resources: Add system resource allocator

Start a system resource allocator that will be able to manage the
resources specific to each architecture.

Change-Id: I98cf35c280fefd7b0000801eb7405a236373b753
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1089719
Reviewed-by: Sonny Rao <sonnyrao@chromium.org>

Cargo.lock

@@ -304,6 +304,7 @@ name = "resources"
 version = "0.1.0"
 dependencies = [
  "data_model 0.1.0",
+ "sys_util 0.1.0",
 ]
 
 [[package]]

resources/Cargo.toml

@@ -5,3 +5,4 @@ authors = ["The Chromium OS Authors"]
 
 [dependencies]
 data_model = { path = "../data_model" }
+sys_util = { path = "../sys_util" }

resources/src/lib.rs

@@ -4,6 +4,10 @@
 
 //! Manages system resources that can be allocated to VMs and their devices.
 
+extern crate sys_util;
+
 mod address_allocator;
+mod system_allocator;
 
 pub use address_allocator::AddressAllocator;
+pub use system_allocator::{AddressRanges, SystemAllocator};

resources/src/system_allocator.rs

@@ -0,0 +1,130 @@
+// Copyright 2018 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+use address_allocator::AddressAllocator;
+use sys_util::pagesize;
+
+/// Manages allocating system resources such as address space and interrupt numbers.
+///
+/// # Example - Use the `SystemAddress` builder.
+///
+/// ```
+/// # use sys_util::AddressRanges;
+///   if let Some(mut a) = AddressRanges::new()
+///           .add_io_addresses(0x1000, 0x10000)
+///           .add_device_addresses(0x10000000, 0x10000000)
+///           .add_mmio_addresses(0x30000000, 0x10000)
+///           .create_allocator(5) {
+///       assert_eq!(a.allocate_irq(), Some(5));
+///       assert_eq!(a.allocate_irq(), Some(6));
+///       assert_eq!(a.allocate_device_addresses(0x100), Some(0x10000000));
+///   }
+/// ```
+#[derive(Debug, Eq, PartialEq)]
+pub struct SystemAllocator {
+    io_address_space: AddressAllocator,
+    device_address_space: AddressAllocator,
+    mmio_address_space: AddressAllocator,
+    next_irq: u32,
+}
+
+impl SystemAllocator {
+    /// Creates a new `SystemAllocator` for managing addresses and irq numvers.
+    /// Can return `None` if `base` + `size` overflows a u64 or if alignment isn't a power
+    /// of two.
+    ///
+    /// * `io_base` - The starting address of IO memory.
+    /// * `io_size` - The size of IO memory.
+    /// * `dev_base` - The starting address of device memory.
+    /// * `dev_size` - The size of device memory.
+    /// * `mmio_base` - The starting address of MMIO space.
+    /// * `mmio_size` - The size of MMIO space.
+    /// * `first_irq` - The first irq number to give out.
+    fn new(io_base: u64, io_size: u64,
+               dev_base: u64, dev_size: u64,
+               mmio_base: u64, mmio_size: u64,
+               first_irq: u32)
+            -> Option<Self> {
+        let page_size = pagesize() as u64;
+        Some(SystemAllocator {
+            io_address_space: AddressAllocator::new(io_base, io_size, Some(0x400))?,
+            device_address_space: AddressAllocator::new(dev_base, dev_size, Some(page_size))?,
+            mmio_address_space: AddressAllocator::new(mmio_base, mmio_size, Some(page_size))?,
+            next_irq: first_irq,
+        })
+    }
+
+    /// Reserves the next available system irq number.
+    pub fn allocate_irq(&mut self) -> Option<u32> {
+        if let Some(irq_num) = self.next_irq.checked_add(1) {
+            self.next_irq = irq_num;
+            Some(irq_num - 1)
+        } else {
+            None
+        }
+    }
+
+    /// Reserves a section of `size` bytes of IO address space.
+    pub fn allocate_io_addresses(&mut self, size: u64) -> Option<u64> {
+        self.io_address_space.allocate(size)
+    }
+
+    /// Reserves a section of `size` bytes of device address space.
+    pub fn allocate_device_addresses(&mut self, size: u64) -> Option<u64> {
+        self.device_address_space.allocate(size)
+    }
+
+    /// Reserves a section of `size` bytes of device address space.
+    pub fn allocate_mmio_addresses(&mut self, size: u64) -> Option<u64> {
+        self.mmio_address_space.allocate(size)
+    }
+}
+
+/// Used to build a system address map for use in creating a `SystemAllocator`.
+pub struct AddressRanges {
+    io_base: Option<u64>,
+    io_size: Option<u64>,
+    mmio_base: Option<u64>,
+    mmio_size: Option<u64>,
+    device_base: Option<u64>,
+    device_size: Option<u64>,
+}
+
+impl AddressRanges {
+    pub fn new() -> Self {
+        AddressRanges {
+            io_base: None,
+            io_size: None,
+            mmio_base: None,
+            mmio_size: None,
+            device_base: None,
+            device_size: None,
+        }
+    }
+
+    pub fn add_io_addresses(mut self, base: u64, size: u64) -> Self {
+        self.io_base = Some(base);
+        self.io_size = Some(size);
+        self
+    }
+
+    pub fn add_mmio_addresses(mut self, base: u64, size: u64) -> Self {
+        self.mmio_base = Some(base);
+        self.mmio_size = Some(size);
+        self
+    }
+
+    pub fn add_device_addresses(mut self, base: u64, size: u64) -> Self {
+        self.device_base = Some(base);
+        self.device_size = Some(size);
+        self
+    }
+
+    pub fn create_allocator(&self, first_irq: u32) -> Option<SystemAllocator> {
+        SystemAllocator::new(self.io_base?, self.io_size?,
+                             self.device_base?, self.device_size?,
+                             self.mmio_base?, self.mmio_size?,
+                             first_irq)
+    }
+}