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/* Overlay manager for SPU.

   Copyright 2006, 2007, 2008 Free Software Foundation, Inc.

   This file is part of the GNU Binutils.

   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 3 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
   MA 02110-1301, USA.  */

/* MFC DMA defn's.  */
#define MFC_GET_CMD             0x40
#define MFC_MAX_DMA_SIZE        0x4000
#define MFC_TAG_UPDATE_ALL      2
#define MFC_TAG_ID              0

/* Register usage.  */
#define reserved1       $75
#define parm            $75
#define tab1            reserved1
#define tab2            reserved1
#define vma             reserved1
#define oldvma          reserved1
#define newmask         reserved1
#define map             reserved1

#define reserved2       $76
#define off1            reserved2
#define off2            reserved2
#define present1        reserved2
#define present2        reserved2
#define sz              reserved2
#define cmp             reserved2
#define add64           reserved2
#define cgbits          reserved2
#define off3            reserved2
#define off4            reserved2
#define addr4           reserved2
#define off5            reserved2
#define tagstat         reserved2

#define reserved3       $77
#define size1           reserved3
#define size2           reserved3
#define rv3             reserved3
#define ealo            reserved3
#define cmd             reserved3
#define off64           reserved3
#define tab3            reserved3
#define tab4            reserved3
#define tab5            reserved3

#define reserved4       $78
#define ovl             reserved4
#define rv2             reserved4
#define rv5             reserved4
#define cgshuf          reserved4
#define newovl          reserved4
#define irqtmp1         reserved4
#define irqtmp2         reserved4

#define reserved5       $79
#define target          reserved5

#define save1           $74
#define rv4             save1
#define rv7             save1
#define tagid           save1
#define maxsize         save1
#define pbyte           save1
#define pbit            save1

#define save2           $73
#define cur             save2
#define rv6             save2
#define osize           save2
#define zovl            save2
#define oldovl          save2
#define newvma          save2

#define save3           $72
#define rv1             save3
#define ea64            save3
#define buf3            save3
#define genwi           save3
#define newmap          save3
#define oldmask         save3

#define save4           $71
#define irq_stat        save4

        .text
        .align  4
        .type   __rv_pattern, @object
        .size   __rv_pattern, 16
__rv_pattern:
        .word   0x00010203, 0x10111213, 0x80808080, 0x80808080

        .type   __cg_pattern, @object
        .size   __cg_pattern, 16
__cg_pattern:
        .word   0x04050607, 0x80808080, 0x80808080, 0x80808080

        .type   __ovly_current, @object
        .size   __ovly_current, 16
__ovly_current:
        .space  16

/*
 * __ovly_return - stub for returning from overlay functions.
 *
 * On entry the four slots of $lr are:
 *   __ovly_return, prev ovl index, caller return addr, undefined.
 *
 * Load the previous overlay and jump to the caller return address.
 * Updates __ovly_current.
 */
        .align  4
        .global __ovly_return
        .type   __ovly_return, @function
__ovly_return:
        ila     tab1, _ovly_table - 16                          # 0,2   0
        shlqbyi ovl, $lr, 4                                     # 1,4   0
#nop
        shlqbyi target, $lr, 8                                  # 1,4   1
#nop; lnop
#nop; lnop
        shli    off1, ovl, 4                                    # 0,4   4
#lnop
#nop
        hbr     ovly_ret9, target                               # 1,15  5
#nop; lnop
#nop; lnop
#nop
        lqx     vma, tab1, off1                                 # 1,6   8
#ifdef OVLY_IRQ_SAVE
        nop
        stqd    save4, -64($sp)                                 # 1,6   9
#else
#nop; lnop
#endif
#nop; lnop
#nop; lnop
#nop; lnop
#nop; lnop
#nop
        rotqbyi size1, vma, 4                                   # 1,4   14
#nop
        stqd    save3, -48($sp)                                 # 1,6   15
#nop
        stqd    save2, -32($sp)                                 # 1,6   16
#nop
        stqd    save1, -16($sp)                                 # 1,6   17
        andi    present1, size1, 1                              # 0,2   18
        stqr    ovl, __ovly_current                             # 1,6   18
#nop; lnop
#nop
        brz     present1, do_load                               # 1,4   20
ovly_ret9:
#nop
        bi      target                                          # 1,4   21

