arch mem

kernel/rustkernel/src/arch/interrupt.rs

@@ -1,10 +1,13 @@
 //! Architecture-agnostic interrupt handling.
 
 #[cfg(target_arch = "riscv64")]
-pub use super::riscv::plic::plic_claim as handle_interrupt;
-#[cfg(target_arch = "riscv64")]
-pub use super::riscv::plic::plic_complete as complete_interrupt;
-#[cfg(target_arch = "riscv64")]
-pub use super::riscv::plic::plicinit as init;
-#[cfg(target_arch = "riscv64")]
-pub use super::riscv::plic::plicinithart as inithart;
+pub use super::riscv::{
+    asm::{
+        intr_get as interrupts_enabled, intr_off as disable_interrupts,
+        intr_on as enable_interrupts,
+    },
+    plic::{
+        plic_claim as handle_interrupt, plic_complete as complete_interrupt, plicinit as init,
+        plicinithart as inithart,
+    },
+};

kernel/rustkernel/src/arch/mem.rs

@@ -0,0 +1,19 @@
+//! Architecture-agnostic memory management.
+
+#[cfg(target_arch = "riscv64")]
+pub use super::riscv::{
+    asm::sfence_vma as flush_cached_pages,
+    mem::{
+        Pagetable, PagetableEntry, KERNEL_BASE, PAGE_SIZE, PHYSICAL_END, TRAMPOLINE, TRAPFRAME,
+        PTE_V, PTE_R, PTE_W, PTE_X, PTE_U,
+        VIRTUAL_MAX,
+    },
+};
+
+pub fn round_up_page(size: usize) -> usize {
+    (size + PAGE_SIZE - 1) & !(PAGE_SIZE - 1)
+}
+
+pub fn round_down_page(addr: usize) -> usize {
+    addr & !(PAGE_SIZE - 1)
+}

kernel/rustkernel/src/arch/mod.rs

@@ -1,6 +1,9 @@
 #[cfg(target_arch = "riscv64")]
 pub mod riscv;
+#[cfg(target_arch = "riscv64")]
+pub use riscv::hardware;
 
 pub mod cpu;
 pub mod interrupt;
+pub mod mem;
 pub mod power;

kernel/rustkernel/src/arch/riscv/asm.rs

@@ -245,7 +245,7 @@ pub unsafe fn r_ra() -> u64 {
     x
 }
 
-// Flush the TLB.
+// Flush the Translation Look-aside Buffer (TLB).
 #[inline(always)]
 pub unsafe fn sfence_vma() {
     // The "zero, zero" means flush all TLB entries.

kernel/rustkernel/src/arch/riscv/hardware.rs

@@ -0,0 +1,7 @@
+// QEMU puts UART registers here in physical memory.
+pub const UART0: usize = 0x10000000;
+pub const UART0_IRQ: usize = 10;
+
+// Virtio MMIO interface
+pub const VIRTIO0: usize = 0x10001000;
+pub const VIRTIO0_IRQ: usize = 1;

kernel/rustkernel/src/arch/riscv/mem.rs

@@ -0,0 +1,91 @@
+// Physical memory layout
+
+// QEMU -machine virt is setup like this,
+// based on QEMU's hw/riscv/virt.c
+//
+// 00001000 - boot ROM, provided by qemu
+// 02000000 - CLINT
+// 0C000000 - PLIC
+// 10000000 - uart0
+// 10001000 - virtio disk
+// 80000000 - boot ROM jumps here in machine mode (kernel loads the kernel here)
+// unused after 8000000
+
+// The kernel uses physical memory as so:
+// 80000000 - entry.S, then kernel text and data
+// end      - start of kernel page allocation data
+// PHYSTOP  - end of RAM used by the kernel
+
+pub type PagetableEntry = u64;
+pub type Pagetable = *mut [PagetableEntry; 512];
+
+/// The PagetableEntry is valid.
+pub const PTE_V: i32 = 1 << 0;
+/// The PagetableEntry is readable.
+pub const PTE_R: i32 = 1 << 1;
+/// The PagetableEntry is writable.
+pub const PTE_W: i32 = 1 << 2;
+/// The PagetableEntry is executable.
+pub const PTE_X: i32 = 1 << 3;
+/// The PagetableEntry is user-accessible.
+pub const PTE_U: i32 = 1 << 4;
+
+/// Page-based 39-bit virtual addressing.
+/// Details at section 5.4 of the RISC-V specification.
+pub const SATP_SV39: u64 = 8 << 60;
+
+pub fn make_satp(pagetable: Pagetable) -> u64 {
+    SATP_SV39 | (pagetable as usize as u64 >> 12)
+}
+
+/// Bytes per page.
+pub const PAGE_SIZE: usize = 4096;
+/// Bits of offset within a page
+const PAGE_OFFSET: usize = 12;
+/// The kernel starts here.
+pub const KERNEL_BASE: usize = 0x8000_0000;
+/// The end of physical memory.
+pub const PHYSICAL_END: usize = KERNEL_BASE + (128 * 1024 * 1024);
+/// The maximum virtual address.
+///
+/// VIRTUAL_MAX is actually one bit less than the max allowed by
+/// Sv39 to avoid having to sign-extend virtual addresses
+/// that have the high bit set.
+pub const VIRTUAL_MAX: usize = 1 << (9 + 9 + 9 + 12 - 1);
+/// Map the trampoline page to the highest
+/// address in both user and kernel space.
+pub const TRAMPOLINE: usize = VIRTUAL_MAX - PAGE_SIZE;
+/// Map kernel stacks beneath the trampoline,
+/// each surrounded by invalid guard pages.
+pub fn kstack(page: usize) -> usize {
+    TRAMPOLINE - (page + 1) * 2 * PAGE_SIZE
+}
+/// User memory layout.
+/// Address zero first:
+/// - text
+/// - original data and bss
+/// - fixed-size stack
+/// - expandable heap
+///   ...
+/// - TRAPFRAME (p->trapframe, used by the trampoline)
+/// - TRAMPOLINE (the same page as in the kernel)
+pub const TRAPFRAME: usize = TRAMPOLINE - PAGE_SIZE;
+
+// Convert a physical address to a PagetableEntry.
+pub fn pa2pte(pa: usize) -> usize {
+    (pa >> 12) << 10
+}
+// Convert a PagetableEntry to a physical address.
+pub fn pte2pa(pte: usize) -> usize {
+    (pte >> 10) << 12
+}
+
+// Extract the three 9-bit page table indices from a virtual address.
+const PXMASK: usize = 0x1ffusize; // 9 bits.
+
+fn pxshift(level: usize) -> usize {
+    PAGE_OFFSET + (level * 9)
+}
+pub fn px(level: usize, virtual_addr: usize) -> usize {
+    (virtual_addr >> pxshift(level)) & PXMASK
+}

