diff options
Diffstat (limited to 'kalloc.c')
-rw-r--r-- | kalloc.c | 58 |
1 files changed, 20 insertions, 38 deletions
@@ -3,13 +3,14 @@ // and pipe buffers. Allocates 4096-byte pages. #include "types.h" -#include "defs.h" #include "param.h" #include "memlayout.h" -#include "mmu.h" #include "spinlock.h" +#include "riscv.h" +#include "defs.h" + +void freerange(void *pa_start, void *pa_end); -void freerange(void *vstart, void *vend); extern char end[]; // first address after kernel loaded from ELF file // defined by the kernel linker script in kernel.ld @@ -19,36 +20,22 @@ struct run { struct { struct spinlock lock; - int use_lock; struct run *freelist; } kmem; -// Initialization happens in two phases. -// 1. main() calls kinit1() while still using entrypgdir to place just -// the pages mapped by entrypgdir on free list. -// 2. main() calls kinit2() with the rest of the physical pages -// after installing a full page table that maps them on all cores. void -kinit1(void *vstart, void *vend) +kinit() { initlock(&kmem.lock, "kmem"); - kmem.use_lock = 0; - freerange(vstart, vend); -} - -void -kinit2(void *vstart, void *vend) -{ - freerange(vstart, vend); - kmem.use_lock = 1; + freerange(end, (void*)PHYSTOP); } void -freerange(void *vstart, void *vend) +freerange(void *pa_start, void *pa_end) { char *p; - p = (char*)PGROUNDUP((uint64)vstart); - for(; p + PGSIZE <= (char*)vend; p += PGSIZE) + p = (char*)PGROUNDUP((uint64)pa_start); + for(; p + PGSIZE <= (char*)pa_end; p += PGSIZE) kfree(p); } //PAGEBREAK: 21 @@ -57,42 +44,37 @@ freerange(void *vstart, void *vend) // call to kalloc(). (The exception is when // initializing the allocator; see kinit above.) void -kfree(char *v) +kfree(void *pa) { struct run *r; - if((uint64)v % PGSIZE || v < end || V2P(v) >= PHYSTOP) + if(((uint64)pa % PGSIZE) != 0 || (char*)pa < end || (uint64)pa >= PHYSTOP) panic("kfree"); // Fill with junk to catch dangling refs. - memset(v, 1, PGSIZE); + memset(pa, 1, PGSIZE); - if(kmem.use_lock) - acquire(&kmem.lock); - r = (struct run*)v; + acquire(&kmem.lock); + r = (struct run*)pa; r->next = kmem.freelist; kmem.freelist = r; - if(kmem.use_lock) - release(&kmem.lock); + release(&kmem.lock); } // Allocate one 4096-byte page of physical memory. // Returns a pointer that the kernel can use. // Returns 0 if the memory cannot be allocated. -char* +void * kalloc(void) { struct run *r; - if(kmem.use_lock) - acquire(&kmem.lock); + acquire(&kmem.lock); r = kmem.freelist; if(r) kmem.freelist = r->next; - if(kmem.use_lock) - release(&kmem.lock); - if(r != 0 && (uint64) r < KERNBASE) - panic("kalloc"); - return (char*)r; + release(&kmem.lock); + memset((char*)r, 5, PGSIZE); // fill with junk + return (void*)r; } |