1 /* Overlay manager for SPU.
3 Copyright 2006, 2007 Free Software Foundation, Inc.
5 This file is part of GLD, the Gnu Linker.
7 GLD is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GLD is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GLD; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
25 #define MFC_GET_CMD 0x40
26 #define MFC_MAX_DMA_SIZE 0x4000
27 #define MFC_TAG_UPDATE_ALL 2
32 * Temporary register allocations.
33 * These are saved/restored here.
77 .extern _ovly_buf_table
82 .word 0x00010203, 0x1c1d1e1f, 0x00010203, 0x10111213
84 .word 0x04050607, 0x80808080, 0x80808080, 0x80808080
87 * __ovly_return - stub for returning from overlay functions.
93 * $78 old partition number, to be reloaded
94 * $79 return address in old partion number
97 .type __ovly_return, @function
104 .size __ovly_return, . - __ovly_return
107 * __ovly_load - copy an overlay partion to local store.
110 * $78 partition number to be loaded.
111 * $79 branch target in new partition.
112 * $lr link register, containing return addr.
115 * $lr new link register, returning through __ovly_return.
117 * Copy a new overlay partition into local store, or return
118 * immediately if the partition is already resident.
121 .type __ovly_load, @function
124 /* Save temporary registers to stack. */
130 /* Save irq state, then disable interrupts. */
132 ila irqtmp, __ovly_irq_save
133 rdch irq_stat, $SPU_RdMachStat
138 /* Set branch hint to overlay target. */
139 hbr __ovly_load_ret, $79
141 /* Get caller's overlay index by back chaining through stack frames.
142 * Loop until end of stack (back chain all-zeros) or
143 * encountered a link register we set here. */
145 ila retval, __ovly_return
147 __ovly_backchain_loop:
150 ceq cmp, lnkr, retval
153 brz cmp, __ovly_backchain_loop
155 /* If we reached the zero back-chain, then lnkr is bogus. Clear the
156 * part of lnkr that we use later (slot 3). */
157 rotqbyi cmp2, cmp2, 4
158 andc lnkr, lnkr, cmp2
160 /* Set lr = {__ovly_return, prev ovl ndx, caller return adr, callee ovl ndx}. */
161 lqd rv1, (__rv_pattern-__ovly_return+4)(retval)
162 shufb rv2, retval, lnkr, rv1
163 shufb rv3, $lr, $78, rv1
165 selb $lr, rv2, rv3, rv1
167 /* Branch to $79 if non-overlay */
168 brz $78, __ovly_load_restore
170 /* Load values from _ovly_table[$78].
179 ila tab, _ovly_table - 16
183 /* Load values from _ovly_buf_table[buf].
186 * } _ovly_buf_table[];
188 ila tab, _ovly_buf_table
194 /* Branch to $79 now if overlay is already mapped. */
196 brnz cmp, __ovly_load_restore
198 /* Marker for profiling code. If we get here, we are about to load
201 .global __ovly_load_event
202 .type __ovly_load_event, @function
205 /* Set _ovly_buf_table[buf].mapped = $78. */
207 shufb map, $78, map, genwi
210 /* A new partition needs to be loaded. Prepare for DMA loop.
211 * _EAR_ is the 64b base EA, filled in at run time by the
212 * loader, and indicating the value for SPU executable image start.
214 lqd cgshuf, (__cg_pattern-__ovly_return+4)(retval)
215 rotqbyi osize, vma, 4
220 /* 64b add to compute next ea64. */
221 rotqmbyi off64, sz, -4
222 cg cgbits, ea64, off64
223 shufb add64, cgbits, cgbits, cgshuf
224 addx add64, ea64, off64
227 /* Setup DMA parameters, then issue DMA request. */
228 rotqbyi ealo, add64, 4
229 ila maxsize, MFC_MAX_DMA_SIZE
230 cgt cmp, osize, maxsize
231 selb sz, osize, maxsize, cmp
232 ila tagid, MFC_TAG_ID
237 wrch $MFC_TagId, tagid
241 /* Increment vma, decrement size, branch back as needed. */
244 brnz osize, __ovly_xfer_loop
246 /* Save app's tagmask, wait for DMA complete, restore mask. */
247 rdch oldmask, $MFC_RdTagMask
249 ilh newmask, 1 << MFC_TAG_ID
251 ilhu newmask, 1 << (MFC_TAG_ID - 16)
253 wrch $MFC_WrTagMask, newmask
254 ila tagstat, MFC_TAG_UPDATE_ALL
255 wrch $MFC_WrTagUpdate, tagstat
256 rdch tagstat, $MFC_RdTagStat
258 wrch $MFC_WrTagMask, oldmask
260 .global _ovly_debug_event
261 .type _ovly_debug_event, @function
263 /* GDB inserts debugger trap here. */
268 /* Conditionally re-enable interrupts. */
269 andi irq_stat, irq_stat, 1
270 ila irqtmp, __ovly_irq_restore
271 binze irq_stat, irqtmp
276 /* Restore saved registers. */
282 /* Branch to target address. */
285 .size __ovly_load, . - __ovly_load