1 //! 这是暴露给C的接口,用于在C语言中使用Rust的内存分配器。 2 3 use core::intrinsics::unlikely; 4 5 use alloc::vec::Vec; 6 use hashbrown::HashMap; 7 use system_error::SystemError; 8 9 use crate::{ 10 include::bindings::bindings::{gfp_t, PAGE_U_S}, 11 kerror, 12 libs::{align::page_align_up, spinlock::SpinLock}, 13 mm::MMArch, 14 }; 15 16 use super::{ 17 allocator::page_frame::PageFrameCount, init::mm_init, kernel_mapper::KernelMapper, 18 mmio_buddy::mmio_pool, no_init::pseudo_map_phys, page::PageFlags, MemoryManagementArch, 19 PhysAddr, VirtAddr, 20 }; 21 22 lazy_static! { 23 // 用于记录内核分配给C的空间信息 24 static ref C_ALLOCATION_MAP: SpinLock<HashMap<VirtAddr, (VirtAddr, usize, usize)>> = SpinLock::new(HashMap::new()); 25 } 26 27 /// [EXTERN TO C] Use pseudo mapper to map physical memory to virtual memory. 28 #[no_mangle] 29 pub unsafe extern "C" fn rs_pseudo_map_phys(vaddr: usize, paddr: usize, size: usize) { 30 let vaddr = VirtAddr::new(vaddr); 31 let paddr = PhysAddr::new(paddr); 32 let count = PageFrameCount::new(page_align_up(size) / MMArch::PAGE_SIZE); 33 pseudo_map_phys(vaddr, paddr, count); 34 } 35 36 /// [EXTERN TO C] Use kernel mapper to map physical memory to virtual memory. 37 #[no_mangle] 38 pub unsafe extern "C" fn rs_map_phys(vaddr: usize, paddr: usize, size: usize, flags: usize) { 39 let mut vaddr = VirtAddr::new(vaddr); 40 let mut paddr = PhysAddr::new(paddr); 41 let count = PageFrameCount::new(page_align_up(size) / MMArch::PAGE_SIZE); 42 // kdebug!("rs_map_phys: vaddr: {vaddr:?}, paddr: {paddr:?}, count: {count:?}, flags: {flags:?}"); 43 44 let mut page_flags: PageFlags<MMArch> = PageFlags::new().set_execute(true).set_write(true); 45 if flags & PAGE_U_S as usize != 0 { 46 page_flags = page_flags.set_user(true); 47 } 48 49 let mut kernel_mapper = KernelMapper::lock(); 50 let mut kernel_mapper = kernel_mapper.as_mut(); 51 assert!(kernel_mapper.is_some()); 52 for _i in 0..count.data() { 53 let flusher = kernel_mapper 54 .as_mut() 55 .unwrap() 56 .map_phys(vaddr, paddr, page_flags) 57 .unwrap(); 58 59 flusher.flush(); 60 61 vaddr += MMArch::PAGE_SIZE; 62 paddr += MMArch::PAGE_SIZE; 63 } 64 } 65 66 #[no_mangle] 67 pub unsafe extern "C" fn kzalloc(size: usize, _gfp: gfp_t) -> usize { 68 // kdebug!("kzalloc: size: {size}"); 69 return do_kmalloc(size, true); 70 } 71 72 #[no_mangle] 73 pub unsafe extern "C" fn kmalloc(size: usize, _gfp: gfp_t) -> usize { 74 // kdebug!("kmalloc: size: {size}"); 75 // 由于C代码不规范,因此都全部清空 76 return do_kmalloc(size, true); 77 } 78 79 fn do_kmalloc(size: usize, _zero: bool) -> usize { 80 let space: Vec<u8> = vec![0u8; size]; 81 82 assert!(space.len() == size); 83 let (ptr, len, cap) = space.into_raw_parts(); 84 if !ptr.is_null() { 85 let vaddr = VirtAddr::new(ptr as usize); 86 let len = len as usize; 87 let cap = cap as usize; 88 let mut guard = C_ALLOCATION_MAP.lock(); 89 if unlikely(guard.contains_key(&vaddr)) { 90 drop(guard); 91 unsafe { 92 drop(Vec::from_raw_parts(vaddr.data() as *mut u8, len, cap)); 93 } 94 panic!( 95 "do_kmalloc: vaddr {:?} already exists in C Allocation Map, query size: {size}, zero: {_zero}", 96 vaddr 97 ); 98 } 99 // 插入到C Allocation Map中 100 guard.insert(vaddr, (vaddr, len, cap)); 101 return vaddr.data(); 102 } else { 103 return SystemError::ENOMEM.to_posix_errno() as i64 as usize; 104 } 105 } 106 107 #[no_mangle] 108 pub unsafe extern "C" fn kfree(vaddr: usize) -> usize { 109 let vaddr = VirtAddr::new(vaddr); 110 let mut guard = C_ALLOCATION_MAP.lock(); 111 let p = guard.remove(&vaddr); 112 drop(guard); 113 114 if p.is_none() { 115 kerror!("kfree: vaddr {:?} not found in C Allocation Map", vaddr); 116 return SystemError::EINVAL.to_posix_errno() as i64 as usize; 117 } 118 let (vaddr, len, cap) = p.unwrap(); 119 drop(Vec::from_raw_parts(vaddr.data() as *mut u8, len, cap)); 120 return 0; 121 } 122 123 /// @brief 创建一块mmio区域,并将vma绑定到initial_mm 124 /// 125 /// @param size mmio区域的大小(字节) 126 /// 127 /// @param vm_flags 要把vma设置成的标志 128 /// 129 /// @param res_vaddr 返回值-分配得到的虚拟地址 130 /// 131 /// @param res_length 返回值-分配的虚拟地址空间长度 132 /// 133 /// @return int 错误码 134 #[no_mangle] 135 unsafe extern "C" fn rs_mmio_create( 136 size: u32, 137 _vm_flags: u64, 138 res_vaddr: *mut u64, 139 res_length: *mut u64, 140 ) -> i32 { 141 // kdebug!("mmio_create"); 142 let r = mmio_pool().create_mmio(size as usize); 143 if r.is_err() { 144 return r.unwrap_err().to_posix_errno(); 145 } 146 let space_guard = r.unwrap(); 147 *res_vaddr = space_guard.vaddr().data() as u64; 148 *res_length = space_guard.size() as u64; 149 // 由于space_guard drop的时候会自动释放内存,所以这里要忽略它的释放 150 core::mem::forget(space_guard); 151 return 0; 152 } 153 154 /// @brief 取消mmio的映射并将地址空间归还到buddy中 155 /// 156 /// @param vaddr 起始的虚拟地址 157 /// 158 /// @param length 要归还的地址空间的长度 159 /// 160 /// @return Ok(i32) 成功返回0 161 /// 162 /// @return Err(i32) 失败返回错误码 163 #[no_mangle] 164 pub unsafe extern "C" fn rs_mmio_release(vaddr: u64, length: u64) -> i32 { 165 return mmio_pool() 166 .release_mmio(VirtAddr::new(vaddr as usize), length as usize) 167 .unwrap_or_else(|err| err.to_posix_errno()); 168 } 169 170 #[no_mangle] 171 unsafe extern "C" fn rs_mm_init() { 172 mm_init(); 173 } 174