You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: paging.rs
    path of file: ./repos/rCore/kernel/src/arch/riscv
    
    the code of the file until where you have to start completion: use crate::consts::PHYSICAL_MEMORY_OFFSET;
use crate::memory::{alloc_frame, dealloc_frame, phys_to_virt};
use core::mem::ManuallyDrop;
use log::*;
use rcore_memory::paging::*;
use riscv
    
    fn get_page_slice_mut<'a>(&mut self, addr: usize) -> &'a mut [u8] {
        let frame = self
            .page_table
            .translate_page(Page::of_addr(VirtAddr::new(addr)))
            .unwrap();
        let vaddr = frame.start_address().as_usize() + PHYSICAL_MEMORY_OFFSET;
        unsafe { core::slice::from_raw_parts_mut(vaddr as *mut u8, 0x1000) }
    }