diff options
Diffstat (limited to 'arch/powerpc/platforms/cell/spufs/spu_restore.c')
| -rw-r--r-- | arch/powerpc/platforms/cell/spufs/spu_restore.c | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/spu_restore.c b/arch/powerpc/platforms/cell/spufs/spu_restore.c new file mode 100644 index 00000000000000..0bf723dcd677fe --- /dev/null +++ b/arch/powerpc/platforms/cell/spufs/spu_restore.c @@ -0,0 +1,336 @@ +/* + * spu_restore.c + * + * (C) Copyright IBM Corp. 2005 + * + * SPU-side context restore sequence outlined in + * Synergistic Processor Element Book IV + * + * Author: Mark Nutter <mnutter@us.ibm.com> + * + * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + + +#ifndef LS_SIZE +#define LS_SIZE 0x40000 /* 256K (in bytes) */ +#endif + +typedef unsigned int u32; +typedef unsigned long long u64; + +#include <spu_intrinsics.h> +#include <asm/spu_csa.h> +#include "spu_utils.h" + +#define BR_INSTR 0x327fff80 /* br -4 */ +#define NOP_INSTR 0x40200000 /* nop */ +#define HEQ_INSTR 0x7b000000 /* heq $0, $0 */ +#define STOP_INSTR 0x00000000 /* stop 0x0 */ +#define ILLEGAL_INSTR 0x00800000 /* illegal instr */ +#define RESTORE_COMPLETE 0x00003ffc /* stop 0x3ffc */ + +static inline void fetch_regs_from_mem(addr64 lscsa_ea) +{ + unsigned int ls = (unsigned int)®s_spill[0]; + unsigned int size = sizeof(regs_spill); + unsigned int tag_id = 0; + unsigned int cmd = 0x40; /* GET */ + + spu_writech(MFC_LSA, ls); + spu_writech(MFC_EAH, lscsa_ea.ui[0]); + spu_writech(MFC_EAL, lscsa_ea.ui[1]); + spu_writech(MFC_Size, size); + spu_writech(MFC_TagID, tag_id); + spu_writech(MFC_Cmd, cmd); +} + +static inline void restore_upper_240kb(addr64 lscsa_ea) +{ + unsigned int ls = 16384; + unsigned int list = (unsigned int)&dma_list[0]; + unsigned int size = sizeof(dma_list); + unsigned int tag_id = 0; + unsigned int cmd = 0x44; /* GETL */ + + /* Restore, Step 4: + * Enqueue the GETL command (tag 0) to the MFC SPU command + * queue to transfer the upper 240 kb of LS from CSA. + */ + spu_writech(MFC_LSA, ls); + spu_writech(MFC_EAH, lscsa_ea.ui[0]); + spu_writech(MFC_EAL, list); + spu_writech(MFC_Size, size); + spu_writech(MFC_TagID, tag_id); + spu_writech(MFC_Cmd, cmd); +} + +static inline void restore_decr(void) +{ + unsigned int offset; + unsigned int decr_running; + unsigned int decr; + + /* Restore, Step 6: + * If the LSCSA "decrementer running" flag is set + * then write the SPU_WrDec channel with the + * decrementer value from LSCSA. + */ + offset = LSCSA_QW_OFFSET(decr_status); + decr_running = regs_spill[offset].slot[0]; + if (decr_running) { + offset = LSCSA_QW_OFFSET(decr); + decr = regs_spill[offset].slot[0]; + spu_writech(SPU_WrDec, decr); + } +} + +static inline void write_ppu_mb(void) +{ + unsigned int offset; + unsigned int data; + + /* Restore, Step 11: + * Write the MFC_WrOut_MB channel with the PPU_MB + * data from LSCSA. + */ + offset = LSCSA_QW_OFFSET(ppu_mb); + data = regs_spill[offset].slot[0]; + spu_writech(SPU_WrOutMbox, data); +} + +static inline void write_ppuint_mb(void) +{ + unsigned int offset; + unsigned int data; + + /* Restore, Step 12: + * Write the MFC_WrInt_MB channel with the PPUINT_MB + * data from LSCSA. + */ + offset = LSCSA_QW_OFFSET(ppuint_mb); + data = regs_spill[offset].slot[0]; + spu_writech(SPU_WrOutIntrMbox, data); +} + +static inline void restore_fpcr(void) +{ + unsigned int offset; + vector unsigned int fpcr; + + /* Restore, Step 13: + * Restore the floating-point status and control + * register from the LSCSA. + */ + offset = LSCSA_QW_OFFSET(fpcr); + fpcr = regs_spill[offset].v; + spu_mtfpscr(fpcr); +} + +static inline void restore_srr0(void) +{ + unsigned int offset; + unsigned int srr0; + + /* Restore, Step 14: + * Restore the SPU SRR0 data from the LSCSA. + */ + offset = LSCSA_QW_OFFSET(srr0); + srr0 = regs_spill[offset].slot[0]; + spu_writech(SPU_WrSRR0, srr0); +} + +static inline void restore_event_mask(void) +{ + unsigned int offset; + unsigned int event_mask; + + /* Restore, Step 15: + * Restore the SPU_RdEventMsk data from the LSCSA. + */ + offset = LSCSA_QW_OFFSET(event_mask); + event_mask = regs_spill[offset].slot[0]; + spu_writech(SPU_WrEventMask, event_mask); +} + +static inline void restore_tag_mask(void) +{ + unsigned int offset; + unsigned int tag_mask; + + /* Restore, Step 16: + * Restore the SPU_RdTagMsk data from the LSCSA. + */ + offset = LSCSA_QW_OFFSET(tag_mask); + tag_mask = regs_spill[offset].slot[0]; + spu_writech(MFC_WrTagMask, tag_mask); +} + +static inline void