kernel/amd64: acpi: Support parsing MADT

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

1 files changed, 74 insertions, 0 deletions

diff --git a/sys/arch/amd64/amd64/acpi_machdep.c b/sys/arch/amd64/amd64/acpi_machdep.c
new file mode 100644
index 0000000..5f3b3bf
--- /dev/null
+++ b/sys/arch/amd64/amd64/acpi_machdep.c
@@ -0,0 +1,74 @@
+/*
+ * 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 <sys/panic.h>
+#include <sys/syslog.h>
+#include <dev/acpi/acpi.h>
+#include <dev/acpi/acpivar.h>
+#include <dev/acpi/tables.h>
+
+#define pr_trace(fmt, ...) kprintf("acpi: " fmt, ##__VA_ARGS__)
+
+int
+acpi_init_madt(void)
+{
+    struct acpi_madt *madt = acpi_query("APIC");
+    struct apic_header *apichdr;
+    struct ioapic *ioapic = NULL;
+    uint8_t *cur, *end;
+
+    if (madt == NULL) {
+        panic("Could not find MADT!\n");
+    }
+
+    cur = (uint8_t *)(madt + 1);
+    end = (uint8_t *)madt + madt->hdr.length;
+
+    while (cur < end) {
+        apichdr = (void *)cur;
+        if (apichdr->type == APIC_TYPE_IO_APIC) {
+            /*
+             * TODO: Figure out how to use multiple I/O APICs
+             */
+            if (ioapic != NULL) {
+                pr_trace("Skipping I/O APIC with ID %d\n", ioapic->ioapic_id);
+                break;
+            }
+
+            ioapic = (struct ioapic *)cur;
+            pr_trace("Detected I/O APIC (id=%d, gsi_base=%d)\n",
+                ioapic->ioapic_id, ioapic->gsi_base);
+        }
+
+        cur += apichdr->length;
+    }
+
+    return 0;
+
+}