summaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/tcm.c
blob: f5cf660eefccda61515b0f33a56db0bf692d3b51 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
/*
 * Copyright (C) 2008-2009 ST-Ericsson AB
 * License terms: GNU General Public License (GPL) version 2
 * TCM memory handling for ARM systems
 *
 * Author: Linus Walleij <linus.walleij@stericsson.com>
 * Author: Rickard Andersson <rickard.andersson@stericsson.com>
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/stddef.h>
#include <linux/ioport.h>
#include <linux/genalloc.h>
#include <linux/string.h> /* memcpy */
#include <asm/cputype.h>
#include <asm/mach/map.h>
#include <asm/memory.h>
#include "tcm.h"

static struct gen_pool *tcm_pool;

/* TCM section definitions from the linker */
extern char __itcm_start, __sitcm_text, __eitcm_text;
extern char __dtcm_start, __sdtcm_data, __edtcm_data;

/* These will be increased as we run */
u32 dtcm_end = DTCM_OFFSET;
u32 itcm_end = ITCM_OFFSET;

/*
 * TCM memory resources
 */
static struct resource dtcm_res = {
	.name = "DTCM RAM",
	.start = DTCM_OFFSET,
	.end = DTCM_OFFSET,
	.flags = IORESOURCE_MEM
};

static struct resource itcm_res = {
	.name = "ITCM RAM",
	.start = ITCM_OFFSET,
	.end = ITCM_OFFSET,
	.flags = IORESOURCE_MEM
};

static struct map_desc dtcm_iomap[] __initdata = {
	{
		.virtual	= DTCM_OFFSET,
		.pfn		= __phys_to_pfn(DTCM_OFFSET),
		.length		= 0,
		.type		= MT_MEMORY_DTCM
	}
};

static struct map_desc itcm_iomap[] __initdata = {
	{
		.virtual	= ITCM_OFFSET,
		.pfn		= __phys_to_pfn(ITCM_OFFSET),
		.length		= 0,
		.type		= MT_MEMORY_ITCM
	}
};

/*
 * Allocate a chunk of TCM memory
 */
void *tcm_alloc(size_t len)
{
	unsigned long vaddr;

	if (!tcm_pool)
		return NULL;

	vaddr = gen_pool_alloc(tcm_pool, len);
	if (!vaddr)
		return NULL;

	return (void *) vaddr;
}
EXPORT_SYMBOL(tcm_alloc);

/*
 * Free a chunk of TCM memory
 */
void tcm_free(void *addr, size_t len)
{
	gen_pool_free(tcm_pool, (unsigned long) addr, len);
}
EXPORT_SYMBOL(tcm_free);

static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
				  u32 *offset)
{
	const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
				    256, 512, 1024, -1, -1, -1, -1 };
	u32 tcm_region;
	int tcm_size;

	/*
	 * If there are more than one TCM bank of this type,
	 * select the TCM bank to operate on in the TCM selection
	 * register.
	 */
	if (banks > 1)
		asm("mcr	p15, 0, %0, c9, c2, 0"
		    : /* No output operands */
		    : "r" (bank));

	/* Read the special TCM region register c9, 0 */
	if (!type)
		asm("mrc	p15, 0, %0, c9, c1, 0"
		    : "=r" (tcm_region));
	else
		asm("mrc	p15, 0, %0, c9, c1, 1"
		    : "=r" (tcm_region));

	tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
	if (tcm_size < 0) {
		pr_err("CPU: %sTCM%d of unknown size\n",
		       type ? "I" : "D", bank);
		return -EINVAL;
	} else if (tcm_size > 32) {
		pr_err("CPU: %sTCM%d larger than 32k found\n",
		       type ? "I" : "D", bank);
		return -EINVAL;
	} else {
		pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
			type ? "I" : "D",
			bank,
			tcm_size,
			(tcm_region & 0xfffff000U),
			(tcm_region & 1) ? "" : "not ");
	}

	/* Force move the TCM bank to where we want it, enable */
	tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1;

	if (!type)
		asm("mcr	p15, 0, %0, c9, c1, 0"
		    : /* No output operands */
		    : "r" (tcm_region));
	else
		asm("mcr	p15, 0, %0, c9, c1, 1"
		    : /* No output operands */
		    : "r" (tcm_region));

