1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Simple memory allocator for on-board SRAM
4 *
5 * Maintainer : Sylvain Munaut <tnt@246tNt.com>
6 *
7 * Copyright (C) 2005 Sylvain Munaut <tnt@246tNt.com>
8 */
9
10#include <linux/err.h>
11#include <linux/kernel.h>
12#include <linux/export.h>
13#include <linux/slab.h>
14#include <linux/spinlock.h>
15#include <linux/string.h>
16#include <linux/ioport.h>
17#include <linux/of.h>
18#include <linux/of_address.h>
19
20#include <asm/io.h>
21#include <asm/mmu.h>
22
23#include <linux/fsl/bestcomm/sram.h>
24
25
26/* Struct keeping our 'state' */
27struct bcom_sram *bcom_sram = NULL;
28EXPORT_SYMBOL_GPL(bcom_sram); /* needed for inline functions */
29
30
31/* ======================================================================== */
32/* Public API */
33/* ======================================================================== */
34/* DO NOT USE in interrupts, if needed in irq handler, we should use the
35 _irqsave version of the spin_locks */
36
37int bcom_sram_init(struct device_node *sram_node, char *owner)
38{
39 int rv;
40 const u32 *regaddr_p;
41 struct resource res;
42 unsigned int psize;
43
44 /* Create our state struct */
45 if (bcom_sram) {
46 printk(KERN_ERR "%s: bcom_sram_init: "
47 "Already initialized !\n", owner);
48 return -EBUSY;
49 }
50
51 bcom_sram = kmalloc(size: sizeof(struct bcom_sram), GFP_KERNEL);
52 if (!bcom_sram) {
53 printk(KERN_ERR "%s: bcom_sram_init: "
54 "Couldn't allocate internal state !\n", owner);
55 return -ENOMEM;
56 }
57
58 /* Get address and size of the sram */
59 rv = of_address_to_resource(dev: sram_node, index: 0, r: &res);
60 if (rv) {
61 printk(KERN_ERR "%s: bcom_sram_init: "
62 "Invalid device node !\n", owner);
63 goto error_free;
64 }
65
66 bcom_sram->base_phys = res.start;
67 bcom_sram->size = resource_size(res: &res);
68
69 /* Request region */
70 if (!request_mem_region(res.start, resource_size(&res), owner)) {
71 printk(KERN_ERR "%s: bcom_sram_init: "
72 "Couldn't request region !\n", owner);
73 rv = -EBUSY;
74 goto error_free;
75 }
76
77 /* Map SRAM */
78 /* sram is not really __iomem */
79 bcom_sram->base_virt = (void *)ioremap(offset: res.start, size: resource_size(res: &res));
80
81 if (!bcom_sram->base_virt) {
82 printk(KERN_ERR "%s: bcom_sram_init: "
83 "Map error SRAM zone 0x%08lx (0x%0x)!\n",
84 owner, (long)bcom_sram->base_phys, bcom_sram->size );
85 rv = -ENOMEM;
86 goto error_release;
87 }
88
89 /* Create an rheap (defaults to 32 bits word alignment) */
90 bcom_sram->rh = rh_create(4);
91
92 /* Attach the free zones */
93 regaddr_p = NULL;
94 psize = 0;
95
96 if (!regaddr_p || !psize) {
97 /* Attach the whole zone */
98 rh_attach_region(bcom_sram->rh, 0, bcom_sram->size);
99 } else {
100 /* Attach each zone independently */
101 while (psize >= 2 * sizeof(u32)) {
102 phys_addr_t zbase = of_translate_address(np: sram_node, addr: regaddr_p);
103 rh_attach_region(bcom_sram->rh, zbase - bcom_sram->base_phys, regaddr_p[1]);
104 regaddr_p += 2;
105 psize -= 2 * sizeof(u32);
106 }
107 }
108
109 /* Init our spinlock */
110 spin_lock_init(&bcom_sram->lock);
111
112 return 0;
113
114error_release:
115 release_mem_region(res.start, resource_size(&res));
116error_free:
117 kfree(objp: bcom_sram);
118 bcom_sram = NULL;
119
120 return rv;
121}
122EXPORT_SYMBOL_GPL(bcom_sram_init);
123
124void bcom_sram_cleanup(void)
125{
126 /* Free resources */
127 if (bcom_sram) {
128 rh_destroy(bcom_sram->rh);
129 iounmap(addr: (void __iomem *)bcom_sram->base_virt);
130 release_mem_region(bcom_sram->base_phys, bcom_sram->size);
131 kfree(objp: bcom_sram);
132 bcom_sram = NULL;
133 }
134}
135EXPORT_SYMBOL_GPL(bcom_sram_cleanup);
136
137void* bcom_sram_alloc(int size, int align, phys_addr_t *phys)
138{
139 unsigned long offset;
140
141 spin_lock(lock: &bcom_sram->lock);
142 offset = rh_alloc_align(bcom_sram->rh, size, align, NULL);
143 spin_unlock(lock: &bcom_sram->lock);
144
145 if (IS_ERR_VALUE(offset))
146 return NULL;
147
148 *phys = bcom_sram->base_phys + offset;
149 return bcom_sram->base_virt + offset;
150}
151EXPORT_SYMBOL_GPL(bcom_sram_alloc);
152
153void bcom_sram_free(void *ptr)
154{
155 unsigned long offset;
156
157 if (!ptr)
158 return;
159
160 offset = ptr - bcom_sram->base_virt;
161
162 spin_lock(lock: &bcom_sram->lock);
163 rh_free(bcom_sram->rh, offset);
164 spin_unlock(lock: &bcom_sram->lock);
165}
166EXPORT_SYMBOL_GPL(bcom_sram_free);
167

source code of linux/drivers/dma/bestcomm/sram.c