aarch64/mmu: add io remap

crate/memory/src/memory_set.rs

@@ -98,6 +98,7 @@ pub struct MemoryAttr {
     user: bool,
     readonly: bool,
     execute: bool,
+    mmio: bool,
     hide: bool,
 }
 
@@ -114,6 +115,10 @@ impl MemoryAttr {
         self.execute = true;
         self
     }
+    pub fn mmio(mut self) -> Self {
+        self.mmio = true;
+        self
+    }
     pub fn hide(mut self) -> Self {
         self.hide = true;
         self
@@ -122,8 +127,9 @@ impl MemoryAttr {
         if self.user { entry.set_user(true); }
         if self.readonly { entry.set_writable(false); }
         if self.execute { entry.set_execute(true); }
+        if self.mmio { entry.set_mmio(false); }
         if self.hide { entry.set_present(false); }
-        if self.user || self.readonly || self.execute || self.hide { entry.update(); }
+        if self.user || self.readonly || self.execute || self.mmio || self.hide { entry.update(); }
     }
 }
 

crate/memory/src/paging/mod.rs

@@ -57,4 +57,6 @@ pub trait Entry {
     fn set_user(&mut self, value: bool);
     fn execute(&self) -> bool;
     fn set_execute(&mut self, value: bool);
+    fn mmio(&self) -> bool;
+    fn set_mmio(&mut self, value: bool);
 }

kernel/src/arch/aarch64/board/raspi3/mod.rs

@@ -6,7 +6,8 @@ pub mod irq;
 pub mod timer;
 pub mod serial;
 
-pub const IO_BASE: usize = bcm2837::IO_BASE;
+pub const IO_REMAP_BASE: usize = bcm2837::IO_BASE;
+pub const IO_REMAP_END: usize = 0x40001000;
 
 pub fn init() {
     assert_has_not_been_called!("board::init must be called only once");

kernel/src/arch/aarch64/memory.rs

@@ -25,7 +25,7 @@ pub fn init_mmu_early() {
     let frame_lvl4 = Frame::containing_address(PhysAddr::new(&PAGE_TABLE_LVL4 as *const _ as u64));
     let frame_lvl3 = Frame::containing_address(PhysAddr::new(&PAGE_TABLE_LVL3 as *const _ as u64));
     let frame_lvl2 = Frame::containing_address(PhysAddr::new(&PAGE_TABLE_LVL2 as *const _ as u64));
-    super::paging::setup_page_table(frame_lvl4, frame_lvl3, frame_lvl2);
+    super::paging::setup_temp_page_table(frame_lvl4, frame_lvl3, frame_lvl2);
 
     // device.
     MAIR_EL1.write(
@@ -111,9 +111,8 @@ fn remap_the_kernel() {
     ms.push(MemoryArea::new_identity(srodata as usize, erodata as usize, MemoryAttr::default().readonly(), "rodata"));
     ms.push(MemoryArea::new_identity(sbss as usize, ebss as usize, MemoryAttr::default(), "bss"));
 
-    // ensure the level 2 page table exists
-    ms.push(MemoryArea::new_identity(0x40000000, 0x40200000, MemoryAttr::default(), "arm_control"));
-    super::paging::remap_device_2mib(&mut ms, 0x3F000000, 0x40200000);
+    use arch::board::{IO_REMAP_BASE, IO_REMAP_END};
+    ms.push(MemoryArea::new_identity(IO_REMAP_BASE, IO_REMAP_END, MemoryAttr::default().mmio(), "io_remap"));
 
     unsafe { ms.activate(); }
     use core::mem::forget;

kernel/src/arch/aarch64/paging.rs

@@ -12,7 +12,7 @@ use aarch64::paging::{FrameAllocator, FrameDeallocator, Page, PhysFrame as Frame
 use aarch64::paging::memory_attribute::*;
 
 // need 3 page
-pub fn setup_page_table(frame_lvl4: Frame, frame_lvl3: Frame, frame_lvl2: Frame) {
+pub fn setup_temp_page_table(frame_lvl4: Frame, frame_lvl3: Frame, frame_lvl2: Frame) {
     let p4 = unsafe { &mut *(frame_lvl4.start_address().as_u64() as *mut Aarch64PageTable) };
     let p3 = unsafe { &mut *(frame_lvl3.start_address().as_u64() as *mut Aarch64PageTable) };
     let p2 = unsafe { &mut *(frame_lvl2.start_address().as_u64() as *mut Aarch64PageTable) };
@@ -25,8 +25,8 @@ pub fn setup_page_table(frame_lvl4: Frame, frame_lvl3: Frame, frame_lvl2: Frame)
     for page in Page::<Size2MiB>::range_of(start_addr, end_addr) {
         let paddr = PhysAddr::new(page.start_address().as_u64());
 
