2 * Copyright (C) 2008-2009 ST-Ericsson AB
3 * License terms: GNU General Public License (GPL) version 2
4 * TCM memory handling for ARM systems
6 * Author: Linus Walleij <linus.walleij@stericsson.com>
7 * Author: Rickard Andersson <rickard.andersson@stericsson.com>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/stddef.h>
13 #include <linux/ioport.h>
14 #include <linux/genalloc.h>
15 #include <linux/string.h> /* memcpy */
16 #include <asm/cputype.h>
17 #include <asm/mach/map.h>
18 #include <asm/memory.h>
21 static struct gen_pool *tcm_pool;
23 /* TCM section definitions from the linker */
24 extern char __itcm_start, __sitcm_text, __eitcm_text;
25 extern char __dtcm_start, __sdtcm_data, __edtcm_data;
27 /* These will be increased as we run */
28 u32 dtcm_end = DTCM_OFFSET;
29 u32 itcm_end = ITCM_OFFSET;
32 * TCM memory resources
34 static struct resource dtcm_res = {
38 .flags = IORESOURCE_MEM
41 static struct resource itcm_res = {
45 .flags = IORESOURCE_MEM
48 static struct map_desc dtcm_iomap[] __initdata = {
50 .virtual = DTCM_OFFSET,
51 .pfn = __phys_to_pfn(DTCM_OFFSET),
53 .type = MT_MEMORY_DTCM
57 static struct map_desc itcm_iomap[] __initdata = {
59 .virtual = ITCM_OFFSET,
60 .pfn = __phys_to_pfn(ITCM_OFFSET),
62 .type = MT_MEMORY_ITCM
67 * Allocate a chunk of TCM memory
69 void *tcm_alloc(size_t len)
76 vaddr = gen_pool_alloc(tcm_pool, len);
80 return (void *) vaddr;
82 EXPORT_SYMBOL(tcm_alloc);
85 * Free a chunk of TCM memory
87 void tcm_free(void *addr, size_t len)
89 gen_pool_free(tcm_pool, (unsigned long) addr, len);
91 EXPORT_SYMBOL(tcm_free);
93 static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
96 const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
97 256, 512, 1024, -1, -1, -1, -1 };
102 * If there are more than one TCM bank of this type,
103 * select the TCM bank to operate on in the TCM selection
107 asm("mcr p15, 0, %0, c9, c2, 0"
108 : /* No output operands */
111 /* Read the special TCM region register c9, 0 */
113 asm("mrc p15, 0, %0, c9, c1, 0"
114 : "=r" (tcm_region));
116 asm("mrc p15, 0, %0, c9, c1, 1"
117 : "=r" (tcm_region));
119 tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
121 pr_err("CPU: %sTCM%d of unknown size\n",
122 type ? "I" : "D", bank);
124 } else if (tcm_size > 32) {
125 pr_err("CPU: %sTCM%d larger than 32k found\n",
126 type ? "I" : "D", bank);
129 pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
133 (tcm_region & 0xfffff000U),
134 (tcm_region & 1) ? "" : "not ");
137 /* Not much fun you can do with a size 0 bank */
141 /* Force move the TCM bank to where we want it, enable */
142 tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1;
145 asm("mcr p15, 0, %0, c9, c1, 0"
146 : /* No output operands */
149 asm("mcr p15, 0, %0, c9, c1, 1"
150 : /* No output operands */
153 /* Increase offset */
154 *offset += (tcm_size << 10);
156 pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
160 (tcm_region & 0xfffff000U));
165 * This initializes the TCM memory
167 void __init tcm_init(void)
169 u32 tcm_status = read_cpuid_tcmstatus();
170 u8 dtcm_banks = (tcm_status >> 16) & 0x03;
171 u8 itcm_banks = (tcm_status & 0x03);
172 size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data;
173 size_t itcm_code_sz = &__eitcm_text - &__sitcm_text;
180 /* Values greater than 2 for D/ITCM banks are "reserved" */
186 /* Setup DTCM if present */
187 if (dtcm_banks > 0) {
188 for (i = 0; i < dtcm_banks; i++) {
189 ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
193 /* This means you compiled more code than fits into DTCM */
194 if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) {
195 pr_info("CPU DTCM: %u bytes of code compiled to "
196 "DTCM but only %lu bytes of DTCM present\n",
197 dtcm_code_sz, (dtcm_end - DTCM_OFFSET));
200 dtcm_res.end = dtcm_end - 1;
201 request_resource(&iomem_resource, &dtcm_res);
202 dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
203 iotable_init(dtcm_iomap, 1);
204 /* Copy data from RAM to DTCM */
205 start = &__sdtcm_data;
208 memcpy(start, ram, dtcm_code_sz);
209 pr_debug("CPU DTCM: copied data from %p - %p\n",
211 } else if (dtcm_code_sz) {
212 pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
213 "DTCM banks present in CPU\n", dtcm_code_sz);
217 /* Setup ITCM if present */
218 if (itcm_banks > 0) {
219 for (i = 0; i < itcm_banks; i++) {
220 ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
224 /* This means you compiled more code than fits into ITCM */
225 if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) {
226 pr_info("CPU ITCM: %u bytes of code compiled to "
227 "ITCM but only %lu bytes of ITCM present\n",
228 itcm_code_sz, (itcm_end - ITCM_OFFSET));
231 itcm_res.end = itcm_end - 1;
232 request_resource(&iomem_resource, &itcm_res);
233 itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
234 iotable_init(itcm_iomap, 1);
235 /* Copy code from RAM to ITCM */
236 start = &__sitcm_text;
239 memcpy(start, ram, itcm_code_sz);
240 pr_debug("CPU ITCM: copied code from %p - %p\n",
242 } else if (itcm_code_sz) {
243 pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
244 "ITCM banks present in CPU\n", itcm_code_sz);
249 * This creates the TCM memory pool and has to be done later,
250 * during the core_initicalls, since the allocator is not yet
251 * up and running when the first initialization runs.
253 static int __init setup_tcm_pool(void)
255 u32 tcm_status = read_cpuid_tcmstatus();
256 u32 dtcm_pool_start = (u32) &__edtcm_data;
257 u32 itcm_pool_start = (u32) &__eitcm_text;
261 * Set up malloc pool, 2^2 = 4 bytes granularity since
262 * the TCM is sometimes just 4 KiB. NB: pages and cache
263 * line alignments does not matter in TCM!
265 tcm_pool = gen_pool_create(2, -1);
267 pr_debug("Setting up TCM memory pool\n");
269 /* Add the rest of DTCM to the TCM pool */
270 if (tcm_status & (0x03 << 16)) {
271 if (dtcm_pool_start < dtcm_end) {
272 ret = gen_pool_add(tcm_pool, dtcm_pool_start,
273 dtcm_end - dtcm_pool_start, -1);
275 pr_err("CPU DTCM: could not add DTCM " \
276 "remainder to pool!\n");
279 pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
280 "the TCM memory pool\n",
281 dtcm_end - dtcm_pool_start,
286 /* Add the rest of ITCM to the TCM pool */
287 if (tcm_status & 0x03) {
288 if (itcm_pool_start < itcm_end) {
289 ret = gen_pool_add(tcm_pool, itcm_pool_start,
290 itcm_end - itcm_pool_start, -1);
292 pr_err("CPU ITCM: could not add ITCM " \
293 "remainder to pool!\n");
296 pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
297 "the TCM memory pool\n",
298 itcm_end - itcm_pool_start,
305 core_initcall(setup_tcm_pool);