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>
19 #include <asm/system_info.h>
21 static struct gen_pool
*tcm_pool
;
22 static bool dtcm_present
;
23 static bool itcm_present
;
25 /* TCM section definitions from the linker */
26 extern char __itcm_start
, __sitcm_text
, __eitcm_text
;
27 extern char __dtcm_start
, __sdtcm_data
, __edtcm_data
;
29 /* These will be increased as we run */
30 u32 dtcm_end
= DTCM_OFFSET
;
31 u32 itcm_end
= ITCM_OFFSET
;
34 * TCM memory resources
36 static struct resource dtcm_res
= {
40 .flags
= IORESOURCE_MEM
43 static struct resource itcm_res
= {
47 .flags
= IORESOURCE_MEM
50 static struct map_desc dtcm_iomap
[] __initdata
= {
52 .virtual = DTCM_OFFSET
,
53 .pfn
= __phys_to_pfn(DTCM_OFFSET
),
55 .type
= MT_MEMORY_DTCM
59 static struct map_desc itcm_iomap
[] __initdata
= {
61 .virtual = ITCM_OFFSET
,
62 .pfn
= __phys_to_pfn(ITCM_OFFSET
),
64 .type
= MT_MEMORY_ITCM
69 * Allocate a chunk of TCM memory
71 void *tcm_alloc(size_t len
)
78 vaddr
= gen_pool_alloc(tcm_pool
, len
);
82 return (void *) vaddr
;
84 EXPORT_SYMBOL(tcm_alloc
);
87 * Free a chunk of TCM memory
89 void tcm_free(void *addr
, size_t len
)
91 gen_pool_free(tcm_pool
, (unsigned long) addr
, len
);
93 EXPORT_SYMBOL(tcm_free
);
95 bool tcm_dtcm_present(void)
99 EXPORT_SYMBOL(tcm_dtcm_present
);
101 bool tcm_itcm_present(void)
105 EXPORT_SYMBOL(tcm_itcm_present
);
107 static int __init
setup_tcm_bank(u8 type
, u8 bank
, u8 banks
,
110 const int tcm_sizes
[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
111 256, 512, 1024, -1, -1, -1, -1 };
116 * If there are more than one TCM bank of this type,
117 * select the TCM bank to operate on in the TCM selection
121 asm("mcr p15, 0, %0, c9, c2, 0"
122 : /* No output operands */
125 /* Read the special TCM region register c9, 0 */
127 asm("mrc p15, 0, %0, c9, c1, 0"
128 : "=r" (tcm_region
));
130 asm("mrc p15, 0, %0, c9, c1, 1"
131 : "=r" (tcm_region
));
133 tcm_size
= tcm_sizes
[(tcm_region
>> 2) & 0x0f];
135 pr_err("CPU: %sTCM%d of unknown size\n",
136 type
? "I" : "D", bank
);
138 } else if (tcm_size
> 32) {
139 pr_err("CPU: %sTCM%d larger than 32k found\n",
140 type
? "I" : "D", bank
);
143 pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
147 (tcm_region
& 0xfffff000U
),
148 (tcm_region
& 1) ? "" : "not ");
151 /* Not much fun you can do with a size 0 bank */
155 /* Force move the TCM bank to where we want it, enable */
156 tcm_region
= *offset
| (tcm_region
& 0x00000ffeU
) | 1;
159 asm("mcr p15, 0, %0, c9, c1, 0"
160 : /* No output operands */
163 asm("mcr p15, 0, %0, c9, c1, 1"
164 : /* No output operands */
167 /* Increase offset */
168 *offset
+= (tcm_size
<< 10);
170 pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
174 (tcm_region
& 0xfffff000U
));
179 * This initializes the TCM memory
181 void __init
tcm_init(void)
186 size_t dtcm_code_sz
= &__edtcm_data
- &__sdtcm_data
;
187 size_t itcm_code_sz
= &__eitcm_text
- &__sitcm_text
;
195 * Prior to ARMv5 there is no TCM, and trying to read the status
196 * register will hang the processor.
