From 65358e670588910c0bb756ef4fecca3e9918e8b7 Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Thu, 13 Aug 2026 00:43:15 -0300
Subject: [PATCH] sysctl: SYS_CTL_HW_CPUS_ONLINE

---
 kernel-src/include/kernel/sysctl.h |  3 ++
 kernel-src/sys/ctl/hw.c            | 44 ++++++++++++++++++++++++++++++
 kernel-src/sys/ctl/sysctl.c        |  2 ++
 3 files changed, 49 insertions(+)
 create mode 100644 kernel-src/sys/ctl/hw.c

diff --git a/kernel-src/include/kernel/sysctl.h b/kernel-src/include/kernel/sysctl.h
index 0046a97c..87c12df4 100644
--- a/kernel-src/include/kernel/sysctl.h
+++ b/kernel-src/include/kernel/sysctl.h
@@ -7,9 +7,11 @@
 #define SYS_CTL_NAME_MAX 6
 
 #define SYS_CTL_KERN 1
+#define SYS_CTL_HW 2
 #define SYS_CTL_KERN_PROC 1
 #define SYS_CTL_KERN_PROC_ALL 1
 #define SYS_CTL_KERN_CONSOLE_LOCK 2
+#define SYS_CTL_HW_CPUS_ONLINE 1
 
 #define SYS_CTL_KERN_PROC_INFO_NAME_SIZE 64
 #define SYS_CTL_KERN_PROC_INFO_TTY_NAME_SIZE 64
@@ -39,5 +41,6 @@ typedef struct {
 
 int sysctl(const int *name, size_t name_len, void *oldp, size_t *old_lenp, void *newp, size_t new_len);
 int sysctl_kern(const int *name, size_t name_len, void *oldp, size_t *old_lenp, void *newp, size_t new_len);
+int sysctl_hw(const int *name, size_t name_len, void *oldp, size_t *old_lenp, void *newp, size_t new_len);
 
 #endif
diff --git a/kernel-src/sys/ctl/hw.c b/kernel-src/sys/ctl/hw.c
new file mode 100644
index 00000000..ae8ed8b5
--- /dev/null
+++ b/kernel-src/sys/ctl/hw.c
@@ -0,0 +1,44 @@
+#include <kernel/sysctl.h>
+#include <kernel/usercopy.h>
+#include <arch/smp.h>
+
+static int ctl_cpus_online(const int *, size_t name_len, void *oldp, size_t *old_lenp, void *newp, size_t) {
+	if (name_len != 0)
+		return EINVAL;
+
+	if (newp)
+		return EPERM;
+
+	if (!old_lenp)
+		return EINVAL;
+
+	size_t old_len = 0;
+	if (oldp) {
+		int error = USERCOPY_POSSIBLY_FROM_USER(&old_len, old_lenp, sizeof(old_len));
+		if (error)
+			return error;
+	}
+
+	size_t required_len = sizeof(size_t);
+	int error = USERCOPY_POSSIBLY_TO_USER(old_lenp, &required_len, sizeof(required_len));
+	if (error)
+		return error;
+
+	if (!oldp)
+		return 0;
+
+	if (old_len < required_len)
+		return ENOMEM;
+
+	size_t cpus_online = arch_smp_get_cpu_count();
+	return USERCOPY_POSSIBLY_TO_USER(oldp, &cpus_online, sizeof(cpus_online));
+}
+
+int sysctl_hw(const int *name, size_t name_len, void *oldp, size_t *old_lenp, void *newp, size_t new_len) {
+	switch (*name) {
+		case SYS_CTL_HW_CPUS_ONLINE:
+			return ctl_cpus_online(name + 1, name_len - 1, oldp, old_lenp, newp, new_len);
+	}
+
+	return EINVAL;
+}
diff --git a/kernel-src/sys/ctl/sysctl.c b/kernel-src/sys/ctl/sysctl.c
index a946264f..90ce4158 100644
--- a/kernel-src/sys/ctl/sysctl.c
+++ b/kernel-src/sys/ctl/sysctl.c
@@ -9,6 +9,8 @@ int sysctl(const int *name, size_t name_len, void *oldp, size_t *old_lenp, void
 	switch (*name) {
 		case SYS_CTL_KERN:
 			return sysctl_kern(name + 1, name_len - 1, oldp, old_lenp, newp, new_len);
+		case SYS_CTL_HW:
+			return sysctl_hw(name + 1, name_len - 1, oldp, old_lenp, newp, new_len);
 		default:
 			return EINVAL;
 	}