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Diffstat (limited to 'arch/powerpc/mm/44x_mmu.c')
-rw-r--r--arch/powerpc/mm/44x_mmu.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c
new file mode 100644
index 000000000000..3d79ce281b67
--- /dev/null
+++ b/arch/powerpc/mm/44x_mmu.c
@@ -0,0 +1,120 @@
+/*
+ * 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/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 "mmu_decl.h"
+
+extern char etext[], _stext[];
+
+/* Used by the 44x TLB replacement exception handler.
+ * Just needed it declared someplace.
+ */
+unsigned int tlb_44x_index = 0;
+unsigned int tlb_44x_hwater = 62;
+
+/*
+ * "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 = 0;
+
+ __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_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));
+}
+
+/*
+ * MMU_init_hw does the chip-specific initialization of the MMU hardware.
+ */
+void __init MMU_init_hw(void)
+{
+ flush_instruction_cache();
+}
+
+unsigned long __init mmu_mapin_ram(void)
+{
+ unsigned int pinned_tlbs = 1;
+ int i;
+
+ /* 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);
+ }
+
+ return total_lowmem;
+}