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(sram_pool, len, dma); 32 33 } 34 EXPORT_SYMBOL(sram_alloc); 35 36 void sram_free(void *addr, size_t len) 37 { 38 gen_pool_free(sram_pool, (unsigned long) addr, 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(phys, len); 65 if (!addr) 66 return -ENOMEM; 67 status = gen_pool_add_virt(sram_pool, (unsigned long) addr, 68 phys, len, -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