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mop3/kernel/amd64/smp.c
kamkow1 270ff507d4
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Implement lock IRQ nesting via stack variables/contexts
2026-01-14 22:11:56 +01:00

95 lines
2.0 KiB
C

#include <amd64/apic.h>
#include <amd64/init.h>
#include <amd64/intr_defs.h>
#include <amd64/mm.h>
#include <amd64/msr-index.h>
#include <amd64/msr.h>
#include <libk/std.h>
#include <libk/string.h>
#include <limine/requests.h>
#include <mm/liballoc.h>
#include <sync/spin_lock.h>
#include <sys/debug.h>
#include <sys/smp.h>
#include <sys/syscall.h>
/// Cpu ID counter
static atomic_uint cpu_counter = 0;
/// The CPUs
static struct cpu cpus[CPUS_MAX];
static atomic_int cpu_init_count;
/// Allocate a CPU structure
struct cpu* cpu_make (void) {
int id = atomic_fetch_add (&cpu_counter, 1);
struct cpu* cpu = &cpus[id];
memset (cpu, 0, sizeof (*cpu));
cpu->lock = SPIN_LOCK_INIT;
cpu->id = id;
amd64_wrmsr (MSR_GS_BASE, (uint64_t)cpu);
return cpu;
}
struct cpu* cpu_get (void) {
struct cpu* ptr = (struct cpu*)amd64_rdmsr (MSR_GS_BASE);
return ptr;
}
void cpu_request_sched (struct cpu* cpu) {
struct limine_mp_response* mp = limine_mp_request.response;
for (size_t i = 0; i < mp->cpu_count; i++) {
if (cpu->id == i) {
amd64_lapic_ipi (mp->cpus[i]->lapic_id, CPU_REQUEST_SCHED);
break;
}
}
}
/// Bootstrap code for non-BSP CPUs
static void amd64_smp_bootstrap (struct limine_mp_info* mp_info) {
amd64_load_kernel_cr3 ();
struct cpu* cpu = cpu_make ();
amd64_init (cpu, true); /* gdt + idt */
syscall_init ();
amd64_lapic_init (1000);
DEBUG ("CPU %u is online!\n", thiscpu->id);
__asm__ volatile ("sti");
atomic_fetch_sub (&cpu_init_count, 1);
for (;;)
;
}
/// Initialize SMP subsystem for AMD64. Start AP CPUs
void smp_init (void) {
amd64_lapic_init (1000);
struct limine_mp_response* mp = limine_mp_request.response;
cpu_init_count = mp->cpu_count - 1; /* Don't include BSP */
for (size_t i = 0; i < mp->cpu_count; i++) {
if (mp->cpus[i]->lapic_id != thiscpu->id) {
DEBUG ("Trying CPU %u\n", mp->cpus[i]->lapic_id);
mp->cpus[i]->goto_address = &amd64_smp_bootstrap;
}
}
while (atomic_load (&cpu_init_count) > 0)
;
DEBUG ("All CPUs are online\n");
}