-        use arch::board::IO_BASE;
-        if paddr.as_u64() >= IO_BASE as u64 {
+        use arch::board::IO_REMAP_BASE;
+        if paddr.as_u64() >= IO_REMAP_BASE as u64 {
             p2[page.p2_index()].set_block::<Size2MiB>(paddr, block_flags | EF::PXN, MairDevice::attr_value());
         } else {
             p2[page.p2_index()].set_block::<Size2MiB>(paddr, block_flags, MairNormal::attr_value());
@@ -39,54 +39,10 @@ pub fn setup_page_table(frame_lvl4: Frame, frame_lvl3: Frame, frame_lvl2: Frame)
     p4[0].set_frame(frame_lvl3, EF::default(), MairNormal::attr_value());
     p4[RECURSIVE_INDEX].set_frame(frame_lvl4, EF::default(), MairNormal::attr_value());
 
-    // warn!("p2");
-    // for i in 0..512 {
-    //     if p2[i].flags().bits() != 0 {
-    //         info!("{:x?} {:x?} {:x?}",i, &p2[i] as *const _ as usize, p2[i]);
-    //     }
-    // }
-    // warn!("p3");
-    // for i in 0..512 {
-    //     if p3[i].flags().bits() != 0 {
-    //         info!("{:x?} {:x?} {:x?}",i, &p3[i] as *const _ as usize, p3[i]);
-    //     }
-    // }
-    // warn!("p4");
-    // for i in 0..512 {
-    //     if p4[i].flags().bits() != 0 {
-    //         info!("{:x?} {:x?} {:x?}",i, &p4[i] as *const _ as usize, p4[i]);
-    //     }
-    // }
-
     ttbr_el1_write(0, frame_lvl4);
     tlb_invalidate_all();
 }
 
-/// map the range [start, end) as device memory, insert to the MemorySet
-pub fn remap_device_2mib(ms: &mut MemorySet<InactivePageTable0>, start_addr: usize, end_addr: usize) {
-    ms.edit(|active_table| {
-        for page in Page::<Size2MiB>::range_of(start_addr, end_addr) {
-            let paddr = PhysAddr::new(page.start_address().as_u64());
-            let p2 = unsafe { &mut *active_table.0.p2_ptr(page) };
-            p2[page.p2_index()].set_block::<Size2MiB>(paddr, EF::default() - EF::TABLE_OR_PAGE, MairDevice::attr_value());
-        }
-
-        // let p2 = unsafe { &mut *(0o777_777_000_000_0000 as *mut Aarch64PageTable) };
-        // for i in 0..512 {
-        //     if p2[i].flags().bits() != 0 {
-        //         info!("{:x?} {:x?} {:x?}",i, &p2[i] as *const _ as usize, p2[i]);
-        //     }
-        // }
-
-        // let p2 = unsafe { &mut *(0o777_777_000_001_0000 as *mut Aarch64PageTable) };
-        // for i in 0..512 {
-        //     if p2[i].flags().bits() != 0 {
-        //         info!("{:x?} {:x?} {:x?}",i, &p2[i] as *const _ as usize, p2[i]);
-        //     }
-        // }
-    });
-}
-
 pub struct ActivePageTable(RecursivePageTable<'static>);
 
 pub struct PageEntry(PageTableEntry);
@@ -201,6 +157,8 @@ impl Entry for PageEntry {
             false => self.as_flags().set(EF::PXN, !value),
         }
     }
+    fn mmio(&self) -> bool { self.0.attr().value == MairDevice::attr_value().value }
+    fn set_mmio(&mut self, value: bool) { self.0.modify_attr(MairDevice::attr_value()); }
 }
 
 impl PageEntry {

kernel/src/arch/riscv32/paging.rs

@@ -126,6 +126,8 @@ impl Entry for PageEntry {
     fn set_user(&mut self, value: bool) { self.as_flags().set(EF::USER, value); }
     fn execute(&self) -> bool { self.0.flags().contains(EF::EXECUTABLE) }
     fn set_execute(&mut self, value: bool) { self.as_flags().set(EF::EXECUTABLE, value); }
+    fn mmio(&self) -> bool { unimplemented!() }
+    fn set_mmio(&mut self, value: bool) { unimplemented!() }
 }
 
 impl PageEntry {

kernel/src/arch/x86_64/paging.rs

@@ -138,6 +138,8 @@ impl Entry for PageEntry {
     }
     fn execute(&self) -> bool { !self.0.flags().contains(EF::NO_EXECUTE) }
     fn set_execute(&mut self, value: bool) { self.as_flags().set(EF::NO_EXECUTE, !value); }
+    fn mmio(&self) -> bool { unimplemented!() }
+    fn set_mmio(&mut self, value: bool) { unimplemented!() }
 }
 
 impl PageEntry {
@@ -261,4 +263,4 @@ impl FrameDeallocator<Size4KiB> for FrameAllocatorForX86 {
     fn dealloc(&mut self, frame: Frame) {
         dealloc_frame(frame.start_address().as_u64() as usize);
     }
-}
+}