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}