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use core::sync::atomic::{AtomicUsize, Ordering};
use multiboot::{MemoryType, Multiboot};
use crate::arch::x86_64::kernel::{get_limit, get_mbinfo};
use crate::arch::x86_64::mm::paddr_to_slice;
use crate::arch::x86_64::mm::paging::{BasePageSize, PageSize};
use crate::collections::Node;
use crate::mm;
use crate::mm::freelist::{FreeList, FreeListEntry};
use crate::synch::spinlock::*;
static PHYSICAL_FREE_LIST: SpinlockIrqSave<FreeList> = SpinlockIrqSave::new(FreeList::new());
static TOTAL_MEMORY: AtomicUsize = AtomicUsize::new(0);
fn detect_from_multiboot_info() -> Result<(), ()> {
let mb_info = get_mbinfo();
if mb_info == 0 {
return Err(());
}
let mb = unsafe { Multiboot::new(mb_info as u64, paddr_to_slice).unwrap() };
let all_regions = mb
.memory_regions()
.expect("Could not find a memory map in the Multiboot information");
let ram_regions = all_regions.filter(|m| {
m.memory_type() == MemoryType::Available
&& m.base_address() + m.length() > mm::kernel_end_address() as u64
});
let mut found_ram = false;
for m in ram_regions {
found_ram = true;
let start_address = if m.base_address() <= mm::kernel_start_address() as u64 {
mm::kernel_end_address()
} else {
m.base_address() as usize
};
let entry = Node::new(FreeListEntry {
start: start_address,
end: (m.base_address() + m.length()) as usize,
});
let _ = TOTAL_MEMORY.fetch_add((m.base_address() + m.length()) as usize, Ordering::SeqCst);
PHYSICAL_FREE_LIST.lock().list.push(entry);
}
assert!(
found_ram,
"Could not find any available RAM in the Multiboot Memory Map"
);
Ok(())
}
fn detect_from_limits() -> Result<(), ()> {
let limit = get_limit();
if limit == 0 {
return Err(());
}
let entry = Node::new(FreeListEntry {
start: mm::kernel_end_address(),
end: limit,
});
TOTAL_MEMORY.store(limit, Ordering::SeqCst);
PHYSICAL_FREE_LIST.lock().list.push(entry);
Ok(())
}
pub fn init() {
detect_from_multiboot_info()
.or_else(|_e| detect_from_limits())
.unwrap();
}
pub fn total_memory_size() -> usize {
TOTAL_MEMORY.load(Ordering::SeqCst)
}
pub fn allocate(size: usize) -> Result<usize, ()> {
assert!(size > 0);
assert_eq!(
size % BasePageSize::SIZE,
0,
"Size {:#X} is not a multiple of {:#X}",
size,
BasePageSize::SIZE
);
PHYSICAL_FREE_LIST.lock().allocate(size)
}
pub fn allocate_aligned(size: usize, alignment: usize) -> Result<usize, ()> {
assert!(size > 0);
assert!(alignment > 0);
assert_eq!(
size % alignment,
0,
"Size {:#X} is not a multiple of the given alignment {:#X}",
size,
alignment
);
assert_eq!(
alignment % BasePageSize::SIZE,
0,
"Alignment {:#X} is not a multiple of {:#X}",
alignment,
BasePageSize::SIZE
);
PHYSICAL_FREE_LIST.lock().allocate_aligned(size, alignment)
}
pub fn deallocate(physical_address: usize, size: usize) {
assert!(
physical_address >= mm::kernel_end_address(),
"Physical address {:#X} is not >= KERNEL_END_ADDRESS",
physical_address
);
assert!(size > 0);
assert_eq!(
size % BasePageSize::SIZE,
0,
"Size {:#X} is not a multiple of {:#X}",
size,
BasePageSize::SIZE
);
PHYSICAL_FREE_LIST.lock().deallocate(physical_address, size);
}
pub fn print_information() {
PHYSICAL_FREE_LIST
.lock()
.print_information(" PHYSICAL MEMORY FREE LIST ");
}