kern/misc: Add x2APIC support

vlang · Jul 4, 2024 · 593c7f2 · 593c7f2
1 parent bb35959
commit 593c7f2
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Showing 4 changed files with 55 additions and 5 deletions.
diff --git a/kernel/main.v b/kernel/main.v
@@ -103,6 +103,8 @@ pub fn kmain() {
 	idt.initialise()
 	isr.initialise()
 
+	x2apic_mode = smp_req.response.flags & 1 != 0
+
 	// Init terminal
 	term.initialise()
 	serial.early_initialise()

diff --git a/kernel/modules/acpi/madt.v b/kernel/modules/acpi/madt.v
@@ -29,6 +29,16 @@ pub:
 	flags        u32
 }
 
+@[packed]
+struct MADTLocalX2Apic {
+pub:
+	header MADTHeader
+	reserved [2]u8
+	x2apic_id u32
+	flags u32
+	processor_id u32
+}
+
 @[packed]
 struct MADTIoApic {
 pub:
@@ -61,6 +71,7 @@ pub:
 __global (
 	madt             &MADT
 	madt_local_apics []&MADTLocalApic
+	madt_local_x2apics []&MADTLocalX2Apic
 	madt_io_apics    []&MADTIoApic
 	madt_isos        []&MADTISO
 	madt_nmis        []&MADTNMI
@@ -83,6 +94,12 @@ fn madt_init() {
 				println('acpi/madt: Found local APIC #${madt_local_apics.len}')
 				madt_local_apics << unsafe { &MADTLocalApic(header) }
 			}
+			9 {
+				if x2apic_mode {
+					println('acpi/madt: Found local x2APIC #${madt_local_x2apics.len}')
+					madt_local_x2apics << unsafe { &MADTLocalX2Apic(header) }
+				}
+			}
 			1 {
 				println('acpi/madt: Found IO APIC #${madt_io_apics.len}')
 				madt_io_apics << unsafe { &MADTIoApic(header) }

diff --git a/kernel/modules/x86/apic/apic.v b/kernel/modules/x86/apic/apic.v
@@ -22,22 +22,47 @@ const (
 
 __global (
 	lapic_base = u64(0)
+	x2apic_mode = bool(false)
 )
 
-fn lapic_read(reg u32) u32 {
+fn xapic_read(reg u32) u32 {
 	if lapic_base == u64(0) {
 		lapic_base = u64(msr.rdmsr(0x1b) & 0xfffff000) + higher_half
 	}
 	return kio.mmin(&u32(lapic_base + reg))
 }
 
-fn lapic_write(reg u32, val u32) {
+fn x2apic_read(reg u32) u64 {
+	return msr.rdmsr(0x800 + (reg >> 4))
+}
+
+fn xapic_write(reg u32, val u32) {
 	if lapic_base == u64(0) {
 		lapic_base = u64(msr.rdmsr(0x1b) & 0xfffff000) + higher_half
 	}
 	kio.mmout(&u32(lapic_base + reg), val)
 }
 
+fn x2apic_write(reg u32, val u64) {
+	msr.wrmsr(0x800 + (reg >> 4), val)
+}
+
+fn lapic_read(reg u32) u64 {
+	if x2apic_mode {
+		return x2apic_read(reg)
+	} else {
+		return xapic_read(reg)
+	}
+}
+
+fn lapic_write(reg u32, val u64) {
+	if x2apic_mode {
+		x2apic_write(reg, val)
+	} else {
+		xapic_write(reg, u32(val))
+	}
+}
+
 pub fn lapic_timer_stop() {
 	lapic_write(apic.lapic_reg_timer_initcnt, 0)
 	lapic_write(apic.lapic_reg_timer, (1 << 16))
@@ -86,9 +111,13 @@ pub fn lapic_eoi() {
 	lapic_write(apic.lapic_reg_eoi, 0)
 }
 
-pub fn lapic_send_ipi(lapic_id u8, vector u8) {
-	lapic_write(apic.lapic_reg_icr1, u32(lapic_id) << 24)
-	lapic_write(apic.lapic_reg_icr0, vector)
+pub fn lapic_send_ipi(lapic_id u32, vector u8) {
+	if x2apic_mode {
+		x2apic_write(apic.lapic_reg_icr0, (u64(lapic_id) << 32) | vector)
+	} else {
+		xapic_write(apic.lapic_reg_icr1, u32(lapic_id) << 24)
+		xapic_write(apic.lapic_reg_icr0, vector)
+	}
 }
 
 fn io_apic_read(io_apic int, reg u32) u32 {

diff --git a/kernel/modules/x86/smp/smp.v b/kernel/modules/x86/smp/smp.v
@@ -19,6 +19,7 @@ __global (
 @[_linker_section: '.requests']
 __global (
 	volatile smp_req = limine.LimineSMPRequest{
+		flags: 1 // x2apic allowed
 		response: unsafe { nil }
 	}
 )
@@ -28,6 +29,7 @@ pub fn initialise() {
 
 	println('smp: BSP LAPIC ID:    ${smp_tag.bsp_lapic_id:x}')
 	println('smp: Total CPU count: ${smp_tag.cpu_count}')
+	println('smp: Using x2APIC:    ${x2apic_mode}')
 
 	smp_info_array := smp_tag.cpus