kernel/rustkernel/src/arch/riscv/memlayout.rs

@@ -1,54 +0,0 @@
-// Physical memory layout
-
-// QEMU -machine virt is setup like this,
-// based on QEMU's hw/riscv/virt.c
-//
-// 00001000 - boot ROM, provided by qemu
-// 02000000 - CLINT
-// 0C000000 - PLIC
-// 10000000 - uart0
-// 10001000 - virtio disk
-// 80000000 - boot ROM jumps here in machine mode (kernel loads the kernel here)
-// unused after 8000000
-
-// The kernel uses physical memory as so:
-// 80000000 - entry.S, then kernel text and data
-// end      - start of kernel page allocation data
-// PHYSTOP  - end of RAM used by the kernel
-
-use super::{MAXVA, PGSIZE};
-
-// QEMU puts UART registers here in physical memory.
-pub const UART0: usize = 0x10000000;
-pub const UART0_IRQ: usize = 10;
-
-// Virtio MMIO interface
-pub const VIRTIO0: usize = 0x10001000;
-pub const VIRTIO0_IRQ: usize = 1;
-
-// The kernel expects there to be RAM
-// for use by the kernel and user pages
-// from physical address 0x80000000 to PHYSTOP.
-pub const KERNBASE: u64 = 0x80000000;
-pub const PHYSTOP: u64 = KERNBASE + 128 * 1024 * 1024;
-
-// Map the trampoline page to the highest address,
-// in both user and kernel space.
-pub const TRAMPOLINE: u64 = MAXVA - PGSIZE;
-
-// Map kernel stacks beneath the trampoline,
-// each surrounded by invalid guard pages.
-pub fn kstack(p: u64) -> u64 {
-    TRAMPOLINE - (p + 1) * 2 * PGSIZE
-}
-
-// User memory layout.
-// Address zero first:
-// - text
-// - original data and bss
-// - fixed-size stack
-// - expandable heap
-//   ...
-// - TRAPFRAME (p->trapframe, used by the trampoline)
-// - TRAMPOLINE (the same page as in the kernel)
-pub const TRAPFRAME: u64 = TRAMPOLINE - PGSIZE;

kernel/rustkernel/src/arch/riscv/mod.rs

@@ -1,17 +1,13 @@
 pub mod asm;
 pub mod clint;
 pub mod cpu;
-pub mod memlayout;
+pub mod mem;
+pub mod hardware;
 pub mod plic;
 pub mod power;
 pub mod start;
 
-pub use asm::*;
-pub use memlayout::*;
-
-pub type Pde = u64;
-pub type PagetableEntry = u64;
-pub type Pagetable = *mut [PagetableEntry; 512];
+pub use mem::make_satp;
 
 /// Previous mode
 pub const MSTATUS_MPP_MASK: u64 = 3 << 11;
@@ -45,70 +41,3 @@ pub const MIE_MEIE: u64 = 1 << 11;
 pub const MIE_MTIE: u64 = 1 << 7;
 /// Machine-mode Software Interrupt Enable
 pub const MIE_MSIE: u64 = 1 << 3;
-
-pub const SATP_SV39: u64 = 8 << 60;
-
-pub fn make_satp(pagetable: Pagetable) -> u64 {
-    SATP_SV39 | (pagetable as usize as u64 >> 12)
-}
-
-/// Bytes per page
-pub const PGSIZE: u64 = 4096;
-/// Bits of offset within a page
-pub const PGSHIFT: usize = 12;
-
-pub fn pg_round_up(sz: u64) -> u64 {
-    (sz + PGSIZE - 1) & !(PGSIZE - 1)
-}
-pub fn pg_round_down(a: u64) -> u64 {
-    a & !(PGSIZE - 1)
-}
-
-// Valid.
-pub const PTE_V: i32 = 1 << 0;
-pub const PTE_R: i32 = 1 << 1;
-pub const PTE_W: i32 = 1 << 2;
-pub const PTE_X: i32 = 1 << 3;
-// User can access.
-pub const PTE_U: i32 = 1 << 4;
-
-/*
-// shift a physical address to the right place for a PTE.
-#define PA2PTE(pa) ((((uint64)pa) >> 12) << 10)
-
-#define PTE2PA(pte) (((pte) >> 10) << 12)
-
-#define PTE_FLAGS(pte) ((pte) & 0x3FF)
-
-// extract the three 9-bit page table indices from a virtual address.
-#define PXMASK          0x1FF // 9 bits
-#define PXSHIFT(level)  (PGSHIFT+(9*(level)))
-#define PX(level, va) ((((uint64) (va)) >> PXSHIFT(level)) & PXMASK)
-*/
-
-/// Shift a physical address to the right place for a PTE.
-pub fn pa2pte(pa: usize) -> usize {
-    (pa >> 12) << 10
-}
-
-pub fn pte2pa(pte: usize) -> usize {
-    (pte >> 10) << 12
-}
-
-// Extract the three 9-bit page table indices from a virtual address.
-pub const PXMASK: usize = 0x1ffusize; // 9 bits.
-
-pub fn pxshift(level: usize) -> usize {
-    PGSHIFT + (level * 9)
-}
-
-pub fn px(level: usize, virtual_addr: usize) -> usize {
-    (virtual_addr >> pxshift(level)) & PXMASK
-}
-
-/// One beyond the highest possible virtual address.
-///
-/// MAXVA is actually one bit less than the max allowed by
-/// Sv39, to avoid having to sign-extend virtual addresses
-/// that have the high bit set.
-pub const MAXVA: u64 = 1u64 << (9 + 9 + 9 + 12 - 1);

