[ACPIHP PATCH part4 7/9] ACPI/processor: cache parsed APIC ID in processor driver data structure

From: Jiang Liu
Date: Sun Nov 04 2012 - 10:25:05 EST


Enhance ACPI processor driver to cache parsed APIC ID in processor
driver data structure, and avoid reparsing again in _acpi_map_lsapic().
This change also makes fake CPU hotplug possible because we have no
dependency on _MAT method anymore.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
arch/ia64/kernel/acpi.c | 38 ++++----------------------------------
arch/x86/kernel/acpi/boot.c | 38 +++-----------------------------------
drivers/acpi/internal.h | 2 ++
drivers/acpi/processor_core.c | 28 +++++++++++++++++++++++-----
drivers/acpi/processor_driver.c | 11 ++++++++---
include/acpi/processor.h | 1 +
include/linux/acpi.h | 2 +-
7 files changed, 42 insertions(+), 78 deletions(-)

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 44057885..f0da941 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -880,40 +880,10 @@ __init void prefill_possible_map(void)
set_cpu_possible(i, true);
}

-static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu)
+static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
{
- struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
- union acpi_object *obj;
- struct acpi_madt_local_sapic *lsapic;
cpumask_t tmp_map;
- int cpu, physid;
-
- if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
- return -EINVAL;
-
- if (!buffer.length || !buffer.pointer)
- return -EINVAL;
-
- obj = buffer.pointer;
- if (obj->type != ACPI_TYPE_BUFFER)
- {
- kfree(buffer.pointer);
- return -EINVAL;
- }
-
- lsapic = (struct acpi_madt_local_sapic *)obj->buffer.pointer;
-
- if ((lsapic->header.type != ACPI_MADT_TYPE_LOCAL_SAPIC) ||
- (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))) {
- kfree(buffer.pointer);
- return -EINVAL;
- }
-
- physid = ((lsapic->id << 8) | (lsapic->eid));
-
- kfree(buffer.pointer);
- buffer.length = ACPI_ALLOCATE_BUFFER;
- buffer.pointer = NULL;
+ int cpu;

cpumask_complement(&tmp_map, cpu_present_mask);
cpu = cpumask_first(&tmp_map);
@@ -932,9 +902,9 @@ static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu)
}

/* wrapper to silence section mismatch warning */
-int __ref acpi_map_lsapic(acpi_handle handle, int *pcpu)
+int __ref acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
{
- return _acpi_map_lsapic(handle, pcpu);
+ return _acpi_map_lsapic(handle, physid, pcpu);
}
EXPORT_SYMBOL(acpi_map_lsapic);

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index e651f7a..5e76952 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -608,44 +608,12 @@ static void __cpuinit acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
#endif
}

-static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu)
+static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
{
- struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
- union acpi_object *obj;
- struct acpi_madt_local_apic *lapic;
cpumask_var_t tmp_map, new_map;
- u8 physid;
int cpu;
int retval = -ENOMEM;

- if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
- return -EINVAL;
-
- if (!buffer.length || !buffer.pointer)
- return -EINVAL;
-
- obj = buffer.pointer;
- if (obj->type != ACPI_TYPE_BUFFER ||
- obj->buffer.length < sizeof(*lapic)) {
- kfree(buffer.pointer);
- return -EINVAL;
- }
-
- lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer;
-
- if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC ||
- !(lapic->lapic_flags & ACPI_MADT_ENABLED)) {
- kfree(buffer.pointer);
- return -EINVAL;
- }
-
- physid = lapic->id;
-
- kfree(buffer.pointer);
- buffer.length = ACPI_ALLOCATE_BUFFER;
- buffer.pointer = NULL;
- lapic = NULL;
-
if (!alloc_cpumask_var(&tmp_map, GFP_KERNEL))
goto out;

