diff options
Diffstat (limited to 'arch/powerpc/cpu/mpc8xx/plprcr_write.S')
| -rw-r--r-- | arch/powerpc/cpu/mpc8xx/plprcr_write.S | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc8xx/plprcr_write.S b/arch/powerpc/cpu/mpc8xx/plprcr_write.S new file mode 100644 index 000000000..e32567114 --- /dev/null +++ b/arch/powerpc/cpu/mpc8xx/plprcr_write.S @@ -0,0 +1,135 @@ +/* + * (C) Copyright 2004 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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 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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <mpc8xx.h> +#include <ppc_asm.tmpl> +#include <asm/cache.h> + +#define CACHE_CMD_ENABLE 0x02000000 +#define CACHE_CMD_DISABLE 0x04000000 +#define CACHE_CMD_LOAD_LOCK 0x06000000 +#define CACHE_CMD_UNLOCK_LINE 0x08000000 +#define CACHE_CMD_UNLOCK_ALL 0x0A000000 +#define CACHE_CMD_INVALIDATE 0x0C000000 +#define SPEED_PLPRCR_WAIT_5CYC 150 +#define _CACHE_ALIGN_SIZE 16 + + + .text + .align 2 + .globl plprcr_write_866 + +/* + * void plprcr_write_866 (long plprcr) + * Write PLPRCR, including workaround for device errata SIU4 and SIU9. + */ + +plprcr_write_866: + mfspr r10, LR /* save the Link Register value */ + + /* turn instruction cache on (no MMU required for instructions) + */ + lis r4, CACHE_CMD_ENABLE@h + ori r4, r4, CACHE_CMD_ENABLE@l + mtspr IC_CST, r4 + isync + + /* clear IC_CST error bits + */ + mfspr r4, IC_CST + + bl plprcr_here + +plprcr_here: + mflr r5 + + /* calculate relocation offset + */ + lis r4, plprcr_here@h + ori r4, r4, plprcr_here@l + sub r5, r5, r4 + + /* calculate first address of this function + */ + lis r6, plprcr_write_866@h + ori r6, r6, plprcr_write_866@l + add r6, r6, r5 + + /* calculate end address of this function + */ + lis r7, plprcr_end@h + ori r7, r7, plprcr_end@l + add r7, r7, r5 + + /* load and lock code addresses + */ + mr r5, r6 + +plprcr_loop: + mtspr IC_ADR, r5 + addi r5, r5, _CACHE_ALIGN_SIZE /* increment by one line */ + + lis r4, CACHE_CMD_LOAD_LOCK@h + ori r4, r4, CACHE_CMD_LOAD_LOCK@l + mtspr IC_CST, r4 + isync + + cmpw r5, r7 + blt plprcr_loop + + /* IC_CST error bits not evaluated + */ + + /* switch PLPRCR + */ + mfspr r4, IMMR /* read IMMR */ + rlwinm r4, r4, 0, 0, 15 /* only high 16 bits count */ + + /* write sequence according to MPC866 Errata + */ + stw r3, PLPRCR(r4) + isync + + lis r3, SPEED_PLPRCR_WAIT_5CYC@h + ori r3, r3, SPEED_PLPRCR_WAIT_5CYC@l + +plprcr_wait: + cmpwi r3, 0 + beq plprcr_wait_end + nop + subi r3, r3, 1 + b plprcr_wait + +plprcr_wait_end: + + /* unlock instruction cache but leave it enabled + */ + lis r4, CACHE_CMD_UNLOCK_ALL@h + ori r4, r4, CACHE_CMD_UNLOCK_ALL@l + mtspr IC_CST, r4 + isync + + mtspr LR, r10 /* restore original Link Register value */ + blr + +plprcr_end: |