kernel/rustkernel/src/arch/riscv/plic.rs

@@ -1,9 +1,7 @@
 //! The RISC-V Platform Level Interrupt Controller (PLIC)
 
-use crate::{
-    arch::riscv::{UART0_IRQ, VIRTIO0_IRQ},
-    proc::cpu::Cpu,
-};
+use super::hardware::{UART0_IRQ, VIRTIO0_IRQ};
+use crate::proc::cpu::Cpu;
 
 // QEMU puts platform-level interrupt controller (PLIC) here.
 pub const PLIC: usize = 0x0c000000;

kernel/rustkernel/src/console/uart.rs

@@ -25,7 +25,7 @@ const LSR_RX_READY: u8 = 1 << 0;
 /// THR can accept another character to send
 const LSR_TX_IDLE: u8 = 1 << 5;
 
-pub static UART0: Uart = Uart::new(crate::arch::riscv::memlayout::UART0);
+pub static UART0: Uart = Uart::new(crate::arch::hardware::UART0);
 
 enum Register {
     ReceiveHolding,

kernel/rustkernel/src/mem/kalloc.rs

@@ -3,7 +3,7 @@
 //! and pipe buffers. Allocates whole 4096-byte pages.
 
 use crate::{
-    arch::riscv::{memlayout::PHYSTOP, pg_round_up, PGSIZE},
+    arch::mem::{round_up_page, PAGE_SIZE, PHYSICAL_END},
     mem::memset,
     sync::spinlock::Spinlock,
 };
@@ -34,15 +34,15 @@ pub struct KernelMemory {
 
 pub unsafe fn kinit() {
     kmem.lock = Spinlock::new();
-    freerange(addr_of_mut!(end).cast(), PHYSTOP as *mut u8)
+    freerange(addr_of_mut!(end).cast(), PHYSICAL_END as *mut u8)
 }
 
 unsafe fn freerange(pa_start: *mut u8, pa_end: *mut u8) {
-    let mut p = pg_round_up(pa_start as usize as u64) as *mut u8;
+    let mut p = round_up_page(pa_start as usize) as *mut u8;
 
-    while p.add(PGSIZE as usize) <= pa_end {
+    while p.add(PAGE_SIZE) <= pa_end {
         kfree(p.cast());
-        p = p.add(PGSIZE as usize);
+        p = p.add(PAGE_SIZE);
     }
 }
 
@@ -52,14 +52,14 @@ unsafe fn freerange(pa_start: *mut u8, pa_end: *mut u8) {
 /// allocator - see kinit above.
 #[no_mangle]
 pub unsafe extern "C" fn kfree(pa: *mut u8) {
-    if (pa as usize as u64 % PGSIZE) != 0
+    if (pa as usize % PAGE_SIZE) != 0
         || pa <= addr_of_mut!(end) as *mut u8
-        || pa >= PHYSTOP as *mut u8
+        || pa >= PHYSICAL_END as *mut u8
     {
         panic!("kfree");
     }
 
-    memset(pa, 0, PGSIZE as u32);
+    memset(pa, 0, PAGE_SIZE as u32);
 
     let run: *mut Run = pa.cast();
 
@@ -82,7 +82,7 @@ pub unsafe extern "C" fn kalloc() -> *mut u8 {
     }
 
     if !run.is_null() {
-        memset(run.cast(), 0, PGSIZE as u32);
+        memset(run.cast(), 0, PAGE_SIZE as u32);
     }
 
     run as *mut u8

kernel/rustkernel/src/mem/virtual_memory.rs

@@ -1,11 +1,17 @@
 use crate::{
-    arch::riscv::{
+    arch::{
+        self,
+        hardware::{UART0, VIRTIO0},
+        mem::{
+            round_down_page, round_up_page, Pagetable, PagetableEntry, KERNEL_BASE, PAGE_SIZE,
+            PHYSICAL_END, TRAMPOLINE, VIRTUAL_MAX, PTE_R, PTE_U, PTE_V, PTE_W, PTE_X,
+        },
+        riscv::{
             asm, make_satp,
-        memlayout::{KERNBASE, PHYSTOP, TRAMPOLINE, UART0, VIRTIO0},
-        pg_round_down, pg_round_up,
             plic::PLIC,
             power::QEMU_POWER,
-        pte2pa, Pagetable, PagetableEntry, MAXVA, PGSIZE, PTE_R, PTE_U, PTE_V, PTE_W, PTE_X,
+            mem::pte2pa,
+        },
     },
     mem::{
         kalloc::{kalloc, kfree},
@@ -28,26 +34,32 @@ pub static mut KERNEL_PAGETABLE: Pagetable = null_mut();
 /// Make a direct-map page table for the kernel.
 pub unsafe fn kvmmake() -> Pagetable {
     let pagetable = kalloc() as Pagetable;
-    memset(pagetable.cast(), 0, PGSIZE as u32);
+    memset(pagetable.cast(), 0, PAGE_SIZE as u32);
 