	/* Increase offset */
	*offset += (tcm_size << 10);

	pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
		type ? "I" : "D",
		bank,
		tcm_size,
		(tcm_region & 0xfffff000U));
	return 0;
}

/*
 * This initializes the TCM memory
 */
void __init tcm_init(void)
{
	u32 tcm_status = read_cpuid_tcmstatus();
	u8 dtcm_banks = (tcm_status >> 16) & 0x03;
	u8 itcm_banks = (tcm_status & 0x03);
	char *start;
	char *end;
	char *ram;
	int ret;
	int i;

	/* Setup DTCM if present */
	if (dtcm_banks > 0) {
		for (i = 0; i < dtcm_banks; i++) {
			ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
			if (ret)
				return;
		}
		dtcm_res.end = dtcm_end - 1;
		request_resource(&iomem_resource, &dtcm_res);
		dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
		iotable_init(dtcm_iomap, 1);
		/* Copy data from RAM to DTCM */
		start = &__sdtcm_data;
		end   = &__edtcm_data;
		ram   = &__dtcm_start;
		/* This means you compiled more code than fits into DTCM */
		BUG_ON((end - start) > (dtcm_end - DTCM_OFFSET));
		memcpy(start, ram, (end-start));
		pr_debug("CPU DTCM: copied data from %p - %p\n", start, end);
	}

	/* Setup ITCM if present */
	if (itcm_banks > 0) {
		for (i = 0; i < itcm_banks; i++) {
			ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
			if (ret)
				return;
		}
		itcm_res.end = itcm_end - 1;
		request_resource(&iomem_resource, &itcm_res);
		itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
		iotable_init(itcm_iomap, 1);
		/* Copy code from RAM to ITCM */
		start = &__sitcm_text;
		end   = &__eitcm_text;
		ram   = &__itcm_start;
		/* This means you compiled more code than fits into ITCM */
		BUG_ON((end - start) > (itcm_end - ITCM_OFFSET));
		memcpy(start, ram, (end-start));
		pr_debug("CPU ITCM: copied code from %p - %p\n", start, end);
	}
}

/*
 * This creates the TCM memory pool and has to be done later,
 * during the core_initicalls, since the allocator is not yet
 * up and running when the first initialization runs.
 */
static int __init setup_tcm_pool(void)
{
	u32 tcm_status = read_cpuid_tcmstatus();
	u32 dtcm_pool_start = (u32) &__edtcm_data;
	u32 itcm_pool_start = (u32) &__eitcm_text;
	int ret;

	/*
	 * Set up malloc pool, 2^2 = 4 bytes granularity since
	 * the TCM is sometimes just 4 KiB. NB: pages and cache
	 * line alignments does not matter in TCM!
	 */
	tcm_pool = gen_pool_create(2, -1);

	pr_debug("Setting up TCM memory pool\n");

	/* Add the rest of DTCM to the TCM pool */
	if (tcm_status & (0x03 << 16)) {
		if (dtcm_pool_start < dtcm_end) {
			ret = gen_pool_add(tcm_pool, dtcm_pool_start,
					   dtcm_end - dtcm_pool_start, -1);
			if (ret) {
				pr_err("CPU DTCM: could not add DTCM " \
				       "remainder to pool!\n");
				return ret;
			}
			pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
				 "the TCM memory pool\n",
				 dtcm_end - dtcm_pool_start,
				 dtcm_pool_start);
		}
	}

	/* Add the rest of ITCM to the TCM pool */
	if (tcm_status & 0x03) {
		if (itcm_pool_start < itcm_end) {
			ret = gen_pool_add(tcm_pool, itcm_pool_start,
					   itcm_end - itcm_pool_start, -1);
			if (ret) {
				pr_err("CPU ITCM: could not add ITCM " \
				       "remainder to pool!\n");
				return ret;
			}
			pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
				 "the TCM memory pool\n",
				 itcm_end - itcm_pool_start,
				 itcm_pool_start);
		}
	}
	return 0;
}

core_initcall(setup_tcm_pool);
OpenPOWER on IntegriCloud