xref: /linux/arch/sh/kernel/cpu/sh3/probe.c (revision 8a84fc15ae5cafcc366dd85cf8e1ab2040679abc)
1 /*
2  * arch/sh/kernel/cpu/sh3/probe.c
3  *
4  * CPU Subtype Probing for SH-3.
5  *
6  * Copyright (C) 1999, 2000  Niibe Yutaka
7  * Copyright (C) 2002  Paul Mundt
8  *
9  * This file is subject to the terms and conditions of the GNU General Public
10  * License.  See the file "COPYING" in the main directory of this archive
11  * for more details.
12  */
13 
14 #include <linux/init.h>
15 #include <asm/processor.h>
16 #include <asm/cache.h>
17 #include <asm/io.h>
18 
19 int __init detect_cpu_and_cache_system(void)
20 {
21 	unsigned long addr0, addr1, data0, data1, data2, data3;
22 
23 	jump_to_P2();
24 	/*
25 	 * Check if the entry shadows or not.
26 	 * When shadowed, it's 128-entry system.
27 	 * Otherwise, it's 256-entry system.
28 	 */
29 	addr0 = CACHE_OC_ADDRESS_ARRAY + (3 << 12);
30 	addr1 = CACHE_OC_ADDRESS_ARRAY + (1 << 12);
31 
32 	/* First, write back & invalidate */
33 	data0  = ctrl_inl(addr0);
34 	ctrl_outl(data0&~(SH_CACHE_VALID|SH_CACHE_UPDATED), addr0);
35 	data1  = ctrl_inl(addr1);
36 	ctrl_outl(data1&~(SH_CACHE_VALID|SH_CACHE_UPDATED), addr1);
37 
38 	/* Next, check if there's shadow or not */
39 	data0 = ctrl_inl(addr0);
40 	data0 ^= SH_CACHE_VALID;
41 	ctrl_outl(data0, addr0);
42 	data1 = ctrl_inl(addr1);
43 	data2 = data1 ^ SH_CACHE_VALID;
44 	ctrl_outl(data2, addr1);
45 	data3 = ctrl_inl(addr0);
46 
47 	/* Lastly, invaliate them. */
48 	ctrl_outl(data0&~SH_CACHE_VALID, addr0);
49 	ctrl_outl(data2&~SH_CACHE_VALID, addr1);
50 
51 	back_to_P1();
52 
53 	cpu_data->dcache.ways		= 4;
54 	cpu_data->dcache.entry_shift	= 4;
55 	cpu_data->dcache.linesz		= L1_CACHE_BYTES;
56 	cpu_data->dcache.flags		= 0;
57 
58 	/*
59 	 * 7709A/7729 has 16K cache (256-entry), while 7702 has only
60 	 * 2K(direct) 7702 is not supported (yet)
61 	 */
62 	if (data0 == data1 && data2 == data3) {	/* Shadow */
63 		cpu_data->dcache.way_incr	= (1 << 11);
64 		cpu_data->dcache.entry_mask	= 0x7f0;
65 		cpu_data->dcache.sets		= 128;
66 		cpu_data->type = CPU_SH7708;
67 
68 		cpu_data->flags |= CPU_HAS_MMU_PAGE_ASSOC;
69 	} else {				/* 7709A or 7729  */
70 		cpu_data->dcache.way_incr	= (1 << 12);
71 		cpu_data->dcache.entry_mask	= 0xff0;
72 		cpu_data->dcache.sets		= 256;
73 		cpu_data->type = CPU_SH7729;
74 
75 #if defined(CONFIG_CPU_SUBTYPE_SH7706)
76 		cpu_data->type = CPU_SH7706;
77 #endif
78 #if defined(CONFIG_CPU_SUBTYPE_SH7710)
79 		cpu_data->type = CPU_SH7710;
80 #endif
81 #if defined(CONFIG_CPU_SUBTYPE_SH7705)
82 		cpu_data->type = CPU_SH7705;
83 
84 #if defined(CONFIG_SH7705_CACHE_32KB)
85 		cpu_data->dcache.way_incr	= (1 << 13);
86 		cpu_data->dcache.entry_mask	= 0x1ff0;
87 		cpu_data->dcache.sets		= 512;
88 		ctrl_outl(CCR_CACHE_32KB, CCR3);
89 #else
90 		ctrl_outl(CCR_CACHE_16KB, CCR3);
91 #endif
92 #endif
93 	}
94 
95 	/*
96 	 * SH-3 doesn't have separate caches
97 	 */
98 	cpu_data->dcache.flags |= SH_CACHE_COMBINED;
99 	cpu_data->icache = cpu_data->dcache;
100 
101 	return 0;
102 }
103 
104