Vystem 0.2

shelter/lib/include/std/smp.h

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: MPL-2.0
+#ifndef SH_LIB_SMP_H
+#define SH_LIB_SMP_H
+#include "std/type.h"
+#include "std/status.h"
+#include "cpu/ap.h"
+#include "cpu/serial.h"
+#include "cpu/asm.h"
+// Write GS base register
+inline void sh_smp_write_gs_base(sh_uint64 value) {
+  sh_uint32 low=(sh_uint32)(value);
+  sh_uint32 high=(sh_uint32)(value>>32);
+  __asm__ volatile ("wrmsr"::"c"(0xC0000101),"a"(low),"d"(high));
+}
+// Return CPU struct of this CPU
+inline sh_ap_CPU_STRUCT *sh_smp_gs_base() {
+  sh_uint32 low,high;
+  __asm__ volatile ("rdmsr":"=a"(low),"=d"(high):"c"(0xC0000101));
+  return (sh_ap_CPU_STRUCT*)(((sh_uint64)high<<32)|low);
+}
+// Lock structure, unlocked lock have lapic_id to SH_UINT32_MAX
+typedef struct {
+  volatile sh_uint32 spinlock;
+  sh_uint32 lapic_id;
+} sh_SPIN_LOCK;
+// Create an unlocked lock, intended for creation of global variables.
+#define SH_LOCK() {.spinlock=0,.lapic_id=SH_UINT32_MAX}
+// Create an unlocked lock, intended for creation of local variables
+#define SH_LOCK_LOCAL() ((sh_SPIN_LOCK){.spinlock=0,.lapic_id=SH_UINT32_MAX})
+// Lock a spinlock
+inline void sh_spin_lock(sh_SPIN_LOCK *lock) {
+  while (__atomic_test_and_set(&lock->spinlock,__ATOMIC_ACQUIRE)) {
+    while (lock->spinlock) {
+      __asm__ volatile ("pause");
+    }
+  }
+  if (sh_smp_gs_base()==SH_NULLPTR) {
+    sh_serial_send_byte('!');
+    while (SH_TRUE) {}
+  }
+  lock->lapic_id=sh_smp_gs_base()->lapic_id;
+}
+// Unlock a spinlock
+inline void sh_spin_unlock(sh_SPIN_LOCK *lock) {
+  lock->lapic_id=SH_UINT32_MAX;
+  __atomic_clear(&lock->spinlock,__ATOMIC_RELEASE);
+}
+// Try to lock a spinlock, doesn't wait for it to be unlocked, return SH_TRUE if lock is now owned by us
+inline sh_bool sh_spin_trylock(sh_SPIN_LOCK *lock) {
+  if (__atomic_test_and_set(&lock->spinlock,__ATOMIC_ACQUIRE)) return SH_FALSE;
+  lock->lapic_id=sh_smp_gs_base()->lapic_id;
+  return SH_TRUE;
+}
+// Return which CPU is locking the lock
+inline sh_uint32 sh_spin_wholock(sh_SPIN_LOCK *lock) {
+  return lock->lapic_id;
+}
+// Set CPU count (aka max_cpu_id+1)
+void sh_smp_set_cpu_count(sh_int16 cpu_count);
+// Return CPU count, return -1 if this value isn't initialized
+sh_int16 sh_smp_get_cpu_count();
+// Memory barrier
+inline void sh_mb() {
+  sh_asm_mfence();
+}
+// Read memory barrier
+inline void sh_rmb() {
+  sh_asm_lfence();
+}
+// Write memory barrier
+inline void sh_wmb() {
+  sh_asm_sfence();
+}
+#endif