From df12b147b079005868fc7f8d6a4b3693aecc707c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Kr=C3=B6ning?= Date: Wed, 8 May 2024 16:58:08 +0200 Subject: [PATCH] fix(mm): remove freelist module MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Martin Kröning --- src/mm/freelist.rs | 229 --------------------------------------------- src/mm/mod.rs | 6 -- 2 files changed, 235 deletions(-) delete mode 100644 src/mm/freelist.rs diff --git a/src/mm/freelist.rs b/src/mm/freelist.rs deleted file mode 100644 index 2b11721976..0000000000 --- a/src/mm/freelist.rs +++ /dev/null @@ -1,229 +0,0 @@ -use core::alloc::AllocError; -use core::cmp::Ordering; - -use align_address::Align; -use smallvec::SmallVec; - -#[derive(Debug)] -pub struct FreeListEntry { - pub start: usize, - pub end: usize, -} - -impl FreeListEntry { - pub const fn new(start: usize, end: usize) -> Self { - FreeListEntry { start, end } - } -} - -#[derive(Debug)] -pub struct FreeList { - list: SmallVec<[FreeListEntry; 16]>, -} - -impl FreeList { - pub const fn new() -> Self { - Self { - list: SmallVec::new_const(), - } - } - - pub fn push(&mut self, entry: FreeListEntry) { - self.list.push(entry); - } - - pub fn allocate(&mut self, size: usize, alignment: Option) -> Result { - trace!("Allocating {} bytes from Free List {self:p}", size); - - let new_size = if let Some(align) = alignment { - size + align - } else { - size - }; - - // Find a region in the Free List that has at least the requested size. - for (i, node) in self.list.iter_mut().enumerate() { - let (region_start, region_size) = (node.start, node.end - node.start); - - match region_size.cmp(&new_size) { - Ordering::Greater => { - // We have found a region that is larger than the requested size. - // Return the address to the beginning of that region and shrink the region by that size. - if let Some(align) = alignment { - let new_addr = region_start.align_up(align); - node.start += size + (new_addr - region_start); - if new_addr != region_start { - let new_entry = FreeListEntry::new(region_start, new_addr); - self.list.insert(i, new_entry); - } - return Ok(new_addr); - } else { - node.start += size; - return Ok(region_start); - } - } - Ordering::Equal => { - // We have found a region that has exactly the requested size. - // Return the address to the beginning of that region and move the node into the pool for deletion or reuse. - if let Some(align) = alignment { - let new_addr = region_start.align_up(align); - if new_addr != region_start { - node.end = new_addr; - } - return Ok(new_addr); - } else { - self.list.remove(i); - return Ok(region_start); - } - } - Ordering::Less => {} - } - } - - Err(AllocError) - } - - #[cfg(all(target_arch = "x86_64", not(feature = "pci")))] - pub fn reserve(&mut self, address: usize, size: usize) -> Result<(), AllocError> { - trace!( - "Try to reserve {} bytes at {:#X} from Free List {self:p}", - size, - address - ); - - // Find a region in the Free List that has at least the requested size. - for (i, node) in self.list.iter_mut().enumerate() { - let (region_start, region_size) = (node.start, node.end - node.start); - - if address > region_start && address + size < region_start + region_size { - node.start = address + size; - let new_entry = FreeListEntry::new(region_start, address); - self.list.insert(i, new_entry); - return Ok(()); - } else if address > region_start && address + size == region_start + region_size { - node.start = address + size; - return Ok(()); - } else if address == region_start && address + size < region_start + region_size { - node.start = region_start + size; - return Ok(()); - } - } - - Err(AllocError) - } - - pub fn deallocate(&mut self, address: usize, size: usize) { - trace!( - "Deallocating {} bytes at {:#X} from Free List {self:p}", - size, - address - ); - - let end = address + size; - - for (i, node) in self.list.iter_mut().enumerate() { - let (region_start, region_end) = (node.start, node.end); - - if region_start == end { - // The deallocated memory extends this free memory region to the left. - node.start = address; - - // Check if it can even reunite with the previous region. - if i > 0 { - if let Some(prev_node) = self.list.get_mut(i - 1) { - let prev_region_end = prev_node.end; - - if prev_region_end == address { - // It can reunite, so let the current region span over the reunited region and move the duplicate node - // into the pool for deletion or reuse. - prev_node.end = region_end; - self.list.remove(i); - } - } - } - - return; - } else if region_end == address { - node.end = end; - - // Check if it can even reunite with the next region. - if let Some(next_node) = self.list.get_mut(i + 1) { - let next_region_start = next_node.start; - - if next_region_start == end { - // It can reunite, so let the current region span over the reunited region and move the duplicate node - // into the pool for deletion or reuse. - next_node.start = region_start; - self.list.remove(i); - } - } - - return; - } else if end < region_start { - // The deallocated memory does not extend any memory region and needs an own entry in the Free List. - // Get that entry from the node pool. - // We search the list from low to high addresses and insert us before the first entry that has a - // higher address than us. - let new_entry = FreeListEntry::new(address, end); - self.list.insert(i, new_entry); - return; - } - } - - // We could not find an entry with a higher address than us. - // So we become the new last entry in the list. Get that entry from the node pool. - let new_element = FreeListEntry::new(address, end); - self.push(new_element); - } - - pub fn print_information(&self, header: &str) { - infoheader!(header); - - for node in self.list.iter() { - info!("{:#016X} - {:#016X}", node.start, node.end); - } - - infofooter!(); - } -} - -#[cfg(all(test, not(target_os = "none")))] -mod tests { - use super::*; - - #[test] - fn allocate() { - let mut freelist = FreeList::new(); - let entry = FreeListEntry::new(0x10000, 0x100000); - - freelist.push(entry); - let addr = freelist.allocate(0x1000, None); - - assert_eq!(addr.unwrap(), 0x10000); - - for node in &freelist.list { - assert_eq!(node.start, 0x11000); - assert_eq!(node.end, 0x100000); - } - - let addr = freelist.allocate(0x1000, Some(0x2000)); - let mut iter = freelist.list.iter(); - assert_eq!(iter.next().unwrap().start, 0x11000); - assert_eq!(iter.next().unwrap().start, 0x13000); - } - - #[test] - fn deallocate() { - let mut freelist = FreeList::new(); - let entry = FreeListEntry::new(0x10000, 0x100000); - - freelist.push(entry); - let addr = freelist.allocate(0x1000, None); - freelist.deallocate(addr.unwrap(), 0x1000); - - for node in &freelist.list { - assert_eq!(node.start, 0x10000); - assert_eq!(node.end, 0x100000); - } - } -} diff --git a/src/mm/mod.rs b/src/mm/mod.rs index 34a5f0c33d..38ffadf7d9 100644 --- a/src/mm/mod.rs +++ b/src/mm/mod.rs @@ -1,11 +1,5 @@ pub mod allocator; pub mod device_alloc; -#[cfg(not(any( - target_arch = "x86_64", - target_arch = "aarch64", - target_arch = "riscv64" -)))] -pub mod freelist; use core::mem; use core::ops::Range;