feat(pl/ke): initial amd64 support

2026-10-30 23:08:21 +00:00 · 2026-03-28 19:14:17 +01:00
parent 2e82a695e1
commit c6e63ed2bf
18 changed files with 279 additions and 87 deletions
@@ -0,0 +1,148 @@
+const b = @import("base");
+const ke = b.ke;
+
+const std = @import("std");
+
+pub const Cpu = struct {
+    self_ptr: *Cpu,
+    percpu_offset: usize,
+};
+
+pub const ThreadContext = struct {
+    rdi: u64,
+    rsi: u64,
+    rbx: u64,
+    rsp: u64,
+    rbp: u64,
+    r12: u64,
+    r13: u64,
+    r14: u64,
+    r15: u64,
+
+    fn thread_trampoline(entry: usize, arg: usize) callconv(.c) void {
+        const entry_fn: *const fn (?*anyopaque) void = @ptrFromInt(entry);
+        entry_fn(@ptrFromInt(arg));
+        // TODO: This shouldn't be reached!!!
+    }
+
+    pub fn init(stack: b.VAddr, stack_size: usize, entry: *const fn (?*anyopaque) void, arg: ?*anyopaque) @This() {
+        var ctx: @This() = undefined;
+        ctx.rdi = @intFromPtr(entry);
+        ctx.rsi = @intFromPtr(arg);
+
+        var sp = stack + stack_size;
+        {
+            sp -= @sizeOf(usize);
+            @as(*usize, @ptrFromInt(sp)).* = 0;
+
+            sp -= @sizeOf(usize);
+            @as(*usize, @ptrFromInt(sp)).* = @intFromPtr(&thread_trampoline);
+        }
+        ctx.rsp = sp;
+
+        return ctx;
+    }
+
+    export fn do_switch_to() callconv(.naked) void {
+        const asm_template = std.fmt.comptimePrint(
+            \\movq %%rbx, {d}(%%rdi)
+            \\movq %%rsp, {d}(%%rdi)
+            \\movq %%rbp, {d}(%%rdi)
+            \\movq %%r12, {d}(%%rdi)
+            \\movq %%r13, {d}(%%rdi)
+            \\movq %%r14, {d}(%%rdi)
+            \\movq %%r15, {d}(%%rdi)
+            \\
+            \\movq {d}(%%rsi), %%rbx
+            \\movq {d}(%%rsi), %%rsp
+            \\movq {d}(%%rsi), %%rbp
+            \\movq {d}(%%rsi), %%r12
+            \\movq {d}(%%rsi), %%r13
+            \\movq {d}(%%rsi), %%r14
+            \\movq {d}(%%rsi), %%r15
+            \\movq {d}(%%rsi), %%rdi
+            \\movq {d}(%%rsi), %%rsi
+            \\
+            \\ret
+        , .{
+            @offsetOf(ThreadContext, "rbx"),
+            @offsetOf(ThreadContext, "rsp"),
+            @offsetOf(ThreadContext, "rbp"),
+            @offsetOf(ThreadContext, "r12"),
+            @offsetOf(ThreadContext, "r13"),
+            @offsetOf(ThreadContext, "r14"),
+            @offsetOf(ThreadContext, "r15"),
+
+            @offsetOf(ThreadContext, "rbx"),
+            @offsetOf(ThreadContext, "rsp"),
+            @offsetOf(ThreadContext, "rbp"),
+            @offsetOf(ThreadContext, "r12"),
+            @offsetOf(ThreadContext, "r13"),
+            @offsetOf(ThreadContext, "r14"),
+            @offsetOf(ThreadContext, "r15"),
+            @offsetOf(ThreadContext, "rdi"),
+            @offsetOf(ThreadContext, "rsi"),
+        });
+
+        asm volatile (asm_template);
+    }
+
+    pub fn switch_to(self: *ThreadContext, new: *ThreadContext) callconv(.c) void {
+        asm volatile (
+            \\call do_switch_to
+            :
+            : [_] "{rdi}" (self),
+              [_] "{rsi}" (new),
+        );
+    }
+};
+
+pub fn curcpu() *ke.Cpu {
+    const asm_template = std.fmt.comptimePrint("movq %%gs:{d}, %[ret]", .{@offsetOf(Cpu, "self_ptr")});
+    const impl_cpu = asm volatile (asm_template
+        : [ret] "=r" (-> *Cpu),
+    );
+
+    return @fieldParentPtr("impl", impl_cpu);
+}
+
+inline fn percpu_ptr_for(variable: anytype, cpu: *ke.Cpu) @TypeOf(variable) {
+    return @ptrFromInt(@intFromPtr(variable) +% cpu.impl.percpu_offset);
+}
+
+pub inline fn percpu_ptr_other(variable: anytype, id: usize) @TypeOf(variable) {
+    return percpu_ptr_for(variable, ke.cpus[id]);
+}
+
+pub inline fn percpu_ptr(variable: anytype) @TypeOf(variable) {
+    return percpu_ptr_for(variable, curcpu());
+}
+
+pub inline fn set_hardware_ipl(_: ke.Ipl) void {}
+
+pub inline fn enable_interrupts() void {
+    asm volatile ("sti");
+}
+
+pub inline fn disable_interrupts() bool {
+    const rflags = asm volatile (
+        \\cli
+        \\pushfq
+        \\popq %[rflags]
+        : [rflags] "=r" (-> usize),
+    );
+
+    return rflags & (1 << 9) != 0;
+}
+
+pub inline fn restore_interrupts(state: bool) void {
+    if (state) {
+        enable_interrupts();
+    } else {
+        _ = disable_interrupts();
+    }
+}
+
+pub inline fn send_resched_ipi(_: *ke.Cpu) void {
+    @panic("TODO send_resched_ipi");
+}