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1 /*
2  * arch/sh/kernel/cpu/sh5/probe.c
3  *
4  * CPU Subtype Probing for SH-5.
5  *
6  * Copyright (C) 2000, 2001  Paolo Alberelli
7  * Copyright (C) 2003 - 2007  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 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/string.h>
16 #include <asm/processor.h>
17 #include <asm/cache.h>
18 #include <asm/tlb.h>
19 
detect_cpu_and_cache_system(void)20 int __init detect_cpu_and_cache_system(void)
21 {
22 	unsigned long long cir;
23 
24 	/*
25 	 * Do peeks in real mode to avoid having to set up a mapping for
26 	 * the WPC registers. On SH5-101 cut2, such a mapping would be
27 	 * exposed to an address translation erratum which would make it
28 	 * hard to set up correctly.
29 	 */
30 	cir = peek_real_address_q(0x0d000008);
31 	if ((cir & 0xffff) == 0x5103)
32 		boot_cpu_data.type = CPU_SH5_103;
33 	else if (((cir >> 32) & 0xffff) == 0x51e2)
34 		/* CPU.VCR aliased at CIR address on SH5-101 */
35 		boot_cpu_data.type = CPU_SH5_101;
36 
37 	/*
38 	 * First, setup some sane values for the I-cache.
39 	 */
40 	boot_cpu_data.icache.ways		= 4;
41 	boot_cpu_data.icache.sets		= 256;
42 	boot_cpu_data.icache.linesz		= L1_CACHE_BYTES;
43 	boot_cpu_data.icache.way_incr		= (1 << 13);
44 	boot_cpu_data.icache.entry_shift	= 5;
45 	boot_cpu_data.icache.way_size		= boot_cpu_data.icache.sets *
46 						  boot_cpu_data.icache.linesz;
47 	boot_cpu_data.icache.entry_mask		= 0x1fe0;
48 	boot_cpu_data.icache.flags		= 0;
49 
50 	/*
51 	 * Next, setup some sane values for the D-cache.
52 	 *
53 	 * On the SH5, these are pretty consistent with the I-cache settings,
54 	 * so we just copy over the existing definitions.. these can be fixed
55 	 * up later, especially if we add runtime CPU probing.
56 	 *
57 	 * Though in the meantime it saves us from having to duplicate all of
58 	 * the above definitions..
59 	 */
60 	boot_cpu_data.dcache		= boot_cpu_data.icache;
61 
62 	/*
63 	 * Setup any cache-related flags here
64 	 */
65 #if defined(CONFIG_CACHE_WRITETHROUGH)
66 	set_bit(SH_CACHE_MODE_WT, &(boot_cpu_data.dcache.flags));
67 #elif defined(CONFIG_CACHE_WRITEBACK)
68 	set_bit(SH_CACHE_MODE_WB, &(boot_cpu_data.dcache.flags));
69 #endif
70 
71 	/* Setup some I/D TLB defaults */
72 	sh64_tlb_init();
73 
74 	return 0;
75 }
76