Make the PCI host bridge probe code more robust when dealing with chip sets

that use configuration mode 1, but still violate the PCI 2.0 specs ...
(Required for the Compaq Proliant, for example.)

1 files changed, 35 insertions, 6 deletions

diff --git a/sys/amd64/pci/pci_bus.c b/sys/amd64/pci/pci_bus.c
index d0621e99cac2..28264260a3f8 100644
--- a/sys/amd64/pci/pci_bus.c
+++ b/sys/amd64/pci/pci_bus.c
@@ -1,6 +1,6 @@
 /**************************************************************************
 **
-**  $Id: pcibus.c,v 1.9 1995/06/28 15:54:57 se Exp $
+**  $Id: pcibus.c,v 1.10 1995/06/30 16:11:42 se Exp $
 **
 **  pci bus subroutines for i386 architecture.
 **
@@ -139,7 +139,9 @@ DATA_SET (pcibus_set, i386pci);
 
 
 #define CONF1_ENABLE       0x80000000ul
-#define CONF1_ENABLE_CHK   0xF0000000ul
+#define CONF1_ENABLE_CHK1  0xF0000000ul
+#define CONF1_ENABLE_CHK2  0xfffffffful
+#define CONF1_ENABLE_RES2  0x80fffffcul
 #define CONF1_ADDR_PORT    0x0cf8
 #define CONF1_DATA_PORT    0x0cfc
 
@@ -159,7 +161,7 @@ pcibus_setup (void)
 	*/
 
 	oldval = inl (CONF1_ADDR_PORT);
-	outl (CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
+	outl (CONF1_ADDR_PORT, CONF1_ENABLE_CHK1);
 	outb (CONF1_ADDR_PORT +3, 0);
 	result = inl (CONF1_ADDR_PORT);
 	outl (CONF1_ADDR_PORT, oldval);
@@ -167,7 +169,8 @@ pcibus_setup (void)
 	if (result & CONF1_ENABLE) {
 		pci_mechanism = 1;
 		pci_maxdevice = 32;
-		return;
+		if (pcibus_read (pcibus_tag (0,0,0), 0) != 0xfffffffful)
+			return;
 	};
 
 	/*---------------------------------------
@@ -180,13 +183,39 @@ pcibus_setup (void)
 	if (!inb (CONF2_ENABLE_PORT) && !inb (CONF2_FORWARD_PORT)) {
 		pci_mechanism = 2;
 		pci_maxdevice = 16;
-		return;
+		if (pcibus_read (pcibus_tag (0,0,0), 0) != 0xfffffffful)
+			return;
 	};
 
+
+	/*-----------------------------------------------------
+	**      Well, is it Configuration mode 1, after all ?
+	**-----------------------------------------------------
+	*/
+
+	oldval = inl (CONF1_ADDR_PORT);
+	outl (CONF1_ADDR_PORT, CONF1_ENABLE_CHK2);
+	result = inl (CONF1_ADDR_PORT);
+	outl (CONF1_ADDR_PORT, oldval);
+
+	if (result == CONF1_ENABLE_RES2) {
+		pci_mechanism = 1;
+		pci_maxdevice = 32;
+		if (pcibus_read (pcibus_tag (0,0,0), 0) != 0xfffffffful)
+			return;
+	}
+	if (result != 0xfffffffful)
+		printf ("pcibus_setup: "
+			"wrote 0x%08x, read back 0x%08x, expected 0x%08x\n", 
+			CONF1_ENABLE_CHK2, result, CONF1_ENABLE_RES2);
+
 	/*---------------------------------------
-	**      No PCI bus available.
+	**      No PCI bus host bridge found
 	**---------------------------------------
 	*/
+
+	pci_mechanism = 0;
+	pci_maxdevice = 0;
 }
 
 /*--------------------------------------------------------------------