lib.rs

/* Copyright (c) [2023] [Syswonder Community]
 *   [Ruxos] is licensed under Mulan PSL v2.
 *   You can use this software according to the terms and conditions of the Mulan PSL v2.
 *   You may obtain a copy of Mulan PSL v2 at:
 *               http://license.coscl.org.cn/MulanPSL2
 *   THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 *   See the Mulan PSL v2 for more details.
 */

//! Structures and functions for PCI bus operations.
//!
//! Currently, it just re-exports structures from the crate [virtio-drivers][1]
//! and its module [`virtio_drivers::transport::pci::bus`][2].
//!
//! [1]: https://docs.rs/virtio-drivers/latest/virtio_drivers/
//! [2]: https://docs.rs/virtio-drivers/latest/virtio_drivers/transport/pci/bus/index.html

#![no_std]

pub use virtio_drivers::transport::pci::bus::ConfigurationAccess;
pub use virtio_drivers::transport::pci::bus::{
    BarInfo, Cam, HeaderType, MemoryBarType, MmioCam, PciError,
};
pub use virtio_drivers::transport::pci::bus::{
    CapabilityInfo, Command, DeviceFunction, DeviceFunctionInfo, PciRoot, Status,
};
/// Used to allocate MMIO regions for PCI BARs.
pub struct PciRangeAllocator {
    _start: u64,
    end: u64,
    current: u64,
}

impl PciRangeAllocator {
    /// Creates a new allocator from a memory range.
    pub const fn new(base: u64, size: u64) -> Self {
        Self {
            _start: base,
            end: base + size,
            current: base,
        }
    }

    /// Allocates a memory region with the given size.
    ///
    /// The `size` should be a power of 2, and the returned value is also a
    /// multiple of `size`.
    pub fn alloc(&mut self, size: u64) -> Option<u64> {
        if !size.is_power_of_two() {
            return None;
        }
        let ret = align_up(self.current, size);
        if ret + size > self.end {
            return None;
        }

        self.current = ret + size;
        Some(ret)
    }
}

const fn align_up(addr: u64, align: u64) -> u64 {
    (addr + align - 1) & !(align - 1)
}