1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * mach-davinci/sram.c - DaVinci simple SRAM allocator
4 *
5 * Copyright (C) 2009 David Brownell
6 */
7#include <linux/module.h>
8#include <linux/init.h>
9#include <linux/io.h>
10#include <linux/genalloc.h>
11
12#include "common.h"
13#include "sram.h"
14
15static struct gen_pool *sram_pool;
16
17struct gen_pool *sram_get_gen_pool(void)
18{
19 return sram_pool;
20}
21
22void *sram_alloc(size_t len, dma_addr_t *dma)
23{
24 dma_addr_t dma_base = davinci_soc_info.sram_dma;
25
26 if (dma)
27 *dma = 0;
28 if (!sram_pool || (dma && !dma_base))
29 return NULL;
30
31 return gen_pool_dma_alloc(pool: sram_pool, size: len, dma);
32
33}
34EXPORT_SYMBOL(sram_alloc);
35
36void sram_free(void *addr, size_t len)
37{
38 gen_pool_free(pool: sram_pool, addr: (unsigned long) addr, size: len);
39}
40EXPORT_SYMBOL(sram_free);
41
42
43/*
44 * REVISIT This supports CPU and DMA access to/from SRAM, but it
45 * doesn't (yet?) support some other notable uses of SRAM: as TCM
46 * for data and/or instructions; and holding code needed to enter
47 * and exit suspend states (while DRAM can't be used).
48 */
49static int __init sram_init(void)
50{
51 phys_addr_t phys = davinci_soc_info.sram_dma;
52 unsigned len = davinci_soc_info.sram_len;
53 int status = 0;
54 void __iomem *addr;
55
56 if (len) {
57 len = min_t(unsigned, len, SRAM_SIZE);
58 sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1);
59 if (!sram_pool)
60 status = -ENOMEM;
61 }
62
63 if (sram_pool) {
64 addr = ioremap(offset: phys, size: len);
65 if (!addr)
66 return -ENOMEM;
67 status = gen_pool_add_virt(pool: sram_pool, addr: (unsigned long) addr,
68 phys, size: len, nid: -1);
69 if (status < 0)
70 iounmap(addr);
71 }
72
73 WARN_ON(status < 0);
74 return status;
75}
76core_initcall(sram_init);
77
78

source code of linux/arch/arm/mach-davinci/sram.c