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' */
30struct bcom_sram *bcom_sram = NULL;
31EXPORT_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
40int 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
125error_release:
126	release_mem_region(bcom_sram->base_phys, bcom_sram->size);
127error_free:
128	kfree(bcom_sram);
129	bcom_sram = NULL;
130
131	return rv;
132}
133EXPORT_SYMBOL_GPL(bcom_sram_init);
134
135void 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}
146EXPORT_SYMBOL_GPL(bcom_sram_cleanup);
147
148void* 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}
162EXPORT_SYMBOL_GPL(bcom_sram_alloc);
163
164void 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}
177EXPORT_SYMBOL_GPL(bcom_sram_free);
178
179