diff options
Diffstat (limited to 'os/port/xalloc.c')
| -rw-r--r-- | os/port/xalloc.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/os/port/xalloc.c b/os/port/xalloc.c new file mode 100644 index 00000000..73310089 --- /dev/null +++ b/os/port/xalloc.c @@ -0,0 +1,246 @@ +#include "u.h" +#include "../port/lib.h" +#include "mem.h" +#include "dat.h" +#include "fns.h" + +#define datoff ((ulong)((Xhdr*)0)->data) + +enum +{ + Chunk = 64*1024, + Nhole = 128, + Magichole = 0xDeadBabe, +}; + +typedef struct Hole Hole; +typedef struct Xalloc Xalloc; +typedef struct Xhdr Xhdr; + +struct Hole +{ + ulong addr; + ulong size; + ulong top; + Hole* link; +}; + +struct Xhdr +{ + ulong size; + ulong magix; + char data[1]; +}; + +struct Xalloc +{ + Lock; + Hole hole[Nhole]; + Hole* flist; + Hole* table; +}; + +static Xalloc xlists; + +static void +ixprt() +{ + xsummary(); + ixsummary(); +} + +void +xinit(void) +{ + Hole *h, *eh; + + eh = &xlists.hole[Nhole-1]; + for(h = xlists.hole; h < eh; h++) + h->link = h+1; + + xlists.flist = xlists.hole; + + if(conf.npage1) + xhole(conf.base1, conf.npage1*BY2PG); + conf.npage1 = conf.base1+(conf.npage1*BY2PG); + + if(conf.npage0) + xhole(conf.base0, conf.npage0*BY2PG); + conf.npage0 = conf.base0+(conf.npage0*BY2PG); + + /* Save the bounds of kernel alloc memory for kernel mmu mapping */ + conf.base0 = (ulong)KADDR(conf.base0); + conf.base1 = (ulong)KADDR(conf.base1); + conf.npage0 = (ulong)KADDR(conf.npage0); + conf.npage1 = (ulong)KADDR(conf.npage1); + + debugkey('x', "xalloc/ialloc", ixprt, 0); +} + +void* +xspanalloc(ulong size, int align, ulong span) +{ + ulong a, v, t; + + a = (ulong)xalloc(size+align+span); + if(a == 0) + panic("xspanalloc: %lud %d %lux\n", size, align, span); + + if(span > 2) { + v = (a + span) & ~(span-1); + t = v - a; + if(t > 0) + xhole(PADDR(a), t); + t = a + span - v; + if(t > 0) + xhole(PADDR(v+size+align), t); + } + else + v = a; + + if(align > 1) + v = (v + align) & ~(align-1); + + return (void*)v; +} + +void* +xallocz(ulong size, int zero) +{ + Xhdr *p; + Hole *h, **l; + + size += BY2V + sizeof(Xhdr); + size &= ~(BY2V-1); + + ilock(&xlists); + l = &xlists.table; + for(h = *l; h; h = h->link) { + if(h->size >= size) { + p = (Xhdr*)h->addr; + h->addr += size; + h->size -= size; + if(h->size == 0) { + *l = h->link; + h->link = xlists.flist; + xlists.flist = h; + } + iunlock(&xlists); + p = KADDR(p); + p->magix = Magichole; + p->size = size; + if(zero) + memset(p->data, 0, size); + return p->data; + } + l = &h->link; + } + iunlock(&xlists); + return nil; +} + +void* +xalloc(ulong size) +{ + return xallocz(size, 1); +} + +void +xfree(void *p) +{ + Xhdr *x; + + x = (Xhdr*)((ulong)p - datoff); + if(x->magix != Magichole) { + xsummary(); + panic("xfree(0x%lux) 0x%lux!=0x%lux", p, (ulong)Magichole, x->magix); + } + xhole(PADDR(x), x->size); +} + +int +xmerge(void *vp, void *vq) +{ + Xhdr *p, *q; + + p = vp; + if((uchar*)vp+p->size == (uchar*)vq) { + q = vq; + p->size += q->size; + return 1; + } + return 0; +} + +void +xhole(ulong addr, ulong size) +{ + ulong top; + Hole *h, *c, **l; + + if(size == 0) + return; + + top = addr + size; + ilock(&xlists); + l = &xlists.table; + for(h = *l; h; h = h->link) { + if(h->top == addr) { + h->size += size; + h->top = h->addr+h->size; + c = h->link; + if(c && h->top == c->addr) { + h->top += c->size; + h->size += c->size; + h->link = c->link; + c->link = xlists.flist; + xlists.flist = c; + } + iunlock(&xlists); + return; + } + if(h->addr > addr) + break; + l = &h->link; + } + if(h && top == h->addr) { + h->addr -= size; + h->size += size; + iunlock(&xlists); + return; + } + + if(xlists.flist == nil) { + iunlock(&xlists); + print("xfree: no free holes, leaked %lud bytes\n", size); + return; + } + + h = xlists.flist; + xlists.flist = h->link; + h->addr = addr; + h->top = top; + h->size = size; + h->link = *l; + *l = h; + iunlock(&xlists); +} + +void +xsummary(void) +{ + int i; + Hole *h; + + i = 0; + for(h = xlists.flist; h; h = h->link) + i++; + + print("%d holes free\n", i); + i = 0; + for(h = xlists.table; h; h = h->link) { + print("%.8lux %.8lux %lud\n", h->addr, h->top, h->size); + i += h->size; + } + print("%d bytes free\n", i); +} |