From 5656805520121e9192c1a4137a6ff1785d4aea03 Mon Sep 17 00:00:00 2001
From: Yuke Peng <pengyuke.pyk@antgroup.com>
Date: Fri, 5 May 2023 03:07:26 -0700
Subject: [PATCH] Impl MMIO access method

---
 framework/jinux-frame/src/arch/x86/mmio.rs |  19 ++++
 framework/jinux-frame/src/arch/x86/mod.rs  |   1 +
 framework/jinux-frame/src/lib.rs           |   2 +
 framework/jinux-frame/src/mmio.rs          | 104 +++++++++++++++++++++
 4 files changed, 126 insertions(+)
 create mode 100644 framework/jinux-frame/src/arch/x86/mmio.rs
 create mode 100644 framework/jinux-frame/src/mmio.rs

diff --git a/framework/jinux-frame/src/arch/x86/mmio.rs b/framework/jinux-frame/src/arch/x86/mmio.rs
new file mode 100644
index 000000000..fa6105521
--- /dev/null
+++ b/framework/jinux-frame/src/arch/x86/mmio.rs
@@ -0,0 +1,19 @@
+use acpi::PciConfigRegions;
+
+pub fn start_address() -> usize {
+    let start = PciConfigRegions::new(
+        &*crate::arch::x86::kernel::acpi::ACPI_TABLES
+            .get()
+            .unwrap()
+            .lock(),
+    )
+    .unwrap();
+
+    // all zero to get the start address
+    start.physical_address(0, 0, 0, 0).unwrap() as usize
+}
+
+pub fn end_address() -> usize {
+    // 4G-20M
+    0xFEC0_0000
+}
diff --git a/framework/jinux-frame/src/arch/x86/mod.rs b/framework/jinux-frame/src/arch/x86/mod.rs
index dce3cc7fe..f3b2724ac 100644
--- a/framework/jinux-frame/src/arch/x86/mod.rs
+++ b/framework/jinux-frame/src/arch/x86/mod.rs
@@ -4,6 +4,7 @@ pub mod device;
 pub(crate) mod irq;
 mod kernel;
 pub(crate) mod mm;
+pub(crate) mod mmio;
 pub(crate) mod timer;
 
 use alloc::fmt;
diff --git a/framework/jinux-frame/src/lib.rs b/framework/jinux-frame/src/lib.rs
index 6dbc55618..5efb51168 100644
--- a/framework/jinux-frame/src/lib.rs
+++ b/framework/jinux-frame/src/lib.rs
@@ -20,6 +20,7 @@ pub mod config;
 pub mod cpu;
 mod error;
 pub mod logger;
+pub mod mmio;
 pub mod prelude;
 pub mod sync;
 pub mod task;
@@ -47,6 +48,7 @@ pub fn init() {
     vm::init();
     trap::init();
     arch::after_all_init();
+    mmio::init();
     register_irq_common_callback();
     invoke_c_init_funcs();
 }
diff --git a/framework/jinux-frame/src/mmio.rs b/framework/jinux-frame/src/mmio.rs
new file mode 100644
index 000000000..cd7b686e3
--- /dev/null
+++ b/framework/jinux-frame/src/mmio.rs
@@ -0,0 +1,104 @@
+use core::{mem::size_of, ops::Range};
+use pod::Pod;
+use spin::Once;
+
+use crate::{
+    vm::{Paddr, Vaddr, VmIo},
+    Error,
+};
+
+static CHECKER: Once<MmioChecker> = Once::new();
+
+pub(crate) fn init() {
+    CHECKER.call_once(|| MmioChecker {
+        start: crate::arch::mmio::start_address(),
+        end: crate::arch::mmio::end_address(),
+    });
+    log::info!(
+        "MMIO start: 0x{:x}, end: 0x{:x}",
+        CHECKER.get().unwrap().start,
+        CHECKER.get().unwrap().end
+    );
+}
+
+#[derive(Debug, Clone)]
+pub struct Mmio {
+    virtual_address: Vaddr,
+    limit: usize,
+}
+
+impl VmIo for Mmio {
+    fn read_bytes(&self, offset: usize, buf: &mut [u8]) -> crate::Result<()> {
+        self.check_range(offset, buf.len())?;
+        unsafe {
+            core::ptr::copy(
+                self.virtual_address as *const u8,
+                buf.as_mut_ptr(),
+                buf.len(),
+            );
+        }
+        Ok(())
+    }
+
+    fn write_bytes(&self, offset: usize, buf: &[u8]) -> crate::Result<()> {
+        self.check_range(offset, buf.len())?;
+        unsafe {
+            core::ptr::copy(buf.as_ptr(), self.virtual_address as *mut u8, buf.len());
+        }
+        Ok(())
+    }
+
+    fn read_val<T: Pod>(&self, offset: usize) -> crate::Result<T> {
+        self.check_range(offset, size_of::<T>())?;
+        Ok(unsafe { core::ptr::read((self.virtual_address + offset) as *const T) })
+    }
+
+    fn write_val<T: Pod>(&self, offset: usize, new_val: &T) -> crate::Result<()> {
+        self.check_range(offset, size_of::<T>())?;
+        unsafe { core::ptr::write((self.virtual_address + offset) as *mut T, *new_val) };
+        Ok(())
+    }
+}
+
+impl Mmio {
+    pub fn new(range: Range<Paddr>) -> Option<Mmio> {
+        if CHECKER.get().unwrap().check(&range) {
+            Some(Mmio {
+                virtual_address: crate::vm::paddr_to_vaddr(range.start),
+                limit: range.len(),
+            })
+        } else {
+            None
+        }
+    }
+
+    pub fn paddr(&self) -> Paddr {
+        crate::vm::vaddr_to_paddr(self.virtual_address).unwrap()
+    }
+
+    fn check_range(&self, offset: usize, len: usize) -> crate::Result<()> {
+        let sum = offset.checked_add(len).ok_or(Error::InvalidArgs)?;
+        if sum > self.limit {
+            log::error!(
+                "attempt to access address out of bounds, limit:0x{:x}, access position:0x{:x}",
+                self.limit,
+                sum
+            );
+            Err(Error::InvalidArgs)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+struct MmioChecker {
+    start: Paddr,
+    end: Paddr,
+}
+
+impl MmioChecker {
+    /// Check whether the physical address is in MMIO region.
+    fn check(&self, range: &Range<Paddr>) -> bool {
+        range.start >= self.start && range.end < self.end
+    }
+}