/*
 * __ovly_load - copy an overlay partion to local store.
 *
 * On entry $75 points to a word consisting of the overlay index in
 * the top 14 bits, and the target address in the bottom 18 bits.
 *
 * Sets up $lr to return via __ovly_return.  If $lr is already set
 * to return via __ovly_return, don't change it.  In that case we
 * have a tail call from one overlay function to another.
 * Updates __ovly_current.
 */
        .align  3
        .global __ovly_load
        .type   __ovly_load, @function
__ovly_load:
#if OVL_STUB_SIZE == 8
########
#nop
        lqd     target, 0(parm)                                 # 1,6   -11
#nop; lnop
#nop; lnop
#nop; lnop
#nop; lnop
#nop; lnop
#nop
        rotqby  target, target, parm                            # 1,4   -5
        ila     tab2, _ovly_table - 16                          # 0,2   -4
        stqd    save3, -48($sp)                                 # 1,6   -4
#nop
        stqd    save2, -32($sp)                                 # 1,6   -3
#nop
        stqd    save1, -16($sp)                                 # 1,6   -2
        rotmi   ovl, target, -18                                # 0,4   -1
        hbr     ovly_load9, target                              # 1,15  -1
        ila     rv1, __ovly_return                              # 0,2   0
#lnop
#nop; lnop
#nop
        lqr     cur, __ovly_current                             # 1,6   2
        shli    off2, ovl, 4                                    # 0,4   3
        stqr    ovl, __ovly_current                             # 1,6   3
        ceq     rv2, $lr, rv1                                   # 0,2   4
        lqr     rv3, __rv_pattern                               # 1,6   4
#nop; lnop
#nop; lnop
#nop
        lqx     vma, tab2, off2                                 # 1,6   7
########
#else /* OVL_STUB_SIZE == 16 */
########
        ila     tab2, _ovly_table - 16                          # 0,2   0
        stqd    save3, -48($sp)                                 # 1,6   0
        ila     rv1, __ovly_return                              # 0,2   1
        stqd    save2, -32($sp)                                 # 1,6   1
        shli    off2, ovl, 4                                    # 0,4   2
        lqr     cur, __ovly_current                             # 1,6   2
        nop
        stqr    ovl, __ovly_current                             # 1,6   3
        ceq     rv2, $lr, rv1                                   # 0,2   4
        lqr     rv3, __rv_pattern                               # 1,6   4
#nop
        hbr     ovly_load9, target                              # 1,15  5
#nop
        lqx     vma, tab2, off2                                 # 1,6   6
#nop
        stqd    save1, -16($sp)                                 # 1,6   7
########
#endif

#nop; lnop
#nop; lnop
#nop
        shufb   rv4, rv1, cur, rv3                              # 1,4   10
#nop
        fsmb    rv5, rv2                                        # 1,4   11
#nop
        rotqmbyi rv6, $lr, -8                                   # 1,4   12
#nop
        rotqbyi size2, vma, 4                                   # 1,4   13
#nop
        lqd     save3, -48($sp)                                 # 1,6   14
#nop; lnop
        or      rv7, rv4, rv6                                   # 0,2   16
        lqd     save2, -32($sp)                                 # 1,6   16
        andi    present2, size2, 1                              # 0,2   17
#ifdef OVLY_IRQ_SAVE
        stqd    save4, -64($sp)                                 # 1,6   17
#else
        lnop                                                    # 1,0   17
#endif
        selb    $lr, rv7, $lr, rv5                              # 0,2   18
        lqd     save1, -16($sp)                                 # 1,6   18
#nop
        brz     present2, do_load                               # 1,4   19
ovly_load9:
#nop
        bi      target                                          # 1,4   20

