Hello everyone,
I'm working on Microzed board on an AMP architecture without using OpenAMP.
My CPU0 runs a Linux OS (kernel 4.4). My CPU1 runs a FreeRTOS. Each Application have to exchange data to the other one. so I'm using DDR as a shared memory and SGI as Inter processor interrupt system. My FreeRTOS application is located at 0x0F010000, and my Shared memory is located at 0x0F000000.
I've developped a module driver to managed to the SGI's and the access to the shared memory (read, write, ...). And I get -EBUSY error while trying to get DDR ressources from 0x0F000000 to 0x0F00FFFF.
I've try different ways :
- I've Changed memory size in device tree
memory {
device_type = "memory";
reg = <0x0 0x0F000000>;
};
but the /proc/meminfo still see 1Gbyte RAM size (see here under)
MemTotal: 1031656 kB
MemFree: 1011788 kB
MemAvailable: 1009032 kB
And modprobe mydev still returns an error.
- I've added mem=240M in kernel boot command line (in device tree), but Linux Freeze at "Starting Kernel" step
- I've used memmap argument in kernel boot command line ==> it does not work and I've later that it is not supported on ARM.
- I've add a device tree node (reserved-memory)
reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;
ddr_memp0: amp_memp@0f000000 {
reg = <0x0f000000 0x010000>;
};
ddr_appcpu1: amp_appcpu1@0f010000 {
reg = <0x0f010000 0x050000>;
};
};
==> the /proc/meminfo still see 1Gbyte RAM size (see here under) and modprobe mydriver still returns the same error
MemTotal: 1031656 kB
MemFree: 1011788 kB
MemAvailable: 1009032 kB
- I've try the free ressources located between 0x0F000000 and 0x0F060000 (see driver code here under) ==> But I got an error message explaining that the resources do not exist (Trying to free nonexistent resource <000000000f000000-000000000f00ffff>)
Does someone can give me some working clues to secure my DDR shared and my freertos code and data memory ?
Thanks for you help !!!
________________________________________________________________________________________
I give here under the probe function of my driver
<code>
static int ae_memp_probe(struct platform_device *pdev){
void * pdata; /* platform data pointer */
struct resource *res;
u32 rq_irq, wr_irq, u32_mem_addr;
long s32_mem_size;
int rtn;
printk(KERN_INFO "ae_memp_probe : Allocating ae_memp ressources\n");
memp_reg_mgr = kzalloc(sizeof(struct ae_memp), GFP_KERNEL);
if (!memp_reg_mgr){
printk(KERN_ERR "ae_memp_probe : allocation failed\n");
return rtn;
}else{
printk(KERN_INFO "ae_memp_probe : Getting platform data\n");
pdata = dev_get_platdata(&pdev->dev);
if (pdata == NULL ){
printk(KERN_ERR "ae_memp_probe : platform data NULL pointer\n");
}
printk(KERN_INFO "ae_memp_probe : Getting Information from Device Tree\n");
of_property_read_u32(pdev->dev.of_node, "mem_addr", &u32_mem_addr);
if (!u32_mem_addr){
printk(KERN_ALERT "ae_memp_probe : mem_addr not found\n");
mem_addr = (char *)0x0F000000;
u32_mem_addr=0x0F000000;
} else {
mem_addr=(char *)u32_mem_addr;
printk(KERN_INFO "ae_memp_probe : read mem_addr=0x%lx\n", (unsigned long)mem_addr);
}
of_property_read_u32(pdev->dev.of_node, "mem_size",(u32*)&s32_mem_size);
if (s32_mem_size <= 0 ){
printk(KERN_ALERT "ae_memp_probe : s32_mem_size not found or bad value\n");
s32_mem_size=100;
} else {
printk(KERN_INFO "ae_memp_probe : read s32_mem_size=%ld\n", s32_mem_size);
}
/* Freeing shared Memory region */
release_region (u32_mem_addr, (unsigned long)s32_mem_size); /* does not work */
printk(KERN_INFO "ae_memp_probe : Getting Platform ressources\n");
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL){
printk(KERN_ALERT "ae_memp_probe : Failed to get platform ressources\n");
return -ECANCELED;
}
memp_reg_mgr->ram.mem_addr= devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(memp_reg_mgr->ram.mem_addr)) {
rtn = PTR_ERR(memp_reg_mgr->ram.mem_addr);
return rtn;
}
printk(KERN_INFO "ae_memp_probe : Configuring IPI\n");
clear_ipi_handler(memp_reg_mgr->irqmgr.rd_irq);
rtn = set_ipi_handler(memp_reg_mgr->irqmgr.rd_irq, ae_memp_irqhandler, "ae_memp_irqhandler");
if (rtn != 0){
printk(KERN_ERR "ERREUR : ae_memp_probe - Echec de requete de l'IRQ\n");
return rtn;
}
printk(KERN_INFO "ae_memp_probe success - Module Loaded\n");
return 0;
}
return -ECANCELED;
}
static const struct of_device_id ae_memp_of_match[] = {
{ .compatible = "ae,ddr_memp_1.0.a", },
{}
};
MODULE_DEVICE_TABLE(of, ae_memp_of_match);
static struct platform_driver ae_memp_driver = {
.probe = ae_memp_probe,
.remove = ae_memp_remove,
.driver = {
.name = AE_MEMP_DEVICE,
.of_match_table = ae_memp_of_match,
},
};
module_platform_driver(ae_memp_driver);
</code>
_______________________________________________________________________________
My device tree :
/ {
cpus {
cpu@0 {
operating-points = <666666 1000000 333333 1000000>;
};
};
chosen {
bootargs = "console=ttyPS0,115200 root=/dev/ram ramdisk_size=65535 maxcpus=1 ip=192.168.1.192 clk_ignore_unused rw earlyprintk";
};
aliases {
ethernet0 = &gem0;
serial0 = &uart1;
spi0 = &qspi;
spi1 = &spi0;
};
memory {
device_type = "memory";
reg = <0x0 0x40000000>;
};
reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;
ddr_memp0: amp_memp@0f000000 {
reg = <0x0f000000 0x010000>;
};
ddr_appcpu1: amp_appcpu1@0f010000 {
reg = <0x0f010000 0x050000>;
};
};
memp0: ae_memp@0f000000 {
compatible = "ae,ddr_memp_1.0.a";
reg = <0x0f000000 0x010000>;
memory-region = <&ddr_memp0>;
rd_irq= <2>;
wr_irq= <1>;
mem_addr=<0x0F000000>;
mem_size=<0x010000>;
};
};
