On 4/26/24 23:51, Jonathan Cameron wrote:
If CONFIG_ACPI_PROCESSOR provide a helper to retrieve the
acpi_handle for a given CPU allowing access to methods
in DSDT.
Tested-by: Miguel Luis <miguel.luis@xxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
v8: Code simplification suggested by Rafael.
Fixup ;; spotted by Gavin
---
drivers/acpi/acpi_processor.c | 11 +++++++++++
include/linux/acpi.h | 7 +++++++
2 files changed, 18 insertions(+)
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 3b180e21f325..ecc2721fecae 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -35,6 +35,17 @@ EXPORT_PER_CPU_SYMBOL(processors);
struct acpi_processor_errata errata __read_mostly;
EXPORT_SYMBOL_GPL(errata);
+acpi_handle acpi_get_processor_handle(int cpu)
+{
+ struct acpi_processor *pr;
+
+ pr = per_cpu(processors, cpu);
+ if (pr)
+ return pr->handle;
+
+ return NULL;
+}
+
Maybe it's worthy to have more check here, something like below.
However, it's also fine without the extra check.
if (cpu >= nr_cpu_ids || !cpu_possible(cpu))
return NULL;
static int acpi_processor_errata_piix4(struct pci_dev *dev)
{
u8 value1 = 0;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 34829f2c517a..9844a3f9c4e5 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -309,6 +309,8 @@ int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id,
int acpi_unmap_cpu(int cpu);
#endif /* CONFIG_ACPI_HOTPLUG_CPU */
+acpi_handle acpi_get_processor_handle(int cpu);
+
#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr);
#endif
@@ -1077,6 +1079,11 @@ static inline bool acpi_sleep_state_supported(u8 sleep_state)
return false;
}
+static inline acpi_handle acpi_get_processor_handle(int cpu)
+{
+ return NULL;
+}
+
#endif /* !CONFIG_ACPI */
extern void arch_post_acpi_subsys_init(void);
Thanks,
Gavin
