Re: [PATCH, RFC] Create 'slot' sysfs attributein/sys/devices/system/cpu/cpuN/topology/

Alex Chiang
2008-03-26T18:59:12Z

Hi Tony,

* Luck, Tony <tony.luck@intel.com>:
> + if (ACPI_SUCCESS(acpi_get_handle(pr->handle, "_SUN", &handle))) {
> + status = acpi_evaluate_object(pr->handle,
> + "_SUN", NULL, &buffer);
> + if (ACPI_FAILURE(status))
> + object.integer.value = -1;
> + } else {
> + 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)
>
> I'm still seeing these messages:
>
> "ACPI: Invalid PBLK length [0]"
>
> for every cpu. Presumably because "object" is a union and when
> you did the "object.integer.value = -1;" you scribbled on some bits
> that were needed in the subsequent code.

Yes, you're right. Sorry about the sloppy code.

Here is v3. I've verified that:

- it's benign on tiger (does not create errors/console
noise). You'll still see the -1 if you cat
/sys/devices/system/cpu/cpuN/topology/slot, but you
would also get the -1 if you cat physical_package_id

- it does the right thing on platforms that do supply
_SUN for processor objects. On my rx2600,
physical_package_id is -1, but I get valid values for
'slot' now.

Thanks.

/ac

Subject: [PATCH] Create 'slot' sysfs attribute in /sys/devices/system/cpu/cpuN/topology/
From: Alex Chiang <achiang@hp.com>

/sys/devices/system/cpu/cpuN/topology/physical_package_id exists,
but may contain incorrect information, especially on older ia64
platforms that do not have modern firmware.

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.

v2 -> v3:
- Stop stomping on existing PBLK in the event of _SUN failure

v1 -> v2:
- Check for _SUN object on CPU before blindly attempting
to call it

Signed-off-by: Alex Chiang <achiang@hp.com>
---
arch/ia64/kernel/setup.c | 1 +
arch/ia64/kernel/topology.c | 6 ++++++
drivers/acpi/processor_core.c | 8 ++++++++
drivers/base/topology.c | 9 +++++++++
include/asm-ia64/cpu.h | 1 +
include/asm-ia64/processor.h | 7 ++++++-
include/asm-ia64/topology.h | 3 +++
include/asm-x86/topology.h | 2 ++
8 files changed, 36 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index 4aa9eae..228d960 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..512de14 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -27,6 +27,12 @@

static struct ia64_cpu *sysfs_cpus;

+void ia64_set_topology_slot(int num, u32 slot)
+{
+ cpu_data(num)->slot = slot;
+}
+EXPORT_SYMBOL_GPL(ia64_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 36a68fa..a3a740d 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -612,6 +612,14 @@ static int acpi_processor_get_info(struct acpi_processor *pr, unsigned has_uid)
request_region(pr->throttling.address, 6, "ACPI CPU throttle");
}

+ /*
+ * If ACPI describes a slot number for this CPU, let's fill it in
+ */
+ 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);
+
return 0;
}

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..f986693 100644
--- a/include/asm-ia64/topology.h
+++ b/include/asm-ia64/topology.h
@@ -110,12 +110,15 @@ 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))
#define smt_capable() (smp_num_siblings > 1)
#endif

+#define arch_set_topology_slot(num, slot) ia64_set_topology_slot(num,slot)
+
#include <asm-generic/topology.h>

#endif /* _ASM_IA64_TOPOLOGY_H */
diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index 8af05a9..d4c922c 100644
--- a/include/asm-x86/topology.h
+++ b/include/asm-x86/topology.h
@@ -180,6 +180,8 @@ extern cpumask_t cpu_coregroup_map(int cpu);
#define topology_thread_siblings(cpu) (per_cpu(cpu_sibling_map, cpu))
#endif

+#define arch_set_topology_slot(num, slot)
+
#ifdef CONFIG_SMP
#define mc_capable() (boot_cpu_data.x86_max_cores > 1)
#define smt_capable() (smp_num_siblings > 1)
--
1.5.3.1.g1e61