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| 1 | +use core::{ops::Deref, ptr::NonNull}; |
| 2 | + |
| 3 | +/// Describes a physical mapping created by `AcpiHandler::map_physical_region` and unmapped by |
| 4 | +/// `AcpiHandler::unmap_physical_region`. The region mapped must be at least `size_of::<T>()` |
| 5 | +/// bytes, but may be bigger. |
| 6 | +/// |
| 7 | +/// See `PhysicalMapping::new` for the meaning of each field. |
| 8 | +#[derive(Debug)] |
| 9 | +pub struct PhysicalMapping<H, T> |
| 10 | +where |
| 11 | + H: AcpiHandler, |
| 12 | +{ |
| 13 | + physical_start: usize, |
| 14 | + virtual_start: NonNull<T>, |
| 15 | + region_length: usize, // Can be equal or larger than size_of::<T>() |
| 16 | + mapped_length: usize, // Differs from `region_length` if padding is added for alignment |
| 17 | + handler: H, |
| 18 | +} |
| 19 | + |
| 20 | +impl<H, T> PhysicalMapping<H, T> |
| 21 | +where |
| 22 | + H: AcpiHandler, |
| 23 | +{ |
| 24 | + /// Construct a new `PhysicalMapping`. |
| 25 | + /// |
| 26 | + /// - `physical_start` should be the physical address of the structure to be mapped. |
| 27 | + /// - `virtual_start` should be the corresponding virtual address of that structure. It may differ from the |
| 28 | + /// start of the region mapped due to requirements of the paging system. It must be a valid, non-null |
| 29 | + /// pointer. |
| 30 | + /// - `region_length` should be the number of bytes requested to be mapped. It must be equal to or larger than |
| 31 | + /// `size_of::<T>()`. |
| 32 | + /// - `mapped_length` should be the number of bytes mapped to fulfill the request. It may be equal to or larger |
| 33 | + /// than `region_length`, due to requirements of the paging system or other reasoning. |
| 34 | + /// - `handler` should be the same `AcpiHandler` that created the mapping. When the `PhysicalMapping` is |
| 35 | + /// dropped, it will be used to unmap the structure. |
| 36 | + pub unsafe fn new( |
| 37 | + physical_start: usize, |
| 38 | + virtual_start: NonNull<T>, |
| 39 | + region_length: usize, |
| 40 | + mapped_length: usize, |
| 41 | + handler: H, |
| 42 | + ) -> Self { |
| 43 | + Self { physical_start, virtual_start, region_length, mapped_length, handler } |
| 44 | + } |
| 45 | + |
| 46 | + pub fn physical_start(&self) -> usize { |
| 47 | + self.physical_start |
| 48 | + } |
| 49 | + |
| 50 | + pub fn virtual_start(&self) -> NonNull<T> { |
| 51 | + self.virtual_start |
| 52 | + } |
| 53 | + |
| 54 | + pub fn region_length(&self) -> usize { |
| 55 | + self.region_length |
| 56 | + } |
| 57 | + |
| 58 | + pub fn mapped_length(&self) -> usize { |
| 59 | + self.mapped_length |
| 60 | + } |
| 61 | + |
| 62 | + pub fn handler(&self) -> &H { |
| 63 | + &self.handler |
| 64 | + } |
| 65 | +} |
| 66 | + |
| 67 | +unsafe impl<H: AcpiHandler + Send, T: Send> Send for PhysicalMapping<H, T> {} |
| 68 | + |
| 69 | +impl<H, T> Deref for PhysicalMapping<H, T> |
| 70 | +where |
| 71 | + H: AcpiHandler, |
| 72 | +{ |
| 73 | + type Target = T; |
| 74 | + |
| 75 | + fn deref(&self) -> &T { |
| 76 | + unsafe { self.virtual_start.as_ref() } |
| 77 | + } |
| 78 | +} |
| 79 | + |
| 80 | +impl<H, T> Drop for PhysicalMapping<H, T> |
| 81 | +where |
| 82 | + H: AcpiHandler, |
| 83 | +{ |
| 84 | + fn drop(&mut self) { |
| 85 | + H::unmap_physical_region(self) |
| 86 | + } |
| 87 | +} |
| 88 | + |
| 89 | +/// An implementation of this trait must be provided to allow `acpi` to access platform-specific |
| 90 | +/// functionality, such as mapping regions of physical memory. You are free to implement these |
| 91 | +/// however you please, as long as they conform to the documentation of each function. The handler is stored in |
| 92 | +/// every `PhysicalMapping` so it's able to unmap itself when dropped, so this type needs to be something you can |
| 93 | +/// clone/move about freely (e.g. a reference, wrapper over `Rc`, marker struct, etc.). |
| 94 | +pub trait AcpiHandler: Clone { |
| 95 | + /// Given a physical address and a size, map a region of physical memory that contains `T` (note: the passed |
| 96 | + /// size may be larger than `size_of::<T>()`). The address is not neccessarily page-aligned, so the |
| 97 | + /// implementation may need to map more than `size` bytes. The virtual address the region is mapped to does not |
| 98 | + /// matter, as long as it is accessible to `acpi`. |
| 99 | + /// |
| 100 | + /// See the documentation on `PhysicalMapping::new` for an explanation of each field on the `PhysicalMapping` |
| 101 | + /// return type. |
| 102 | + /// |
| 103 | + /// ## Safety |
| 104 | + /// |
| 105 | + /// - `physical_address` must point to a valid `T` in physical memory. |
| 106 | + /// - `size` must be at least `size_of::<T>()`. |
| 107 | + unsafe fn map_physical_region<T>(&self, physical_address: usize, size: usize) -> PhysicalMapping<Self, T>; |
| 108 | + |
| 109 | + /// Unmap the given physical mapping. This is called when a `PhysicalMapping` is dropped, you should **not** manually call this. |
| 110 | + /// |
| 111 | + /// Note: A reference to the handler used to construct `region` can be acquired by calling [`PhysicalMapping::handler`]. |
| 112 | + fn unmap_physical_region<T>(region: &PhysicalMapping<Self, T>); |
| 113 | +} |
| 114 | + |
| 115 | +#[cfg(test)] |
| 116 | +mod tests { |
| 117 | + use super::*; |
| 118 | + |
| 119 | + #[test] |
| 120 | + #[allow(dead_code)] |
| 121 | + fn test_send_sync() { |
| 122 | + // verify that PhysicalMapping implements Send and Sync |
| 123 | + fn test_send_sync<T: Send>() {} |
| 124 | + fn caller<H: AcpiHandler + Send, T: Send>() { |
| 125 | + test_send_sync::<PhysicalMapping<H, T>>(); |
| 126 | + } |
| 127 | + } |
| 128 | +} |
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