/**
* xenbus_map_ring_valloc
* @dev: xenbus device
* @gnt_ref: grant reference
* @vaddr: pointer to address to be filled out by mapping
*
* Based on Rusty Russell's skeleton driver's map_page.
* Map a page of memory into this domain from another domain's grant table.
* xenbus_map_ring_valloc allocates a page of virtual address space, maps the
* page to that address, and sets *vaddr to that address.
* Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
* or -ENOMEM on error. If an error is returned, device will switch to
* XenbusStateClosing and the error message will be saved in XenStore.
*/
int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void **vaddr)
{
struct gnttab_map_grant_ref op = {
.flags = GNTMAP_host_map,
.ref = gnt_ref,
.dom = dev->otherend_id,
};
struct vm_struct *area;
*vaddr = NULL;
area = xen_alloc_vm_area(PAGE_SIZE);
if (!area)
return -ENOMEM;
op.host_addr = (unsigned long)area->addr;
if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
BUG();
if (op.status != GNTST_okay) {
xen_free_vm_area(area);
xenbus_dev_fatal(dev, op.status,
"mapping in shared page %d from domain %d",
gnt_ref, dev->otherend_id);
return op.status;
}
/* Stuff the handle in an unused field */
area->phys_addr = (unsigned long)op.handle;
*vaddr = area->addr;
return 0;
}
EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
/**
* xenbus_map_ring
* @dev: xenbus device
* @gnt_ref: grant reference
* @handle: pointer to grant handle to be filled
* @vaddr: address to be mapped to
*
* Map a page of memory into this domain from another domain's grant table.
* xenbus_map_ring does not allocate the virtual address space (you must do
* this yourself!). It only maps in the page to the specified address.
* Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
* or -ENOMEM on error. If an error is returned, device will switch to
* XenbusStateClosing and the error message will be saved in XenStore.
*/
int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
grant_handle_t *handle, void *vaddr)
{
struct gnttab_map_grant_ref op = {
.host_addr = (unsigned long)vaddr,
.flags = GNTMAP_host_map,
.ref = gnt_ref,
.dom = dev->otherend_id,
};
if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
BUG();
if (op.status != GNTST_okay) {
xenbus_dev_fatal(dev, op.status,
"mapping in shared page %d from domain %d",
gnt_ref, dev->otherend_id);
} else
*handle = op.handle;
return op.status;
}
EXPORT_SYMBOL_GPL(xenbus_map_ring);
/**
* xenbus_unmap_ring_vfree
* @dev: xenbus device
* @vaddr: addr to unmap
*
* Based on Rusty Russell's skeleton driver's unmap_page.
* Unmap a page of memory in this domain that was imported from another domain.
* Use xenbus_unmap_ring_vfree if you mapped in your memory with
* xenbus_map_ring_valloc (it will free the virtual address space).
* Returns 0 on success and returns GNTST_* on error
* (see xen/include/interface/grant_table.h).
*/
int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
{
struct vm_struct *area;
struct gnttab_unmap_grant_ref op = {
.host_addr = (unsigned long)vaddr,
};
/* It'd be nice if linux/vmalloc.h provided a find_vm_area(void *addr)
* method so that we don't have to muck with vmalloc internals here.
* We could force the user to hang on to their struct vm_struct from
* xenbus_map_ring_valloc, but these 6 lines considerably simplify
* this API.
*/
read_lock(&vmlist_lock);
for (area = vmlist; area != NULL; area = area->next) {
if (area->addr == vaddr)
break;
}
read_unlock(&vmlist_lock);
if (!area) {
xenbus_dev_error(dev, -ENOENT,
"can't find mapped virtual address %p", vaddr);
return GNTST_bad_virt_addr;
}
op.handle = (grant_handle_t)area->phys_addr;
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
BUG();
if (op.status == GNTST_okay)
xen_free_vm_area(area);
else
xenbus_dev_error(dev, op.status,
"unmapping page at handle %d error %d",
(int16_t)area->phys_addr, op.status);
return op.status;
}
EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
/**
* xenbus_unmap_ring
* @dev: xenbus device
* @handle: grant handle
* @vaddr: addr to unmap
*
* Unmap a page of memory in this domain that was imported from another domain.
