| /****************************************************************************** |
| * Client-facing interface for the Xenbus driver. In other words, the |
| * interface between the Xenbus and the device-specific code, be it the |
| * frontend or the backend of that driver. |
| * |
| * Copyright (C) 2005 XenSource Ltd |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License version 2 |
| * as published by the Free Software Foundation; or, when distributed |
| * separately from the Linux kernel or incorporated into other |
| * software packages, subject to the following license: |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this source file (the "Software"), to deal in the Software without |
| * restriction, including without limitation the rights to use, copy, modify, |
| * merge, publish, distribute, sublicense, and/or sell copies of the Software, |
| * and to permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #include <linux/mm.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include <linux/spinlock.h> |
| #include <linux/vmalloc.h> |
| #include <linux/export.h> |
| #include <asm/xen/hypervisor.h> |
| #include <xen/page.h> |
| #include <xen/interface/xen.h> |
| #include <xen/interface/event_channel.h> |
| #include <xen/balloon.h> |
| #include <xen/events.h> |
| #include <xen/grant_table.h> |
| #include <xen/xenbus.h> |
| #include <xen/xen.h> |
| #include <xen/features.h> |
| |
| #include "xenbus.h" |
| |
| #define XENBUS_PAGES(_grants) (DIV_ROUND_UP(_grants, XEN_PFN_PER_PAGE)) |
| |
| #define XENBUS_MAX_RING_PAGES (XENBUS_PAGES(XENBUS_MAX_RING_GRANTS)) |
| |
| struct xenbus_map_node { |
| struct list_head next; |
| union { |
| struct { |
| struct vm_struct *area; |
| } pv; |
| struct { |
| struct page *pages[XENBUS_MAX_RING_PAGES]; |
| unsigned long addrs[XENBUS_MAX_RING_GRANTS]; |
| void *addr; |
| } hvm; |
| }; |
| grant_handle_t handles[XENBUS_MAX_RING_GRANTS]; |
| unsigned int nr_handles; |
| }; |
| |
| struct map_ring_valloc { |
| struct xenbus_map_node *node; |
| |
| /* Why do we need two arrays? See comment of __xenbus_map_ring */ |
| union { |
| unsigned long addrs[XENBUS_MAX_RING_GRANTS]; |
| pte_t *ptes[XENBUS_MAX_RING_GRANTS]; |
| }; |
| phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS]; |
| |
| struct gnttab_map_grant_ref map[XENBUS_MAX_RING_GRANTS]; |
| struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS]; |
| |
| unsigned int idx; /* HVM only. */ |
| }; |
| |
| static DEFINE_SPINLOCK(xenbus_valloc_lock); |
| static LIST_HEAD(xenbus_valloc_pages); |
| |
| struct xenbus_ring_ops { |
| int (*map)(struct xenbus_device *dev, struct map_ring_valloc *info, |
| grant_ref_t *gnt_refs, unsigned int nr_grefs, |
| void **vaddr); |
| int (*unmap)(struct xenbus_device *dev, void *vaddr); |
| }; |
| |
| static const struct xenbus_ring_ops *ring_ops __read_mostly; |
| |
| const char *xenbus_strstate(enum xenbus_state state) |
| { |
| static const char *const name[] = { |
| [ XenbusStateUnknown ] = "Unknown", |
| [ XenbusStateInitialising ] = "Initialising", |
| [ XenbusStateInitWait ] = "InitWait", |
| [ XenbusStateInitialised ] = "Initialised", |
| [ XenbusStateConnected ] = "Connected", |
| [ XenbusStateClosing ] = "Closing", |
| [ XenbusStateClosed ] = "Closed", |
| [XenbusStateReconfiguring] = "Reconfiguring", |
| [XenbusStateReconfigured] = "Reconfigured", |
| }; |
| return (state < ARRAY_SIZE(name)) ? name[state] : "INVALID"; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_strstate); |
| |
| /** |
| * xenbus_watch_path - register a watch |
| * @dev: xenbus device |
| * @path: path to watch |
| * @watch: watch to register |
| * @callback: callback to register |
| * |
| * Register a @watch on the given path, using the given xenbus_watch structure |
| * for storage, and the given @callback function as the callback. Return 0 on |
| * success, or -errno on error. On success, the given @path will be saved as |
| * @watch->node, and remains the caller's to free. On error, @watch->node will |
| * be NULL, the device will switch to %XenbusStateClosing, and the error will |
| * be saved in the store. |
| */ |
| int xenbus_watch_path(struct xenbus_device *dev, const char *path, |
| struct xenbus_watch *watch, |
| void (*callback)(struct xenbus_watch *, |
