Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / arch / arm / kernel / tcm.c
1 /*
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
5  *
6  * Author: Linus Walleij <linus.walleij@stericsson.com>
7  * Author: Rickard Andersson <rickard.andersson@stericsson.com>
8  */
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/page.h> /* PAGE_SHIFT */
17 #include <asm/cputype.h>
18 #include <asm/mach/map.h>
19 #include <mach/memory.h>
20 #include "tcm.h"
21
22 /* Scream and warn about misuse */
23 #if !defined(ITCM_OFFSET) || !defined(ITCM_END) || \
24     !defined(DTCM_OFFSET) || !defined(DTCM_END)
25 #error "TCM support selected but offsets not defined!"
26 #endif
27
28 static struct gen_pool *tcm_pool;
29
30 /* TCM section definitions from the linker */
31 extern char __itcm_start, __sitcm_text, __eitcm_text;
32 extern char __dtcm_start, __sdtcm_data, __edtcm_data;
33
34 /*
35  * TCM memory resources
36  */
37 static struct resource dtcm_res = {
38         .name = "DTCM RAM",
39         .start = DTCM_OFFSET,
40         .end = DTCM_END,
41         .flags = IORESOURCE_MEM
42 };
43
44 static struct resource itcm_res = {
45         .name = "ITCM RAM",
46         .start = ITCM_OFFSET,
47         .end = ITCM_END,
48         .flags = IORESOURCE_MEM
49 };
50
51 static struct map_desc dtcm_iomap[] __initdata = {
52         {
53                 .virtual        = DTCM_OFFSET,
54                 .pfn            = __phys_to_pfn(DTCM_OFFSET),
55                 .length         = (DTCM_END - DTCM_OFFSET + 1),
56                 .type           = MT_UNCACHED
57         }
58 };
59
60 static struct map_desc itcm_iomap[] __initdata = {
61         {
62                 .virtual        = ITCM_OFFSET,
63                 .pfn            = __phys_to_pfn(ITCM_OFFSET),
64                 .length         = (ITCM_END - ITCM_OFFSET + 1),
65                 .type           = MT_UNCACHED
66         }
67 };
68
69 /*
70  * Allocate a chunk of TCM memory
71  */
72 void *tcm_alloc(size_t len)
73 {
74         unsigned long vaddr;
75
76         if (!tcm_pool)
77                 return NULL;
78
79         vaddr = gen_pool_alloc(tcm_pool, len);
80         if (!vaddr)
81                 return NULL;
82
83         return (void *) vaddr;
84 }
85 EXPORT_SYMBOL(tcm_alloc);
86
87 /*
88  * Free a chunk of TCM memory
89  */
90 void tcm_free(void *addr, size_t len)
91 {
92         gen_pool_free(tcm_pool, (unsigned long) addr, len);
93 }
94 EXPORT_SYMBOL(tcm_free);
95
96
97 static void __init setup_tcm_bank(u8 type, u32 offset, u32 expected_size)
98 {
99         const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
100                                     256, 512, 1024, -1, -1, -1, -1 };
101         u32 tcm_region;
102         int tcm_size;
103
104         /* Read the special TCM region register c9, 0 */
105         if (!type)
106                 asm("mrc        p15, 0, %0, c9, c1, 0"
107                     : "=r" (tcm_region));
108         else
109                 asm("mrc        p15, 0, %0, c9, c1, 1"
110                     : "=r" (tcm_region));
111
112         tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
113         if (tcm_size < 0) {
114                 pr_err("CPU: %sTCM of unknown size!\n",
115                         type ? "I" : "D");
116         } else {
117                 pr_info("CPU: found %sTCM %dk @ %08x, %senabled\n",
118                         type ? "I" : "D",
119                         tcm_size,
120                         (tcm_region & 0xfffff000U),
121                         (tcm_region & 1) ? "" : "not ");
122         }
123
124         if (tcm_size != expected_size) {
125                 pr_crit("CPU: %sTCM was detected %dk but expected %dk!\n",
126                        type ? "I" : "D",
127                        tcm_size,
128                        expected_size);
129                 /* Adjust to the expected size? what can we do... */
130         }
131
132         /* Force move the TCM bank to where we want it, enable */
133         tcm_region = offset | (tcm_region & 0x00000ffeU) | 1;
134
135         if (!type)
136                 asm("mcr        p15, 0, %0, c9, c1, 0"
137                     : /* No output operands */
138                     : "r" (tcm_region));
139         else
140                 asm("mcr        p15, 0, %0, c9, c1, 1"
141                     : /* No output operands */
