Initial commit

src/hal/smp.c

@@ -0,0 +1,112 @@
+#include <limine.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <SFB25.h>
+#include "gdt.h"
+#include "smp.h"
+#include "apic.h"
+#include "idt.h"
+#include "../mm/vmm.h"
+#include <lock.h>
+#include <io.h>
+#include <string.h>
+
+static volatile struct limine_smp_request smp_request = {
+    .id = LIMINE_SMP_REQUEST,
+    .revision = 0,
+};
+
+extern void s_load_idt();
+extern void s_load_gdt();
+extern uint64_t hhdmoffset;
+
+/* Returns the CPU structure for this particular CPU */
+cpu_state *get_cpu_struct(){
+    return (cpu_state*)rdmsr(GSBASE);
+}
+
+uint64_t get_cpu_count(){
+    return smp_request.response->cpu_count;
+}
+
+bool get_cpu_struct_initialized(){
+    if(rdmsr(GSBASE) < hhdmoffset){
+        return false;
+    }
+
+    return true;
+}
+
+atomic_flag ap_init_lock = ATOMIC_FLAG_INIT;
+
+void ap_init(struct limine_smp_info *smp_info){
+
+    acquire_lock(&ap_init_lock);
+
+    /* Load the GDT */
+    s_load_gdt();
+
+    /* Load the IDT */
+    s_load_idt();
+
+    /* Set the CR3 context */
+    extern uint64_t *kernel_page_map;
+
+    vmm_set_ctx(kernel_page_map);
+
+    asm volatile(
+        "movq %%cr3, %%rax\n\
+    movq %%rax, %%cr3\n"
+        : : : "rax"
+    );
+
+    cpu_state *cpu_struct = (cpu_state*)kmalloc(sizeof(cpu_state));
+    memset(cpu_struct, 0, sizeof(cpu_state));
+    cpu_struct->lapic_id = smp_info->lapic_id;
+
+    wrmsr(KERNELGSBASE, (uint64_t)cpu_struct);
+    wrmsr(GSBASE, (uint64_t)cpu_struct);
+
+    /* Initialize APIC & APIC timer */
+    ap_apic_init();
+
+    free_lock(&ap_init_lock);
+
+    for(;;);
+
+    scheduler_init();
+}
+
+void smp_init(){
+    
+    if(!smp_request.response){
+        klog(LOG_ERROR, __func__, "Failed to get SMP request");
+        kkill();
+    }
+
+    struct limine_smp_response *smp_response = smp_request.response;
+
+    kprintf("smp: {d} CPUs\n", smp_response->cpu_count);
+
+    for(uint64_t i = 0; i < smp_response->cpu_count; i++){
+        /* Pointer to smp_info is passed in RDI by Limine, so no need to pass any arguments here */
+        smp_response->cpus[i]->goto_address = &ap_init;
+    }
+
+    /* -- Setup CPU structure for BSP -- */
+
+    /* Allocate CPU structure */
+    cpu_state *cpu_struct = (cpu_state*)kmalloc(sizeof(cpu_state));
+    cpu_struct->lapic_id = smp_response->cpus[0]->lapic_id;
+
+    wrmsr(KERNELGSBASE, (uint64_t)cpu_struct);
+    wrmsr(GSBASE, (uint64_t)cpu_struct);
+
+    /* If one of the APs has halted, then halt the BSP */
+    extern bool kernel_killed;
+    if(kernel_killed == true){
+        kkill();
+    }
+
+}