     // QEMU test interface used for power management.
     kvmmap(
         pagetable,
         QEMU_POWER as u64,
         QEMU_POWER as u64,
-        PGSIZE,
+        PAGE_SIZE as u64,
         PTE_R | PTE_W,
     );
 
     // UART registers
-    kvmmap(pagetable, UART0 as u64, UART0 as u64, PGSIZE, PTE_R | PTE_W);
+    kvmmap(
+        pagetable,
+        UART0 as u64,
+        UART0 as u64,
+        PAGE_SIZE as u64,
+        PTE_R | PTE_W,
+    );
 
     // VirtIO MMIO disk interface
     kvmmap(
         pagetable,
         VIRTIO0 as u64,
         VIRTIO0 as u64,
-        PGSIZE,
+        PAGE_SIZE as u64,
         PTE_R | PTE_W,
     );
 
@@ -65,9 +77,9 @@ pub unsafe fn kvmmake() -> Pagetable {
     // Map kernel text executable and read-only.
     kvmmap(
         pagetable,
-        KERNBASE,
-        KERNBASE,
-        etext_addr - KERNBASE,
+        KERNEL_BASE as u64,
+        KERNEL_BASE as u64,
+        etext_addr - KERNEL_BASE as u64,
         PTE_R | PTE_X,
     );
 
@@ -76,7 +88,7 @@ pub unsafe fn kvmmake() -> Pagetable {
         pagetable,
         etext_addr,
         etext_addr,
-        PHYSTOP - etext_addr,
+        PHYSICAL_END as u64 - etext_addr,
         PTE_R | PTE_W,
     );
 
@@ -84,9 +96,9 @@ pub unsafe fn kvmmake() -> Pagetable {
     // the highest virtual address in the kernel.
     kvmmap(
         pagetable,
-        TRAMPOLINE,
+        TRAMPOLINE as u64,
         addr_of!(trampoline) as usize as u64,
-        PGSIZE,
+        PAGE_SIZE as u64,
         PTE_R | PTE_X,
     );
 
@@ -104,12 +116,12 @@ pub unsafe fn kvminit() {
 /// Switch hardware pagetable register to the kernel's pagetable and enable paging.
 pub unsafe fn kvminithart() {
     // Wait for any previous writes to the pagetable memory to finish.
-    asm::sfence_vma();
+    arch::mem::flush_cached_pages();
 
     asm::w_satp(make_satp(KERNEL_PAGETABLE));
 
     // Flush stale entries from the TLB.
-    asm::sfence_vma();
+    arch::mem::flush_cached_pages();
 }
 
 /// Return the address of the PTE in pagetable
@@ -127,7 +139,7 @@ pub unsafe fn kvminithart() {
 /// - 30..39: 9 bits of level 0 index.
 /// - 39..64: Must be zero.
 pub unsafe fn walk(mut pagetable: Pagetable, virtual_addr: u64, alloc: i32) -> *mut PagetableEntry {
-    if virtual_addr > MAXVA {
+    if virtual_addr > VIRTUAL_MAX as u64 {
         panic!("walk");
     }
 
@@ -150,7 +162,7 @@ pub unsafe fn walk(mut pagetable: Pagetable, virtual_addr: u64, alloc: i32) -> *
                 return null_mut();
             }
 
-            memset(pagetable.cast(), 0, PGSIZE as u32);
+            memset(pagetable.cast(), 0, PAGE_SIZE as u32);
             *pte = (((pagetable as usize) >> 12) << 10) as PagetableEntry | PTE_V as u64;
         }
 
@@ -165,7 +177,7 @@ pub unsafe fn walk(mut pagetable: Pagetable, virtual_addr: u64, alloc: i32) -> *
 /// Can only be used to look up user pages.
 #[no_mangle]
 pub unsafe extern "C" fn walkaddr(pagetable: Pagetable, virtual_addr: u64) -> u64 {
-    if virtual_addr > MAXVA {
+    if virtual_addr > VIRTUAL_MAX as u64 {
         return 0;
     }
 
@@ -211,8 +223,8 @@ pub unsafe extern "C" fn mappages(
         panic!("mappages: size = 0");
     }
 
-    let mut a = pg_round_down(virtual_addr);
-    let last = pg_round_down(virtual_addr + size - 1);
+    let mut a = round_down_page(virtual_addr as usize) as u64;
+    let last = round_down_page((virtual_addr + size - 1) as usize) as u64;
 
     loop {
         let pte = walk(pagetable, a, 1);
@@ -229,8 +241,8 @@ pub unsafe extern "C" fn mappages(
         if a == last {
             break;
         } else {
-            a += PGSIZE;
-            physical_addr += PGSIZE;
+            a += PAGE_SIZE as u64;
+            physical_addr += PAGE_SIZE as u64;
         }
     }
 
