From 1e12ccddb38ef9d2ed57659d897b5225b237dd90 Mon Sep 17 00:00:00 2001
From: Garen Tyler <garentyler@garen.dev>
Date: Thu, 9 Nov 2023 18:56:39 -0700
Subject: [PATCH] arch power

---
 kernel/rustkernel/src/arch/mod.rs             |  1 +
 kernel/rustkernel/src/arch/power.rs           |  4 ++++
 kernel/rustkernel/src/arch/riscv/memlayout.rs |  3 ---
 kernel/rustkernel/src/arch/riscv/mod.rs       |  1 +
 kernel/rustkernel/src/arch/riscv/power.rs     |  8 ++++++++
 kernel/rustkernel/src/mem/virtual_memory.rs   | 11 +++++++++--
 kernel/rustkernel/src/syscall.rs              |  8 ++------
 7 files changed, 25 insertions(+), 11 deletions(-)
 create mode 100644 kernel/rustkernel/src/arch/power.rs
 create mode 100644 kernel/rustkernel/src/arch/riscv/power.rs

diff --git a/kernel/rustkernel/src/arch/mod.rs b/kernel/rustkernel/src/arch/mod.rs
index 632c9a7..862ad7a 100644
--- a/kernel/rustkernel/src/arch/mod.rs
+++ b/kernel/rustkernel/src/arch/mod.rs
@@ -2,3 +2,4 @@
 pub mod riscv;
 
 pub mod interrupt;
+pub mod power;
diff --git a/kernel/rustkernel/src/arch/power.rs b/kernel/rustkernel/src/arch/power.rs
new file mode 100644
index 0000000..a4eeaef
--- /dev/null
+++ b/kernel/rustkernel/src/arch/power.rs
@@ -0,0 +1,4 @@
+//! Architecture-agnostic power handling.
+
+#[cfg(target_arch = "riscv64")]
+pub use super::riscv::power::shutdown;
diff --git a/kernel/rustkernel/src/arch/riscv/memlayout.rs b/kernel/rustkernel/src/arch/riscv/memlayout.rs
index 64901fb..8758457 100644
--- a/kernel/rustkernel/src/arch/riscv/memlayout.rs
+++ b/kernel/rustkernel/src/arch/riscv/memlayout.rs
@@ -18,9 +18,6 @@
 
 use super::{MAXVA, PGSIZE};
 
-// QEMU test interface. Used for power off and on.
-pub const QEMU_POWER: u64 = 0x100000u64;
-
 // QEMU puts UART registers here in physical memory.
 pub const UART0: usize = 0x10000000;
 pub const UART0_IRQ: usize = 10;
diff --git a/kernel/rustkernel/src/arch/riscv/mod.rs b/kernel/rustkernel/src/arch/riscv/mod.rs
index c982135..d5866eb 100644
--- a/kernel/rustkernel/src/arch/riscv/mod.rs
+++ b/kernel/rustkernel/src/arch/riscv/mod.rs
@@ -2,6 +2,7 @@ pub mod asm;
 pub mod clint;
 pub mod memlayout;
 pub mod plic;
+pub mod power;
 pub mod start;
 
 pub use asm::*;
diff --git a/kernel/rustkernel/src/arch/riscv/power.rs b/kernel/rustkernel/src/arch/riscv/power.rs
new file mode 100644
index 0000000..116a141
--- /dev/null
+++ b/kernel/rustkernel/src/arch/riscv/power.rs
@@ -0,0 +1,8 @@
+/// QEMU test interface. Used for power off and on.
+pub const QEMU_POWER: usize = 0x100000;
+
+pub unsafe fn shutdown() -> ! {
+    let qemu_power = QEMU_POWER as *mut u32;
+    qemu_power.write_volatile(0x5555u32);
+    unreachable!();
+}
diff --git a/kernel/rustkernel/src/mem/virtual_memory.rs b/kernel/rustkernel/src/mem/virtual_memory.rs
index 18450ec..255d71b 100644
--- a/kernel/rustkernel/src/mem/virtual_memory.rs
+++ b/kernel/rustkernel/src/mem/virtual_memory.rs
@@ -1,9 +1,10 @@
 use crate::{
     arch::riscv::{
         asm, make_satp,
-        memlayout::{KERNBASE, PHYSTOP, QEMU_POWER, TRAMPOLINE, UART0, VIRTIO0},
+        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::{
@@ -30,7 +31,13 @@ pub unsafe fn kvmmake() -> Pagetable {
     memset(pagetable.cast(), 0, PGSIZE as u32);
 
     // QEMU test interface used for power management.
-    kvmmap(pagetable, QEMU_POWER, QEMU_POWER, PGSIZE, PTE_R | PTE_W);
+    kvmmap(
+        pagetable,
+        QEMU_POWER as u64,
+        QEMU_POWER as u64,
+        PGSIZE,
+        PTE_R | PTE_W,
+    );
 
     // UART registers
     kvmmap(pagetable, UART0 as u64, UART0 as u64, PGSIZE, PTE_R | PTE_W);
diff --git a/kernel/rustkernel/src/syscall.rs b/kernel/rustkernel/src/syscall.rs
index 73a313f..ecae1de 100644
--- a/kernel/rustkernel/src/syscall.rs
+++ b/kernel/rustkernel/src/syscall.rs
@@ -1,5 +1,5 @@
 use crate::{
-    arch::riscv::memlayout::QEMU_POWER,
+    arch::power::shutdown,
     fs::{
         self,
         file::{self, File},
@@ -200,11 +200,7 @@ impl Syscall {
                     -1i64 as u64
                 }
             }
-            Syscall::Shutdown => {
-                let qemu_power = QEMU_POWER as usize as *mut u32;
-                qemu_power.write_volatile(0x5555u32);
-                panic!("shutdown");
-            }
+            Syscall::Shutdown => unsafe { shutdown() },
         }
     }
 }