From ea6f485bd905a155ee801044cb8e0e6a129d40c0 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Fri, 24 Feb 2023 21:15:33 -0500
Subject: [PATCH] Add hulk.util and round_up_power_2()

---
 src/hulk/hurl/a1.d   |  8 +++++---
 src/hulk/hurl/hurl.d |  2 +-
 src/hulk/util.d      | 17 +++++++++++++++++
 3 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 src/hulk/util.d

diff --git a/src/hulk/hurl/a1.d b/src/hulk/hurl/a1.d
index bb9861c..df1d786 100644
--- a/src/hulk/hurl/a1.d
+++ b/src/hulk/hurl/a1.d
@@ -5,6 +5,8 @@ module hulk.hurl.a1;
 
 import hulk.hurl;
 import hulk.hippo;
+import hulk.util;
+import hulk.pagetable;
 
 /**
  * The A1 memory allocator is a one-shot memory allocator for kernel memory
@@ -29,15 +31,15 @@ struct A1
     public static void * allocate(size_t size)
     {
         /* Round size up to a multiple of 16. */
-        size = (size + 0xFu) & ~0xFu;
+        size = round_up_power_2(size, 16u);
 
         ulong address = Hurl.A1_BASE + allocated;
 
-        ulong mapped_limit = (address + 0xFFFu) & ~0xFFFu;
+        ulong mapped_limit = round_up_power_2(address, PAGE_SIZE);
 
         allocated += size;
 
-        ulong desired_limit = (Hurl.A1_BASE + allocated + 0xFFFu) & ~0xFFFu;
+        ulong desired_limit = round_up_power_2(Hurl.A1_BASE + allocated, PAGE_SIZE);
 
         while (desired_limit > mapped_limit)
         {
diff --git a/src/hulk/hurl/hurl.d b/src/hulk/hurl/hurl.d
index 83ffae7..f78c51d 100644
--- a/src/hulk/hurl/hurl.d
+++ b/src/hulk/hurl/hurl.d
@@ -155,7 +155,7 @@ struct Hurl
          */
         size_t usable_memory;
         size_t physical_address_limit;
-        const(size_t) fb_size = (header.bootinfo.fb.height * header.bootinfo.fb.stride * 4u + PAGE_SIZE - 1u) & ~(PAGE_SIZE - 1u);
+        const(size_t) fb_size = round_up_power_2(header.bootinfo.fb.height * header.bootinfo.fb.stride * 4u, PAGE_SIZE);
         ulong[2][2] reserved = [
             [header.bootinfo.hulk_phys, LinkerAddresses.hulk_binary_size],
             [cast(ulong)header.bootinfo.fb.buffer, fb_size],
diff --git a/src/hulk/util.d b/src/hulk/util.d
new file mode 100644
index 0000000..f575912
--- /dev/null
+++ b/src/hulk/util.d
@@ -0,0 +1,17 @@
+/**
+ * HULK utility functions.
+ */
+module hulk.util;
+
+/**
+ * Round a value up to the next power of 2.
+ *
+ * @param v Value to round up.
+ * @param p Power of 2 to round up to.
+ *
+ * @return Rounded up value.
+ */
+T round_up_power_2(T)(T v, T p)
+{
+    return (v + p - 1u) & ~(p - 1u);
+}