Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support

 * E500 Book E processors.

 *

 * Copyright 2004 Freescale Semiconductor, Inc

 *

 * 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/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>

extern void loadcam_entry(unsigned int index);

unsigned int tlbcam_index;

unsigned int num_tlbcam_entries;

static unsigned long __cam0, __cam1, __cam2;

extern unsigned long total_lowmem;

extern unsigned long __max_low_memory;

#define MAX_LOW_MEM     CONFIG_LOWMEM_SIZE

#define NUM_TLBCAMS     (16)

struct tlbcam {

        u32     MAS0;

        u32     MAS1;

        u32     MAS2;

        u32     MAS3;

        u32     MAS7;

} TLBCAM[NUM_TLBCAMS];

struct tlbcamrange {

        unsigned long start;

        unsigned long limit;

        phys_addr_t phys;

} tlbcam_addrs[NUM_TLBCAMS];

extern unsigned int tlbcam_index;

/*

 * Return PA for this VA if it is mapped by a CAM, or 0

 */

unsigned long v_mapped_by_tlbcam(unsigned long va)

{

        int b;

        for (b = 0; b < tlbcam_index; ++b)

                if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)

                        return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);

        return 0;

}

/*

 * Return VA for a given PA or 0 if not mapped

 */

unsigned long p_mapped_by_tlbcam(unsigned long pa)

{

        int b;

        for (b = 0; b < tlbcam_index; ++b)

                if (pa >= tlbcam_addrs[b].phys

                    && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)

                              +tlbcam_addrs[b].phys)

                        return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);

        return 0;

}

/*

 * Set up one of the I/D BAT (block address translation) register pairs.

 * The parameters are not checked; in particular size must be a power

 * of 4 between 4k and 256M.

 */

void settlbcam(int index, unsigned long virt, phys_addr_t phys,

                unsigned int size, int flags, unsigned int pid)

{

        unsigned int tsize, lz;

        asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size));

        tsize = (21 - lz) / 2;

#ifdef CONFIG_SMP

        if ((flags & _PAGE_NO_CACHE) == 0)

                flags |= _PAGE_COHERENT;

#endif

        TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);

        TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);

        TLBCAM[index].MAS2 = virt & PAGE_MASK;

        TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;

        TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;

        TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;

        TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;

        TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;

        TLBCAM[index].MAS3 = (phys & PAGE_MASK) | MAS3_SX | MAS3_SR;

        TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);

#ifndef CONFIG_KGDB /* want user access for breakpoints */

        if (flags & _PAGE_USER) {

           TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;

           TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);

        }

#else

        TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;

        TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);

#endif

        tlbcam_addrs[index].start = virt;

        tlbcam_addrs[index].limit = virt + size - 1;

        tlbcam_addrs[index].phys = phys;

        loadcam_entry(index);

}

void invalidate_tlbcam_entry(int index)

{

        TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index);

        TLBCAM[index].MAS1 = ~MAS1_VALID;

        loadcam_entry(index);

}

void __init cam_mapin_ram(unsigned long cam0, unsigned long cam1,

                unsigned long cam2)

{

        settlbcam(0, KERNELBASE, PPC_MEMSTART, cam0, _PAGE_KERNEL, 0);

        tlbcam_index++;

        if (cam1) {

                tlbcam_index++;

                settlbcam(1, KERNELBASE+cam0, PPC_MEMSTART+cam0, cam1, _PAGE_KERNEL, 0);

        }

        if (cam2) {

                tlbcam_index++;

                settlbcam(2, KERNELBASE+cam0+cam1, PPC_MEMSTART+cam0+cam1, cam2, _PAGE_KERNEL, 0);

        }

}

/*

 * 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)

{

        cam_mapin_ram(__cam0, __cam1, __cam2);

        return __cam0 + __cam1 + __cam2;

}

void __init

adjust_total_lowmem(void)

{

        unsigned long max_low_mem = MAX_LOW_MEM;

        unsigned long cam_max = 0x10000000;

        unsigned long ram;

        /* adjust CAM size to max_low_mem */

        if (max_low_mem < cam_max)

                cam_max = max_low_mem;

        /* adjust lowmem size to max_low_mem */

        if (max_low_mem < total_lowmem)

                ram = max_low_mem;

        else

                ram = total_lowmem;

        /* Calculate CAM values */

        __cam0 = 1UL << 2 * (__ilog2(ram) / 2);

        if (__cam0 > cam_max)

                __cam0 = cam_max;

        ram -= __cam0;

        if (ram) {

                __cam1 = 1UL << 2 * (__ilog2(ram) / 2);

                if (__cam1 > cam_max)

                        __cam1 = cam_max;

                ram -= __cam1;

        }

        if (ram) {

                __cam2 = 1UL << 2 * (__ilog2(ram) / 2);

                if (__cam2 > cam_max)

                        __cam2 = cam_max;

                ram -= __cam2;

        }

        printk(KERN_INFO "Memory CAM mapping: CAM0=%ldMb, CAM1=%ldMb,"

                        " CAM2=%ldMb residual: %ldMb\n",

                        __cam0 >> 20, __cam1 >> 20, __cam2 >> 20,

                        (total_lowmem - __cam0 - __cam1 - __cam2) >> 20);

        __max_low_memory = max_low_mem = __cam0 + __cam1 + __cam2;

}