198 if (cpu_architecture() < CPU_ARCH_ARMv5
) {
199 if (dtcm_code_sz
|| itcm_code_sz
)
200 pr_info("CPU TCM: %u bytes of DTCM and %u bytes of "
201 "ITCM code compiled in, but no TCM present "
202 "in pre-v5 CPU\n", dtcm_code_sz
, itcm_code_sz
);
206 tcm_status
= read_cpuid_tcmstatus();
207 dtcm_banks
= (tcm_status
>> 16) & 0x03;
208 itcm_banks
= (tcm_status
& 0x03);
210 /* Values greater than 2 for D/ITCM banks are "reserved" */
216 /* Setup DTCM if present */
217 if (dtcm_banks
> 0) {
218 for (i
= 0; i
< dtcm_banks
; i
++) {
219 ret
= setup_tcm_bank(0, i
, dtcm_banks
, &dtcm_end
);
223 /* This means you compiled more code than fits into DTCM */
224 if (dtcm_code_sz
> (dtcm_end
- DTCM_OFFSET
)) {
225 pr_info("CPU DTCM: %u bytes of code compiled to "
226 "DTCM but only %lu bytes of DTCM present\n",
227 dtcm_code_sz
, (dtcm_end
- DTCM_OFFSET
));
230 dtcm_res
.end
= dtcm_end
- 1;
231 request_resource(&iomem_resource
, &dtcm_res
);
232 dtcm_iomap
[0].length
= dtcm_end
- DTCM_OFFSET
;
233 iotable_init(dtcm_iomap
, 1);
234 /* Copy data from RAM to DTCM */
235 start
= &__sdtcm_data
;
238 memcpy(start
, ram
, dtcm_code_sz
);
239 pr_debug("CPU DTCM: copied data from %p - %p\n",
242 } else if (dtcm_code_sz
) {
243 pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
244 "DTCM banks present in CPU\n", dtcm_code_sz
);
248 /* Setup ITCM if present */
249 if (itcm_banks
> 0) {
250 for (i
= 0; i
< itcm_banks
; i
++) {
251 ret
= setup_tcm_bank(1, i
, itcm_banks
, &itcm_end
);
255 /* This means you compiled more code than fits into ITCM */
256 if (itcm_code_sz
> (itcm_end
- ITCM_OFFSET
)) {
257 pr_info("CPU ITCM: %u bytes of code compiled to "
258 "ITCM but only %lu bytes of ITCM present\n",
259 itcm_code_sz
, (itcm_end
- ITCM_OFFSET
));
262 itcm_res
.end
= itcm_end
- 1;
263 request_resource(&iomem_resource
, &itcm_res
);
264 itcm_iomap
[0].length
= itcm_end
- ITCM_OFFSET
;
265 iotable_init(itcm_iomap
, 1);
266 /* Copy code from RAM to ITCM */
267 start
= &__sitcm_text
;
270 memcpy(start
, ram
, itcm_code_sz
);
271 pr_debug("CPU ITCM: copied code from %p - %p\n",
274 } else if (itcm_code_sz
) {
275 pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
276 "ITCM banks present in CPU\n", itcm_code_sz
);
281 * This creates the TCM memory pool and has to be done later,
282 * during the core_initicalls, since the allocator is not yet
283 * up and running when the first initialization runs.
285 static int __init
setup_tcm_pool(void)
287 u32 dtcm_pool_start
= (u32
) &__edtcm_data
;
288 u32 itcm_pool_start
= (u32
) &__eitcm_text
;
292 * Set up malloc pool, 2^2 = 4 bytes granularity since
293 * the TCM is sometimes just 4 KiB. NB: pages and cache
294 * line alignments does not matter in TCM!
296 tcm_pool
= gen_pool_create(2, -1);
298 pr_debug("Setting up TCM memory pool\n");
300 /* Add the rest of DTCM to the TCM pool */
302 if (dtcm_pool_start
< dtcm_end
) {
303 ret
= gen_pool_add(tcm_pool
, dtcm_pool_start
,
304 dtcm_end
- dtcm_pool_start
, -1);
306 pr_err("CPU DTCM: could not add DTCM " \
307 "remainder to pool!\n");
310 pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
311 "the TCM memory pool\n",
312 dtcm_end
- dtcm_pool_start
,
317 /* Add the rest of ITCM to the TCM pool */
319 if (itcm_pool_start
< itcm_end
) {
320 ret
= gen_pool_add(tcm_pool
, itcm_pool_start
,
321 itcm_end
- itcm_pool_start
, -1);
323 pr_err("CPU ITCM: could not add ITCM " \
324 "remainder to pool!\n");
327 pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
328 "the TCM memory pool\n",
329 itcm_end
- itcm_pool_start
,
336 core_initcall(setup_tcm_pool
);