| const char *, const char *)) |
| { |
| int err; |
| |
| watch->node = path; |
| watch->callback = callback; |
| |
| err = register_xenbus_watch(watch); |
| |
| if (err) { |
| watch->node = NULL; |
| watch->callback = NULL; |
| xenbus_dev_fatal(dev, err, "adding watch on %s", path); |
| } |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_watch_path); |
| |
| |
| /** |
| * xenbus_watch_pathfmt - register a watch on a sprintf-formatted path |
| * @dev: xenbus device |
| * @watch: watch to register |
| * @callback: callback to register |
| * @pathfmt: format of path to watch |
| * |
| * Register a watch on the given @path, using the given xenbus_watch |
| * structure for storage, and the given @callback function as the callback. |
| * Return 0 on success, or -errno on error. On success, the watched path |
| * (@path/@path2) will be saved as @watch->node, and becomes the caller's to |
| * kfree(). On error, watch->node will be NULL, so the caller has nothing to |
| * free, the device will switch to %XenbusStateClosing, and the error will be |
| * saved in the store. |
| */ |
| int xenbus_watch_pathfmt(struct xenbus_device *dev, |
| struct xenbus_watch *watch, |
| void (*callback)(struct xenbus_watch *, |
| const char *, const char *), |
| const char *pathfmt, ...) |
| { |
| int err; |
| va_list ap; |
| char *path; |
| |
| va_start(ap, pathfmt); |
| path = kvasprintf(GFP_NOIO | __GFP_HIGH, pathfmt, ap); |
| va_end(ap); |
| |
| if (!path) { |
| xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch"); |
| return -ENOMEM; |
| } |
| err = xenbus_watch_path(dev, path, watch, callback); |
| |
| if (err) |
| kfree(path); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt); |
| |
| static void xenbus_switch_fatal(struct xenbus_device *, int, int, |
| const char *, ...); |
| |
| static int |
| __xenbus_switch_state(struct xenbus_device *dev, |
| enum xenbus_state state, int depth) |
| { |
| /* We check whether the state is currently set to the given value, and |
| if not, then the state is set. We don't want to unconditionally |
| write the given state, because we don't want to fire watches |
| unnecessarily. Furthermore, if the node has gone, we don't write |
| to it, as the device will be tearing down, and we don't want to |
| resurrect that directory. |
| |
| Note that, because of this cached value of our state, this |
| function will not take a caller's Xenstore transaction |
| (something it was trying to in the past) because dev->state |
| would not get reset if the transaction was aborted. |
| */ |
| |
| struct xenbus_transaction xbt; |
| int current_state; |
| int err, abort; |
| |
| if (state == dev->state) |
| return 0; |
| |
| again: |
| abort = 1; |
| |
| err = xenbus_transaction_start(&xbt); |
| if (err) { |
| xenbus_switch_fatal(dev, depth, err, "starting transaction"); |
| return 0; |
| } |
| |
| err = xenbus_scanf(xbt, dev->nodename, "state", "%d", ¤t_state); |
| if (err != 1) |
| goto abort; |
| |
| err = xenbus_printf(xbt, dev->nodename, "state", "%d", state); |
| if (err) { |
| xenbus_switch_fatal(dev, depth, err, "writing new state"); |
| goto abort; |
| } |
| |
| abort = 0; |
| abort: |
| err = xenbus_transaction_end(xbt, abort); |
| if (err) { |
| if (err == -EAGAIN && !abort) |
| goto again; |
| xenbus_switch_fatal(dev, depth, err, "ending transaction"); |
| } else |
| dev->state = state; |
| |
| return 0; |
| } |
| |
| /** |
| * xenbus_switch_state |
| * @dev: xenbus device |
| * @state: new state |
| * |
| * Advertise in the store a change of the given driver to the given new_state. |
| * Return 0 on success, or -errno on error. On error, the device will switch |
| * to XenbusStateClosing, and the error will be saved in the store. |
| */ |
| int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state state) |
| { |
| return __xenbus_switch_state(dev, state, 0); |
| } |
| |
| EXPORT_SYMBOL_GPL(xenbus_switch_state); |
| |
| int xenbus_frontend_closed(struct xenbus_device *dev) |
| { |
| xenbus_switch_state(dev, XenbusStateClosed); |
| complete(&dev->down); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_frontend_closed); |
| |
| static void xenbus_va_dev_error(struct xenbus_device *dev, int err, |
| const char *fmt, va_list ap) |
| { |
| unsigned int len; |
