Pmem 移植与测试

为了在video设备中分配大块连续物理内存，移植android Pmem

驱动部分：

 

1、 pmem driver 文件从android linux中copy，并配置好makefile和config

2、在devs.c中添加

#ifdef CONFIG_ANDROID_PMEM
#include <linux/android_pmem.h>
#include <linux/memblock.h>
#endif

#ifdef CONFIG_ANDROID_PMEM

static struct android_pmem_platform_data pmem_pdata = {
	.name			= "pmem",
	.no_allocator	= 1,
	.cached			= 1,
	.start			= 0,
	.size			= 0,
};


struct platform_device pmem_device = {
	.name = "android_pmem",
	.id = 0,
	.dev = { .platform_data = &pmem_pdata },
};

void __init s5p_pmem_reserve_mem(phys_addr_t base, unsigned int size)
{

		if (memblock_remove(base, size)) {
			printk(KERN_ERR "Failed to reserve memory for PMEM device (%ld bytes at 0x%08lx)\n",
			       size, (unsigned long)base);
			base = 0;
			return;
		}
		printk(KERN_INFO "reserve memory for PMEM device (%ld bytes at 0x%08lx)\n",
			       size, (unsigned long)base);
		pmem_pdata.start = base;
		pmem_pdata.size = size;
		
}
#endif

在devs.h中添加

#ifdef CONFIG_ANDROID_PMEM
extern struct platform_device pmem_device;
extern void __init s5p_pmem_reserve_mem(phys_addr_t base, unsigned int size);
#endif

在mach-smdkv210.c中添加

static void __init smdkv210_reserve(void)
{
	s5p_mfc_reserve_mem(0x3b800000, 36 << 20, 0x3dc00000, 36 << 20);
#ifdef CONFIG_ANDROID_PMEM
	s5p_pmem_reserve_mem(0x3b000000, 8 << 20);
#endif
}

static struct platform_device *smdkv210_devices[] 中加入变量

#ifdef CONFIG_ANDROID_PMEM
&pmem_device,
#endif

测试程序：

#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <time.h>
#include <sys/mman.h>
#include <assert.h>
#include <linux/videodev2.h>
#include <linux/fb.h>
#include <pthread.h>
#include <poll.h>
#include <semaphore.h>
#include "android_pmem.h"

int main()
{
	int pmem_fd;
	void *pmem_base;
	unsigned int size;
	struct pmem_region region;

	pmem_fd = open("/dev/pmem", O_RDWR, 0);//打开设备，为了操作硬件引擎，要noncache的
	printf("pmem_fd:%d\n", pmem_fd);
	if (pmem_fd >= 0)  
	{       
        if (ioctl(pmem_fd, PMEM_GET_TOTAL_SIZE, &region) < 0) //获取全部空间            
			perror("PMEM_GET_TOTAL_SIZE failed\n");
			
       
		size = region.len;
		printf("region.len:0x%08x offset:0x%08x\n",region.len, region.offset);
		pmem_base = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, pmem_fd, 0);//mmap操作
		
		if (pmem_base == MAP_FAILED)            
		{	pmem_base = 0;
            close(pmem_fd);
            pmem_fd = -1;
			perror("mmap pmem error!\n");
		}
		printf("pmem_base:0x%08x\n", pmem_base);
    }

	if ( ioctl(pmem_fd, PMEM_GET_PHYS, &region) < 0)
	{//获取物理地址             
		perror("PMEM_GET_PHYS failed\n");
	}
	printf("region:0x%08x\n",region.offset);
	
	if(munmap(pmem_base, size) < 0)
	{
		perror("munmap error\n");
	}
	close(pmem_fd);
	return 0;
}