kupl_mem_copyin

Copy memory from ddr to hbw.

Interface Definition

int kupl_mem_copyin(void *ddr_addr, size_t size, kupl_mem_copyin_flag_t flag, kupl_queue_h queue);

Parameters

**Table 1** Parameter definition
Parameter	Type	Description	Input/Output
ddr_addr	void *	Address of the DDR memory to be copied.	Input
size	size_t	Size of the memory to be copied, in bytes.	Input
flag	kupl_mem_copyin_flag_t	Type of the swap-in operation, including: KUPL_MEM_CREATE: If ddr_addr is not in the present state, create a mapping from ddr to hbw (the state changes to present). Otherwise, increment the reference count by 1. KUPL_MEM_IN: If ddr_addr is not in the present state, create a mapping from ddr to hbw and copy the content from ddr to hbw (the state changes to present). Otherwise, increment the reference count by 1. KUPL_MEM_PUSH: Copies the content from ddr to hbw.	Input
queue	kupl_queue_h	Queue on which the operation is performed.	Input

Return Value

Success: KUPL_OK
Failure: KUPL_ERROR

Examples

#include "kupl.h"
#include <cassert>

static int a = 1;

void query_and_modify(void *args)
{
    void *hbw = kupl_mem_query(&a);
    int ret = kupl_hbw_verify(hbw, sizeof(int), 0);
    *(int *)hbw = 2;
}

int main()
{
    auto queue = kupl_queue_acquire(1);
    kupl_mem_copyin(&a, sizeof(int), KUPL_MEM_IN, queue);
    auto present = kupl_mem_is_present(&a);
    assert(present == true);
    kupl_queue_item_desc_t desc {
        .field_mask = KUPL_QUEUE_ITEM_DESC_FIELD_NAME,
        .func = query_and_modify,
        .args = nullptr,
        .name = "query_and_modify",
    };
    kupl_queue_submit(queue, &desc);
    kupl_mem_copyout(&a, sizeof(int), KUPL_MEM_OUT, queue);
    kupl_queue_wait(queue);
    present = kupl_mem_is_present(&a);
    assert(present == false);
    printf("a: %d\n", a);
}

The execution result is as follows:

a: 2

The preceding example demonstrates the complete swap-in and swap-out process of the ddr and hbw memory. First, use kupl_mem_copyin to copy the memory from ddr to hbw. Then, use kupl_mem_is_present to check memory accessibility. Next, submit an asynchronous task to use kupl_mem_query to look up hbw address for ddr and modify the address. Finally, use kupl_mem_copyout to copy the hbw address back to ddr.

Parent topic: Memory Management Functions