kernel: implement cpu IDs and per-cpu variables

arch/x86_64/acpi/acpi.c

@@ -3,10 +3,5 @@
 
 kern_status_t acpi_init(void)
 {
-	kern_status_t status = acpi_smp_init();
-	if (status != KERN_OK) {
-		return status;
-	}
-	
 	return KERN_OK;
 }

arch/x86_64/acpi/smp.c

@@ -1,6 +1,7 @@
 #include <arch/acpi.h>
 #include <socks/printk.h>
 #include <socks/vm.h>
+#include <socks/cpu.h>
 
 #define AP_TRAMPOLINE_PADDR   0x8000
 #define LAPIC_IPI_STATUS_REG  0x0280
@@ -26,7 +27,7 @@ struct lapic_override_record {
 extern uint8_t acpi_bsp_lapic_id(void);
 extern char ap_trampoline[];
 
-static int send_ipi(void *lapic, unsigned int target_id, uint32_t payload)
+static int __used send_ipi(void *lapic, unsigned int target_id, uint32_t payload)
 {
 	uintptr_t lapic_ptr = (uintptr_t)lapic;
 
@@ -38,7 +39,7 @@ static int send_ipi(void *lapic, unsigned int target_id, uint32_t payload)
 	return 0;
 }
 
-static int init_ap(struct acpi_madt_record *rec, void *bsp_lapic, uint8_t bsp_id)
+static int __used init_ap(struct acpi_madt_record *rec, void *bsp_lapic, uint8_t bsp_id)
 {
 	struct lapic_record *lapic = (struct lapic_record *)(rec + 1);
 	if (!(lapic->l_flags & 0x1) && !(lapic->l_flags & 0x2)) {
@@ -60,7 +61,7 @@ static int init_ap(struct acpi_madt_record *rec, void *bsp_lapic, uint8_t bsp_id
 	return 0;
 }
 
-static void *find_lapic(struct acpi_madt *madt)
+static void *__used find_lapic(struct acpi_madt *madt)
 {
 	phys_addr_t local_apic = madt->m_lapic_ptr;
 
@@ -85,6 +86,7 @@ static void *find_lapic(struct acpi_madt *madt)
 	return vm_phys_to_virt(local_apic);
 }
 
+/*
 kern_status_t acpi_smp_init(void)
 {
 	struct acpi_madt *madt = (struct acpi_madt *)acpi_find_sdt(ACPI_SIG_MADT);
@@ -118,6 +120,54 @@ kern_status_t acpi_smp_init(void)
 		p += rec->r_length;
 	}
 
-	printk("acpi: initialised %u processors", nr_processors);
+	printk("acpi: found %u logical cores", nr_processors);
+	return KERN_OK;
+}
+*/
+
+kern_status_t acpi_scan_cpu_topology(void)
+{
+	struct acpi_madt *madt = (struct acpi_madt *)acpi_find_sdt(ACPI_SIG_MADT);
+	if (!madt) {
+		return KERN_UNSUPPORTED;
+	}
+
+	uint8_t bsp_id = acpi_bsp_lapic_id();
+
+	//void *bsp_lapic = find_lapic(madt);
+
+	unsigned char *p = (unsigned char *)madt + sizeof *madt;
+	unsigned char *madt_end = (unsigned char *)madt + madt->m_base.s_length;
+
+	unsigned int nr_processors = 0;
+
+	while (p < madt_end) {
+		struct acpi_madt_record *rec = (struct acpi_madt_record *)p;
+
+		if (rec->r_type != ACPI_MADT_LAPIC) {
+			p += rec->r_length;
+			continue;
+		}
+
+		struct lapic_record *lapic = (struct lapic_record *)(rec + 1);
+
+		if (!(lapic->l_flags & 0x1) && !(lapic->l_flags & 0x2)) {
+			/* processor cannot be used */
+			continue;
+		}
+
+		cpu_set_available(lapic->l_apic_id);
+		nr_processors++;
+
+		p += rec->r_length;
+	}
+
+	cpu_set_online(bsp_id);
+
+	/* store the BSP ID in the current cpu block */
+	ml_cpu_block *self = ml_this_cpu();
+	self->c_cpu_id = bsp_id;
+
+	printk("acpi: found %u logical cores", nr_processors);
 	return KERN_OK;
 }

