RE: [PATCH 2/2] ia64: Provide ACPI fixup for /proc/cpuinfo/physical_id

Luck, Tony
2008-04-29T22:32:46Z

Alex,

I chewed on this a bit ...

+void ia64_fix_socket_id(int num, u32 slot)
+{
+ if (cpu_data(num)->socket_id == -1)
+ cpu_data(num)->socket_id= slot;
+}
+EXPORT_SYMBOL_GPL(ia64_fix_socket_id);

1) socket_id is only defined when CONFIG_SMP=y, so this breaks UP
build. Fix: Wrap body of this function inside #ifdef
2) should really just name this function "arch_fix_phys_package_id"
and avoid the #define rename in topology.h

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
+ /*
+ * If ACPI describes a slot number for this CPU, we can use it
+ * to fix a broken topology->physical_package_id.
+ */
+ status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
+ if (ACPI_SUCCESS(status))
+ arch_fix_phys_package_id(pr->id, object.integer.value);
+

Comment here still refers to what the previous patch was doing. Should
now say that we are fixing /proc/cpuinfo "physical id".

diff --git a/include/asm-ia64/topology.h b/include/asm-ia64/topology.h
+#define arch_fix_phys_package_id(num, slot) ia64_fix_socket_id(num, slot)

Not needed if we name ia64_fix_socket_id() appropriately. Turn this
into an extern definition for arch_fix_phys_package_id() and drop the
extern from cpu.h

diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
+#define arch_fix_phys_package_id(num, slot)

Style preference is to now use a "static inline void" function for
this to make sure args are correctly typed, and to avoid warnings about
unused variables.

updated version of the patch looks like this ... ok???

-Tony

commit fe086a7bea7ab714930bd48addba961ceeef7634
Author: Alex Chiang <achiang@hp.com>
Date: Tue Apr 29 15:05:29 2008 -0700

[IA64] Provide ACPI fixup for /proc/cpuinfo/physical_id

Legacy HP ia64 platforms currently cannot provide
/proc/cpuinfo/physical_id due to legacy SAL/PAL implementations.
However, that physical topology information can be obtained
via ACPI.

Provide an interface that gives ACPI one last chance to provide
physical_id for these legacy platforms. This logic only comes
into play iff:

- ACPI actually provides slot information for the CPU
- we lack a valid socket_id

Otherwise, we don't do anything.

Since x86 uses the ACPI processor driver as well, we provide a nop
stub function for arch_fix_phys_package_id() in asm-x86/topology.h

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index a2484fc..abb17a6 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -27,6 +27,15 @@

static struct ia64_cpu *sysfs_cpus;

+void arch_fix_phys_package_id(int num, u32 slot)
+{
+#ifdef CONFIG_SMP
+ if (cpu_data(num)->socket_id == -1)
+ cpu_data(num)->socket_id = slot;
+#endif
+}
+EXPORT_SYMBOL_GPL(arch_fix_phys_package_id);
+
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 dd28c91..5241e3f 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -603,6 +603,15 @@ 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, we can use it
+ * ensure we get the right value in the "physical id" field
+ * of /proc/cpuinfo
+ */
+ status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
+ if (ACPI_SUCCESS(status))
+ arch_fix_phys_package_id(pr->id, object.integer.value);
+
return 0;
}

diff --git a/include/asm-ia64/topology.h b/include/asm-ia64/topology.h
index f2f72ef..32863b3 100644
--- a/include/asm-ia64/topology.h
+++ b/include/asm-ia64/topology.h
@@ -116,6 +116,8 @@ void build_cpu_to_node_map(void);
#define smt_capable() (smp_num_siblings > 1)
#endif

+extern void arch_fix_phys_package_id(int num, u32 slot);
+
#define pcibus_to_cpumask(bus) (pcibus_to_node(bus) == -1 ? \
CPU_MASK_ALL : \
node_to_cpumask(pcibus_to_node(bus)) \
diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index 0e6d6b0..4f35a0f 100644
--- a/include/asm-x86/topology.h
+++ b/include/asm-x86/topology.h
@@ -193,6 +193,10 @@ extern cpumask_t cpu_coregroup_map(int cpu);
#define topology_thread_siblings(cpu) (per_cpu(cpu_sibling_map, cpu))
#endif

+static inline void arch_fix_phys_package_id(int num, u32 slot)
+{
+}
+
struct pci_bus;
void set_pci_bus_resources_arch_default(struct pci_bus *b);