From 745f9ebb3ea466890fce627617f9ba1b942105ae Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Tue, 29 Sep 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-09-29

---
 pc/fns.h |  2 ++
 pc/io.h  |  1 +
 pc/mmu.c | 35 ++++++++++++++++++++++++++++++++++-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/pc/fns.h b/pc/fns.h
index ebe7b22b03d579eaca9e3a1a25d10893bffbb647..6a3aa9a5005eee71af83a80daa6505df3d639971 100644
--- a/pc/fns.h
+++ b/pc/fns.h
@@ -32,6 +32,7 @@ int	inb(int);
 ushort	ins(int);
 void	inss(int, void*, int);
 void	insl(int, void*, int);
+ulong	isamem(int);
 void	kbdinit(void);
 void	mathinit(void);
 void	mmuinit(void);
@@ -45,6 +46,7 @@ void	outb(int, int);
 void	outs(int, ushort);
 void	outss(int, void*, int);
 void	outsl(int, void*, int);
+void	pcicreset(void);
 void	prhex(ulong);
 void	procrestore(Proc*);
 void	procsave(Proc*);
diff --git a/pc/io.h b/pc/io.h
index d653db0721f9134902e604d072e26f9d71cd7390..426e0b2e3fc0a0d9ed837a4ffd96908d1f992270 100644
--- a/pc/io.h
+++ b/pc/io.h
@@ -14,6 +14,7 @@ enum
 	 Kbdvec=	Int0vec+1,	/*  keyboard interrupts */
 	 Uart1vec=	Int0vec+3,	/*  modem line */
 	 Uart0vec=	Int0vec+4,	/*  serial line */
+	 PCMCIAvec=	Int0vec+5,	/*  PCMCIA card change */
 	 Floppyvec=	Int0vec+6,	/*  floppy interrupts */
 	 Parallelvec=	Int0vec+7,	/*  parallel port interrupts */
 	Int1vec=	Int0vec+8,
diff --git a/pc/mmu.c b/pc/mmu.c
index 0ac9ad0e8b17f27a9a8d6e6052d67288df58c000..f189bb48cac352aa77f9d93b53e363a5987f7771 100644
--- a/pc/mmu.c
+++ b/pc/mmu.c
@@ -89,6 +89,11 @@ static ulong	*upt;		/* 2nd level page table for struct User */
 #define MAXUMEG 64	/* maximum memory per user process in megabytes */
 #define ONEMEG (1024*1024)
 
+struct
+{
+	ulong addr; 	/* next available address for isa bus memory */
+	ulong end;	/* one past available isa bus memory */
+} isamemalloc;
 
 /*
  *  Create a prototype page map that maps all of memory into
@@ -125,8 +130,16 @@ mmuinit(void)
 	ktoppg.va = (ulong)top;
 	ktoppg.pa = ktoppg.va & ~KZERO;
 
-	/*  map all memory to KZERO */
+	/*  map all memory to KZERO (plus 1 meg for PCMCIA window) */
 	npage = conf.topofmem/BY2PG;
+	if(conf.topofmem < 64*MB){
+		/* for ISA bus memory */
+		isamemalloc.addr = conf.topofmem;
+		isamemalloc.end = conf.topofmem + 2*MB;
+		if(isamemalloc.end > 64*MB)
+			isamemalloc.end = 64*MB;
+		npage += (isamemalloc.end - isamemalloc.addr)/BY2PG;
+	}
 	nbytes = PGROUND(npage*BY2WD);		/* words of page map */
 	nkpt = nbytes/BY2PG;			/* pages of page map */
 	kpt = xspanalloc(nbytes, BY2PG, 0);
@@ -321,3 +334,23 @@ invalidateu(void)
 	/* flush cached mmu entries */
 	putcr3(ktoppg.pa);
 }
+
+/*
+ *  allocate some address space (already mapped into the kernel)
+ *  for ISA bus memory.
+ */
+ulong
+isamem(int len)
+{
+	ulong a, x;
+
+	lock(&isamemalloc);
+	len = PGROUND(len);
+	x = isamemalloc.addr + len;
+	if(x > isamemalloc.end)
+		panic("isamem");
+	a = isamemalloc.addr;
+	isamemalloc.addr = x;
+	unlock(&isamemalloc);
+	return a;
+}