patch-2.4.23 linux-2.4.23/arch/ppc/mm/44x_mmu.c

• Lines: 143
• Date: 2003-11-28 10:26:19.000000000 -0800
• Orig file: linux-2.4.22/arch/ppc/mm/44x_mmu.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.22/arch/ppc/mm/44x_mmu.c linux-2.4.23/arch/ppc/mm/44x_mmu.c
@@ -0,0 +1,142 @@
+/*
+ * Modifications by Matt Porter (mporter@mvista.com) to support
+ * PPC44x Book E processors.
+ *
+ * This file contains the routines for initializing the MMU
+ * on the 4xx series of chips.
+ *  -- paulus
+ * 
+ *  Derived from arch/ppc/mm/init.c:
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ *    Copyright (C) 1996 Paul Mackerras
+ *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ *
+ *  Derived from "arch/i386/mm/init.c"
+ *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+
+#include <asm/pgalloc.h>
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/mmu.h>
+#include <asm/uaccess.h>
+#include <asm/smp.h>
+#include <asm/bootx.h>
+#include <asm/machdep.h>
+#include <asm/setup.h>
+#include <asm/ibm44x.h>
+
+#include "mmu_decl.h"
+#include "mem_pieces.h"
+
+extern char etext[], _stext[];
+extern struct mem_pieces phys_avail;
+
+/* Used by the 44x TLB replacement exception handler.
+ * Just needed it declared someplace.
+ */
+unsigned int tlb_44x_index = 0;
+unsigned int tlb_44x_hwater = 61;
+
+/*
+ * "Pins" a 256MB TLB entry in AS0 for kernel lowmem
+ */
+static void __init
+ppc44x_pin_tlb(int slot, unsigned int virt, unsigned int phys)
+{
+	unsigned long attrib;
+
+	__asm__ __volatile__("\
+	clrrwi	%2,%2,10\n\
+	ori	%2,%2,%4\n\
+	clrrwi	%1,%1,10\n\
+	li	%0,0\n\
+	ori	%0,%0,%5\n\
+	tlbwe	%2,%3,%6\n\
+	tlbwe	%1,%3,%7\n\
+	tlbwe	%0,%3,%8"
+	:
+	: "r" (attrib), "r" (phys), "r" (virt), "r" (slot),
+	  "i" (PPC44x_TLB_VALID | PPC44x_TLB_PAGESZ(PPC44x_PAGESZ_256M)),
+	  "i" (PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G),
+	  "i" (PPC44x_TLB_PAGEID),
+	  "i" (PPC44x_TLB_XLAT),
+	  "i" (PPC44x_TLB_ATTRIB));
+}
+
+/*
+ * Configure PPC44x TLB for AS0 exception processing.
+ */
+static void __init
+ppc44x_tlb_config(void)
+{
+	unsigned int pinned_tlbs = 1;
+	int i;
+
+	/*
+	 * If lowmem is not on a pin tlb entry size boundary,
+	 * then reserve the last page of system memory. This
+	 * eliminates the possibility of a speculative dcache
+	 * fetch past the end of system memory that would
+	 * result in a machine check exception.
+	 */
+	if (total_lowmem & (PPC44x_PIN_SIZE - 1))
+		mem_pieces_remove(&phys_avail, total_lowmem - PAGE_SIZE, PAGE_SIZE, 1);
+
+	/* Determine number of entries necessary to cover lowmem */
+	pinned_tlbs = (unsigned int)
+		(_ALIGN(total_lowmem, PPC44x_PIN_SIZE) >> PPC44x_PIN_SHIFT);
+
+	/* Write upper watermark to save location */
+	tlb_44x_hwater = PPC44x_LOW_SLOT - pinned_tlbs;
+
+	/* If necessary, set additional pinned TLBs */
+	if (pinned_tlbs > 1)
+		for (i = (PPC44x_LOW_SLOT-(pinned_tlbs-1)); i < PPC44x_LOW_SLOT; i++) {
+			unsigned int phys_addr = (PPC44x_LOW_SLOT-i) * PPC44x_PIN_SIZE;
+			ppc44x_pin_tlb(i, phys_addr+PAGE_OFFSET, phys_addr);
+		}
+
+	/* Make sure vmalloc doesn't use virtual space covered by
+	   the last pinned TLB entry. */
+	vmalloc_start = KERNELBASE + _ALIGN(total_lowmem, PPC44x_PIN_SIZE);
+}
+
+/*
+ * MMU_init_hw does the chip-specific initialization of the MMU hardware.
+ */
+void __init MMU_init_hw(void)
+{
+	flush_instruction_cache();
+
+	ppc44x_tlb_config();
+}