1/*
2 * Copyright (C) 2010 Imagination Technologies Ltd.
3 */
4
5#include <linux/init.h>
6#include <linux/kernel.h>
7#include <linux/spinlock.h>
8#include <linux/stddef.h>
9#include <linux/genalloc.h>
10#include <linux/string.h>
11#include <linux/list.h>
12#include <linux/slab.h>
13#include <asm/page.h>
14#include <asm/tcm.h>
15
16struct tcm_pool {
17	struct list_head list;
18	unsigned int tag;
19	unsigned long start;
20	unsigned long end;
21	struct gen_pool *pool;
22};
23
24static LIST_HEAD(pool_list);
25
26static struct tcm_pool *find_pool(unsigned int tag)
27{
28	struct list_head *lh;
29	struct tcm_pool *pool;
30
31	list_for_each(lh, &pool_list) {
32		pool = list_entry(lh, struct tcm_pool, list);
33		if (pool->tag == tag)
34			return pool;
35	}
36
37	return NULL;
38}
39
40/**
41 * tcm_alloc - allocate memory from a TCM pool
42 * @tag: tag of the pool to allocate memory from
43 * @len: number of bytes to be allocated
44 *
45 * Allocate the requested number of bytes from the pool matching
46 * the specified tag. Returns the address of the allocated memory
47 * or zero on failure.
48 */
49unsigned long tcm_alloc(unsigned int tag, size_t len)
50{
51	unsigned long vaddr;
52	struct tcm_pool *pool;
53
54	pool = find_pool(tag);
55	if (!pool)
56		return 0;
57
58	vaddr = gen_pool_alloc(pool->pool, len);
59	if (!vaddr)
60		return 0;
61
62	return vaddr;
63}
64
65/**
66 * tcm_free - free a block of memory to a TCM pool
67 * @tag: tag of the pool to free memory to
68 * @addr: address of the memory to be freed
69 * @len: number of bytes to be freed
70 *
71 * Free the requested number of bytes at a specific address to the
72 * pool matching the specified tag.
73 */
74void tcm_free(unsigned int tag, unsigned long addr, size_t len)
75{
76	struct tcm_pool *pool;
77
78	pool = find_pool(tag);
79	if (!pool)
80		return;
81	gen_pool_free(pool->pool, addr, len);
82}
83
84/**
85 * tcm_lookup_tag - find the tag matching an address
86 * @p: memory address to lookup the tag for
87 *
88 * Find the tag of the tcm memory region that contains the
89 * specified address. Returns %TCM_INVALID_TAG if no such
90 * memory region could be found.
91 */
92unsigned int tcm_lookup_tag(unsigned long p)
93{
94	struct list_head *lh;
95	struct tcm_pool *pool;
96	unsigned long addr = (unsigned long) p;
97
98	list_for_each(lh, &pool_list) {
99		pool = list_entry(lh, struct tcm_pool, list);
100		if (addr >= pool->start && addr < pool->end)
101			return pool->tag;
102	}
103
104	return TCM_INVALID_TAG;
105}
106
107/**
108 * tcm_add_region - add a memory region to TCM pool list
109 * @reg: descriptor of region to be added
110 *
111 * Add a region of memory to the TCM pool list. Returns 0 on success.
112 */
113int __init tcm_add_region(struct tcm_region *reg)
114{
115	struct tcm_pool *pool;
116
117	pool = kmalloc(sizeof(*pool), GFP_KERNEL);
118	if (!pool) {
119		pr_err("Failed to alloc memory for TCM pool!\n");
120		return -ENOMEM;
121	}
122
123	pool->tag = reg->tag;
124	pool->start = reg->res.start;
125	pool->end = reg->res.end;
126
127	/*
128	 * 2^3 = 8 bytes granularity to allow for 64bit access alignment.
129	 * -1 = NUMA node specifier.
130	 */
131	pool->pool = gen_pool_create(3, -1);
132
133	if (!pool->pool) {
134		pr_err("Failed to create TCM pool!\n");
135		kfree(pool);
136		return -ENOMEM;
137	}
138
139	if (gen_pool_add(pool->pool, reg->res.start,
140			 reg->res.end - reg->res.start + 1, -1)) {
141		pr_err("Failed to add memory to TCM pool!\n");
142		return -ENOMEM;
143	}
144	pr_info("Added %s TCM pool (%08x bytes @ %08x)\n",
145		reg->res.name, reg->res.end - reg->res.start + 1,
146		reg->res.start);
147
148	list_add_tail(&pool->list, &pool_list);
149
150	return 0;
151}
152