142                     : "r" (tcm_region));
143
144         pr_debug("CPU: moved %sTCM %dk to %08x, enabled\n",
145                  type ? "I" : "D",
146                  tcm_size,
147                  (tcm_region & 0xfffff000U));
148 }
149
150 /*
151  * This initializes the TCM memory
152  */
153 void __init tcm_init(void)
154 {
155         u32 tcm_status = read_cpuid_tcmstatus();
156         char *start;
157         char *end;
158         char *ram;
159
160         /* Setup DTCM if present */
161         if (tcm_status & (1 << 16)) {
162                 setup_tcm_bank(0, DTCM_OFFSET,
163                                (DTCM_END - DTCM_OFFSET + 1) >> 10);
164                 request_resource(&iomem_resource, &dtcm_res);
165                 iotable_init(dtcm_iomap, 1);
166                 /* Copy data from RAM to DTCM */
167                 start = &__sdtcm_data;
168                 end   = &__edtcm_data;
169                 ram   = &__dtcm_start;
170                 memcpy(start, ram, (end-start));
171                 pr_debug("CPU DTCM: copied data from %p - %p\n", start, end);
172         }
173
174         /* Setup ITCM if present */
175         if (tcm_status & 1) {
176                 setup_tcm_bank(1, ITCM_OFFSET,
177                                (ITCM_END - ITCM_OFFSET + 1) >> 10);
178                 request_resource(&iomem_resource, &itcm_res);
179                 iotable_init(itcm_iomap, 1);
180                 /* Copy code from RAM to ITCM */
181                 start = &__sitcm_text;
182                 end   = &__eitcm_text;
183                 ram   = &__itcm_start;
184                 memcpy(start, ram, (end-start));
185                 pr_debug("CPU ITCM: copied code from %p - %p\n", start, end);
186         }
187 }
188
189 /*
190  * This creates the TCM memory pool and has to be done later,
191  * during the core_initicalls, since the allocator is not yet
192  * up and running when the first initialization runs.
193  */
194 static int __init setup_tcm_pool(void)
195 {
196         u32 tcm_status = read_cpuid_tcmstatus();
197         u32 dtcm_pool_start = (u32) &__edtcm_data;
198         u32 itcm_pool_start = (u32) &__eitcm_text;
199         int ret;
200
201         /*
202          * Set up malloc pool, 2^2 = 4 bytes granularity since
203          * the TCM is sometimes just 4 KiB. NB: pages and cache
204          * line alignments does not matter in TCM!
205          */
206         tcm_pool = gen_pool_create(2, -1);
207
208         pr_debug("Setting up TCM memory pool\n");
209
210         /* Add the rest of DTCM to the TCM pool */
211         if (tcm_status & (1 << 16)) {
212                 if (dtcm_pool_start < DTCM_END) {
213                         ret = gen_pool_add(tcm_pool, dtcm_pool_start,
214                                            DTCM_END - dtcm_pool_start + 1, -1);
215                         if (ret) {
216                                 pr_err("CPU DTCM: could not add DTCM " \
217                                        "remainder to pool!\n");
218                                 return ret;
219                         }
220                         pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
221                                  "the TCM memory pool\n",
222                                  DTCM_END - dtcm_pool_start + 1,
223                                  dtcm_pool_start);
224                 }
225         }
226
227         /* Add the rest of ITCM to the TCM pool */
228         if (tcm_status & 1) {
229                 if (itcm_pool_start < ITCM_END) {
230                         ret = gen_pool_add(tcm_pool, itcm_pool_start,
231                                            ITCM_END - itcm_pool_start + 1, -1);
232                         if (ret) {
233                                 pr_err("CPU ITCM: could not add ITCM " \
234                                        "remainder to pool!\n");
235                                 return ret;
236                         }
237                         pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
238                                  "the TCM memory pool\n",
239                                  ITCM_END - itcm_pool_start + 1,
240                                  itcm_pool_start);
241                 }
242         }
243         return 0;
244 }
245
246 core_initcall(setup_tcm_pool);