Disable kernel preemption, fix requesting rescheduling

kernel/amd64/apic.c

@@ -270,5 +270,5 @@ void amd64_lapic_ipi (uint32_t lapic_id, uint32_t vec) {
   }
 
   amd64_lapic_write (LAPIC_ICR + 0x10, (lapic_id << 24));
-  amd64_lapic_write (LAPIC_ICR, vec);
+  amd64_lapic_write (LAPIC_ICR, vec | (1 << 14));
 }

kernel/amd64/intr.c

@@ -165,10 +165,15 @@ static void amd64_intr_exception (struct saved_regs* regs) {
 
 /* Handle incoming interrupt, dispatch IRQ handlers. */
 void amd64_intr_handler (void* stack_ptr) {
+  spin_lock_ctx_t ctxcpu;
   amd64_load_kernel_cr3 ();
 
   struct saved_regs* regs = stack_ptr;
 
+  spin_lock (&thiscpu->lock, &ctxcpu);
+  memcpy (&thiscpu->regs, regs, sizeof (struct saved_regs));
+  spin_unlock (&thiscpu->lock, &ctxcpu);
+
   if (regs->trap <= 31) {
     amd64_intr_exception (regs);
   } else {
@@ -177,13 +182,7 @@ void amd64_intr_handler (void* stack_ptr) {
     struct irq* irq = irq_find (regs->trap);
 
     if (irq != NULL) {
-      if ((irq->flags & IRQ_INTERRUPT_SAFE))
-        __asm__ volatile ("sti");
-
       irq->func (irq->arg, stack_ptr);
-
-      if ((irq->flags & IRQ_INTERRUPT_SAFE))
-        __asm__ volatile ("cli");
     }
   }
 }

kernel/amd64/mm.c

@@ -418,9 +418,7 @@ static void amd64_tlb_shootdown_irq (void* arg, void* regs) {
 
 /* Continue initializing memory management subsystem for AMD64 after the essential parts were
  * initialized */
-void mm_init2 (void) {
-  irq_attach (&amd64_tlb_shootdown_irq, NULL, TLB_SHOOTDOWN, IRQ_INTERRUPT_SAFE);
-}
+void mm_init2 (void) { irq_attach (&amd64_tlb_shootdown_irq, NULL, TLB_SHOOTDOWN); }
 
 /* Initialize essentials for the AMD64 memory management subsystem */
 void mm_init (void) { kernel_pd.cr3_paddr = amd64_current_cr3 (); }

kernel/amd64/smp.c

@@ -8,6 +8,7 @@
 #include <libk/string.h>
 #include <limine/requests.h>
 #include <mm/liballoc.h>
+#include <proc/proc.h>
 #include <sync/spin_lock.h>
 #include <sys/debug.h>
 #include <sys/smp.h>
@@ -41,6 +42,11 @@ struct cpu* cpu_get (void) {
 }
 
 void cpu_request_sched (struct cpu* cpu) {
+  if (cpu == thiscpu) {
+    proc_sched ();
+    return;
+  }
+
   struct limine_mp_response* mp = limine_mp_request.response;
 
   for (size_t i = 0; i < mp->cpu_count; i++) {

kernel/amd64/smp.h

@@ -2,6 +2,7 @@
 #define _KERNEL_AMD64_SMP_H
 
 #include <amd64/gdt.h>
+#include <amd64/intr.h>
 #include <amd64/tss.h>
 #include <aux/compiler.h>
 #include <libk/rbtree.h>
@@ -20,6 +21,7 @@ struct cpu {
   volatile uint8_t irq_stack[KSTACK_SIZE] ALIGNED (16);
   volatile struct gdt_extended gdt ALIGNED (16);
   volatile struct tss tss;
+  struct saved_regs regs;
 
   uintptr_t lapic_mmio_base;
   uint64_t lapic_ticks;

kernel/amd64/syscall.c

@@ -3,6 +3,7 @@
 #include <amd64/mm.h>
 #include <amd64/msr-index.h>
 #include <amd64/msr.h>
+#include <libk/string.h>
 #include <m/status.h>
 #include <m/syscall_defs.h>
 #include <proc/proc.h>
@@ -13,10 +14,16 @@
 extern void amd64_syscall_entry (void);
 
 int amd64_syscall_dispatch (void* stack_ptr) {
+  spin_lock_ctx_t ctxcpu;
+
   amd64_load_kernel_cr3 ();
 
   struct saved_regs* regs = stack_ptr;
 