@@ -248,11 +260,11 @@ pub unsafe extern "C" fn uvmunmap(
     num_pages: u64,
     do_free: i32,
 ) {
-    if virtual_addr % PGSIZE != 0 {
+    if virtual_addr % PAGE_SIZE as u64 != 0 {
         panic!("uvmunmap: not aligned");
     }
     let mut a = virtual_addr;
-    while a < virtual_addr + num_pages * PGSIZE {
+    while a < virtual_addr + num_pages * PAGE_SIZE as u64 {
         let pte = walk(pagetable, a, 0);
         if pte.is_null() {
             panic!("uvmunmap: walk");
@@ -266,7 +278,7 @@ pub unsafe extern "C" fn uvmunmap(
         }
 
         *pte = 0;
-        a += PGSIZE;
+        a += PAGE_SIZE as u64;
     }
 }
 
@@ -279,25 +291,25 @@ pub unsafe extern "C" fn uvmcreate() -> Pagetable {
     if pagetable.is_null() {
         return null_mut();
     }
-    memset(pagetable.cast(), 0, PGSIZE as u32);
+    memset(pagetable.cast(), 0, PAGE_SIZE as u32);
     pagetable
 }
 
 /// Load the user initcode into address 0 of pagetable for the very first process.
 ///
-/// `size` must be less than `PGSIZE`.
+/// `size` must be less than `PAGE_SIZE`.
 #[no_mangle]
 pub unsafe extern "C" fn uvmfirst(pagetable: Pagetable, src: *mut u8, size: u32) {
-    if size >= PGSIZE as u32 {
+    if size >= PAGE_SIZE as u32 {
         panic!("uvmfirst: more than a page");
     }
 
     let mem = kalloc();
-    memset(mem, 0, PGSIZE as u32);
+    memset(mem, 0, PAGE_SIZE as u32);
     mappages(
         pagetable,
         0,
-        PGSIZE,
+        PAGE_SIZE as u64,
         mem as usize as u64,
         PTE_W | PTE_R | PTE_X | PTE_U,
     );
@@ -319,7 +331,7 @@ pub unsafe extern "C" fn uvmalloc(
         return old_size;
     }
 
-    old_size = pg_round_up(old_size);
+    old_size = round_up_page(old_size as usize) as u64;
     let mut a = old_size;
 
     while a < new_size {
@@ -329,12 +341,12 @@ pub unsafe extern "C" fn uvmalloc(
             return 0;
         }
 
-        memset(mem.cast(), 0, PGSIZE as u32);
+        memset(mem.cast(), 0, PAGE_SIZE as u64 as u32);
 
         if mappages(
             pagetable,
             a,
-            PGSIZE,
+            PAGE_SIZE as u64,
             mem as usize as u64,
             PTE_R | PTE_U | xperm,
         ) != 0
@@ -344,7 +356,7 @@ pub unsafe extern "C" fn uvmalloc(
             return 0;
         }
 
-        a += PGSIZE;
+        a += PAGE_SIZE as u64;
     }
 
     new_size
@@ -361,9 +373,15 @@ pub unsafe extern "C" fn uvmdealloc(pagetable: Pagetable, old_size: u64, new_siz
         return old_size;
     }
 
-    if pg_round_up(new_size) < pg_round_up(old_size) {
-        let num_pages = (pg_round_up(old_size) - pg_round_up(new_size)) / PGSIZE;
-        uvmunmap(pagetable, pg_round_up(new_size), num_pages, 1);
+    if round_up_page(new_size as usize) < round_up_page(old_size as usize) {
+        let num_pages =
+            (round_up_page(old_size as usize) - round_up_page(new_size as usize)) / PAGE_SIZE;
+        uvmunmap(
+            pagetable,
+            round_up_page(new_size as usize) as u64,
+            num_pages as u64,
+            1,
+        );
     }
 
     new_size
@@ -393,7 +411,12 @@ pub unsafe extern "C" fn freewalk(pagetable: Pagetable) {
 #[no_mangle]
 pub unsafe extern "C" fn uvmfree(pagetable: Pagetable, size: u64) {
     if size > 0 {
-        uvmunmap(pagetable, 0, pg_round_up(size) / PGSIZE, 1);
+        uvmunmap(
+            pagetable,
+            0,
+            (round_up_page(size as usize) / PAGE_SIZE) as u64,
+            1,
+        );
     }
     freewalk(pagetable);
 }
@@ -421,19 +444,23 @@ pub unsafe extern "C" fn uvmcopy(old: Pagetable, new: Pagetable, size: u64) -> i
 
         let mem = kalloc();
         if mem.is_null() {
-            uvmunmap(new, 0, i / PGSIZE, 1);
+            uvmunmap(new, 0, i / PAGE_SIZE as u64, 1);
             return -1;
         }
 
-        memmove(mem.cast(), (pa as usize as *mut u8).cast(), PGSIZE as u32);
+        memmove(
+            mem.cast(),
+            (pa as usize as *mut u8).cast(),
+            PAGE_SIZE as u64 as u32,
+        );
 
-        if mappages(new, i, PGSIZE, mem as usize as u64, flags as i32) != 0 {
+        if mappages(new, i, PAGE_SIZE as u64, mem as usize as u64, flags as i32) != 0 {
             kfree(mem.cast());
-            uvmunmap(new, 0, i / PGSIZE, 1);
+            uvmunmap(new, 0, i / PAGE_SIZE as u64, 1);
             return -1;
         }
 
