75 lines
1.7 KiB
C
75 lines
1.7 KiB
C
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/*
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* mach-davinci/sram.c - DaVinci simple SRAM allocator
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*
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* Copyright (C) 2009 David Brownell
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/genalloc.h>
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#include <mach/common.h>
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#include <mach/memory.h>
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#include <mach/sram.h>
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static struct gen_pool *sram_pool;
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void *sram_alloc(size_t len, dma_addr_t *dma)
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{
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unsigned long vaddr;
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dma_addr_t dma_base = davinci_soc_info.sram_dma;
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if (dma)
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*dma = 0;
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if (!sram_pool || (dma && !dma_base))
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return NULL;
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vaddr = gen_pool_alloc(sram_pool, len);
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if (!vaddr)
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return NULL;
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if (dma)
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*dma = dma_base + (vaddr - SRAM_VIRT);
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return (void *)vaddr;
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}
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EXPORT_SYMBOL(sram_alloc);
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void sram_free(void *addr, size_t len)
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{
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gen_pool_free(sram_pool, (unsigned long) addr, len);
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}
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EXPORT_SYMBOL(sram_free);
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/*
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* REVISIT This supports CPU and DMA access to/from SRAM, but it
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* doesn't (yet?) support some other notable uses of SRAM: as TCM
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* for data and/or instructions; and holding code needed to enter
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* and exit suspend states (while DRAM can't be used).
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*/
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static int __init sram_init(void)
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{
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unsigned len = davinci_soc_info.sram_len;
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int status = 0;
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if (len) {
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len = min_t(unsigned, len, SRAM_SIZE);
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sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1);
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if (!sram_pool)
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status = -ENOMEM;
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}
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if (sram_pool)
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status = gen_pool_add(sram_pool, SRAM_VIRT, len, -1);
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WARN_ON(status < 0);
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return status;
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}
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core_initcall(sram_init);
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