/*
 *  Microblaze MMU emulation for qemu.
 *
 *  Copyright (c) 2009 Edgar E. Iglesias
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
 */

#define MMU_R_PID    0
#define MMU_R_ZPR    1
#define MMU_R_TLBX   2
#define MMU_R_TLBLO  3
#define MMU_R_TLBHI  4
#define MMU_R_TLBSX  5

#define RAM_DATA     1
#define RAM_TAG      0

/* Tag portion */
#define TLB_EPN_MASK          0xFFFFFC00 /* Effective Page Number */
#define TLB_PAGESZ_MASK       0x00000380
#define TLB_PAGESZ(x)         (((x) & 0x7) << 7)
#define PAGESZ_1K             0
#define PAGESZ_4K             1
#define PAGESZ_16K            2
#define PAGESZ_64K            3
#define PAGESZ_256K           4
#define PAGESZ_1M             5
#define PAGESZ_4M             6
#define PAGESZ_16M            7
#define TLB_VALID             0x00000040 /* Entry is valid */

/* Data portion */
#define TLB_RPN_MASK          0xFFFFFC00 /* Real Page Number */
#define TLB_PERM_MASK         0x00000300
#define TLB_EX                0x00000200 /* Instruction execution allowed */
#define TLB_WR                0x00000100 /* Writes permitted */
#define TLB_ZSEL_MASK         0x000000F0
#define TLB_ZSEL(x)           (((x) & 0xF) << 4)
#define TLB_ATTR_MASK         0x0000000F
#define TLB_W                 0x00000008 /* Caching is write-through */
#define TLB_I                 0x00000004 /* Caching is inhibited */
#define TLB_M                 0x00000002 /* Memory is coherent */
#define TLB_G                 0x00000001 /* Memory is guarded from prefetch */

#define TLB_ENTRIES    64

struct microblaze_mmu
{
    /* Data and tag brams.  */
    uint32_t rams[2][TLB_ENTRIES];
    /* We keep a separate ram for the tids to avoid the 48 bit tag width.  */
    uint8_t tids[TLB_ENTRIES];
    /* Control flops.  */
    uint32_t regs[8];;
};

struct microblaze_mmu_lookup
{
    uint32_t paddr;
    uint32_t vaddr;
    unsigned int size;
    unsigned int idx;
    int prot;
    enum {
        ERR_PROT, ERR_MISS, ERR_HIT
    } err;
};

void mmu_flip_um(CPUState *env, unsigned int um);
unsigned int mmu_translate(struct microblaze_mmu *mmu,
                           struct microblaze_mmu_lookup *lu,
                           target_ulong vaddr, int rw, int mmu_idx);
uint32_t mmu_read(CPUState *env, uint32_t rn);
void mmu_write(CPUState *env, uint32_t rn, uint32_t v);
void mmu_init(struct microblaze_mmu *mmu);