,21 @@ int cache_setup_acpi(unsigned int cpu) return status; } +/** + * acpi_pptt_cpu_is_thread() - Determine if logical CPU is a thread + * @cpu: Kernel logical CPU number + * + * + * Return: 1, a thread + * 0, not a thread + * -ENOENT if the PPTT doesn't exist, the CPU cannot be found or + * the table revision isn't new enough. + */ +int acpi_pptt_cpu_is_thread(unsigned int cpu) +{ + return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD); +} + /** * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU * @cpu: Kernel logical CPU number @@ -641,7 +693,6 @@ int find_acpi_cpu_cache_topology(unsigned int cpu, int level) return ret; } - /** * find_acpi_cpu_topology_package() - Determine a unique CPU package value * @cpu: Kernel logical CPU number diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 98440df7fe42..513833233c65 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1314,10 +1314,15 @@ static inline int lpit_read_residency_count_address(u64 *address) #endif #ifdef CONFIG_ACPI_PPTT +int acpi_pptt_cpu_is_thread(unsigned int cpu); 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); #else +static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) +{ + return -EINVAL; +} static inline int find_acpi_cpu_topology(unsigned int cpu, int level) { return -EINVAL;
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 <jeremy.linton@arm.com> --- drivers/acpi/pptt.c | 53 +++++++++++++++++++++++++++++++++++++++++++- include/linux/acpi.h | 5 +++++ 2 files changed, 57 insertions(+), 1 deletion(-)