/*
* Copyright (c) 2006 Manuel Bouyer.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Helper routines for the backend drivers. This implements the necessary
* functions to map a bunch of pages from foreign domains into our kernel VM
* space, do I/O to it, and unmap it.
*/
/*
* Map the memory referenced via grefp to supplied VA space.
* If there is a failure for particular gref, no memory is mapped
* and error is returned.
*/
int
xen_shm_map(int nentries, int domid, grant_ref_t *grefp, vaddr_t va,
grant_handle_t *handlep, int flags)
{
gnttab_map_grant_ref_t op[XENSHM_MAX_PAGES_PER_REQUEST];
int ret, i;
#ifndef XENPV
paddr_t base_paddr;
#endif
for (i = 0; i < nentries; i++) {
#ifndef XENPV
op[i].host_addr = base_paddr + i * PAGE_SIZE;
#else
op[i].host_addr = va + i * PAGE_SIZE;
#endif
op[i].dom = domid;
op[i].ref = grefp[i];
op[i].flags = GNTMAP_host_map |
((flags & XSHM_RO) ? GNTMAP_readonly : 0);
}
ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, op, nentries);
if (__predict_false(ret < 0)) {
#ifdef DIAGNOSTIC
printf("%s: HYPERVISOR_grant_table_op failed %d\n", __func__,
ret);
#endif
ret = EINVAL;
goto err1;
}
/*
* If ret is positive, it means there was an error in processing,
* and only first ret entries were actually handled. If it's zero,
* it only means all entries were processed, but there could still
* be failure.
*/
if (__predict_false(ret > 0 && ret < nentries)) {
nentries = ret;
}
for (i = 0; i < nentries; i++) {
if (__predict_false(op[i].status)) {
#ifdef DIAGNOSTIC
printf("%s: op[%d] bad status %d gref %u\n", __func__,
i, op[i].status, grefp[i]);
#endif
ret = 1;
continue;
}
handlep[i] = op[i].handle;
}
if (__predict_false(ret > 0)) {
int uncnt = 0;
gnttab_unmap_grant_ref_t unop[XENSHM_MAX_PAGES_PER_REQUEST];
/*
* When returning error, make sure the successfully mapped
* entries are unmapped before returning the error.
* xen_shm_unmap() can't be used, it assumes
* linear consecutive space.
*/
for (i = uncnt = 0; i < nentries; i++) {
if (op[i].status == 0) {
#ifndef XENPV
unop[uncnt].host_addr =
base_paddr + i * PAGE_SIZE;
#else
unop[uncnt].host_addr = va + i * PAGE_SIZE;
#endif
unop[uncnt].dev_bus_addr = 0;
unop[uncnt].handle = handlep[i];
uncnt++;
}
}
if (uncnt > 0) {
ret = HYPERVISOR_grant_table_op(
GNTTABOP_unmap_grant_ref, unop, uncnt);
if (ret != 0) {
panic("%s: unmap on error recovery failed"
" %d", __func__, ret);
}
}
#ifdef DIAGNOSTIC
printf("%s: HYPERVISOR_grant_table_op bad entry\n",
__func__);
#endif
ret = EINVAL;
goto err1;
}
#ifndef XENPV
for (i = 0; i < nentries; i++) {
pmap_kenter_pa(va + i * PAGE_SIZE,
base_paddr + i * PAGE_SIZE,
VM_PROT_READ | VM_PROT_WRITE, 0);
}
#endif
