1 /*
2 * Simple memory allocator for on-board SRAM
3 *
4 *
5 * Maintainer : Sylvain Munaut <tnt@246tNt.com>
6 *
7 * Copyright (C) 2005 Sylvain Munaut <tnt@246tNt.com>
8 *
9 * This file is licensed under the terms of the GNU General Public License
10 * version 2. This program is licensed "as is" without any warranty of any
11 * kind, whether express or implied.
12 */
13
14 #include <linux/err.h>
15 #include <linux/kernel.h>
16 #include <linux/export.h>
17 #include <linux/slab.h>
18 #include <linux/spinlock.h>
19 #include <linux/string.h>
20 #include <linux/ioport.h>
21 #include <linux/of.h>
22
23 #include <asm/io.h>
24 #include <asm/mmu.h>
25
26 #include "sram.h"
27
28
29 /* Struct keeping our 'state' */
30 struct bcom_sram *bcom_sram = NULL;
31 EXPORT_SYMBOL_GPL(bcom_sram); /* needed for inline functions */
32
33
34 /* ======================================================================== */
35 /* Public API */
36 /* ======================================================================== */
37 /* DO NOT USE in interrupts, if needed in irq handler, we should use the
38 _irqsave version of the spin_locks */
39
bcom_sram_init(struct device_node * sram_node,char * owner)40 int bcom_sram_init(struct device_node *sram_node, char *owner)
41 {
42 int rv;
43 const u32 *regaddr_p;
44 u64 regaddr64, size64;
45 unsigned int psize;
46
47 /* Create our state struct */
48 if (bcom_sram) {
49 printk(KERN_ERR "%s: bcom_sram_init: "
50 "Already initialized !\n", owner);
51 return -EBUSY;
52 }
53
54 bcom_sram = kmalloc(sizeof(struct bcom_sram), GFP_KERNEL);
55 if (!bcom_sram) {
56 printk(KERN_ERR "%s: bcom_sram_init: "
57 "Couldn't allocate internal state !\n", owner);
58 return -ENOMEM;
59 }
60
61 /* Get address and size of the sram */
62 regaddr_p = of_get_address(sram_node, 0, &size64, NULL);
63 if (!regaddr_p) {
64 printk(KERN_ERR "%s: bcom_sram_init: "
65 "Invalid device node !\n", owner);
66 rv = -EINVAL;
67 goto error_free;
68 }
69
70 regaddr64 = of_translate_address(sram_node, regaddr_p);
71
72 bcom_sram->base_phys = (phys_addr_t) regaddr64;
73 bcom_sram->size = (unsigned int) size64;
74
75 /* Request region */
76 if (!request_mem_region(bcom_sram->base_phys, bcom_sram->size, owner)) {
77 printk(KERN_ERR "%s: bcom_sram_init: "
78 "Couldn't request region !\n", owner);
79 rv = -EBUSY;
80 goto error_free;
81 }
82
83 /* Map SRAM */
84 /* sram is not really __iomem */
85 bcom_sram->base_virt = (void*) ioremap(bcom_sram->base_phys, bcom_sram->size);
86
87 if (!bcom_sram->base_virt) {
88 printk(KERN_ERR "%s: bcom_sram_init: "
89 "Map error SRAM zone 0x%08lx (0x%0x)!\n",
90 owner, (long)bcom_sram->base_phys, bcom_sram->size );
91 rv = -ENOMEM;
92 goto error_release;
93 }
94
95 /* Create an rheap (defaults to 32 bits word alignment) */
96 bcom_sram->rh = rh_create(4);
97
98 /* Attach the free zones */
99 #if 0
100 /* Currently disabled ... for future use only */
101 reg_addr_p = of_get_property(sram_node, "available", &psize);
102 #else
103 regaddr_p = NULL;
104 psize = 0;
105 #endif
106
107 if (!regaddr_p || !psize) {
108 /* Attach the whole zone */
109 rh_attach_region(bcom_sram->rh, 0, bcom_sram->size);
110 } else {
111 /* Attach each zone independently */
112 while (psize >= 2 * sizeof(u32)) {
113 phys_addr_t zbase = of_translate_address(sram_node, regaddr_p);
114 rh_attach_region(bcom_sram->rh, zbase - bcom_sram->base_phys, regaddr_p[1]);
115 regaddr_p += 2;
116 psize -= 2 * sizeof(u32);
117 }
118 }
119
120 /* Init our spinlock */
121 spin_lock_init(&bcom_sram->lock);
122
123 return 0;
124
125 error_release:
126 release_mem_region(bcom_sram->base_phys, bcom_sram->size);
127 error_free:
128 kfree(bcom_sram);
129 bcom_sram = NULL;
130
131 return rv;
132 }
133 EXPORT_SYMBOL_GPL(bcom_sram_init);
134
bcom_sram_cleanup(void)135 void bcom_sram_cleanup(void)
136 {
137 /* Free resources */
138 if (bcom_sram) {
139 rh_destroy(bcom_sram->rh);
140 iounmap((void __iomem *)bcom_sram->base_virt);
141 release_mem_region(bcom_sram->base_phys, bcom_sram->size);
142 kfree(bcom_sram);
143 bcom_sram = NULL;
144 }
145 }
146 EXPORT_SYMBOL_GPL(bcom_sram_cleanup);
147
bcom_sram_alloc(int size,int align,phys_addr_t * phys)148 void* bcom_sram_alloc(int size, int align, phys_addr_t *phys)
149 {
150 unsigned long offset;
151
152 spin_lock(&bcom_sram->lock);
153 offset = rh_alloc_align(bcom_sram->rh, size, align, NULL);
154 spin_unlock(&bcom_sram->lock);
155
156 if (IS_ERR_VALUE(offset))
157 return NULL;
158
159 *phys = bcom_sram->base_phys + offset;
160 return bcom_sram->base_virt + offset;
161 }
162 EXPORT_SYMBOL_GPL(bcom_sram_alloc);
163
bcom_sram_free(void * ptr)164 void bcom_sram_free(void *ptr)
165 {
166 unsigned long offset;
167
168 if (!ptr)
169 return;
170
171 offset = ptr - bcom_sram->base_virt;
172
173 spin_lock(&bcom_sram->lock);
174 rh_free(bcom_sram->rh, offset);
175 spin_unlock(&bcom_sram->lock);
176 }
177 EXPORT_SYMBOL_GPL(bcom_sram_free);
178
179