acpi: use multiboot2-provided RSDP structure when available

Signed-off-by: Pawel Wieczorkiewicz <[email protected]>

Author: wipawel

arch/x86/boot/multiboot.c

@@ -149,6 +149,23 @@ void init_multiboot(unsigned long *addr, const char **cmdline) {
 
             printk("[multiboot2] EFI64 Pointer: 0x%p\n", efi64->pointer);
         } break;
+
+        case MULTIBOOT2_TAG_TYPE_ACPI_OLD: {
+            struct multiboot2_tag_old_acpi *acpi = (struct multiboot2_tag_old_acpi *) tag;
+
+            acpi_rsdp = _paddr(&acpi->rsdp);
+
+            printk("[multiboot2] ACPI RSDPv1: 0x%016lx\n", acpi_rsdp);
+        } break;
+
+        case MULTIBOOT2_TAG_TYPE_ACPI_NEW: {
+            struct multiboot2_tag_new_acpi *acpi = (struct multiboot2_tag_new_acpi *) tag;
+
+            acpi_rsdp = _paddr(&acpi->rsdp);
+
+            printk("[multiboot2] ACPI RSDPv2: 0x%016lx\n", acpi_rsdp);
+        } break;
+
         case MULTIBOOT2_TAG_TYPE_LOAD_BASE_ADDR: {
             struct multiboot2_tag_load_base_addr *addr =
                 (struct multiboot2_tag_load_base_addr *) tag;

common/acpi.c

@@ -28,6 +28,8 @@
 #include <setup.h>
 #include <string.h>
 
+paddr_t acpi_rsdp = 0;
+
 static const char *madt_int_bus_names[] = {
     [ACPI_MADT_INT_BUS_ISA] = "ISA",
 };
@@ -115,6 +117,9 @@ static rsdp_rev1_t *acpi_find_rsdp(void) {
     uint32_t ebda_addr;
     rsdp_rev1_t *rsdp;
 
+    if (acpi_rsdp)
+        return (rsdp_rev1_t *) acpi_rsdp;
+
     ebda_addr = get_bios_ebda_addr();
     rsdp =
         find_rsdp(paddr_to_virt_kern(ebda_addr), paddr_to_virt_kern(ebda_addr + KB(1)));

drivers/acpi/acpica/osl.c

@@ -23,6 +23,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #ifdef KTF_ACPICA
+#include <acpi_ktf.h>
 #include <cpu.h>
 #include <ktf.h>
 #include <mm/slab.h>
@@ -186,7 +187,11 @@ ACPI_STATUS AcpiOsWritePort(ACPI_IO_ADDRESS Address, UINT32 Value, UINT32 Width)
 ACPI_PHYSICAL_ADDRESS AcpiOsGetRootPointer(void) {
     ACPI_PHYSICAL_ADDRESS pa = 0;
 
-    AcpiFindRootPointer(&pa);
+    if (acpi_rsdp)
+        pa = (ACPI_PHYSICAL_ADDRESS) acpi_rsdp;
+    else
+        AcpiFindRootPointer(&pa);
+
     return pa;
 }
 

include/acpi_ktf.h

@@ -47,6 +47,8 @@
 
 extern unsigned acpi_get_nr_cpus(void);
 
+extern paddr_t acpi_rsdp;
+
 #ifndef KTF_ACPICA
 #define RSDP_SIGNATURE (('R') | ('S' << 8) | ('D' << 16) | ('P' << 24))
 #define RSDT_SIGNATURE (('R') | ('S' << 8) | ('D' << 16) | ('T' << 24))