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