From 3169ec51cbd7194c8bb148bb26c01f563f8e7bae Mon Sep 17 00:00:00 2001
From: boreddevnl <chris@boreddev.nl>
Date: Thu, 2 Apr 2026 20:21:06 +0200
Subject: [PATCH] FEAT: SYSTEM_CMD_PARALLEL_RUN

---
 src/sys/syscall.c           | 67 ++++++++++++++++++++++++++++++++++++-
 src/sys/syscall.h           |  1 +
 src/userland/libc/syscall.c |  4 +++
 src/userland/libc/syscall.h |  1 +
 4 files changed, 72 insertions(+), 1 deletion(-)

diff --git a/src/sys/syscall.c b/src/sys/syscall.c
index 9d8b8b8..310dd78 100644
--- a/src/sys/syscall.c
+++ b/src/sys/syscall.c
@@ -36,9 +36,44 @@ static inline void wrmsr(uint32_t msr, uint64_t value) {
 }
 
 extern void isr128_wrapper(void);
+extern void* kmalloc(size_t size);
+extern void kfree(void* ptr);
+
+typedef struct {
+    void (*fn)(void *);
+    void *arg;
+    uint64_t pml4_phys;
+    volatile int *completion_counter;
+} smp_user_task_t;
+
+static void smp_user_wrapper(void *arg) {
+    smp_user_task_t *task = (smp_user_task_t *)arg;
+    if (!task) return;
+
+    uint64_t old_cr3;
+    asm volatile("mov %%cr3, %0" : "=r"(old_cr3));
+    
+    // Switch to user address space if necessary
+    bool switch_cr3 = (task->pml4_phys != 0 && task->pml4_phys != old_cr3);
+    if (switch_cr3) {
+        asm volatile("mov %0, %%cr3" :: "r"(task->pml4_phys) : "memory");
+    }
+
+    if (task->fn) {
+        task->fn(task->arg);
+    }
+
+    if (switch_cr3) {
+        asm volatile("mov %0, %%cr3" :: "r"(old_cr3) : "memory");
+    }
+
+    if (task->completion_counter) {
+        __sync_fetch_and_add(task->completion_counter, -1);
+    }
+
+}
 
 void syscall_init(void) {
-    // SMP-Safe System Calls using int 0x80 (configured in idt.c)
 }
 
 static void user_window_close(Window *win) {
@@ -1280,6 +1315,36 @@ static uint64_t syscall_handler_inner(registers_t *regs) {
             extern void get_os_info(os_info_t *info);
             get_os_info(info);
             return 0;
+        } else if (cmd == SYSTEM_CMD_PARALLEL_RUN) {
+            void (*user_fn)(void*) = (void (*)(void*))arg2;
+            void **args = (void **)arg3;
+            int count = (int)arg4;
+
+            if (count <= 0) return 0;
+            if (count > 64) count = 64; 
+
+            volatile int completion_counter = count;
+            uint64_t current_pml4 = proc->pml4_phys;
+
+            smp_user_task_t tasks[64];
+            
+            for (int i = 0; i < count; i++) {
+                tasks[i].fn = user_fn;
+                tasks[i].arg = args[i];
+                tasks[i].pml4_phys = current_pml4;
+                tasks[i].completion_counter = &completion_counter;
+                
+                extern void work_queue_submit(void (*fn)(void*), void *arg);
+                work_queue_submit(smp_user_wrapper, &tasks[i]);
+            }
+
+            extern bool work_queue_drain_one(void);
+            while (completion_counter > 0) {
+                if (!work_queue_drain_one()) {
+                    asm volatile("pause");
+                }
+            }
+            return 0;
         }
         return -1;
     }
diff --git a/src/sys/syscall.h b/src/sys/syscall.h
index 2301165..86305d7 100644
--- a/src/sys/syscall.h
+++ b/src/sys/syscall.h
@@ -58,6 +58,7 @@ typedef struct {
 #define SYSTEM_CMD_SLEEP 46
 #define SYSTEM_CMD_SET_RESOLUTION 47
 #define SYSTEM_CMD_GET_OS_INFO 49
+#define SYSTEM_CMD_PARALLEL_RUN 50
 
 void syscall_init(void);
 uint64_t syscall_handler_c(registers_t *regs);
diff --git a/src/userland/libc/syscall.c b/src/userland/libc/syscall.c
index 2be5e55..2148ccb 100644
--- a/src/userland/libc/syscall.c
+++ b/src/userland/libc/syscall.c
@@ -255,3 +255,7 @@ int sys_get_os_info(os_info_t *info) {
     return (int)syscall5(SYS_SYSTEM, SYSTEM_CMD_GET_OS_INFO, (uint64_t)info, 0, 0, 0);
 }
 
+void sys_parallel_run(void (*fn)(void*), void **args, int count) {
+    syscall5(SYS_SYSTEM, SYSTEM_CMD_PARALLEL_RUN, (uint64_t)fn, (uint64_t)args, (uint64_t)count, 0);
+}
+
diff --git a/src/userland/libc/syscall.h b/src/userland/libc/syscall.h
index 595f952..95dd037 100644
--- a/src/userland/libc/syscall.h
+++ b/src/userland/libc/syscall.h
@@ -76,6 +76,7 @@
 #define SYSTEM_CMD_TCP_RECV_NB 42
 #define SYSTEM_CMD_YIELD 43
 #define SYSTEM_CMD_GET_OS_INFO 49
+#define SYSTEM_CMD_PARALLEL_RUN 50
 
 // Internal assembly entry into Ring 0
 extern uint64_t syscall0(uint64_t sys_num);