ref: 99db038e2825266e84ddb381718f3d047dc6d733
dir: /sys/src/9/port/allocb.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "error.h" enum { Hdrspc = 64, /* leave room for high-level headers */ Tlrspc = 16, /* extra room at the end for pad/crc/mac */ Bdead = 0x51494F42, /* "QIOB" */ }; static Block* _allocb(int size) { Block *b; uintptr addr; size += Tlrspc; size = ROUND(size, BLOCKALIGN); if((b = mallocz(sizeof(Block)+BLOCKALIGN+Hdrspc+size, 0)) == nil) return nil; b->next = nil; b->list = nil; b->free = nil; b->flag = 0; /* align start of data portion by rounding up */ addr = (uintptr)b; addr = ROUND(addr + sizeof(Block), BLOCKALIGN); b->base = (uchar*)addr; /* align end of data portion by rounding down */ b->lim = (uchar*)b + msize(b); addr = (uintptr)b->lim; addr &= ~(BLOCKALIGN-1); b->lim = (uchar*)addr; /* leave room at beginning for added headers */ b->wp = b->rp = b->lim - size; return b; } Block* allocb(int size) { Block *b; /* * Check in a process and wait until successful. */ if(up == nil) panic("allocb without up: %#p", getcallerpc(&size)); while((b = _allocb(size)) == nil){ if(up->nlocks || m->ilockdepth || !islo()){ xsummary(); mallocsummary(); panic("allocb: no memory for %d bytes", size); } if(!waserror()){ resrcwait("no memory for allocb"); poperror(); } } setmalloctag(b, getcallerpc(&size)); return b; } Block* iallocb(int size) { Block *b; if((b = _allocb(size)) == nil){ static ulong nerr; if((nerr++%10000)==0){ if(nerr > 10000000){ xsummary(); mallocsummary(); panic("iallocb: out of memory"); } iprint("iallocb: no memory for %d bytes\n", size); } return nil; } setmalloctag(b, getcallerpc(&size)); b->flag = BINTR; return b; } void freeb(Block *b) { void *dead = (void*)Bdead; if(b == nil) return; /* * drivers which perform non cache coherent DMA manage their own buffer * pool of uncached buffers and provide their own free routine. */ if(b->free != nil) { b->next = nil; b->list = nil; b->free(b); return; } /* poison the block in case someone is still holding onto it */ b->next = dead; b->list = dead; b->rp = dead; b->wp = dead; b->lim = dead; b->base = dead; free(b); } void checkb(Block *b, char *msg) { void *dead = (void*)Bdead; if(b == dead) panic("checkb b %s %#p", msg, b); if(b->base == dead || b->lim == dead || b->next == dead || b->rp == dead || b->wp == dead){ print("checkb: base %#p lim %#p next %#p\n", b->base, b->lim, b->next); print("checkb: rp %#p wp %#p\n", b->rp, b->wp); panic("checkb dead: %s", msg); } if(b->base > b->lim) panic("checkb 0 %s %#p %#p", msg, b->base, b->lim); if(b->rp < b->base) panic("checkb 1 %s %#p %#p", msg, b->base, b->rp); if(b->wp < b->base) panic("checkb 2 %s %#p %#p", msg, b->base, b->wp); if(b->rp > b->lim) panic("checkb 3 %s %#p %#p", msg, b->rp, b->lim); if(b->wp > b->lim) panic("checkb 4 %s %#p %#p", msg, b->wp, b->lim); }