arch/x86_64/cpu.c

@@ -1,7 +1,9 @@
 #include <socks/machine/cpu.h>
+#include <arch/msr.h>
 
 int ml_cpu_block_init(ml_cpu_block *p)
 {
+	p->c_this = p;
 	gdt_init(&p->c_gdt, &p->c_gdt_ptr);
 	idt_init(&p->c_idt_ptr);
 	return 0;
@@ -11,5 +13,6 @@ int ml_cpu_block_use(ml_cpu_block *p)
 {
 	gdt_load(&p->c_gdt_ptr);
 	idt_load(&p->c_idt_ptr);
+	wrmsr(MSR_GS_BASE, (uint64_t)p);
 	return 0;
 }

arch/x86_64/cpu_ctrl.S

@@ -6,3 +6,35 @@ ml_halt_cpu:
 1:	cli
 	hlt
 	jmp 1b
+
+
+	.global ml_this_cpu
+	.type ml_this_cpu, @function
+
+ml_this_cpu:
+	movq %gs:0, %rax
+	ret
+
+
+	.global rdmsr
+	.type rdmsr, @function
+
+rdmsr:
+	mov %rdi, %rcx
+	rdmsr
+	shl $32, %rdx
+	orq %rax, %rdx
+	ret
+
+	.global wrmsr
+	.type wrmsr, @function
+
+wrmsr:
+	mov %rdi, %rcx
+	mov %rsi, %rax
+	mov %rsi, %rdx
+	shr $32, %rdx
+
+	wrmsr
+
+	ret

arch/x86_64/include/arch/acpi.h

@@ -36,7 +36,7 @@ struct acpi_rsdp {
 		struct acpi_rsdp_20 rsdp_20;
 	};
 } __packed;
-		  
+
 struct acpi_sdt {
 	char s_sig[4];
 	uint32_t s_length;
@@ -66,7 +66,7 @@ struct acpi_madt {
 } __packed;
 
 extern kern_status_t acpi_init(void);
-extern kern_status_t acpi_smp_init(void);
+extern kern_status_t acpi_scan_cpu_topology(void);
 
 extern struct acpi_sdt *acpi_find_sdt(uint32_t sig);
 

arch/x86_64/include/arch/msr.h

@@ -0,0 +1,12 @@
+#ifndef ARCH_MSR_H_
+#define ARCH_MSR_H_
+
+#include <stdint.h>
+
+#define MSR_GS_BASE 0xC0000101
+
+/* defined in cpu_ctrl.S */
+extern uint64_t rdmsr(uint32_t id);
+extern void wrmsr(uint32_t id, uint64_t val);
+
+#endif

arch/x86_64/include/socks/machine/cpu.h

@@ -4,11 +4,16 @@
 #include <arch/gdt.h>
 #include <arch/irq.h>
 
+#define ml_cpu_block_get_id(p) ((p)->c_cpu_id)
+
 typedef struct ml_cpu_block {
+	struct ml_cpu_block *c_this;
+
 	struct gdt c_gdt;
 	struct gdt_ptr c_gdt_ptr;
 
 	struct idt_ptr c_idt_ptr;
+	unsigned int c_cpu_id;
 } ml_cpu_block;
 
 extern int ml_init_bootcpu(void);
@@ -18,5 +23,6 @@ extern int ml_cpu_block_use(ml_cpu_block *p);
 
 /* defined in cpu_ctrl.S */
 extern void ml_halt_cpu(void);
+extern ml_cpu_block *ml_this_cpu(void);
 
 #endif

arch/x86_64/init.c

@@ -3,6 +3,8 @@
 #include <socks/object.h>
 #include <arch/e820.h>
 #include <socks/init.h>
+#include <socks/percpu.h>
+#include <socks/cpu.h>
 #include <socks/memblock.h>
 #include <socks/vm.h>
 #include <socks/printk.h>
@@ -53,7 +55,13 @@ int ml_init(uintptr_t arg)
 
 	pmap_bootstrap();
 
-	acpi_init();
+	acpi_scan_cpu_topology();
+	init_per_cpu_areas();
+
+	cpu_data_t *this_cpu = get_this_cpu();
+	this_cpu->c_flags = CPU_ONLINE;
+	this_cpu->c_id = this_cpu();
+	put_cpu(this_cpu);
 
 	vm_zone_descriptor_t vm_zones[] = {
 		{ .zd_id = VM_ZONE_DMA, .zd_node = 0, .zd_name = "dma", .zd_base = 0x00, .zd_limit = 0xffffff },