@@ -683,9 +651,9 @@ out:
}

/* wrapper to silence section mismatch warning */
-int __ref acpi_map_lsapic(acpi_handle handle, int *pcpu)
+int __ref acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
{
- return _acpi_map_lsapic(handle, pcpu);
+ return _acpi_map_lsapic(handle, physid, pcpu);
}
EXPORT_SYMBOL(acpi_map_lsapic);

diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index d2c4d83..19d8555 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -47,6 +47,8 @@ int acpi_bus_init_power(struct acpi_device *device);

int acpi_wakeup_device_init(void);
void acpi_early_processor_set_pdc(void);
+int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id);
+int acpi_map_cpuid(int apic_id, u32 acpi_id);

/* --------------------------------------------------------------------------
Embedded Controller
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index eff7222..8fd25cc 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -163,16 +163,24 @@ exit:
return apic_id;
}

-int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
+int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
{
-#ifdef CONFIG_SMP
- int i;
-#endif
- int apic_id = -1;
+ int apic_id;

apic_id = map_mat_entry(handle, type, acpi_id);
if (apic_id == -1)
apic_id = map_madt_entry(type, acpi_id);
+
+ return apic_id;
+}
+EXPORT_SYMBOL_GPL(acpi_get_apicid);
+
+int acpi_map_cpuid(int apic_id, u32 acpi_id)
+{
+#ifdef CONFIG_SMP
+ int i;
+#endif
+
if (apic_id == -1) {
/*
* On UP processor, there is no _MAT or MADT table.
@@ -212,6 +220,16 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
#endif
return -1;
}
+EXPORT_SYMBOL_GPL(acpi_map_cpuid);
+
+int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
+{
+ int apic_id;
+
+ apic_id = acpi_get_apicid(handle, type, acpi_id);
+
+ return acpi_map_cpuid(apic_id, acpi_id);
+}
EXPORT_SYMBOL_GPL(acpi_get_cpuid);

static bool __init processor_physically_present(acpi_handle handle)
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 22214fc..9a02210 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -57,6 +57,7 @@
#include <acpi/acpi_drivers.h>
#include <acpi/processor.h>
#include <acpi/acpi_hotplug.h>
+#include "internal.h"

#define PREFIX "ACPI: "

@@ -303,7 +304,8 @@ static int acpi_processor_get_info(struct acpi_device *device)
device_declaration = 1;
pr->acpi_id = value;
}
- cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
+ pr->apic_id = acpi_get_apicid(pr->handle, device_declaration, pr->acpi_id);
+ cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id);

/* Handle UP system running SMP kernel, with no LAPIC in MADT */
if (!cpu0_initialized && (cpu_index == -1) &&
@@ -689,7 +691,7 @@ static int acpi_processor_get_dev_info(struct acpi_device *device,
static int acpi_processor_pre_configure(struct acpi_device *device,
struct acpihp_cancel_context *ctx)
{
- int result;
+ int result = -EINVAL;
struct acpi_processor *pr;

if (!device || !acpi_driver_data(device))
@@ -698,7 +700,10 @@ static int acpi_processor_pre_configure(struct acpi_device *device,

/* Generate CPUID for hot-added CPUs */
if (pr->id == -1) {
- result = acpi_map_lsapic(device->handle, &pr->id);
+ if (pr->apic_id == -1)
+ return result;
+
+ result = acpi_map_lsapic(device->handle, pr->apic_id, &pr->id);
if (result)
return result;
BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 9e1c980..e25cc4e 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -197,6 +197,7 @@ struct acpi_processor_flags {
struct acpi_processor {
acpi_handle handle;
u32 acpi_id;
+ int apic_id;
u32 id;
u32 pblk;
int performance_platform_limit;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 90be989..774ce2b 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -101,7 +101,7 @@ void acpi_numa_arch_fixup(void);

#ifdef CONFIG_ACPI_HOTPLUG_CPU
/* Arch dependent functions for cpu hotplug support */
-int acpi_map_lsapic(acpi_handle handle, int *pcpu);
+int acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu);
int acpi_unmap_lsapic(int cpu);
#endif /* CONFIG_ACPI_HOTPLUG_CPU */

--
1.7.9.5

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