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wdenkc178d3d2004-01-24 20:25:54 +00001/*
2 * (C) Copyright 2004
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 *
Wolfgang Denk3765b3e2013-10-07 13:07:26 +02005 * SPDX-License-Identifier: GPL-2.0+
wdenkc178d3d2004-01-24 20:25:54 +00006 */
7
8#include <mpc8xx.h>
9#include <ppc_asm.tmpl>
10#include <asm/cache.h>
11
12#define CACHE_CMD_ENABLE 0x02000000
13#define CACHE_CMD_DISABLE 0x04000000
14#define CACHE_CMD_LOAD_LOCK 0x06000000
15#define CACHE_CMD_UNLOCK_LINE 0x08000000
16#define CACHE_CMD_UNLOCK_ALL 0x0A000000
17#define CACHE_CMD_INVALIDATE 0x0C000000
18#define SPEED_PLPRCR_WAIT_5CYC 150
19#define _CACHE_ALIGN_SIZE 16
20
21
22 .text
23 .align 2
24 .globl plprcr_write_866
25
26/*
27 * void plprcr_write_866 (long plprcr)
28 * Write PLPRCR, including workaround for device errata SIU4 and SIU9.
29 */
30
31plprcr_write_866:
32 mfspr r10, LR /* save the Link Register value */
33
34 /* turn instruction cache on (no MMU required for instructions)
35 */
36 lis r4, CACHE_CMD_ENABLE@h
37 ori r4, r4, CACHE_CMD_ENABLE@l
38 mtspr IC_CST, r4
39 isync
40
41 /* clear IC_CST error bits
42 */
43 mfspr r4, IC_CST
44
45 bl plprcr_here
46
47plprcr_here:
48 mflr r5
49
50 /* calculate relocation offset
51 */
52 lis r4, plprcr_here@h
53 ori r4, r4, plprcr_here@l
54 sub r5, r5, r4
55
56 /* calculate first address of this function
57 */
58 lis r6, plprcr_write_866@h
59 ori r6, r6, plprcr_write_866@l
60 add r6, r6, r5
61
62 /* calculate end address of this function
63 */
64 lis r7, plprcr_end@h
65 ori r7, r7, plprcr_end@l
66 add r7, r7, r5
67
68 /* load and lock code addresses
69 */
70 mr r5, r6
71
72plprcr_loop:
73 mtspr IC_ADR, r5
74 addi r5, r5, _CACHE_ALIGN_SIZE /* increment by one line */
75
76 lis r4, CACHE_CMD_LOAD_LOCK@h
77 ori r4, r4, CACHE_CMD_LOAD_LOCK@l
78 mtspr IC_CST, r4
79 isync
80
81 cmpw r5, r7
82 blt plprcr_loop
83
84 /* IC_CST error bits not evaluated
85 */
86
87 /* switch PLPRCR
88 */
89 mfspr r4, IMMR /* read IMMR */
90 rlwinm r4, r4, 0, 0, 15 /* only high 16 bits count */
91
92 /* write sequence according to MPC866 Errata
93 */
94 stw r3, PLPRCR(r4)
95 isync
96
97 lis r3, SPEED_PLPRCR_WAIT_5CYC@h
98 ori r3, r3, SPEED_PLPRCR_WAIT_5CYC@l
99
100plprcr_wait:
101 cmpwi r3, 0
102 beq plprcr_wait_end
103 nop
104 subi r3, r3, 1
105 b plprcr_wait
106
107plprcr_wait_end:
108
wdenka6cccae2004-02-06 21:48:22 +0000109 /* unlock instruction cache but leave it enabled
wdenkc178d3d2004-01-24 20:25:54 +0000110 */
111 lis r4, CACHE_CMD_UNLOCK_ALL@h
112 ori r4, r4, CACHE_CMD_UNLOCK_ALL@l
113 mtspr IC_CST, r4
114 isync
115
wdenkc178d3d2004-01-24 20:25:54 +0000116 mtspr LR, r10 /* restore original Link Register value */
117 blr
118
119plprcr_end: