Imbus/xv6-riscv-kernel
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group locks into structs they protect.

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few naming nits.
This commit is contained in:
rsc 2009-05-31 05:12:21 +00:00
parent 949e55902b
commit 34295f461a
10 changed files with 82 additions and 80 deletions
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26
kalloc.c
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@ -10,13 +10,15 @@
#include "param.h"
#include "spinlock.h"
struct spinlock kalloc_lock;
struct run {
struct run *next;
int len; // bytes
};
struct run *freelist;
struct {
struct spinlock lock;
struct run *freelist;
} kmem;
// Initialize free list of physical pages.
// This code cheats by just considering one megabyte of
@ -29,7 +31,7 @@ kinit(void)
uint mem;
char *start;
initlock(&kalloc_lock, "kalloc");
initlock(&kmem.lock, "kmem");
start = (char*) &end;
start = (char*) (((uint)start + PAGE) & ~(PAGE-1));
mem = 256; // assume computer has 256 pages of RAM
@ -52,10 +54,10 @@ kfree(char *v, int len)
// Fill with junk to catch dangling refs.
memset(v, 1, len);
acquire(&kalloc_lock);
acquire(&kmem.lock);
p = (struct run*)v;
pend = (struct run*)(v + len);
for(rp=&freelist; (r=*rp) != 0 && r <= pend; rp=&r->next){
for(rp=&kmem.freelist; (r=*rp) != 0 && r <= pend; rp=&r->next){
rend = (struct run*)((char*)r + r->len);
if(r <= p && p < rend)
panic("freeing free page");
@ -80,7 +82,7 @@ kfree(char *v, int len)
*rp = p;
out:
release(&kalloc_lock);
release(&kmem.lock);
}
// Allocate n bytes of physical memory.
@ -95,21 +97,21 @@ kalloc(int n)
if(n % PAGE || n <= 0)
panic("kalloc");
acquire(&kalloc_lock);
for(rp=&freelist; (r=*rp) != 0; rp=&r->next){
acquire(&kmem.lock);
for(rp=&kmem.freelist; (r=*rp) != 0; rp=&r->next){
if(r->len == n){
*rp = r->next;
release(&kalloc_lock);
release(&kmem.lock);
return (char*)r;
}
if(r->len > n){
r->len -= n;
p = (char*)r + r->len;
release(&kalloc_lock);
release(&kmem.lock);
return p;
}
}
release(&kalloc_lock);
release(&kmem.lock);
cprintf("kalloc: out of memory\n");
return 0;