int
uvm_mmap_dev(struct proc *p, void **addrp, size_t len, dev_t dev,
off_t off)
{
struct uvm_object *uobj;
int error, flags, prot;
flags = MAP_SHARED;
prot = VM_PROT_READ | VM_PROT_WRITE;
if (*addrp)
flags |= MAP_FIXED;
else
*addrp = (void *)p->p_emul->e_vm_default_addr(p,
(vaddr_t)p->p_vmspace->vm_daddr, len,
p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN);
uobj = udv_attach(dev, prot, off, len);
if (uobj == NULL)
return EINVAL;
error = uvm_mmap(&p->p_vmspace->vm_map, (vaddr_t *)addrp,
(vsize_t)len, prot, prot, flags, UVM_ADV_RANDOM, uobj, off,
p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
return error;
}
int
uvm_mmap(vm_map_t map, vaddr_t *addr, vsize_t size, vm_prot_t prot,
vm_prot_t maxprot, int flags, caddr_t handle, voff_t foff,
vsize_t locklimit, struct proc *p)
{
struct uvm_object *uobj;
struct vnode *vp;
int error;
int advice = UVM_ADV_NORMAL;
uvm_flag_t uvmflag = 0;
vsize_t align = 0; /* userland page size */
/*
* check params
*/
if (size == 0)
return(0);
if (foff & PAGE_MASK)
return(EINVAL);
if ((prot & maxprot) != prot)
return(EINVAL);
/*
* for non-fixed mappings, round off the suggested address.
* for fixed mappings, check alignment and zap old mappings.
*/
if ((flags & MAP_FIXED) == 0) {
*addr = round_page(*addr); /* round */
} else {
if (*addr & PAGE_MASK)
return(EINVAL);
uvmflag |= UVM_FLAG_FIXED;
uvm_unmap_p(map, *addr, *addr + size, p); /* zap! */
}
/*
* handle anon vs. non-anon mappings. for non-anon mappings attach
* to underlying vm object.
*/
if (flags & MAP_ANON) {
if ((flags & MAP_FIXED) == 0 && size >= __LDPGSZ)
align = __LDPGSZ;
foff = UVM_UNKNOWN_OFFSET;
uobj = NULL;
if ((flags & MAP_SHARED) == 0)
/* XXX: defer amap create */
uvmflag |= UVM_FLAG_COPYONW;
else
/* shared: create amap now */
uvmflag |= UVM_FLAG_OVERLAY;
} else {
vp = (struct vnode *) handle; /* get vnode */
if (vp->v_type != VCHR) {
uobj = uvn_attach((void *) vp, (flags & MAP_SHARED) ?
maxprot : (maxprot & ~VM_PROT_WRITE));
if (uobj) {
assert((void*)uobj == vp);
if (flags & MAP_DENYWRITE)
uvmflag |= UVM_FLAG_DENYWRITE;
if ((flags & MAP_SHARED)
&& (maxprot & VM_PROT_WRITE))
uvmflag |= UVM_FLAG_WRITECOUNT;
}
#ifndef UBC
/*
* XXXCDC: hack from old code
* don't allow vnodes which have been mapped
* shared-writeable to persist [forces them to be
* flushed out when last reference goes].
* XXXCDC: interesting side effect: avoids a bug.
* note that in WRITE [ufs_readwrite.c] that we
* allocate buffer, uncache, and then do the write.
* the problem with this is that if the uncache causes
* VM data to be flushed to the same area of the file
* we are writing to... in that case we've got the
* buffer locked and our process goes to sleep forever.
*
* XXXCDC: checking maxprot protects us from the
* "persistbug" program but this is not a long term
* solution.
*
* XXXCDC: we don't bother calling uncache with the vp
* VOP_LOCKed since we know that we are already
* holding a valid reference to the uvn (from the
* uvn_attach above), and thus it is impossible for
* the uncache to kill the uvn and trigger I/O.
*/
if (flags & MAP_SHARED) {
if ((prot & VM_PROT_WRITE) ||
(maxprot & VM_PROT_WRITE)) {
uvm_vnp_uncache(vp);
}
}
#else
/* XXX for now, attach doesn't gain a ref */
VREF(vp);
#endif
} else {
uobj = udv_attach((void *) &vp->v_rdev,
(flags & MAP_SHARED) ? maxprot :
(maxprot & ~VM_PROT_WRITE), foff, size);
/*
* XXX Some devices don't like to be mapped with
* XXX PROT_EXEC, but we don't really have a
* XXX better way of handling this, right now
*/
if (uobj == NULL && (prot & PROT_EXEC) == 0) {
maxprot &= ~VM_PROT_EXECUTE;
uobj = udv_attach((void *) &vp->v_rdev,
(flags & MAP_SHARED) ? maxprot :
(maxprot & ~VM_PROT_WRITE), foff, size);
}
advice = UVM_ADV_RANDOM;
}
if (uobj == NULL)
return((vp->v_type == VREG) ? ENOMEM : EINVAL);
if ((flags & MAP_SHARED) == 0)
uvmflag |= UVM_FLAG_COPYONW;
}
/*
* set up mapping flags
*/
uvmflag = UVM_MAPFLAG(prot, maxprot,
(flags & MAP_SHARED) ? UVM_INH_SHARE : UVM_INH_COPY,
advice, uvmflag);
error = uvm_map_p(map, addr, size, uobj, foff, align, uvmflag, p);
if (error == 0) {
/*
* POSIX 1003.1b -- if our address space was configured
* to lock all future mappings, wire the one we just made.
*/
if (prot == VM_PROT_NONE) {
/*
* No more work to do in this case.
*/
return (0);
}
vm_map_lock(map);
if (map->flags & VM_MAP_WIREFUTURE) {
if ((atop(size) + uvmexp.wired) > uvmexp.wiredmax
#ifdef pmap_wired_count
|| (locklimit != 0 && (size +
ptoa(pmap_wired_count(vm_map_pmap(map)))) >
locklimit)
#endif
) {
error = ENOMEM;
vm_map_unlock(map);
/* unmap the region! */
uvm_unmap(map, *addr, *addr + size);
goto bad;
}
/*
* uvm_map_pageable() always returns the map
* unlocked.
*/
error = uvm_map_pageable(map, *addr, *addr + size,
FALSE, UVM_LK_ENTER);
if (error != 0) {
/* unmap the region! */
uvm_unmap(map, *addr, *addr + size);
goto bad;
}
return (0);
}
vm_map_unlock(map);
return (0);
}
/*
* errors: first detach from the uobj, if any.
*/
if (uobj)
uobj->pgops->pgo_detach(uobj);
bad:
return (error);
}
