Hi Len, Tony, A while back, I submitted a patch to expose the value of the _SUN method for CPUs. On ia64, the "physical id" field in /proc/cpuinfo isn't sufficient for some legacy HP ia64 platforms, as they do not have a modern SAL or PAL. http://lkml.org/lkml/2007/10/30/529 That patch wasn't so great because as Len pointed out, /proc/acpi is a deprecated interface. Here is another try that attempts to present a generic "slot" attribute in sysfs that leaves the various architectures free to implement however they like. Yes, I am aware of the physical_package_id attribute. However, that doesn't necessarily map to a slot on the system board. Additionally, it's broken on the same ia64 systems where /proc/cpuinfo is broken, because it's trying to read the same field. :-/ On ia64, I have a somewhat ugly implementation, where the ACPI processor driver is filling in the answer. I chose this approach because I couldn't figure out how to do it in the base CPU driver, since calling the _SUN method requires the ACPI interpreter to be initialized, and it didn't look like that was the case when we did things like identify_siblings(), for instance. Finally, there is something that looks odd in struct cpuinfo_ia64, where there are now two #ifdef CONFIG_SMP statements. I did this because adding the new 'slot' member created a 4-byte hole in the struct. It felt a little cleaner to me to move the 'int cpu;' member upwards to fill in the hole, and then my 'slot' could take the spot of 'cpu'. I'd like to get feedback on both: - the concept in general of creating a new sysfs attribute - the ia64 implementation, specifically Thanks. /ac From: Alex Chiang <achiang@xxxxxx> Physical slot information for CPUs is important for many reasons, including managability. For instance, if a platform supports physical CPU hotplug, it would be nice for the user to know which physical CPU module to actually unplug after offlining it. The "physical id" field in /proc/cpuinfo is broken/missing on older ia64 platforms that do not have modern firmware. /sys/devices/system/cpu/cpuN/topology/physical_package_id exists, but is broken on those same platforms because it's simply reading the same field that would have been presented in /proc/cpuinfo. Create a 'slot' attribute and define an interface that may be populated via alternate sources, without breaking existing functionality. Implement this interface on ia64 by invoking the _SUN method on a per cpu basis. Leave other archs alone for now. Signed-off-by: Alex Chiang <achiang@xxxxxx> --- arch/ia64/kernel/setup.c | 1 + arch/ia64/kernel/topology.c | 6 ++++++ drivers/acpi/processor_core.c | 5 +++++ drivers/base/topology.c | 9 +++++++++ include/asm-ia64/cpu.h | 1 + include/asm-ia64/processor.h | 7 ++++++- include/asm-ia64/topology.h | 1 + include/asm-x86/cpu.h | 1 + 8 files changed, 30 insertions(+), 1 deletions(-) diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c index ebd1a09..34de68a 100644 --- a/arch/ia64/kernel/setup.c +++ b/arch/ia64/kernel/setup.c @@ -735,6 +735,7 @@ identify_cpu (struct cpuinfo_ia64 *c) */ c->threads_per_core = c->cores_per_socket = c->num_log = 1; c->socket_id = -1; + c->slot = -1; identify_siblings(c); diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c index a2484fc..3810b48 100644 --- a/arch/ia64/kernel/topology.c +++ b/arch/ia64/kernel/topology.c @@ -27,6 +27,12 @@ static struct ia64_cpu *sysfs_cpus; +void arch_set_topology_slot(int num, u32 slot) +{ + cpu_data(num)->slot = slot; +} +EXPORT_SYMBOL(arch_set_topology_slot); + int arch_register_cpu(int num) { #if defined (CONFIG_ACPI) && defined (CONFIG_HOTPLUG_CPU) diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c index a3cc8a9..89a9ad5 100644 --- a/drivers/acpi/processor_core.c +++ b/drivers/acpi/processor_core.c @@ -590,6 +590,11 @@ static int acpi_processor_get_info(struct acpi_processor *pr, unsigned has_uid) ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id, pr->acpi_id)); + status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer); + if (ACPI_FAILURE(status)) + object.integer.value = -1; + arch_set_topology_slot(pr->id, object.integer.value); + if (!object.processor.pblk_address) ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n")); else if (object.processor.pblk_length != 6) diff --git a/drivers/base/topology.c b/drivers/base/topology.c index e1d3ad4..4fcffca 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -57,6 +57,14 @@ define_one_ro(physical_package_id); #define ref_physical_package_id_attr #endif +#ifdef topology_slot +define_id_show_func(slot); +define_one_ro(slot); +#define ref_slot_attr &attr_slot.attr, +#else +#define ref_slot_attr +#endif + #ifdef topology_core_id define_id_show_func(core_id); define_one_ro(core_id); @@ -83,6 +91,7 @@ define_one_ro(core_siblings); static struct attribute *default_attrs[] = { ref_physical_package_id_attr + ref_slot_attr ref_core_id_attr ref_thread_siblings_attr ref_core_siblings_attr diff --git a/include/asm-ia64/cpu.h b/include/asm-ia64/cpu.h index e87fa32..393e545 100644 --- a/include/asm-ia64/cpu.h +++ b/include/asm-ia64/cpu.h @@ -14,6 +14,7 @@ DECLARE_PER_CPU(struct ia64_cpu, cpu_devices); DECLARE_PER_CPU(int, cpu_state); +extern void arch_set_topology_slot(int num, u32 slot); extern int arch_register_cpu(int num); #ifdef CONFIG_HOTPLUG_CPU extern void arch_unregister_cpu(int); diff --git a/include/asm-ia64/processor.h b/include/asm-ia64/processor.h index 741f7ec..066553c 100644 --- a/include/asm-ia64/processor.h +++ b/include/asm-ia64/processor.h @@ -125,6 +125,10 @@ struct ia64_psr { */ struct cpuinfo_ia64 { __u32 softirq_pending; + +#ifdef CONFIG_SMP + int cpu; +#endif __u64 itm_delta; /* # of clock cycles between clock ticks */ __u64 itm_next; /* interval timer mask value to use for next clock tick */ __u64 nsec_per_cyc; /* (1000000000<<IA64_NSEC_PER_CYC_SHIFT)/itc_freq */ @@ -140,7 +144,6 @@ struct cpuinfo_ia64 { #ifdef CONFIG_SMP __u64 loops_per_jiffy; - int cpu; __u32 socket_id; /* physical processor socket id */ __u16 core_id; /* core id */ __u16 thread_id; /* thread id */ @@ -150,6 +153,8 @@ struct cpuinfo_ia64 { __u8 threads_per_core; /* Threads per core */ #endif + __u32 slot; /* physical slot; can differ from socket_id */ + /* CPUID-derived information: */ __u64 ppn; __u64 features; diff --git a/include/asm-ia64/topology.h b/include/asm-ia64/topology.h index 2d67b72..3b0ab1c 100644 --- a/include/asm-ia64/topology.h +++ b/include/asm-ia64/topology.h @@ -110,6 +110,7 @@ void build_cpu_to_node_map(void); #ifdef CONFIG_SMP #define topology_physical_package_id(cpu) (cpu_data(cpu)->socket_id) +#define topology_slot(cpu) (cpu_data(cpu)->slot) #define topology_core_id(cpu) (cpu_data(cpu)->core_id) #define topology_core_siblings(cpu) (cpu_core_map[cpu]) #define topology_thread_siblings(cpu) (per_cpu(cpu_sibling_map, cpu)) diff --git a/include/asm-x86/cpu.h b/include/asm-x86/cpu.h index 73f2ea8..43132a2 100644 --- a/include/asm-x86/cpu.h +++ b/include/asm-x86/cpu.h @@ -11,6 +11,7 @@ struct x86_cpu { struct cpu cpu; }; +extern void arch_set_topology_slot(int num, u32 slot); #ifdef CONFIG_HOTPLUG_CPU extern int arch_register_cpu(int num); extern void arch_unregister_cpu(int); -- 1.5.3.1.g1e61 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
