Go back to separate tests for configuration mechanism 1 and mechanism 2.

Require the state of the configuration enable bits to be OFF assuming
that the BIOS left them that way, as it should anyway to avoid bad things
to happen.

The tests themselves are copied from the previous release, with the
exception of CONF1_ENABLE_MSK1 having the LSB set. This bit should be
read back as '0', since only DWORD addresses are legal.

1 files changed, 57 insertions, 54 deletions

diff --git a/sys/i386/isa/pcibus.c b/sys/i386/isa/pcibus.c
index 14c020f..7b93bd0 100644
--- a/sys/i386/isa/pcibus.c
+++ b/sys/i386/isa/pcibus.c
@@ -1,6 +1,6 @@
 /**************************************************************************
 **
-**  $Id: pcibus.c,v 1.15 1995/09/22 19:10:54 se Exp $
+**  $Id: pcibus.c,v 1.16 1995/10/09 21:56:24 se Exp $
 **
 **  pci bus subroutines for i386 architecture.
 **
@@ -147,7 +147,7 @@ DATA_SET (pcibus_set, i386pci);
 #define CONF1_ENABLE       0x80000000ul
 #define CONF1_ENABLE_CHK   0x80000000ul
 #define CONF1_ENABLE_CHK1  0xFF000001ul
-#define CONF1_ENABLE_MSK1  0x80000000ul
+#define CONF1_ENABLE_MSK1  0x80000001ul
 #define CONF1_ENABLE_RES1  0x80000000ul
 
 #define CONF2_ENABLE_PORT  0x0cf8
@@ -181,31 +181,13 @@ pcibus_check (void)
 static void
 pcibus_setup (void)
 {
-	unsigned long mode1res,oldval;
-	unsigned char mode2res;
+	unsigned long mode1res,oldval1;
+	unsigned char mode2res,oldval2;
 
-	oldval = inl (CONF1_ADDR_PORT);
-	outl (CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
-	outb (CONF2_ENABLE_PORT, CONF2_ENABLE_CHK);
-	mode1res = inl(CONF1_ADDR_PORT);
-	mode2res = inb(CONF2_ENABLE_PORT);
-	outb (CONF2_ENABLE_PORT, 0);
-	outl (CONF1_ADDR_PORT, oldval);
+	oldval1 = inl (CONF1_ADDR_PORT);
 
 	if (bootverbose) {
-		printf ("pcibus_setup(1):\tmode1res=0x%08lx (0x%08lx), "
-			"mode2res=0x%02x (0x%02x)\n",
-			mode1res,CONF1_ENABLE_CHK,
-			(int)mode2res,CONF2_ENABLE_CHK);
-	}
-
-	/*---------------------------------------
-	**	No PCI, if neither mode1res nor mode2res could be read back
-	**---------------------------------------
-	*/
-
-	if ((mode1res != CONF1_ENABLE_CHK) && (mode2res != CONF2_ENABLE_CHK)) {
-		return;
+		printf ("pcibus_setup(1):\tmode1 addr port (0x0cf8) is 0x%08lx\n", oldval1);
 	}
 
 	/*---------------------------------------
@@ -213,50 +195,71 @@ pcibus_setup (void)
 	**---------------------------------------
 	*/
 
-	pci_mechanism = 1;
-	pci_maxdevice = 32;
+	if ((oldval1 & CONF1_ENABLE) == 0) {
 
-	outl (CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
-	outb (CONF1_ADDR_PORT +3, 0);
-	mode1res = inl (CONF1_ADDR_PORT);
-	outl (CONF1_ADDR_PORT, oldval);
+		pci_mechanism = 1;
+		pci_maxdevice = 32;
 
-	if (bootverbose)
-		printf ("pcibus_setup(2):\tmode1res=0x%08lx (0x%08lx)\n", 
-			mode1res, CONF1_ENABLE_CHK);
+		outl (CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
+		outb (CONF1_ADDR_PORT +3, 0);
+		mode1res = inl (CONF1_ADDR_PORT);
+		outl (CONF1_ADDR_PORT, oldval1);
 
-	if (mode1res) {
-		if (pcibus_check()) 
-			return;
-	};
+		if (bootverbose)
+		    printf ("pcibus_setup(1a):\tmode1res=0x%08lx (0x%08lx)\n", 
+			    mode1res, CONF1_ENABLE_CHK);
 
-	outl (CONF1_ADDR_PORT, CONF1_ENABLE_CHK1);
-	outl (CONF1_DATA_PORT, 0);
-	mode1res = inl(CONF1_ADDR_PORT);
-	outl (CONF1_ADDR_PORT, oldval);
+		if (mode1res) {
+			if (pcibus_check()) 
+				return;
+		};
 
-	if (bootverbose)
-		printf ("pcibus_setup(3):\tmode1res=0x%08lx (0x%08lx)\n", 
-			mode1res, CONF1_ENABLE_CHK1);
+		outl (CONF1_ADDR_PORT, CONF1_ENABLE_CHK1);
+		mode1res = inl(CONF1_ADDR_PORT);
+		outl (CONF1_ADDR_PORT, oldval1);
 
-	if ((mode1res & CONF1_ENABLE_MSK1) == CONF1_ENABLE_RES1) {
-		if (pcibus_check()) 
-			return;
-	};
+		if (bootverbose)
+		    printf ("pcibus_setup(1b):\tmode1res=0x%08lx (0x%08lx)\n", 
+			    mode1res, CONF1_ENABLE_CHK1);
+
+		if ((mode1res & CONF1_ENABLE_MSK1) == CONF1_ENABLE_RES1) {
+			if (pcibus_check()) 
+				return;
+		};
+	}
 
 	/*---------------------------------------
 	**      Try configuration mechanism 2 ...
 	**---------------------------------------
 	*/
 
-	if (bootverbose)
-		printf ("pcibus_setup(4):\tnow trying mechanism 2\n");
+	oldval2 = inb (CONF2_ENABLE_PORT);
+
+	if (bootverbose) {
+		printf ("pcibus_setup(2):\tmode 2 enable port (0x0cf8) is 0x%02x\n", oldval2);
+	}
+
+	if ((oldval2 & 0xf0) == 0) {
 
-	pci_mechanism = 2;
-	pci_maxdevice = 16;
+		pci_mechanism = 2;
+		pci_maxdevice = 16;
+			
+		outb (CONF2_ENABLE_PORT, CONF2_ENABLE_CHK);
+		mode2res = inb(CONF2_ENABLE_PORT);
+		outb (CONF2_ENABLE_PORT, oldval2);
 
-	if (pcibus_check()) 
-	    return;
+		if (bootverbose)
+		    printf ("pcibus_setup(2a):\tmode2res=0x%02x (0x%02x)\n", 
+			    mode2res, CONF2_ENABLE_CHK);
+
+		if (mode2res == CONF2_ENABLE_RES) {
+		    if (bootverbose)
+			printf ("pcibus_setup(2a):\tnow trying mechanism 2\n");
+
+			if (pcibus_check()) 
+				return;
+		}
+	}
 
 	/*---------------------------------------
 	**      No PCI bus host bridge found