1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/sh/kernel/cpu/sh3/probe.c
4 *
5 * CPU Subtype Probing for SH-3.
6 *
7 * Copyright (C) 1999, 2000 Niibe Yutaka
8 * Copyright (C) 2002 Paul Mundt
9 */
10
11 #include <linux/init.h>
12 #include <asm/processor.h>
13 #include <asm/cache.h>
14 #include <asm/io.h>
15
16 void cpu_probe(void)
17 {
18 unsigned long addr0, addr1, data0, data1, data2, data3;
19
20 jump_to_uncached();
21 /*
22 * Check if the entry shadows or not.
23 * When shadowed, it's 128-entry system.
24 * Otherwise, it's 256-entry system.
25 */
26 addr0 = CACHE_OC_ADDRESS_ARRAY + (3 << 12);
27 addr1 = CACHE_OC_ADDRESS_ARRAY + (1 << 12);
28
29 /* First, write back & invalidate */
30 data0 = __raw_readl(addr0);
31 __raw_writel(data0&~(SH_CACHE_VALID|SH_CACHE_UPDATED), addr0);
32 data1 = __raw_readl(addr1);
33 __raw_writel(data1&~(SH_CACHE_VALID|SH_CACHE_UPDATED), addr1);
34
35 /* Next, check if there's shadow or not */
36 data0 = __raw_readl(addr0);
37 data0 ^= SH_CACHE_VALID;
38 __raw_writel(data0, addr0);
39 data1 = __raw_readl(addr1);
40 data2 = data1 ^ SH_CACHE_VALID;
41 __raw_writel(data2, addr1);
42 data3 = __raw_readl(addr0);
43
44 /* Lastly, invaliate them. */
45 __raw_writel(data0&~SH_CACHE_VALID, addr0);
46 __raw_writel(data2&~SH_CACHE_VALID, addr1);
47
48 back_to_cached();
49
50 boot_cpu_data.dcache.ways = 4;
51 boot_cpu_data.dcache.entry_shift = 4;
52 boot_cpu_data.dcache.linesz = L1_CACHE_BYTES;
53 boot_cpu_data.dcache.flags = 0;
54
55 /*
56 * 7709A/7729 has 16K cache (256-entry), while 7702 has only
57 * 2K(direct) 7702 is not supported (yet)
58 */
59 if (data0 == data1 && data2 == data3) { /* Shadow */
60 boot_cpu_data.dcache.way_incr = (1 << 11);
61 boot_cpu_data.dcache.entry_mask = 0x7f0;
62 boot_cpu_data.dcache.sets = 128;
63 boot_cpu_data.type = CPU_SH7708;
64
65 boot_cpu_data.flags |= CPU_HAS_MMU_PAGE_ASSOC;
66 } else { /* 7709A or 7729 */
67 boot_cpu_data.dcache.way_incr = (1 << 12);
68 boot_cpu_data.dcache.entry_mask = 0xff0;
69 boot_cpu_data.dcache.sets = 256;
70 boot_cpu_data.type = CPU_SH7729;
71
72 #if defined(CONFIG_CPU_SUBTYPE_SH7706)
73 boot_cpu_data.type = CPU_SH7706;
74 #endif
75 #if defined(CONFIG_CPU_SUBTYPE_SH7710)
76 boot_cpu_data.type = CPU_SH7710;
77 #endif
78 #if defined(CONFIG_CPU_SUBTYPE_SH7712)
79 boot_cpu_data.type = CPU_SH7712;
80 #endif
81 #if defined(CONFIG_CPU_SUBTYPE_SH7720)
82 boot_cpu_data.type = CPU_SH7720;
83 #endif
84 #if defined(CONFIG_CPU_SUBTYPE_SH7721)
85 boot_cpu_data.type = CPU_SH7721;
86 #endif
87 #if defined(CONFIG_CPU_SUBTYPE_SH7705)
88 boot_cpu_data.type = CPU_SH7705;
89
90 #if defined(CONFIG_SH7705_CACHE_32KB)
91 boot_cpu_data.dcache.way_incr = (1 << 13);
92 boot_cpu_data.dcache.entry_mask = 0x1ff0;
93 boot_cpu_data.dcache.sets = 512;
94 __raw_writel(CCR_CACHE_32KB, CCR3_REG);
95 #else
96 __raw_writel(CCR_CACHE_16KB, CCR3_REG);
97 #endif
98 #endif
99 }
100
101 /*
102 * SH-3 doesn't have separate caches
103 */
104 boot_cpu_data.dcache.flags |= SH_CACHE_COMBINED;
105 boot_cpu_data.icache = boot_cpu_data.dcache;
106
107 boot_cpu_data.family = CPU_FAMILY_SH3;
108 }
109
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