restore_complete(void) +{ + extern void exit_fini(void); + unsigned int *exit_instrs = (unsigned int *)exit_fini; + unsigned int offset; + unsigned int stopped_status; + unsigned int stopped_code; + + /* Restore, Step 18: + * Issue a stop-and-signal instruction with + * "good context restore" signal value. + * + * Restore, Step 19: + * There may be additional instructions placed + * here by the PPE Sequence for SPU Context + * Restore in order to restore the correct + * "stopped state". + * + * This step is handled here by analyzing the + * LSCSA.stopped_status and then modifying the + * exit() function to behave appropriately. + */ + + offset = LSCSA_QW_OFFSET(stopped_status); + stopped_status = regs_spill[offset].slot[0]; + stopped_code = regs_spill[offset].slot[1]; + + switch (stopped_status) { + case SPU_STOPPED_STATUS_P_I: + /* SPU_Status[P,I]=1. Add illegal instruction + * followed by stop-and-signal instruction after + * end of restore code. + */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = ILLEGAL_INSTR; + exit_instrs[2] = STOP_INSTR | stopped_code; + break; + case SPU_STOPPED_STATUS_P_H: + /* SPU_Status[P,H]=1. Add 'heq $0, $0' followed + * by stop-and-signal instruction after end of + * restore code. + */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = HEQ_INSTR; + exit_instrs[2] = STOP_INSTR | stopped_code; + break; + case SPU_STOPPED_STATUS_S_P: + /* SPU_Status[S,P]=1. Add nop instruction + * followed by 'br -4' after end of restore + * code. + */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = STOP_INSTR | stopped_code; + exit_instrs[2] = NOP_INSTR; + exit_instrs[3] = BR_INSTR; + break; + case SPU_STOPPED_STATUS_S_I: + /* SPU_Status[S,I]=1. Add illegal instruction + * followed by 'br -4' after end of restore code. + */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = ILLEGAL_INSTR; + exit_instrs[2] = NOP_INSTR; + exit_instrs[3] = BR_INSTR; + break; + case SPU_STOPPED_STATUS_I: + /* SPU_Status[I]=1. Add illegal instruction followed + * by infinite loop after end of restore sequence. + */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = ILLEGAL_INSTR; + exit_instrs[2] = NOP_INSTR; + exit_instrs[3] = BR_INSTR; + break; + case SPU_STOPPED_STATUS_S: + /* SPU_Status[S]=1. Add two 'nop' instructions. */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = NOP_INSTR; + exit_instrs[2] = NOP_INSTR; + exit_instrs[3] = BR_INSTR; + break; + case SPU_STOPPED_STATUS_H: + /* SPU_Status[H]=1. Add 'heq $0, $0' instruction + * after end of restore code. + */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = HEQ_INSTR; + exit_instrs[2] = NOP_INSTR; + exit_instrs[3] = BR_INSTR; + break; + case SPU_STOPPED_STATUS_P: + /* SPU_Status[P]=1. Add stop-and-signal instruction + * after end of restore code. + */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = STOP_INSTR | stopped_code; + break; + case SPU_STOPPED_STATUS_R: + /* SPU_Status[I,S,H,P,R]=0. Add infinite loop. */ + exit_instrs[0] = RESTORE_COMPLETE; + exit_instrs[1] = NOP_INSTR; + exit_instrs[2] = NOP_INSTR; + exit_instrs[3] = BR_INSTR; + break; + default: + /* SPU_Status[R]=1. No additonal instructions. */ + break; + } + spu_sync(); +} + +/** + * main - entry point for SPU-side context restore. + * + * This code deviates from the documented sequence in the + * following aspects: + * + * 1. The EA for LSCSA is passed from PPE in the + * signal notification channels. + * 2. The register spill area is pulled by SPU + * into LS, rather than pushed by PPE. + * 3. All 128 registers are restored by exit(). + * 4. The exit() function is modified at run + * time in order to properly restore the + * SPU_Status register. + */ +int main() +{ + addr64 lscsa_ea; + + lscsa_ea.ui[0] = spu_readch(SPU_RdSigNotify1); + lscsa_ea.ui[1] = spu_readch(SPU_RdSigNotify2); + fetch_regs_from_mem(lscsa_ea); + + set_event_mask(); /* Step 1. */ + set_tag_mask(); /* Step 2. */ + build_dma_list(lscsa_ea); /* Step 3. */ + restore_upper_240kb(lscsa_ea); /* Step 4. */ + /* Step 5: done by 'exit'. */ + restore_decr(); /* Step 6. */ + enqueue_putllc(lscsa_ea); /* Step 7. */ + set_tag_update(); /* Step 8. */ + read_tag_status(); /* Step 9. */ + read_llar_status(); /* Step 10. */ + write_ppu_mb(); /* Step 11. */ + write_ppuint_mb(); /* Step 12. */ + restore_fpcr(); /* Step 13. */ + restore_srr0(); /* Step 14. */ + restore_event_mask(); /* Step 15. */ + restore_tag_mask(); /* Step 16. */ + /* Step 17. done by 'exit'. */ + restore_complete(); /* Step 18. */ + + return 0; +} |