/*
* The caller must hold dev_pager_mtx
*/
static vm_page_t
dev_pager_getfake(vm_paddr_t paddr, int pat_mode)
{
vm_page_t m;
m = kmalloc(sizeof(*m), M_FICTITIOUS_PAGES, M_WAITOK|M_ZERO);
pmap_page_init(m);
m->flags = PG_BUSY | PG_FICTITIOUS;
m->valid = VM_PAGE_BITS_ALL;
m->dirty = 0;
m->busy = 0;
m->queue = PQ_NONE;
m->object = NULL;
m->wire_count = 1;
m->hold_count = 0;
m->phys_addr = paddr;
m->pat_mode = pat_mode;
return (m);
}
/* ARGSUSED */
int
memrw(struct cdev *dev, struct uio *uio, int flags)
{
struct iovec *iov;
int error = 0;
vm_offset_t va, eva, off, v;
vm_prot_t prot;
struct vm_page m;
vm_page_t marr;
vm_size_t cnt;
cnt = 0;
error = 0;
GIANT_REQUIRED;
pmap_page_init(&m);
while (uio->uio_resid > 0 && !error) {
iov = uio->uio_iov;
if (iov->iov_len == 0) {
uio->uio_iov++;
uio->uio_iovcnt--;
if (uio->uio_iovcnt < 0)
panic("memrw");
continue;
}
if (dev2unit(dev) == CDEV_MINOR_MEM) {
v = uio->uio_offset;
off = uio->uio_offset & PAGE_MASK;
cnt = PAGE_SIZE - ((vm_offset_t)iov->iov_base &
PAGE_MASK);
cnt = min(cnt, PAGE_SIZE - off);
cnt = min(cnt, iov->iov_len);
m.phys_addr = trunc_page(v);
marr = &m;
error = uiomove_fromphys(&marr, off, cnt, uio);
}
else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
va = uio->uio_offset;
va = trunc_page(uio->uio_offset);
eva = round_page(uio->uio_offset
+ iov->iov_len);
/*
* Make sure that all the pages are currently resident
* so that we don't create any zero-fill pages.
*/
if (va >= VM_MIN_KERNEL_ADDRESS &&
eva <= VM_MAX_KERNEL_ADDRESS) {
for (; va < eva; va += PAGE_SIZE)
if (pmap_extract(kernel_pmap, va) == 0)
return (EFAULT);
prot = (uio->uio_rw == UIO_READ)
? VM_PROT_READ : VM_PROT_WRITE;
va = uio->uio_offset;
if (kernacc((void *) va, iov->iov_len, prot)
== FALSE)
return (EFAULT);
}
va = uio->uio_offset;
error = uiomove((void *)va, iov->iov_len, uio);
continue;
}
}
return (error);
}
