kernel: sched: Add initial sched related code

Signed-off-by: Ian Moffett <ian@osmora.org>

2 files changed, 142 insertions, 2 deletions

diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c
index 8763b51..0c59730 100644
--- a/sys/arch/amd64/amd64/cpu.c
+++ b/sys/arch/amd64/amd64/cpu.c
@@ -27,7 +27,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <machine/cpu.h>
+#include <machine/cpu_mp.h>
 #include <sys/cdefs.h>
 
 __KERNEL_META("$Hyra$: cpu.c, Ian Marco Moffett, "
@@ -49,5 +49,12 @@ amd64_get_bsp(void)
 struct cpu_info *
 amd64_this_cpu(void)
 {
-    return amd64_get_bsp();
+    struct cpu_ctx *cctx;
+
+    if (!mp_supported()) {
+        return amd64_get_bsp();
+    }
+
+    cctx = (void *)read_gs_base();
+    return cctx->ci;
 }
diff --git a/sys/arch/amd64/amd64/cpu_mp.c b/sys/arch/amd64/amd64/cpu_mp.c
new file mode 100644
index 0000000..c382439
--- /dev/null
+++ b/sys/arch/amd64/amd64/cpu_mp.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <machine/cpu_mp.h>
+#include <sys/machdep.h>
+#include <sys/limine.h>
+#include <sys/types.h>
+#include <sys/syslog.h>
+#include <sys/sched.h>
+#include <sys/cpu.h>
+#include <vm/dynalloc.h>
+#include <assert.h>
+
+__MODULE_NAME("cpu_mp");
+__KERNEL_META("$Hyra$: cpu_mp.c, Ian Marco Moffett, "
+              "SMP related code");
+
+static volatile struct limine_smp_request g_smp_req = {
+    .id = LIMINE_SMP_REQUEST,
+    .revision = 0
+};
+
+static bool is_mp_supported = false;
+
+static void
+ap_create_cctx(struct cpu_info *ci)
+{
+    struct cpu_ctx *cctx;
+
+    cctx = dynalloc(sizeof(struct cpu_ctx));
+    __assert(cctx != NULL);
+
+    cctx->ci = ci;
+
+    /* Set *our* %GS now... */
+    wrmsr(IA32_KERNEL_GS_BASE, (uintptr_t)cctx);
+
+    if (!is_mp_supported) {
+        is_mp_supported = true;
+    }
+}
+
+static void
+ap_trampoline(struct limine_smp_info *si)
+{
+    struct cpu_info *ci;
+
+    ci = (void *)si->extra_argument;
+
+    pre_init();
+    ap_create_cctx(ci);
+    processor_init();
+
+    sched_init_processor(ci);
+
+    /* Should not be reached */
+    __assert(0);
+    __builtin_unreachable();
+}
+
+/*
+ * Returns true if SMP is supported.
+ */
+bool
+mp_supported(void)
+{
+    return is_mp_supported;
+}
+
+void
+ap_bootstrap(struct cpu_info *ci)
+{
+    struct limine_smp_response *resp = g_smp_req.response;
+    struct limine_smp_info **cpus;
+    struct cpu_info *ap_ci = NULL;
+    size_t cpu_init_counter;
+
+    /* Should not happen */
+    __assert(resp != NULL);
+
+    cpus = resp->cpus;
+    cpu_init_counter = resp->cpu_count - 1;
+
+    if (resp->cpu_count == 1) {
+        /* TODO: Allow single core processing */
+        panic("System only has 1 core!\n");
+    }
+
+    /* Create processor context */
+    ap_create_cctx(ci);
+
+    KINFO("Bootstrapping %d cores...\n", cpu_init_counter);
+    for (size_t i = 0; i < resp->cpu_count; ++i) {
+        if (ci->id == cpus[i]->lapic_id) {
+            KINFO("Skip %d (BSP)... continue\n", ci->id);
+            continue;
+        }
+
+        ap_ci = dynalloc(sizeof(struct cpu_info));
+        __assert(ap_ci != NULL);
+        cpu_attach(ap_ci);
+
+        cpus[i]->extra_argument = (uintptr_t)dynalloc(sizeof(struct cpu_info));
+        cpus[i]->goto_address = ap_trampoline;
+    }
+    KINFO("AP bootstrap done for all cores\n");
+}