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/*
* Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
/*!
* @file plat-mxc/sdma/sdma_malloc.c
* @brief This file contains functions for SDMA non-cacheable buffers allocation
*
* SDMA (Smart DMA) is used for transferring data between MCU and peripherals
*
* @ingroup SDMA
*/
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/genalloc.h>
#include <linux/iram_alloc.h>
#include <asm/dma.h>
#include <mach/hardware.h>
#define DEBUG 0
#if DEBUG
#define DPRINTK(fmt, args...) printk("%s: " fmt, __FUNCTION__ , ## args)
#else
#define DPRINTK(fmt, args...)
#endif
#ifdef CONFIG_SDMA_IRAM
#define IRAM_SDMA_SIZE SZ_4K
#endif
/*!
* Defines SDMA non-cacheable buffers pool
*/
static struct dma_pool *pool;
static struct gen_pool *sdma_iram_pool;
/*!
* SDMA memory conversion hashing structure
*/
typedef struct {
struct list_head node;
/*! Virtual address */
void *virt;
/*! Physical address */
unsigned long phys;
int size;
bool in_iram;
} virt_phys_struct;
static struct list_head alloc_list;
/*!
* Defines the size of each buffer in SDMA pool.
* The size must be at least 512 bytes, because
* sdma channel control blocks array size is 512 bytes
*/
#define SDMA_POOL_SIZE 1024
#ifdef CONFIG_SDMA_IRAM
static unsigned long iram_paddr;
static void *iram_vaddr;
#define iram_phys_to_virt(p) (iram_vaddr + ((p) - iram_paddr))
#define iram_virt_to_phys(v) (iram_paddr + ((v) - iram_vaddr))
#endif
/*!
* Virtual to physical address conversion functio
*
* @param buf pointer to virtual address
*
* @return physical address
*/
unsigned long sdma_virt_to_phys(void *buf)
{
u32 offset = (u32) buf & (~PAGE_MASK);
virt_phys_struct *p;
DPRINTK("searching for vaddr 0x%p\n", buf);
list_for_each_entry(p, &alloc_list, node) {
if (((u32)p->virt & PAGE_MASK) == ((u32) buf & PAGE_MASK)) {
return (p->phys & PAGE_MASK) | offset;
}
}
if (virt_addr_valid(buf)) {
return virt_to_phys(buf);
}
printk(KERN_WARNING
"SDMA malloc: could not translate virt address 0x%p\n", buf);
return 0;
}
/*!
* Physical to virtual address conversion functio
*
* @param buf pointer to physical address
*
* @return virtual address
*/
void *sdma_phys_to_virt(unsigned long buf)
{
u32 offset = buf & (~PAGE_MASK);
virt_phys_struct *p;
DPRINTK("searching for paddr 0x%p\n", buf);
list_for_each_entry(p, &alloc_list, node) {
if ((p->phys & PAGE_MASK) == (buf & PAGE_MASK)) {
return (void *)(((u32)p->virt & PAGE_MASK) | offset);
}
}
printk(KERN_WARNING
"SDMA malloc: could not translate phys address 0x%lx\n", buf);
return 0;
}
/*!
* Allocates uncacheable buffer
*
* @param size size of allocated buffer
* @return pointer to buffer
*/
void *sdma_malloc(size_t size)
{
void *buf;
dma_addr_t dma_addr;
virt_phys_struct *p;
if (size > SDMA_POOL_SIZE) {
printk(KERN_WARNING
"size in sdma_malloc is more than %d bytes\n",
SDMA_POOL_SIZE);
return 0;
}
buf = dma_pool_alloc(pool, GFP_KERNEL, &dma_addr);
if (buf == 0)
return 0;
p = kzalloc(sizeof(*p), GFP_KERNEL);
p->virt = buf;
p->phys = dma_addr;
list_add_tail(&p->node, &alloc_list);
DPRINTK("allocated vaddr 0x%p\n", buf);
return buf;
}
/*!
* Frees uncacheable buffer
*
* @param buf buffer pointer for deletion
*/
void sdma_free(void *buf)
{
virt_phys_struct *p;
list_for_each_entry(p, &alloc_list, node) {
if (p->virt == buf) {
if (p->in_iram)
gen_pool_free(sdma_iram_pool, p->phys, p->size);
else
dma_pool_free(pool, p->virt, p->phys);
list_del(&p->node);
kfree(p);
return;
}
}
}
#ifdef CONFIG_SDMA_IRAM
/*!
* Allocates uncacheable buffer from IRAM
*/
void *sdma_iram_malloc(size_t size)
{
virt_phys_struct *p = kzalloc(sizeof(*p), GFP_KERNEL);
unsigned long buf;
buf = gen_pool_alloc(sdma_iram_pool, size);
if (!buf) {
kfree(p);
return NULL;
}
p->virt = iram_vaddr + (buf - iram_paddr);
p->phys = buf;
p->size = size;
p->in_iram = true;
list_add_tail(&p->node, &alloc_list);
return p->virt;
}
#endif /*CONFIG_SDMA_IRAM */
/*!
* SDMA buffers pool initialization function
*/
void __init init_sdma_pool(void)
{
pool = dma_pool_create("SDMA", NULL, SDMA_POOL_SIZE, 0, 0);
#ifdef CONFIG_SDMA_IRAM
iram_vaddr = iram_alloc(SZ_4K, &iram_paddr);
sdma_iram_pool = gen_pool_create(6, -1);
gen_pool_add(sdma_iram_pool, iram_paddr, SZ_4K, -1);
#endif
INIT_LIST_HEAD(&alloc_list);
}
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("MXC Linux SDMA API");
MODULE_LICENSE("GPL");
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