[PATCH v6 2/2] x86/devicetree: Use CPU description from Device Tree

From: Ivan Gorinov
Date: Tue Mar 13 2018 - 18:14:57 EST


Current x86 Device Tree implementation does not support multiprocessing.
Use new DT bindings to describe the processors.

Signed-off-by: Ivan Gorinov <ivan.gorinov@xxxxxxxxx>
---
arch/x86/kernel/devicetree.c | 39 ++++++++++++++++++++++++++++-----------
1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 5cd387f..a601f08 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -131,31 +131,46 @@ static void __init dtb_setup_hpet(void)
#endif
}

+static void __init dtb_cpu_setup(void)
+{
+ struct device_node *dn;
+ u32 apic_id, version;
+ int ret;
+
+ version = GET_APIC_VERSION(apic_read(APIC_LVR));
+ for_each_node_by_type(dn, "cpu") {
+ ret = of_property_read_u32(dn, "reg", &apic_id);
+ if (ret < 0) {
+ pr_warn("%pOF: missing local APIC ID\n", dn);
+ continue;
+ }
+ generic_processor_info(apic_id, version);
+ }
+}
+
static void __init dtb_lapic_setup(void)
{
#ifdef CONFIG_X86_LOCAL_APIC
struct device_node *dn;
struct resource r;
+ unsigned long lapic_addr = APIC_DEFAULT_PHYS_BASE;
int ret;

dn = of_find_compatible_node(NULL, NULL, "intel,ce4100-lapic");
- if (!dn)
- return;
-
- ret = of_address_to_resource(dn, 0, &r);
- if (WARN_ON(ret))
- return;
+ if (dn) {
+ ret = of_address_to_resource(dn, 0, &r);
+ if (WARN_ON(ret))
+ return;
+ lapic_addr = r.start;
+ }

/* Did the boot loader setup the local APIC ? */
if (!boot_cpu_has(X86_FEATURE_APIC)) {
- if (apic_force_enable(r.start))
+ if (apic_force_enable(lapic_addr))
return;
}
- 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)));
+ register_lapic_address(lapic_addr);
#endif
}

@@ -260,6 +275,7 @@ static void __init dtb_ioapic_setup(void) {}
static void __init dtb_apic_setup(void)
{
dtb_lapic_setup();
+ dtb_cpu_setup();
dtb_ioapic_setup();
}

@@ -297,6 +313,7 @@ void __init x86_dtb_init(void)
if (!of_have_populated_dt())
return;

+ smp_found_config = 1;
dtb_setup_hpet();
dtb_apic_setup();
}
--
2.7.4