swiotlb_late_init_with

int
swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
{
    unsigned long i, bytes;
 
    bytes = nslabs << IO_TLB_SHIFT;
 
    io_tlb_nslabs = nslabs;
    io_tlb_start = virt_to_phys(tlb);
    io_tlb_end = io_tlb_start + bytes;
 
    set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
    memset(tlb, 0, bytes);
 
    /*
     * Allocate and initialize the free list array.  This array is used
     * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
     * between io_tlb_start and io_tlb_end.
     */
    io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
                                  get_order(io_tlb_nslabs * sizeof(int)));
    if (!io_tlb_list)
        goto cleanup3;
 
    io_tlb_orig_addr = (phys_addr_t *)
        __get_free_pages(GFP_KERNEL,
                 get_order(io_tlb_nslabs *
                       sizeof(phys_addr_t)));
    if (!io_tlb_orig_addr)
        goto cleanup4;
 
    for (i = 0; i < io_tlb_nslabs; i++) {
        io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
        io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
    }
    io_tlb_index = 0;
 
    swiotlb_print_info();
 
    late_alloc = 1;
 
    swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT);
 
    return 0;
 
cleanup4:
    free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
                                                     sizeof(int)));
    io_tlb_list = NULL;
cleanup3:
    swiotlb_cleanup();
    return -ENOMEM;
}
函数源码