* Returns 0 on success and returns GNTST_* on error
* (see xen/include/interface/grant_table.h).
*/
int xenbus_unmap_ring(struct xenbus_device *dev,
grant_handle_t handle, void *vaddr)
{
struct gnttab_unmap_grant_ref op = {
.host_addr = (unsigned long)vaddr,
.handle = handle,
};
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
BUG();
if (op.status != GNTST_okay)
xenbus_dev_error(dev, op.status,
"unmapping page at handle %d error %d",
handle, op.status);
return op.status;
}
EXPORT_SYMBOL_GPL(xenbus_unmap_ring);
/**
* xenbus_read_driver_state
* @path: path for driver
*
* Return the state of the driver rooted at the given store path, or
* XenbusStateUnknown if no state can be read.
*/
enum xenbus_state xenbus_read_driver_state(const char *path)
{
enum xenbus_state result;
int err = xenbus_gather(XBT_NIL, path, "state", "%d", &result, NULL);
if (err)
result = XenbusStateUnknown;
return result;
}
EXPORT_SYMBOL_GPL(xenbus_read_driver_state);
int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void **vaddr)
{
struct gnttab_map_grant_ref op = {
.flags = GNTMAP_host_map,
.ref = gnt_ref,
.dom = dev->otherend_id,
};
struct vm_struct *area;
*vaddr = NULL;
area = xen_alloc_vm_area(PAGE_SIZE);
if (!area)
return -ENOMEM;
op.host_addr = (unsigned long)area->addr;
if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
BUG();
if (op.status != GNTST_okay) {
xen_free_vm_area(area);
xenbus_dev_fatal(dev, op.status,
"mapping in shared page %d from domain %d",
gnt_ref, dev->otherend_id);
return op.status;
}
area->phys_addr = (unsigned long)op.handle;
*vaddr = area->addr;
return 0;
}
EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
grant_handle_t *handle, void *vaddr)
{
struct gnttab_map_grant_ref op = {
.host_addr = (unsigned long)vaddr,
.flags = GNTMAP_host_map,
.ref = gnt_ref,
.dom = dev->otherend_id,
};
if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
BUG();
if (op.status != GNTST_okay) {
xenbus_dev_fatal(dev, op.status,
"mapping in shared page %d from domain %d",
gnt_ref, dev->otherend_id);
} else
*handle = op.handle;
return op.status;
}
EXPORT_SYMBOL_GPL(xenbus_map_ring);
int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
{
struct vm_struct *area;
struct gnttab_unmap_grant_ref op = {
.host_addr = (unsigned long)vaddr,
};
read_lock(&vmlist_lock);
for (area = vmlist; area != NULL; area = area->next) {
if (area->addr == vaddr)
break;
}
read_unlock(&vmlist_lock);
if (!area) {
xenbus_dev_error(dev, -ENOENT,
"can't find mapped virtual address %p", vaddr);
return GNTST_bad_virt_addr;
}
op.handle = (grant_handle_t)area->phys_addr;
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
BUG();
if (op.status == GNTST_okay)
xen_free_vm_area(area);
else
xenbus_dev_error(dev, op.status,
"unmapping page at handle %d error %d",
(int16_t)area->phys_addr, op.status);
return op.status;
}
EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
int xenbus_unmap_ring(struct xenbus_device *dev,
grant_handle_t handle, void *vaddr)
{
struct gnttab_unmap_grant_ref op = {
.host_addr = (unsigned long)vaddr,
.handle = handle,
};
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
BUG();
if (op.status != GNTST_okay)
xenbus_dev_error(dev, op.status,
"unmapping page at handle %d error %d",
handle, op.status);
return op.status;
}
EXPORT_SYMBOL_GPL(xenbus_unmap_ring);
enum xenbus_state xenbus_read_driver_state(const char *path)
{
enum xenbus_state result;
int err = xenbus_gather(XBT_NIL, path, "state", "%d", &result, NULL);
if (err)
result = XenbusStateUnknown;
return result;
}
EXPORT_SYMBOL_GPL(xenbus_read_driver_state);
