From b3b6a55c781305fa10b9d137d927d237e1796c85 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 25 Jul 1995 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1995-07-25

---
 pc/devether.c |   1 +
 pc/mem.h      |   2 +-
 pc/pci.c      | 119 ++++++++++++++++++++++++++++++++++++++++----------
 pc/scsi.c     |   3 +-
 4 files changed, 101 insertions(+), 24 deletions(-)

diff --git a/pc/devether.c b/pc/devether.c
index d265197ddd6b33fb512a5d483c47bb1e6fec4f75..a7bc7414c6d789a5c0d3a78fedbcbf82d91aa87d 100644
--- a/pc/devether.c
+++ b/pc/devether.c
@@ -246,6 +246,7 @@ etherreset(void)
 			memmove(ctlr->addr, ctlr->ea, sizeof(ctlr->ea));
 			memmove(ctlr->bcast, etherbcast, sizeof(etherbcast));
 
+			ctlr->ctlrno = ctlrno;
 			ether[ctlrno] = ctlr;
 			ctlr = 0;
 			break;
diff --git a/pc/mem.h b/pc/mem.h
index d4f16a31089dda898f7d9604e41174548d3b5923..a829ab1ad884b039140be694860506c4881dd46e 100644
--- a/pc/mem.h
+++ b/pc/mem.h
@@ -20,7 +20,7 @@
 /*
  * Time
  */
-#define	HZ		(50)			/* clock frequency */
+#define	HZ		(100)			/* clock frequency */
 #define	MS2HZ		(1000/HZ)		/* millisec per clock tick */
 #define	TK2SEC(t)	((t)/HZ)		/* ticks to seconds */
 #define	TK2MS(t)	((((ulong)(t))*1000)/HZ)	/* ticks to milliseconds */
diff --git a/pc/pci.c b/pc/pci.c
index 984aee8cc4a1d3fa57400d252c40214c81174aa1..6a2bec5043f3b1b018ac517dbfa638c1fb82f8e5 100644
--- a/pc/pci.c
+++ b/pc/pci.c
@@ -1,3 +1,7 @@
+/*
+ * Trivial PCI configuration code.
+ * Only deals with bus 0, amongst other glaring omissions.
+ */
 #include "u.h"
 #include "../port/lib.h"
 #include "mem.h"
@@ -8,6 +12,34 @@
 
 static Lock pcicfglock;
 
+static int pcicfgmode = -1;
+
+static void
+pcicfginit(int)
+{
+	/*
+	 * Try to determine which PCI configuration mode is implemented.
+	 * Mode2 uses a byte at 0xCF8 and another at 0xCFA; Mode1 uses
+	 * a DWORD at 0xCF8 and another at 0xCFC and will pass through
+	 * any non-DWORD accesses as normal I/O cycles. There shouldn't be
+	 * a device behind theses addresses so if Mode2 accesses fail try
+	 * for Mode1 (which is preferred, Mode2 is deprecated).
+	 */
+	outb(PCIcse, 0);
+	if(inb(PCIcse) == 0){
+		pcicfgmode = 2;
+		return;
+	}
+
+	outl(PCIaddr, 0);
+	if(inl(PCIaddr) == 0){
+		pcicfgmode = 1;
+		return;
+	}
+
+	pcicfgmode = -1;
+}
+
 /*
  * Read a chunk of PCI configuration space.
  * Assumes arguments are within limits and regno and
@@ -16,44 +48,87 @@ static Lock pcicfglock;
 void
 pcicfgr(int busno, int devno, int funcno, int regno, void* data, int nbytes)
 {
-	ulong* p;
+	ulong addr, *p;
 	int base, len;
 
 	lock(&pcicfglock);
-	outb(PCIcse, 0x80|((funcno & 0x07)<<1));
-	outb(PCIforward, busno);
-
-	base = (0xC000|(devno<<8)) + regno;
-	p = data;
-	for(len = nbytes/sizeof(ulong); len > 0; len--){
-		*p = inl(base);
-		p++;
-		base += sizeof(*p);
+	if(pcicfgmode == -1)
+		pcicfginit(busno);
+
+	switch(pcicfgmode){
+
+	case 1:
+		addr = 0x80000000|((busno & 0xFF)<<16)|((devno & 0x1F)<<11)|((funcno & 0x03)<<8);
+		p = data;
+		for(len = nbytes/sizeof(ulong); len > 0; len--){
+			outl(PCIaddr, addr|(regno & 0xFF));
+			*p = inl(PCIdata);
+			p++;
+			regno += sizeof(ulong);
+		}
+	
+		outl(PCIaddr, 0);
+		break;
+
+	case 2:
+		outb(PCIcse, 0x80|((funcno & 0x07)<<1));
+		outb(PCIforward, busno);
+	
+		base = (0xC000|(devno<<8)) + regno;
+		p = data;
+		for(len = nbytes/sizeof(ulong); len > 0; len--){
+			*p = inl(base);
+			p++;
+			base += sizeof(*p);
+		}
+	
+		outb(PCIcse, 0);
+		break;
 	}
 
-	outb(PCIcse, 0x00);
 	unlock(&pcicfglock);
 }
 
 void
 pcicfgw(int busno, int devno, int funcno, int regno, void* data, int nbytes)
 {
-	ulong* p;
+	ulong addr, *p;
 	int base, len;
 
 	lock(&pcicfglock);
-	outb(PCIcse, 0x80|((funcno & 0x07)<<1));
-	outb(PCIforward, busno);
-
-	base = (0xC000|(devno<<8)) + regno;
-	p = data;
-	for(len = nbytes/sizeof(ulong); len > 0; len--){
-		outl(base, *p);
-		p++;
-		base += sizeof(*p);
+	if(pcicfgmode == -1)
+		pcicfginit(busno);
+
+	switch(pcicfgmode){
+
+	case 1:
+		addr = 0x80000000|((busno & 0xFF)<<16)|((devno & 0x1F)<<11)|((funcno & 0x03)<<8);
+		p = data;
+		for(len = nbytes/sizeof(ulong); len > 0; len--){
+			outl(PCIaddr, addr|(regno & 0xFF));
+			outl(PCIdata, *p);
+			p++;
+			regno += sizeof(ulong);
+		}
+	
+		outl(PCIaddr, 0);
+		break;
+
+	case 2:
+		outb(PCIcse, 0x80|((funcno & 0x07)<<1));
+		outb(PCIforward, busno);
+	
+		base = (0xC000|(devno<<8)) + regno;
+		p = data;
+		for(len = nbytes/sizeof(ulong); len > 0; len--){
+			outl(base, *p);
+			p++;
+			base += sizeof(*p);
+		}
+	
+		outb(PCIcse, 0);
 	}
 
-	outb(PCIcse, 0x00);
 	unlock(&pcicfglock);
 }
 
diff --git a/pc/scsi.c b/pc/scsi.c
index 55463e1aa414f84b1f678e0e9c4683c44a166175..03bac1dde09bdfee958d92e9d09d44e5bfe1e6d3 100644
--- a/pc/scsi.c
+++ b/pc/scsi.c
@@ -206,7 +206,8 @@ scsiinv(int devno, int *type, Target **rt, uchar **inq, char *id)
 					continue;
 				*rt = t;
 				*inq = t->inq;
-				sprint(id, "scsi%d: unit %d", ctlr, unit);
+				if(id)
+					sprint(id, "scsi%d: unit %d", ctlr, unit);
 				return devno;
 			}
 		}