1 // Copyright 2024, Linaro Limited 2 // Author(s): Manos Pitsidianakis <manos.pitsidianakis@linaro.org> 3 // SPDX-License-Identifier: GPL-2.0-or-later 4 5 #![cfg_attr(not(MESON), doc = include_str!("../README.md"))] 6 7 #[rustfmt::skip] 8 pub mod bindings; 9 10 // preserve one-item-per-"use" syntax, it is clearer 11 // for prelude-like modules 12 #[rustfmt::skip] 13 pub mod prelude; 14 15 pub mod bitops; 16 pub mod c_str; 17 pub mod cell; 18 pub mod definitions; 19 pub mod device_class; 20 pub mod irq; 21 pub mod offset_of; 22 pub mod sysbus; 23 pub mod vmstate; 24 pub mod zeroable; 25 26 use std::{ 27 alloc::{GlobalAlloc, Layout}, 28 os::raw::c_void, 29 }; 30 31 #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] 32 extern "C" { 33 fn g_aligned_alloc0( 34 n_blocks: bindings::gsize, 35 n_block_bytes: bindings::gsize, 36 alignment: bindings::gsize, 37 ) -> bindings::gpointer; 38 fn g_aligned_free(mem: bindings::gpointer); 39 } 40 41 #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] 42 extern "C" { 43 fn qemu_memalign(alignment: usize, size: usize) -> *mut c_void; 44 fn qemu_vfree(ptr: *mut c_void); 45 } 46 47 extern "C" { 48 fn g_malloc0(n_bytes: bindings::gsize) -> bindings::gpointer; 49 fn g_free(mem: bindings::gpointer); 50 } 51 52 /// An allocator that uses the same allocator as QEMU in C. 53 /// 54 /// It is enabled by default with the `allocator` feature. 55 /// 56 /// To set it up manually as a global allocator in your crate: 57 /// 58 /// ```ignore 59 /// use qemu_api::QemuAllocator; 60 /// 61 /// #[global_allocator] 62 /// static GLOBAL: QemuAllocator = QemuAllocator::new(); 63 /// ``` 64 #[derive(Clone, Copy, Debug)] 65 #[repr(C)] 66 pub struct QemuAllocator { 67 _unused: [u8; 0], 68 } 69 70 #[cfg_attr(all(feature = "allocator", not(test)), global_allocator)] 71 pub static GLOBAL: QemuAllocator = QemuAllocator::new(); 72 73 impl QemuAllocator { 74 // From the glibc documentation, on GNU systems, malloc guarantees 16-byte 75 // alignment on 64-bit systems and 8-byte alignment on 32-bit systems. See 76 // https://www.gnu.org/software/libc/manual/html_node/Malloc-Examples.html. 77 // This alignment guarantee also applies to Windows and Android. On Darwin 78 // and OpenBSD, the alignment is 16 bytes on both 64-bit and 32-bit systems. 79 #[cfg(all( 80 target_pointer_width = "32", 81 not(any(target_os = "macos", target_os = "openbsd")) 82 ))] 83 pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(8); 84 #[cfg(all( 85 target_pointer_width = "64", 86 not(any(target_os = "macos", target_os = "openbsd")) 87 ))] 88 pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(16); 89 #[cfg(all( 90 any(target_pointer_width = "32", target_pointer_width = "64"), 91 any(target_os = "macos", target_os = "openbsd") 92 ))] 93 pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(16); 94 #[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))] 95 pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = None; 96 97 pub const fn new() -> Self { 98 Self { _unused: [] } 99 } 100 } 101 102 impl Default for QemuAllocator { 103 fn default() -> Self { 104 Self::new() 105 } 106 } 107 108 // Sanity check. 109 const _: [(); 8] = [(); ::core::mem::size_of::<*mut c_void>()]; 110 111 unsafe impl GlobalAlloc for QemuAllocator { 112 unsafe fn alloc(&self, layout: Layout) -> *mut u8 { 113 if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if default.checked_rem(layout.align()) == Some(0)) 114 { 115 // SAFETY: g_malloc0() is safe to call. 116 unsafe { g_malloc0(layout.size().try_into().unwrap()).cast::<u8>() } 117 } else { 118 #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] 119 { 120 // SAFETY: g_aligned_alloc0() is safe to call. 121 unsafe { 122 g_aligned_alloc0( 123 layout.size().try_into().unwrap(), 124 1, 125 layout.align().try_into().unwrap(), 126 ) 127 .cast::<u8>() 128 } 129 } 130 #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] 131 { 132 // SAFETY: qemu_memalign() is safe to call. 133 unsafe { qemu_memalign(layout.align(), layout.size()).cast::<u8>() } 134 } 135 } 136 } 137 138 unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) { 139 if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if default.checked_rem(layout.align()) == Some(0)) 140 { 141 // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid 142 // glib-allocated pointer, so `g_free`ing is safe. 143 unsafe { g_free(ptr.cast::<_>()) } 144 } else { 145 #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] 146 { 147 // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid aligned 148 // glib-allocated pointer, so `g_aligned_free`ing is safe. 149 unsafe { g_aligned_free(ptr.cast::<_>()) } 150 } 151 #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] 152 { 153 // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid aligned 154 // glib-allocated pointer, so `qemu_vfree`ing is safe. 155 unsafe { qemu_vfree(ptr.cast::<_>()) } 156 } 157 } 158 } 159 } 160 161 #[cfg(has_offset_of)] 162 pub use core::mem::offset_of; 163