Implements uk_ppera calculation (#1248)

kernel/src/config/aarch64.rs

@@ -1,3 +1 @@
-use core::num::NonZero;
-
-pub const PAGE_SIZE: NonZero<usize> = unsafe { NonZero::new_unchecked(0x4000) };
+pub const PAGE_SHIFT: usize = 14; // 16K

kernel/src/config/mod.rs

@@ -1,10 +1,14 @@
 pub use self::arch::*;
 
+use core::num::NonZero;
 use macros::elf_note;
 
 #[cfg_attr(target_arch = "aarch64", path = "aarch64.rs")]
 #[cfg_attr(target_arch = "x86_64", path = "x86_64.rs")]
 mod arch;
 
+pub const PAGE_SIZE: NonZero<usize> = NonZero::new(1 << PAGE_SHIFT).unwrap();
+pub const PAGE_MASK: NonZero<usize> = NonZero::new(PAGE_SIZE.get() - 1).unwrap();
+
 #[elf_note(section = ".note.obkrnl.page-size", name = "obkrnl", ty = 0)]
 static NOTE_PAGE_SIZE: [u8; size_of::<usize>()] = PAGE_SIZE.get().to_ne_bytes();

kernel/src/config/x86_64.rs

@@ -1,3 +1 @@
-use core::num::NonZero;
-
-pub const PAGE_SIZE: NonZero<usize> = unsafe { NonZero::new_unchecked(0x1000) };
+pub const PAGE_SHIFT: usize = 12; // 4K

kernel/src/uma/keg.rs

@@ -1,10 +1,10 @@
 use super::slab::RcFree;
 use super::UmaFlags;
-use crate::config::PAGE_SIZE;
+use crate::config::{PAGE_MASK, PAGE_SHIFT, PAGE_SIZE};
 use crate::uma::slab::{Free, SlabHdr};
 use crate::uma::Uma;
 use core::alloc::Layout;
-use core::cmp::max;
+use core::cmp::{max, min};
 use core::num::NonZero;
 
 /// Implementation of `uma_keg` structure.
@@ -30,8 +30,28 @@ impl UmaKeg {
             flags |= UmaFlags::VToSlab;
         }
 
-        if flags.has(UmaFlags::CacheSpread) {
-            todo!()
+        // Get uk_ppera.
+        let ppera = if flags.has(UmaFlags::CacheSpread) {
+            // Round size.
+            let size = if (size.get() & align) == 0 {
+                size.get()
+            } else {
+                (size.get() & !align) + align + 1
+            };
+
+            // Get uk_rsize.
+            let align = align + 1;
+            let rsize = if (size & align) == 0 {
+                // TODO: What is this?
+                size + align
+            } else {
+                size
+            };
+
+            // Get uk_ppera.
+            let pages = (PAGE_SIZE.get() / align * rsize) >> PAGE_SHIFT;
+
+            min(pages, (128 * 1024) / PAGE_SIZE)
         } else {
             // Check if item size exceed slab size.
             let min = Layout::new::<SlabHdr>();
@@ -57,6 +77,15 @@ impl UmaKeg {
                         flags |= UmaFlags::Hash;
                     }
                 }
+
+                // Get uk_ppera.
+                let mut ppera = size.get() >> PAGE_SHIFT;
+
+                if size.get() > (size.get() & !PAGE_MASK.get()) {
+                    ppera += 1;
+                }
+
+                ppera
             } else {
                 // Get uk_rsize.
                 let rsize = max(size, Uma::SMALLEST_UNIT);
@@ -77,8 +106,10 @@ impl UmaKeg {
                 {
                     todo!()
                 }
+
+                1
             }
-        }
+        };
 
         if flags.has(UmaFlags::Offpage) {
             if flags.has(UmaFlags::RefCnt) {
@@ -88,6 +119,18 @@ impl UmaKeg {
             }
         }
 
+        if ppera == 1 {
+            // TODO: Set uk_allocf and uk_freef.
+        }
+
+        if flags.has(UmaFlags::MtxClass) {
+            todo!()
+        }
+
+        if !flags.has(UmaFlags::Offpage) {
+            todo!()
+        }
+
         todo!()
     }
 }

kernel/src/uma/mod.rs

@@ -59,6 +59,8 @@ pub enum UmaFlags {
     Offpage = 0x8,
     /// `UMA_ZONE_MALLOC`.
     Malloc = 0x10,
+    /// `UMA_ZONE_MTXCLASS`.
+    MtxClass = 0x40,
     /// `UMA_ZONE_VM`.
     Vm = 0x80,
     /// `UMA_ZONE_HASH`.