[PATCH v2 2/3] x86: devicetree: enable multiprocessing in DT

[PATCH v2 2/3] x86: devicetree: enable multiprocessing in DT

[Ivan Gorinov]

Adding code to register processors described in Device Tree.
APIC ID is specified in 'intel-apic_id' propery as used in U-Boot.
First address specified in 'reg' is used as default APIC ID.

Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>
---
 arch/x86/kernel/devicetree.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 44189ee..ef1cd85 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -130,6 +130,29 @@ static void __init dtb_setup_hpet(void)
 #endif
 }
 
+static void __init dtb_cpu_setup(void)
+{
+	struct device_node *dn;
+	struct resource r;
+	const void *prop;
+	int apic_id, version;
+	int ret;
+
+	version = GET_APIC_VERSION(apic_read(APIC_LVR));
+	for_each_node_by_type(dn, "cpu") {
+		prop = of_get_property(dn, "intel,apic-id", NULL);
+		if (prop) {
+			apic_id = be32_to_cpup(prop);
+		} else {
+			ret = of_address_to_resource(dn, 0, &r);
+			if (WARN_ON(ret))
+				continue;
+			apic_id = r.start;
+		}
+		generic_processor_info(apic_id, version);
+	}
+}
+
 static void __init dtb_lapic_setup(void)
 {
 #ifdef CONFIG_X86_LOCAL_APIC
@@ -153,8 +176,6 @@ static void __init dtb_lapic_setup(void)
 	smp_found_config = 1;
 	pic_mode = 1;
 	register_lapic_address(r.start);
-	generic_processor_info(boot_cpu_physical_apicid,
-			       GET_APIC_VERSION(apic_read(APIC_LVR)));
 #endif
 }
 
@@ -256,6 +277,7 @@ static void __init dtb_ioapic_setup(void) {}
 static void __init dtb_apic_setup(void)
 {
 	dtb_lapic_setup();
+	dtb_cpu_setup();
 	dtb_ioapic_setup();
 }
 
-- 
2.7.4

Re: [PATCH v2 2/3] x86: devicetree: enable multiprocessing in DT

[Andy Shevchenko]

On Thu, Mar 1, 2018 at 4:45 AM, Ivan Gorinov <ivan.gorinov@intel.com> wrote:
> Adding code to register processors described in Device Tree.
> APIC ID is specified in 'intel-apic_id' propery as used in U-Boot.
> First address specified in 'reg' is used as default APIC ID.

> +       version = GET_APIC_VERSION(apic_read(APIC_LVR));
> +       for_each_node_by_type(dn, "cpu") {
> +               prop = of_get_property(dn, "intel,apic-id", NULL);
> +               if (prop) {
> +                       apic_id = be32_to_cpup(prop);
> +               } else {
> +                       ret = of_address_to_resource(dn, 0, &r);

> +                       if (WARN_ON(ret))

Wouldn't be too much?

Options:
- add _ONCE
- convert to plain pr_warn()

> +                               continue;
> +                       apic_id = r.start;
> +               }
> +               generic_processor_info(apic_id, version);
> +       }


-- 
With Best Regards,
Andy Shevchenko