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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - arch/arm/kernel/tcm.c
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>
22 static struct gen_pool
*tcm_pool
;
23 static bool dtcm_present
;
24 static bool itcm_present
;
26 /* TCM section definitions from the linker */
27 extern char __itcm_start
, __sitcm_text
, __eitcm_text
;
28 extern char __dtcm_start
, __sdtcm_data
, __edtcm_data
;
30 /* These will be increased as we run */
31 u32 dtcm_end
= DTCM_OFFSET
;
32 u32 itcm_end
= ITCM_OFFSET
;
35 * TCM memory resources
37 static struct resource dtcm_res
= {
41 .flags
= IORESOURCE_MEM
44 static struct resource itcm_res
= {
48 .flags
= IORESOURCE_MEM
51 static struct map_desc dtcm_iomap
[] __initdata
= {
53 .virtual = DTCM_OFFSET
,
54 .pfn
= __phys_to_pfn(DTCM_OFFSET
),
56 .type
= MT_MEMORY_DTCM
60 static struct map_desc itcm_iomap
[] __initdata
= {
62 .virtual = ITCM_OFFSET
,
63 .pfn
= __phys_to_pfn(ITCM_OFFSET
),
65 .type
= MT_MEMORY_ITCM
70 * Allocate a chunk of TCM memory
72 void *tcm_alloc(size_t len
)
79 vaddr
= gen_pool_alloc(tcm_pool
, len
);
83 return (void *) vaddr
;
85 EXPORT_SYMBOL(tcm_alloc
);
88 * Free a chunk of TCM memory
90 void tcm_free(void *addr
, size_t len
)
92 gen_pool_free(tcm_pool
, (unsigned long) addr
, len
);
94 EXPORT_SYMBOL(tcm_free
);
96 bool tcm_dtcm_present(void)
100 EXPORT_SYMBOL(tcm_dtcm_present
);
102 bool tcm_itcm_present(void)
106 EXPORT_SYMBOL(tcm_itcm_present
);
108 static int __init
setup_tcm_bank(u8 type
, u8 bank
, u8 banks
,
111 const int tcm_sizes
[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
112 256, 512, 1024, -1, -1, -1, -1 };
117 * If there are more than one TCM bank of this type,
118 * select the TCM bank to operate on in the TCM selection
122 asm("mcr p15, 0, %0, c9, c2, 0"
123 : /* No output operands */
126 /* Read the special TCM region register c9, 0 */
128 asm("mrc p15, 0, %0, c9, c1, 0"
129 : "=r" (tcm_region
));
131 asm("mrc p15, 0, %0, c9, c1, 1"
132 : "=r" (tcm_region
));
134 tcm_size
= tcm_sizes
[(tcm_region
>> 2) & 0x0f];
136 pr_err("CPU: %sTCM%d of unknown size\n",
137 type
? "I" : "D", bank
);
139 } else if (tcm_size
> 32) {
140 pr_err("CPU: %sTCM%d larger than 32k found\n",
141 type
? "I" : "D", bank
);
144 pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
148 (tcm_region
& 0xfffff000U
),
149 (tcm_region
& 1) ? "" : "not ");
152 /* Not much fun you can do with a size 0 bank */
156 /* Force move the TCM bank to where we want it, enable */
157 tcm_region
= *offset
| (tcm_region
& 0x00000ffeU
) | 1;
160 asm("mcr p15, 0, %0, c9, c1, 0"
161 : /* No output operands */
164 asm("mcr p15, 0, %0, c9, c1, 1"
165 : /* No output operands */
168 /* Increase offset */
169 *offset
+= (tcm_size
<< 10);
171 pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
175 (tcm_region
& 0xfffff000U
));
180 * This initializes the TCM memory
182 void __init
tcm_init(void)
187 size_t dtcm_code_sz
= &__edtcm_data
- &__sdtcm_data
;
188 size_t itcm_code_sz
= &__eitcm_text
- &__sitcm_text
;
196 * Prior to ARMv5 there is no TCM, and trying to read the status
197 * register will hang the processor.