| char *printf_buffer; |
| char *path_buffer; |
| |
| #define PRINTF_BUFFER_SIZE 4096 |
| |
| printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL); |
| if (!printf_buffer) |
| return; |
| |
| len = sprintf(printf_buffer, "%i ", -err); |
| vsnprintf(printf_buffer + len, PRINTF_BUFFER_SIZE - len, fmt, ap); |
| |
| dev_err(&dev->dev, "%s\n", printf_buffer); |
| |
| path_buffer = kasprintf(GFP_KERNEL, "error/%s", dev->nodename); |
| if (path_buffer) |
| xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer); |
| |
| kfree(printf_buffer); |
| kfree(path_buffer); |
| } |
| |
| /** |
| * xenbus_dev_error |
| * @dev: xenbus device |
| * @err: error to report |
| * @fmt: error message format |
| * |
| * Report the given negative errno into the store, along with the given |
| * formatted message. |
| */ |
| void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...) |
| { |
| va_list ap; |
| |
| va_start(ap, fmt); |
| xenbus_va_dev_error(dev, err, fmt, ap); |
| va_end(ap); |
| } |
| EXPORT_SYMBOL_GPL(xenbus_dev_error); |
| |
| /** |
| * xenbus_dev_fatal |
| * @dev: xenbus device |
| * @err: error to report |
| * @fmt: error message format |
| * |
| * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by |
| * xenbus_switch_state(dev, XenbusStateClosing) to schedule an orderly |
| * closedown of this driver and its peer. |
| */ |
| |
| void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...) |
| { |
| va_list ap; |
| |
| va_start(ap, fmt); |
| xenbus_va_dev_error(dev, err, fmt, ap); |
| va_end(ap); |
| |
| xenbus_switch_state(dev, XenbusStateClosing); |
| } |
| EXPORT_SYMBOL_GPL(xenbus_dev_fatal); |
| |
| /** |
| * Equivalent to xenbus_dev_fatal(dev, err, fmt, args), but helps |
| * avoiding recursion within xenbus_switch_state. |
| */ |
| static void xenbus_switch_fatal(struct xenbus_device *dev, int depth, int err, |
| const char *fmt, ...) |
| { |
| va_list ap; |
| |
| va_start(ap, fmt); |
| xenbus_va_dev_error(dev, err, fmt, ap); |
| va_end(ap); |
| |
| if (!depth) |
| __xenbus_switch_state(dev, XenbusStateClosing, 1); |
| } |
| |
| /** |
| * xenbus_grant_ring |
| * @dev: xenbus device |
| * @vaddr: starting virtual address of the ring |
| * @nr_pages: number of pages to be granted |
| * @grefs: grant reference array to be filled in |
| * |
| * Grant access to the given @vaddr to the peer of the given device. |
| * Then fill in @grefs with grant references. Return 0 on success, or |
| * -errno on error. On error, the device will switch to |
| * XenbusStateClosing, and the error will be saved in the store. |
| */ |
| int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr, |
| unsigned int nr_pages, grant_ref_t *grefs) |
| { |
| int err; |
| int i, j; |
| |
| for (i = 0; i < nr_pages; i++) { |
| unsigned long gfn; |
| |
| if (is_vmalloc_addr(vaddr)) |
| gfn = pfn_to_gfn(vmalloc_to_pfn(vaddr)); |
| else |
| gfn = virt_to_gfn(vaddr); |
| |
| err = gnttab_grant_foreign_access(dev->otherend_id, gfn, 0); |
| if (err < 0) { |
| xenbus_dev_fatal(dev, err, |
| "granting access to ring page"); |
| goto fail; |
| } |
| grefs[i] = err; |
| |
| vaddr = vaddr + XEN_PAGE_SIZE; |
| } |
| |
| return 0; |
| |
| fail: |
| for (j = 0; j < i; j++) |
| gnttab_end_foreign_access_ref(grefs[j], 0); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_grant_ring); |
| |
| |
| /** |
| * Allocate an event channel for the given xenbus_device, assigning the newly |
| * created local port to *port. Return 0 on success, or -errno on error. On |
| * error, the device will switch to XenbusStateClosing, and the error will be |
| * saved in the store. |
| */ |
| int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port) |
| { |
| struct evtchn_alloc_unbound alloc_unbound; |
| int err; |
| |
| alloc_unbound.dom = DOMID_SELF; |
| alloc_unbound.remote_dom = dev->otherend_id; |
| |
| err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, |
| &alloc_unbound); |
| if (err) |
| xenbus_dev_fatal(dev, err, "allocating event channel"); |
| else |
| *port = alloc_unbound.port; |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn); |
| |
| |
| /** |
| * Free an existing event channel. Returns 0 on success or -errno on error. |
| */ |
| int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port) |
| { |