-        i += PGSIZE;
+        i += PAGE_SIZE as u64;
     }
 
     0
@@ -463,13 +490,13 @@ pub unsafe extern "C" fn copyout(
     mut len: u64,
 ) -> i32 {
     while len > 0 {
-        let va0 = pg_round_down(dst_virtual_addr);
+        let va0 = round_down_page(dst_virtual_addr as usize) as u64;
         let pa0 = walkaddr(pagetable, va0);
         if pa0 == 0 {
             return -1;
         }
 
-        let mut n = PGSIZE - (dst_virtual_addr - va0);
+        let mut n = PAGE_SIZE as u64 - (dst_virtual_addr - va0);
         if n > len {
             n = len;
         }
@@ -481,7 +508,7 @@ pub unsafe extern "C" fn copyout(
 
         len -= n;
         src = src.add(n as usize);
-        dst_virtual_addr = va0 + PGSIZE;
+        dst_virtual_addr = va0 + PAGE_SIZE as u64;
     }
     0
 }
@@ -498,13 +525,13 @@ pub unsafe extern "C" fn copyin(
     mut len: u64,
 ) -> i32 {
     while len > 0 {
-        let va0 = pg_round_down(src_virtual_addr);
+        let va0 = round_down_page(src_virtual_addr as usize) as u64;
         let pa0 = walkaddr(pagetable, va0);
         if pa0 == 0 {
             return -1;
         }
 
-        let mut n = PGSIZE - (src_virtual_addr - va0);
+        let mut n = PAGE_SIZE as u64 - (src_virtual_addr - va0);
         if n > len {
             n = len;
         }
@@ -516,7 +543,7 @@ pub unsafe extern "C" fn copyin(
 
         len -= n;
         dst = dst.add(n as usize);
-        src_virtual_addr = va0 + PGSIZE;
+        src_virtual_addr = va0 + PAGE_SIZE as u64;
     }
     0
 }
@@ -535,13 +562,13 @@ pub unsafe fn copyinstr(
     let mut got_null = false;
 
     while !got_null && max > 0 {
-        let va0 = pg_round_down(src_virtual_addr);
+        let va0 = round_down_page(src_virtual_addr as usize) as u64;
         let pa0 = walkaddr(pagetable, va0);
         if pa0 == 0 {
             return -1;
         }
 
-        let mut n = PGSIZE - (src_virtual_addr - va0);
+        let mut n = PAGE_SIZE as u64 - (src_virtual_addr - va0);
         if n > max {
             n = max;
         }
@@ -562,7 +589,7 @@ pub unsafe fn copyinstr(
             dst = dst.add(1);
         }
 
-        src_virtual_addr = va0 + PGSIZE;
+        src_virtual_addr = va0 + PAGE_SIZE as u64;
     }
 
     if got_null {

kernel/rustkernel/src/proc/process.rs

@@ -7,9 +7,9 @@ use super::{
     trapframe::Trapframe,
 };
 use crate::{
-    arch::riscv::{
-        memlayout::{TRAMPOLINE, TRAPFRAME},
-        Pagetable, PGSIZE, PTE_R, PTE_W, PTE_X,
+    arch::{
+        mem::{Pagetable, PAGE_SIZE, TRAMPOLINE, TRAPFRAME,
+        PTE_R, PTE_W, PTE_X},
     },
     fs::{
         file::{fileclose, filedup, File, Inode},
@@ -197,7 +197,7 @@ impl Process {
             core::mem::size_of::<Context>() as u32,
         );
         p.context.ra = forkret as usize as u64;
-        p.context.sp = p.kernel_stack + PGSIZE;
+        p.context.sp = p.kernel_stack + PAGE_SIZE as u64;
 
         Ok(p)
     }
@@ -260,8 +260,8 @@ impl Process {
         // to and from user space, so not PTE_U.
         if mappages(
             pagetable,
-            TRAMPOLINE,
-            PGSIZE,
+            TRAMPOLINE as u64,
+            PAGE_SIZE as u64,
             addr_of!(trampoline) as usize as u64,
             PTE_R | PTE_X,
         ) < 0
@@ -273,13 +273,13 @@ impl Process {
         // Map the trapframe page just below the trampoline page for trampoline.S.
         if mappages(
             pagetable,
-            TRAPFRAME,
-            PGSIZE,
+            TRAPFRAME as u64,
+            PAGE_SIZE as u64,
             self.trapframe as usize as u64,
             PTE_R | PTE_W,
         ) < 0
         {
-            uvmunmap(pagetable, TRAMPOLINE, 1, 0);
+            uvmunmap(pagetable, TRAMPOLINE as u64, 1, 0);
             uvmfree(pagetable, 0);
             return Err(ProcessError::Allocation);
         }
@@ -288,8 +288,8 @@ impl Process {
     }
     /// Free a process's pagetable and free the physical memory it refers to.
     pub unsafe fn free_pagetable(pagetable: Pagetable, size: usize) {
-        uvmunmap(pagetable, TRAMPOLINE, 1, 0);
-        uvmunmap(pagetable, TRAPFRAME, 1, 0);
+        uvmunmap(pagetable, TRAMPOLINE as u64, 1, 0);
+        uvmunmap(pagetable, TRAPFRAME as u64, 1, 0);
         uvmfree(pagetable, size as u64)
     }
 

kernel/rustkernel/src/proc/scheduler.rs

@@ -4,7 +4,7 @@ use super::{
     process::{proc, Process, ProcessState},
 };
 use crate::{
-    arch::riscv::{intr_get, intr_on},
+    arch,
     sync::spinlock::{Spinlock, SpinlockGuard},
 };
 use core::{
@@ -39,7 +39,7 @@ pub unsafe fn scheduler() -> ! {
 
