| Message ID | 1571054162-71090-2-git-send-email-john.garry@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | [for-stable-5.3,1/2] ACPI/PPTT: Add support for ACPI 6.3 thread flag | expand |
On 15/10/2019 00:29, Sasha Levin wrote: > On Mon, Oct 14, 2019 at 07:56:01PM +0800, John Garry wrote: >> From: Jeremy Linton <jeremy.linton@arm.com> >> >> Commit bbd1b70639f785a970d998f35155c713f975e3ac upstream. >> >> 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> >> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> >> Reviewed-by: Robert Richter <rrichter@marvell.com> >> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >> Signed-off-by: Will Deacon <will@kernel.org> >> Signed-off-by: John Garry <john.garry@huawei.com> > > How far back should these patches be backported? > Hi Sasha, This patchset is for 5.3, and I sent a separate patchset for 4.19, since the backport is a little different and required some hand modification - https://lore.kernel.org/linux-arm-kernel/1571046986-231263-1-git-send-email-john.garry@huawei.com/. 4.19 is as far back as we want. Please note that the patches in this 5.3 series are relevant for 5.2 also, but since 5.2 is EOL, I didn't mention it. We did test 5.2, so you can add there also. Please let me know if any more questions. All the best, John
On Tue, Oct 15, 2019 at 09:16:13AM +0100, John Garry wrote: >On 15/10/2019 00:29, Sasha Levin wrote: >>On Mon, Oct 14, 2019 at 07:56:01PM +0800, John Garry wrote: >>>From: Jeremy Linton <jeremy.linton@arm.com> >>> >>>Commit bbd1b70639f785a970d998f35155c713f975e3ac upstream. >>> >>>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> >>>Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> >>>Reviewed-by: Robert Richter <rrichter@marvell.com> >>>Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >>>Signed-off-by: Will Deacon <will@kernel.org> >>>Signed-off-by: John Garry <john.garry@huawei.com> >> >>How far back should these patches be backported? >> > >Hi Sasha, > >This patchset is for 5.3, and I sent a separate patchset for 4.19, >since the backport is a little different and required some hand >modification - > >https://lore.kernel.org/linux-arm-kernel/1571046986-231263-1-git-send-email-john.garry@huawei.com/. >4.19 is as far back as we want. > >Please note that the patches in this 5.3 series are relevant for 5.2 >also, but since 5.2 is EOL, I didn't mention it. We did test 5.2, so >you can add there also. > >Please let me know if any more questions. I've queued this and the 4.19 patches, thanks! -- Thanks, Sasha
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 1e7ac0bd0d3a..9497298018a9 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -540,6 +540,44 @@ 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 minimum 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. + * 1, any passed flag set + * 0, flag unset + */ +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 = -ENOENT; + + 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) != 0; + + 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 @@ -604,6 +642,20 @@ int cache_setup_acpi(unsigned int cpu) return status; } +/** + * acpi_pptt_cpu_is_thread() - Determine if 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 diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 9426b9aaed86..9d0e20a2ac83 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1302,11 +1302,16 @@ 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_topology_hetero_id(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;