/* If we get here, we are about to load a new overlay.
 * "vma" contains the relevant entry from _ovly_table[].
 *      extern struct {
 *              u32 vma;
 *              u32 size;
 *              u32 file_offset;
 *              u32 buf;
 *      } _ovly_table[];
 */
        .align  3
        .global __ovly_load_event
        .type   __ovly_load_event, @function
__ovly_load_event:
do_load:
#ifdef OVLY_IRQ_SAVE
        ila     irqtmp1, do_load10                              # 0,2   -5
        rotqbyi sz, vma, 8                                      # 1,4   -5
#nop
        rdch    irq_stat, $SPU_RdMachStat                       # 1,6   -4
#nop
        bid     irqtmp1                                         # 1,4   -3
do_load10:
        nop
#else
#nop
        rotqbyi sz, vma, 8                                      # 1,4   0
#endif
        rotqbyi osize, vma, 4                                   # 1,4   1
#nop
        lqa     ea64, _EAR_                                     # 1,6   2
#nop
        lqr     cgshuf, __cg_pattern                            # 1,6   3

/* We could predict the branch at the end of this loop by adding a few
   instructions, and there are plenty of free cycles to do so without
   impacting loop execution time.  However, it doesn't make a great
   deal of sense since we need to wait for the dma to complete anyway.  */
__ovly_xfer_loop:
#nop
        rotqmbyi off64, sz, -4                                  # 1,4   4
#nop; lnop
#nop; lnop
#nop; lnop
        cg      cgbits, ea64, off64                             # 0,2   8
#lnop
#nop; lnop
#nop
        shufb   add64, cgbits, cgbits, cgshuf                   # 1,4   10
#nop; lnop
#nop; lnop
#nop; lnop
        addx    add64, ea64, off64                              # 0,2   14
#lnop
        ila     maxsize, MFC_MAX_DMA_SIZE                       # 0,2   15
        lnop
        ori     ea64, add64, 0                                  # 0,2   16
        rotqbyi ealo, add64, 4                                  # 1,4   16
        cgt     cmp, osize, maxsize                             # 0,2   17
        wrch    $MFC_LSA, vma                                   # 1,6   17
#nop; lnop
        selb    sz, osize, maxsize, cmp                         # 0,2   19
        wrch    $MFC_EAH, ea64                                  # 1,6   19
        ila     tagid, MFC_TAG_ID                               # 0,2   20
        wrch    $MFC_EAL, ealo                                  # 1,6   20
        ila     cmd, MFC_GET_CMD                                # 0,2   21
        wrch    $MFC_Size, sz                                   # 1,6   21
        sf      osize, sz, osize                                # 0,2   22
        wrch    $MFC_TagId, tagid                               # 1,6   22
        a       vma, vma, sz                                    # 0,2   23
        wrch    $MFC_Cmd, cmd                                   # 1,6   23
#nop
        brnz    osize, __ovly_xfer_loop                         # 1,4   24

/* Now update our data structions while waiting for DMA to complete.
   Low bit of .size needs to be cleared on the _ovly_table entry
   corresponding to the evicted overlay, and set on the entry for the
   newly loaded overlay.  Note that no overlay may in fact be evicted
   as _ovly_buf_table[] starts with all zeros.  Don't zap .size entry
   for zero index!  Also of course update the _ovly_buf_table entry.  */
#nop
        lqr     newovl, __ovly_current                          # 1,6   25
#nop; lnop
#nop; lnop
#nop; lnop
#nop; lnop
#nop; lnop
        shli    off3, newovl, 4                                 # 0,4   31
#lnop
        ila     tab3, _ovly_table - 16                          # 0,2   32
#lnop
#nop
        fsmbi   pbyte, 0x100                                    # 1,4   33
#nop; lnop
#nop
        lqx     vma, tab3, off3                                 # 1,6   35
#nop; lnop
        andi    pbit, pbyte, 1                                  # 0,2   37
        lnop
#nop; lnop
#nop; lnop
#nop; lnop
        or      newvma, vma, pbit                               # 0,2   41
        rotqbyi buf3, vma, 12                                   # 1,4   41
#nop; lnop
#nop
        stqx    newvma, tab3, off3                              # 1,6   43
#nop; lnop
        shli    off4, buf3, 2                                   # 1,4   45
#lnop
        ila     tab4, _ovly_buf_table - 4                       # 0,2   46
#lnop
#nop; lnop
#nop; lnop
#nop
        lqx     map, tab4, off4                                 # 1,6   49
#nop
        cwx     genwi, tab4, off4                               # 1,4   50
        a       addr4, tab4, off4                               # 0,2   51
#lnop
#nop; lnop
#nop; lnop
#nop; lnop
#nop
        rotqby  oldovl, map, addr4                              # 1,4   55
#nop
        shufb   newmap, newovl, map, genwi                      # 0,4   56
#if MFC_TAG_ID < 16
        ila     newmask, 1 << MFC_TAG_ID                        # 0,2   57
#else
        ilhu    newmask, 1 << (MFC_TAG_ID - 16)                 # 0,2   57
#endif
#lnop
#nop; lnop
#nop; lnop
        stqd    newmap, 0(addr4)                                # 1,6   60

/* Save app's tagmask, wait for DMA complete, restore mask.  */
        ila     tagstat, MFC_TAG_UPDATE_ALL                     # 0,2   61
        rdch    oldmask, $MFC_RdTagMask                         # 1,6   61
#nop
        wrch    $MFC_WrTagMask, newmask                         # 1,6   62
#nop
        wrch    $MFC_WrTagUpdate, tagstat                       # 1,6   63
#nop
        rdch    tagstat, $MFC_RdTagStat                         # 1,6   64
#nop
        sync                                                    # 1,4   65
/* Any hint prior to the sync is lost.  A hint here allows the branch
   to complete 15 cycles after the hint.  With no hint the branch will
   take 18 or 19 cycles.  */
        ila     tab5, _ovly_table - 16                          # 0,2   66
        hbr     do_load99, target                               # 1,15  66
        shli    off5, oldovl, 4                                 # 0,4   67
        wrch    $MFC_WrTagMask, oldmask                         # 1,6   67
        ceqi    zovl, oldovl, 0                                 # 0,2   68
#lnop
#nop; lnop
#nop
        fsm     zovl, zovl                                      # 1,4   70
#nop
        lqx     oldvma, tab5, off5                              # 1,6   71
#nop
        lqd     save3, -48($sp)                                 # 1,6   72
#nop; lnop
        andc    pbit, pbit, zovl                                # 0,2   74
        lqd     save2, -32($sp)                                 # 1,6   74
#ifdef OVLY_IRQ_SAVE
        ila     irqtmp2, do_load90                              # 0,2   75
#lnop
        andi    irq_stat, irq_stat, 1                           # 0,2   76
#lnop
#else
#nop; lnop
#nop; lnop
#endif
        andc    oldvma, oldvma, pbit                            # 0,2   77
        lqd     save1, -16($sp)                                 # 1,6   77
        nop                                                     # 0,0   78
#lnop
#nop
        stqx    oldvma, tab5, off5                              # 1,6   79
#nop
#ifdef OVLY_IRQ_SAVE
        binze   irq_stat, irqtmp2                               # 1,4   80
do_load90:
#nop
        lqd     save4, -64($sp)                                 # 1,6   84
#else
#nop; lnop
#endif

        .global _ovly_debug_event
        .type   _ovly_debug_event, @function
_ovly_debug_event:
        nop
/* Branch to target address. */
do_load99:
        bi      target                                          # 1,4   81/85

        .size   __ovly_load, . - __ovly_load