u-boot/cpu/mpc8xx/plprcr_write.S

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/*
* (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: