powerpc: Merge enough to start building in arch/powerpc.

[safe/jmp/linux-2.6] / arch / powerpc / mm / 44x_mmu.c

diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c
new file mode 100644 (file)
index 0000000..3d79ce2
--- /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;
+}