199 if (cpu_architecture() < CPU_ARCH_ARMv5
) {
200 if (dtcm_code_sz
|| itcm_code_sz
)
201 pr_info("CPU TCM: %u bytes of DTCM and %u bytes of "
202 "ITCM code compiled in, but no TCM present "
203 "in pre-v5 CPU\n", dtcm_code_sz
, itcm_code_sz
);
207 tcm_status
= read_cpuid_tcmstatus();
208 dtcm_banks
= (tcm_status
>> 16) & 0x03;
209 itcm_banks
= (tcm_status
& 0x03);
211 /* Values greater than 2 for D/ITCM banks are "reserved" */
217 /* Setup DTCM if present */
218 if (dtcm_banks
> 0) {
219 for (i
= 0; i
< dtcm_banks
; i
++) {
220 ret
= setup_tcm_bank(0, i
, dtcm_banks
, &dtcm_end
);
224 /* This means you compiled more code than fits into DTCM */
225 if (dtcm_code_sz
> (dtcm_end
- DTCM_OFFSET
)) {
226 pr_info("CPU DTCM: %u bytes of code compiled to "
227 "DTCM but only %lu bytes of DTCM present\n",
228 dtcm_code_sz
, (dtcm_end
- DTCM_OFFSET
));
231 dtcm_res
.end
= dtcm_end
- 1;
232 request_resource(&iomem_resource
, &dtcm_res
);
233 dtcm_iomap
[0].length
= dtcm_end
- DTCM_OFFSET
;
234 iotable_init(dtcm_iomap
, 1);
235 /* Copy data from RAM to DTCM */
236 start
= &__sdtcm_data
;
239 memcpy(start
, ram
, dtcm_code_sz
);
240 pr_debug("CPU DTCM: copied data from %p - %p\n",
243 } else if (dtcm_code_sz
) {
244 pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
245 "DTCM banks present in CPU\n", dtcm_code_sz
);
249 /* Setup ITCM if present */
250 if (itcm_banks
> 0) {
251 for (i
= 0; i
< itcm_banks
; i
++) {
252 ret
= setup_tcm_bank(1, i
, itcm_banks
, &itcm_end
);
256 /* This means you compiled more code than fits into ITCM */
257 if (itcm_code_sz
> (itcm_end
- ITCM_OFFSET
)) {
258 pr_info("CPU ITCM: %u bytes of code compiled to "
259 "ITCM but only %lu bytes of ITCM present\n",
260 itcm_code_sz
, (itcm_end
- ITCM_OFFSET
));
263 itcm_res
.end
= itcm_end
- 1;
264 request_resource(&iomem_resource
, &itcm_res
);
265 itcm_iomap
[0].length
= itcm_end
- ITCM_OFFSET
;
266 iotable_init(itcm_iomap
, 1);
267 /* Copy code from RAM to ITCM */
268 start
= &__sitcm_text
;
271 memcpy(start
, ram
, itcm_code_sz
);
272 pr_debug("CPU ITCM: copied code from %p - %p\n",
275 } else if (itcm_code_sz
) {
276 pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
277 "ITCM banks present in CPU\n", itcm_code_sz
);
282 * This creates the TCM memory pool and has to be done later,
283 * during the core_initicalls, since the allocator is not yet
284 * up and running when the first initialization runs.
286 static int __init
setup_tcm_pool(void)
288 u32 dtcm_pool_start
= (u32
) &__edtcm_data
;
289 u32 itcm_pool_start
= (u32
) &__eitcm_text
;
293 * Set up malloc pool, 2^2 = 4 bytes granularity since
294 * the TCM is sometimes just 4 KiB. NB: pages and cache
295 * line alignments does not matter in TCM!
297 tcm_pool
= gen_pool_create(2, -1);
299 pr_debug("Setting up TCM memory pool\n");
301 /* Add the rest of DTCM to the TCM pool */
303 if (dtcm_pool_start
< dtcm_end
) {
304 ret
= gen_pool_add(tcm_pool
, dtcm_pool_start
,
305 dtcm_end
- dtcm_pool_start
, -1);
307 pr_err("CPU DTCM: could not add DTCM " \
308 "remainder to pool!\n");
311 pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
312 "the TCM memory pool\n",
313 dtcm_end
- dtcm_pool_start
,
318 /* Add the rest of ITCM to the TCM pool */
320 if (itcm_pool_start
< itcm_end
) {
321 ret
= gen_pool_add(tcm_pool
, itcm_pool_start
,
322 itcm_end
- itcm_pool_start
, -1);
324 pr_err("CPU ITCM: could not add ITCM " \
325 "remainder to pool!\n");
328 pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
329 "the TCM memory pool\n",
330 itcm_end
- itcm_pool_start
,
337 core_initcall(setup_tcm_pool
);