Export the physical address of the RSDP to userland by means

of the `machdep.acpi_root' sysctl. This is required on ia64
because the root pointer hardly ever, if at all, lives in the
first MB of memory and also because scanning the first MB of
memory can cause machine checks.
This provides a save and reliable way for ACPI tools to work
with the tables if ACPI support is present in the kernel. On
ia64 ACPI is non-optional.

1 files changed, 23 insertions, 10 deletions

diff --git a/sys/ia64/acpica/OsdEnvironment.c b/sys/ia64/acpica/OsdEnvironment.c
index 724968e..e4e664e 100644
--- a/sys/ia64/acpica/OsdEnvironment.c
+++ b/sys/ia64/acpica/OsdEnvironment.c
@@ -30,12 +30,20 @@
 /*
  * 6.1 : Environmental support
  */
+#include <sys/types.h>
+#include <sys/linker_set.h>
+#include <sys/sysctl.h>
 
 #include "acpi.h"
 
 extern u_int64_t ia64_efi_acpi_table;
 extern u_int64_t ia64_efi_acpi20_table;
 
+u_long ia64_acpi_root;
+
+SYSCTL_ULONG(_machdep, OID_AUTO, acpi_root, CTLFLAG_RD, &ia64_acpi_root, 0,
+    "The physical address of the RSDP");
+
 ACPI_STATUS
 AcpiOsInitialize(void)
 {
@@ -54,17 +62,22 @@ ACPI_STATUS
 AcpiOsGetRootPointer(UINT32 Flags, ACPI_POINTER *RsdpAddress)
 {
 
-	if (ia64_efi_acpi20_table) {
-		RsdpAddress->PointerType = ACPI_PHYSICAL_POINTER;
-		RsdpAddress->Pointer.Physical = ia64_efi_acpi20_table;
-
-	}
-	else if (ia64_efi_acpi_table) {
-		RsdpAddress->PointerType = ACPI_PHYSICAL_POINTER;
-		RsdpAddress->Pointer.Physical = ia64_efi_acpi_table;
+	if (ia64_acpi_root == 0) {
+		if (ia64_efi_acpi20_table) {
+			/* XXX put under bootverbose. */
+			printf("Using ACPI2.0 table at 0x%lx\n",
+			    ia64_efi_acpi20_table);
+			ia64_acpi_root = ia64_efi_acpi20_table;
+		} else if (ia64_efi_acpi_table) {
+			/* XXX put under bootverbose. */
+			printf("Using ACPI1.x table at 0x%lx\n",
+			    ia64_efi_acpi_table);
+			ia64_acpi_root = ia64_efi_acpi_table;
+		} else
+			return(AE_NOT_FOUND);
 	}
-	else
-		return(AE_NOT_FOUND);
 
+	RsdpAddress->PointerType = ACPI_PHYSICAL_POINTER;
+	RsdpAddress->Pointer.Physical = ia64_acpi_root;
 	return(AE_OK);
 }