     loop {
         // Avoid deadlock by ensuring that devices can interrupt.
-        intr_on();
+        arch::interrupt::enable_interrupts();
 
         for p in &mut proc {
             let _guard = p.lock.lock();
@@ -76,7 +76,7 @@ pub unsafe fn sched() {
         panic!("sched locks");
     } else if p.state == ProcessState::Running {
         panic!("sched running");
-    } else if intr_get() > 0 {
+    } else if arch::interrupt::interrupts_enabled() > 0 {
         panic!("sched interruptible");
     }
 

kernel/rustkernel/src/trap.rs

@@ -1,5 +1,10 @@
 use crate::{
-    arch::{self, riscv::*},
+    arch::{
+        self,
+        mem::{PAGE_SIZE, TRAMPOLINE},
+        hardware::{UART0_IRQ, VIRTIO0_IRQ},
+        riscv::{asm, SSTATUS_SPP, SSTATUS_SPIE, mem::make_satp},
+    },
     println,
     proc::{
         cpu::Cpu,
@@ -27,7 +32,7 @@ pub static CLOCK_TICKS: Mutex<usize> = Mutex::new(0);
 
 /// Set up to take exceptions and traps while in the kernel.
 pub unsafe fn trapinithart() {
-    w_stvec(kernelvec as usize as u64);
+    asm::w_stvec(kernelvec as usize as u64);
 }
 
 pub fn clockintr() {
@@ -43,7 +48,7 @@ pub fn clockintr() {
 ///
 /// Returns 2 if timer interrupt, 1 if other device, 0 if not recognized.
 pub unsafe fn devintr() -> i32 {
-    let scause = r_scause();
+    let scause = asm::r_scause();
 
     if (scause & 0x8000000000000000 > 0) && (scause & 0xff) == 9 {
         // This is a supervisor external interrupt, via PLIC.
@@ -77,7 +82,7 @@ pub unsafe fn devintr() -> i32 {
 
         // Acknowledge the software interrupt by
         // clearing the SSIP bit in sip.
-        w_sip(r_sip() & !2);
+        asm::w_sip(asm::r_sip() & !2);
 
         2
     } else {
@@ -90,10 +95,10 @@ pub struct InterruptBlocker;
 impl InterruptBlocker {
     pub fn new() -> InterruptBlocker {
         unsafe {
-            let interrupts_before = intr_get();
+            let interrupts_before = arch::interrupt::interrupts_enabled();
             let cpu = Cpu::current();
 
-            intr_off();
+            arch::interrupt::disable_interrupts();
 
             if cpu.interrupt_disable_layers == 0 {
                 cpu.previous_interrupts_enabled = interrupts_before;
@@ -109,7 +114,7 @@ impl core::ops::Drop for InterruptBlocker {
         unsafe {
             let cpu = Cpu::current();
 
-            if intr_get() == 1 || cpu.interrupt_disable_layers < 1 {
+            if arch::interrupt::interrupts_enabled() == 1 || cpu.interrupt_disable_layers < 1 {
                 // panic!("pop_off mismatched");
                 return;
             }
@@ -117,7 +122,7 @@ impl core::ops::Drop for InterruptBlocker {
             cpu.interrupt_disable_layers -= 1;
 
             if cpu.interrupt_disable_layers == 0 && cpu.previous_interrupts_enabled == 1 {
-                intr_on();
+                arch::interrupt::enable_interrupts();
             }
             // crate::sync::spinlock::pop_off();
         }
@@ -133,36 +138,36 @@ pub unsafe extern "C" fn usertrapret() {
     // We're about to switch the destination of traps from
     // kerneltrap() to usertrap(), so turn off interrupts until
     // we're back in user space, where usertrap() is correct.
-    intr_off();
+    arch::interrupt::disable_interrupts();
 
     // Send syscalls, interrupts, and exceptions to uservec in trampoline.S
     let trampoline_uservec =
-        TRAMPOLINE + (addr_of!(uservec) as usize as u64) - (addr_of!(trampoline) as usize as u64);
-    w_stvec(trampoline_uservec);
+        TRAMPOLINE + (addr_of!(uservec) as usize) - (addr_of!(trampoline) as usize);
+    asm::w_stvec(trampoline_uservec as u64);
 
     // Set up trapframe values that uservec will need when
     // the process next traps into the kernel.
     // kernel page table
-    (*proc.trapframe).kernel_satp = r_satp();
+    (*proc.trapframe).kernel_satp = asm::r_satp();
     // process's kernel stack
-    (*proc.trapframe).kernel_sp = proc.kernel_stack + PGSIZE;
+    (*proc.trapframe).kernel_sp = proc.kernel_stack + PAGE_SIZE as u64;
     (*proc.trapframe).kernel_trap = usertrap as usize as u64;
     // hartid for Cpu::current_id()
-    (*proc.trapframe).kernel_hartid = r_tp();
+    (*proc.trapframe).kernel_hartid = asm::r_tp();
 
     // Set up the registers that trampoline.S's
     // sret will use to get to user space.
 
