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 | |
15 | static struct gen_pool *sram_pool; |
16 | |
17 | struct gen_pool *sram_get_gen_pool(void) |
18 | { |
19 | return sram_pool; |
20 | } |
21 | |
22 | void *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 | } |
34 | EXPORT_SYMBOL(sram_alloc); |
35 | |
36 | void sram_free(void *addr, size_t len) |
37 | { |
38 | gen_pool_free(pool: sram_pool, addr: (unsigned long) addr, size: len); |
39 | } |
40 | EXPORT_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 | */ |
49 | static 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 | } |
76 | core_initcall(sram_init); |
77 | |
78 | |