+  spin_lock (&thiscpu->lock, &ctxcpu);
+  memcpy (&thiscpu->regs, regs, sizeof (struct saved_regs));
+  spin_unlock (&thiscpu->lock, &ctxcpu);
+
   int syscall_num = regs->rax;
   syscall_handler_func_t func = syscall_find_handler (syscall_num);
 

kernel/irq/irq.c

@@ -14,7 +14,7 @@ struct irq* irq_table[0x100];
 
 static rw_spin_lock_t irqs_lock;
 
-bool irq_attach (void (*func) (void*, void*), void* arg, uint32_t irq_num, uint32_t flags) {
+bool irq_attach (void (*func) (void*, void*), void* arg, uint32_t irq_num) {
   spin_lock_ctx_t ctxiqa;
 
   struct irq* irq = malloc (sizeof (*irq));
@@ -25,7 +25,6 @@ bool irq_attach (void (*func) (void*, void*), void* arg, uint32_t irq_num, uint3
   irq->func = func;
   irq->arg = arg;
   irq->irq_num = irq_num;
-  irq->flags = flags;
 
   rw_spin_write_lock (&irqs_lock, &ctxiqa);
   irq_table[irq_num] = irq;

kernel/irq/irq.h

@@ -4,9 +4,6 @@
 #include <libk/list.h>
 #include <libk/std.h>
 
-#define IRQ_INTERRUPT_SAFE   (1 << 0)
-#define IRQ_INTERRUPT_UNSAFE (1 << 1)
-
 typedef void (*irq_func_t) (void* arg, void* regs);
 
 struct irq {
@@ -15,10 +12,9 @@ struct irq {
   irq_func_t func;
   void* arg;
   uint32_t irq_num;
-  uint32_t flags;
 };
 
-bool irq_attach (irq_func_t, void* arg, uint32_t irq_num, uint32_t flags);
+bool irq_attach (irq_func_t, void* arg, uint32_t irq_num);
 struct irq* irq_find (uint32_t irq_num);
 
 #endif // _KERNEL_IRQ_IRQ_H

kernel/proc/proc.c

@@ -289,7 +289,7 @@ static void proc_reap (void) {
   }
 }
 
-void proc_sched (void* regs) {
+void proc_sched (void) {
   spin_lock_ctx_t ctxcpu, ctxpr;
 
   int s_cycles = atomic_fetch_add (&sched_cycles, 1);
@@ -303,15 +303,13 @@ void proc_sched (void* regs) {
   spin_lock (&cpu->lock, &ctxcpu);
 
   struct proc* prev = cpu->proc_current;
+  next = proc_find_sched (cpu);
 
   if (prev != NULL) {
-    spin_lock (&prev->lock, &ctxpr);
-    memcpy (&prev->pdata.regs, regs, sizeof (struct saved_regs));
+    memcpy (&prev->pdata.regs, &cpu->regs, sizeof (struct saved_regs));
     spin_unlock (&prev->lock, &ctxpr);
   }
 
-  next = proc_find_sched (cpu);
-
   if (next) {
     cpu->proc_current = next;
     spin_unlock (&cpu->lock, &ctxcpu);
@@ -348,7 +346,7 @@ void proc_kill (struct proc* proc) {
 
 static void proc_irq_sched (void* arg, void* regs) {
   (void)arg;
-  proc_sched (regs);
+  proc_sched ();
 }
 
 static void proc_kpproc_init (void) {
@@ -405,8 +403,8 @@ static void proc_kpproc_init (void) {
 
 void proc_init (void) {
 #if defined(__x86_64__)
-  irq_attach (&proc_irq_sched, NULL, SCHED_PREEMPT_TIMER, IRQ_INTERRUPT_SAFE);
-  irq_attach (&proc_irq_sched, NULL, CPU_REQUEST_SCHED, IRQ_INTERRUPT_SAFE);
+  irq_attach (&proc_irq_sched, NULL, SCHED_PREEMPT_TIMER);
+  irq_attach (&proc_irq_sched, NULL, CPU_REQUEST_SCHED);
 #endif
 
   proc_kpproc_init ();

kernel/proc/proc.h

@@ -60,7 +60,7 @@ struct proc {
   struct proc_resources* resources;
 };
 
-void proc_sched (void* regs);
+void proc_sched (void);
 void proc_kill (struct proc* proc);
 bool proc_map (struct proc* proc, uintptr_t start_paddr, uintptr_t start_vaddr, size_t pages,
                uint32_t flags);

kernel/syscall/syscall.c

@@ -179,7 +179,7 @@ DEFINE_SYSCALL (sys_clone) {
 
 /* int sched (void) */
 DEFINE_SYSCALL (sys_sched) {
-  proc_sched (regs);
+  proc_sched ();
   return ST_OK;
 }