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/*

 * arch/arm/mm/mm-rpc.c

 *

 * Extra MM routines for RiscPC architecture

 *

 * Copyright (C) 1998 Russell King

 */

#include <linux/sched.h>

#include <linux/malloc.h>

#include <linux/mman.h>

#include <asm/pgtable.h>

#include <asm/setup.h>

#define NR_DRAM_BANKS   4

#define NR_VRAM_BANKS   1

#define NR_BANKS        (NR_DRAM_BANKS + NR_VRAM_BANKS)

#define FIRST_BANK      0

#define FIRST_DRAM_BANK 0

#define FIRST_VRAM_BANK NR_DRAM_BANKS

#define BANK_SHIFT      26

#define FIRST_DRAM_ADDR 0x10000000

#define PHYS_TO_BANK(x) (((x) >> BANK_SHIFT) & (NR_DRAM_BANKS - 1))

#define BANK_TO_PHYS(x) ((FIRST_DRAM_ADDR) + \

                            (((x) - FIRST_DRAM_BANK) << BANK_SHIFT))

struct ram_bank {

        unsigned int virt_addr;         /* virtual address of the *end* of this bank + 1 */

          signed int phys_offset;       /* offset to physical address of this bank */

};

static struct ram_bank rambank[NR_BANKS];

/*

 * Return the physical (0x10000000 -> 0x20000000) address of

 * the virtual (0xc0000000 -> 0xd0000000) address

 */

unsigned long __virt_to_phys(unsigned long vpage)

{

        unsigned int bank = FIRST_BANK;

        while (vpage >= rambank[bank].virt_addr && bank < NR_BANKS)

                bank ++;

        return vpage - rambank[bank].phys_offset;

}

/*

 * Return the virtual (0xc0000000 -> 0xd0000000) address of

 * the physical (0x10000000 -> 0x20000000) address

 */

unsigned long __phys_to_virt(unsigned long phys)

{

        unsigned int bank;

        if (phys > FIRST_DRAM_ADDR)

                bank = PHYS_TO_BANK(phys);

        else

                bank = FIRST_VRAM_BANK;

        return phys + rambank[bank].phys_offset;

}

void init_dram_banks(struct param_struct *params)

{

        unsigned int bank;

        unsigned int bytes = 0;

        for (bank = FIRST_DRAM_BANK; bank < NR_DRAM_BANKS; bank++) {

                rambank[bank].phys_offset = PAGE_OFFSET + bytes

                                                - BANK_TO_PHYS(bank);

                bytes += params->u1.s.pages_in_bank[bank - FIRST_DRAM_BANK] * PAGE_SIZE;

                rambank[bank].virt_addr   = PAGE_OFFSET + bytes;

        }

        rambank[FIRST_VRAM_BANK].phys_offset = 0xd6000000;

        rambank[FIRST_VRAM_BANK].virt_addr   = 0xe0000000;

//      current->tss.memmap = __virt_to_phys((unsigned long)swapper_pg_dir);

}