4 files changed, 53 insertions, 4 deletions

diff --git a/sys/amd64/amd64/identcpu.c b/sys/amd64/amd64/identcpu.c
index 47d10ff59fd4..a195fcfb680b 100644
--- a/sys/amd64/amd64/identcpu.c
+++ b/sys/amd64/amd64/identcpu.c
@@ -262,14 +262,16 @@ printcpuinfo(void)
 			strcat(cpu_model, "Standard Am486DX");
 			break;
 		case 0x430:
-			strcat(cpu_model, "Am486DX2/4 Write-Through");
+			strcat(cpu_model, "Enhanced Am486DX2 Write-Through");
 			break;
 		case 0x470:
-		case 0x490:
-			strcat(cpu_model, "Enhanced Am486DX4 Write-Back");
+			strcat(cpu_model, "Enhanced Am486DX2 Write-Back");
 			break;
 		case 0x480:
-			strcat(cpu_model, "Enhanced Am486DX4 Write-Through");
+			strcat(cpu_model, "Enhanced Am486DX4/Am5x86 Write-Through");
+			break;
+		case 0x490:
+			strcat(cpu_model, "Enhanced Am486DX4/Am5x86 Write-Back");
 			break;
 		case 0x4E0:
 			strcat(cpu_model, "Am5x86 Write-Through");
@@ -1325,3 +1327,46 @@ print_transmeta_info()
 	       crusoe_frequency, crusoe_voltage, crusoe_percentage);
 }
 
+/*
+ * The AMD Elan sc520 is a system-on-chip gadget which is used in embedded
+ * kind of things, see www.soekris.com for instance, and it has a few quirks
+ * we need to deal with.
+ * Unfortunately we cannot identify the gadget by CPUID output because it
+ * depends on strapping options and only the stepping field may be useful
+ * and those are undocumented from AMDs side.
+ *
+ * So instead we recognize the on-chip host-PCI bridge and call back from
+ * sys/i386/pci/pci_bus.c to here if we find it.
+ */
+
+#include <sys/proc.h>
+#include <vm/vm.h>
+#include <vm/pmap.h>
+
+u_char *elan_mmcr;
+
+void
+init_AMD_Elan_sc520(void)
+{
+	u_int new;
+	int i;
+
+	printf("Doing h0h0magic for AMD Elan sc520\n");
+	elan_mmcr = pmap_mapdev(0xfffef000, 0x1000);
+	printf("MMCR at %p\n", elan_mmcr);
+
+	/*-
+	 * The i8254 is driven with a nonstandard frequency which is
+	 * derived thusly:
+	 *   f = 32768 * 45 * 25 / 31 = 1189161.29...
+	 * We use the sysctl to get the timecounter etc into whack.
+	 */
+	
+	new = 1189161;
+	i = kernel_sysctlbyname(&thread0, "machdep.i8254_freq", 
+	    NULL, 0, 
+	    &new, sizeof new, 
+	    NULL);
+	printf("sysctl machdep.i8254_freq=%d returns %d\n", new, i);
+}
+
diff --git a/sys/amd64/include/cputypes.h b/sys/amd64/include/cputypes.h
index 585df6753a21..999b17436127 100644
--- a/sys/amd64/include/cputypes.h
+++ b/sys/amd64/include/cputypes.h
@@ -68,6 +68,7 @@ struct cpu_nameclass {
 
 extern int	cpu;
 extern int	cpu_class;
+void init_AMD_Elan_sc520(void);
 #endif
 
 #endif /* !_MACHINE_CPUTYPES_H_ */
diff --git a/sys/amd64/include/md_var.h b/sys/amd64/include/md_var.h
index 041362fbc6ab..e75994e5d783 100644
--- a/sys/amd64/include/md_var.h
+++ b/sys/amd64/include/md_var.h
@@ -48,6 +48,7 @@ extern	u_int	cpu_id;
 extern	u_int	cpu_fxsr;
 extern	char	cpu_vendor[];
 extern	u_int	cyrix_did;
+extern	u_char	*elan_mmcr;
 extern	char	kstack[];
 #ifdef PC98
 extern	int	need_pre_dma_flush;
diff --git a/sys/amd64/pci/pci_bus.c b/sys/amd64/pci/pci_bus.c
index 4e325b225b67..65ba7d3cea0e 100644
--- a/sys/amd64/pci/pci_bus.c
+++ b/sys/amd64/pci/pci_bus.c
@@ -40,6 +40,7 @@
 #include <machine/nexusvar.h>
 #include <machine/pci_cfgreg.h>
 #include <machine/segments.h>
+#include <machine/cputypes.h>
 #include <machine/pc/bios.h>
 
 #include "pcib_if.h"
@@ -177,6 +178,7 @@ nexus_pcib_is_host_bridge(int bus, int slot, int func,
 		/* AMD -- vendor 0x1022 */
 	case 0x30001022:
 		s = "AMD Elan SC520 host to PCI bridge";
+		init_AMD_Elan_sc520();
 		break;
 	case 0x70061022:
 		s = "AMD-751 host to PCI bridge";