     // Set S Previous Privelege mode to User.
-    let mut x = r_sstatus();
+    let mut x = asm::r_sstatus();
     // Clear SPP to 0 for user mode.
     x &= !SSTATUS_SPP;
     // Enable interrupts in user mode.
     x |= SSTATUS_SPIE;
-    w_sstatus(x);
+    asm::w_sstatus(x);
 
     // Set S Exception Program Counter to the saved user pc.
-    w_sepc((*proc.trapframe).epc);
+    asm::w_sepc((*proc.trapframe).epc);
 
     // Tell trampoline.S the user page table to switch to.
     let satp = make_satp(proc.pagetable);
@@ -170,8 +175,8 @@ pub unsafe extern "C" fn usertrapret() {
     // Jump to userret in trampoline.S at the top of memory, which
     // switches to the user page table, restores user registers,
     // and switches to user mode with sret.
-    let trampoline_userret = (TRAMPOLINE + (addr_of!(userret) as usize as u64)
-        - (addr_of!(trampoline) as usize as u64)) as usize;
+    let trampoline_userret =
+        TRAMPOLINE + (addr_of!(userret) as usize) - (addr_of!(trampoline) as usize);
     let trampoline_userret = trampoline_userret as *const ();
     // Rust's most dangerous function: core::mem::transmute
     let trampoline_userret = core::mem::transmute::<*const (), fn(u64)>(trampoline_userret);
@@ -182,19 +187,19 @@ pub unsafe extern "C" fn usertrapret() {
 /// on whatever the current kernel stack is.
 #[no_mangle]
 pub unsafe extern "C" fn kerneltrap() {
-    let sepc = r_sepc();
-    let sstatus = r_sstatus();
-    let scause = r_scause();
+    let sepc = asm::r_sepc();
+    let sstatus = asm::r_sstatus();
+    let scause = asm::r_scause();
 
     if sstatus & SSTATUS_SPP == 0 {
         panic!("kerneltrap: not from supervisor mode");
-    } else if intr_get() != 0 {
+    } else if arch::interrupt::interrupts_enabled() != 0 {
         panic!("kerneltrap: interrupts enabled");
     }
 
     let which_dev = devintr();
     if which_dev == 0 {
-        println!("scause {}\nsepc={} stval={}", scause, r_sepc(), r_stval());
+        println!("scause {}\nsepc={} stval={}", scause, asm::r_sepc(), asm::r_stval());
         panic!("kerneltrap");
     } else if which_dev == 2
         && Process::current().is_some()
@@ -206,8 +211,8 @@ pub unsafe extern "C" fn kerneltrap() {
 
     // The yield() may have caused some traps to occur,
     // so restore trap registers for use by kernelvec.S's sepc instruction.
-    w_sepc(sepc);
-    w_sstatus(sstatus);
+    asm::w_sepc(sepc);
+    asm::w_sstatus(sstatus);
 }
 
 /// Handle an interrupt, exception, or system call from userspace.
@@ -215,20 +220,20 @@ pub unsafe extern "C" fn kerneltrap() {
 /// Called from trampoline.S
 #[no_mangle]
 pub unsafe extern "C" fn usertrap() {
-    if r_sstatus() & SSTATUS_SPP != 0 {
+    if asm::r_sstatus() & SSTATUS_SPP != 0 {
         panic!("usertrap: not from user mode");
     }
 
     // Send interrupts and exceptions to kerneltrap(),
     // since we're now in the kernel.
-    w_stvec(kernelvec as usize as u64);
+    asm::w_stvec(kernelvec as usize as u64);
 
     let proc = Process::current().unwrap();
 
     // Save user program counter.
-    (*proc.trapframe).epc = r_sepc();
+    (*proc.trapframe).epc = asm::r_sepc();
 
-    if r_scause() == 8 {
+    if asm::r_scause() == 8 {
         // System call
 
         if proc.is_killed() {
@@ -241,19 +246,19 @@ pub unsafe extern "C" fn usertrap() {
 
         // An interrupt will change sepc, scause, and sstatus,
         // so enable only now that we're done with those registers.
-        intr_on();
+        arch::interrupt::enable_interrupts();
 
         syscall();
     }
 
     let which_dev = devintr();
-    if r_scause() != 8 && which_dev == 0 {
+    if asm::r_scause() != 8 && which_dev == 0 {
         println!(
             "usertrap(): unexpected scause {} {}\n\tsepc={} stval={}",
-            r_scause(),
+            asm::r_scause(),
             proc.pid,
-            r_sepc(),
-            r_stval()
+            asm::r_sepc(),
+            asm::r_stval()
         );
         proc.set_killed(true);
     }
@@ -275,10 +280,10 @@ pub unsafe extern "C" fn usertrap() {
 // are initially off, then push_intr_off, pop_intr_off leaves them off.
 
 pub unsafe fn push_intr_off() {
-    let old = intr_get();
+    let old = arch::interrupt::interrupts_enabled();
     let cpu = Cpu::current();
 
-    intr_off();
+    arch::interrupt::disable_interrupts();
     if cpu.interrupt_disable_layers == 0 {
         cpu.previous_interrupts_enabled = old;
     }
@@ -287,7 +292,7 @@ pub unsafe fn push_intr_off() {
 pub unsafe fn pop_intr_off() {
     let cpu = Cpu::current();
 
-    if intr_get() == 1 {
+    if arch::interrupt::interrupts_enabled() == 1 {
         // crate::panic_byte(b'0');
         panic!("pop_intr_off - interruptible");
     } else if cpu.interrupt_disable_layers < 1 {
@@ -298,6 +303,6 @@ pub unsafe fn pop_intr_off() {
     cpu.interrupt_disable_layers -= 1;
 
     if cpu.interrupt_disable_layers == 0 && cpu.previous_interrupts_enabled == 1 {
-        intr_on();
+        arch::interrupt::enable_interrupts();
     }
 }