| struct evtchn_close close; |
| int err; |
| |
| close.port = port; |
| |
| err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close); |
| if (err) |
| xenbus_dev_error(dev, err, "freeing event channel %u", port); |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_free_evtchn); |
| |
| |
| /** |
| * xenbus_map_ring_valloc |
| * @dev: xenbus device |
| * @gnt_refs: grant reference array |
| * @nr_grefs: number of grant references |
| * @vaddr: pointer to address to be filled out by mapping |
| * |
| * Map @nr_grefs pages of memory into this domain from another |
| * domain's grant table. xenbus_map_ring_valloc allocates @nr_grefs |
| * pages of virtual address space, maps the pages to that address, and |
| * sets *vaddr to that address. Returns 0 on success, and -errno 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, grant_ref_t *gnt_refs, |
| unsigned int nr_grefs, void **vaddr) |
| { |
| int err; |
| struct map_ring_valloc *info; |
| |
| *vaddr = NULL; |
| |
| if (nr_grefs > XENBUS_MAX_RING_GRANTS) |
| return -EINVAL; |
| |
| info = kzalloc(sizeof(*info), GFP_KERNEL); |
| if (!info) |
| return -ENOMEM; |
| |
| info->node = kzalloc(sizeof(*info->node), GFP_KERNEL); |
| if (!info->node) |
| err = -ENOMEM; |
| else |
| err = ring_ops->map(dev, info, gnt_refs, nr_grefs, vaddr); |
| |
| kfree(info->node); |
| kfree(info); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc); |
| |
| /* N.B. sizeof(phys_addr_t) doesn't always equal to sizeof(unsigned |
| * long), e.g. 32-on-64. Caller is responsible for preparing the |
| * right array to feed into this function */ |
| static int __xenbus_map_ring(struct xenbus_device *dev, |
| grant_ref_t *gnt_refs, |
| unsigned int nr_grefs, |
| grant_handle_t *handles, |
| struct map_ring_valloc *info, |
| unsigned int flags, |
| bool *leaked) |
| { |
| int i, j; |
| |
| if (nr_grefs > XENBUS_MAX_RING_GRANTS) |
| return -EINVAL; |
| |
| for (i = 0; i < nr_grefs; i++) { |
| gnttab_set_map_op(&info->map[i], info->phys_addrs[i], flags, |
| gnt_refs[i], dev->otherend_id); |
| handles[i] = INVALID_GRANT_HANDLE; |
| } |
| |
| gnttab_batch_map(info->map, i); |
| |
| for (i = 0; i < nr_grefs; i++) { |
| if (info->map[i].status != GNTST_okay) { |
| xenbus_dev_fatal(dev, info->map[i].status, |
| "mapping in shared page %d from domain %d", |
| gnt_refs[i], dev->otherend_id); |
| goto fail; |
| } else |
| handles[i] = info->map[i].handle; |
| } |
| |
| return 0; |
| |
| fail: |
| for (i = j = 0; i < nr_grefs; i++) { |
| if (handles[i] != INVALID_GRANT_HANDLE) { |
| gnttab_set_unmap_op(&info->unmap[j], |
| info->phys_addrs[i], |
| GNTMAP_host_map, handles[i]); |
| j++; |
| } |
| } |
| |
| if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, info->unmap, j)) |
| BUG(); |
| |
| *leaked = false; |
| for (i = 0; i < j; i++) { |
| if (info->unmap[i].status != GNTST_okay) { |
| *leaked = true; |
| break; |
| } |
| } |
| |
| return -ENOENT; |
| } |
| |
| /** |
| * xenbus_unmap_ring |
| * @dev: xenbus device |
| * @handles: grant handle array |
| * @nr_handles: number of handles in the array |
| * @vaddrs: addresses to unmap |
| * |
| * Unmap 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). |
| */ |
| static int xenbus_unmap_ring(struct xenbus_device *dev, grant_handle_t *handles, |
| unsigned int nr_handles, unsigned long *vaddrs) |
| { |
| struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS]; |
| int i; |
| int err; |
| |
| if (nr_handles > XENBUS_MAX_RING_GRANTS) |
| return -EINVAL; |
| |
| for (i = 0; i < nr_handles; i++) |
| gnttab_set_unmap_op(&unmap[i], vaddrs[i], |
| GNTMAP_host_map, handles[i]); |
| |
| if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i)) |
| BUG(); |
| |
| err = GNTST_okay; |
| for (i = 0; i < nr_handles; i++) { |
| if (unmap[i].status != GNTST_okay) { |
| xenbus_dev_error(dev, unmap[i].status, |
| "unmapping page at handle %d error %d", |
| handles[i], unmap[i].status); |
| err = unmap[i].status; |
| break; |
| } |
| } |
| |
| return err; |
| } |
| |
| static void xenbus_map_ring_setup_grant_hvm(unsigned long gfn, |
| unsigned int goffset, |
| unsigned int len, |
| void *data) |
| { |
| struct map_ring_valloc *info = data; |
| unsigned long vaddr = (unsigned long)gfn_to_virt(gfn); |
| |
| info->phys_addrs[info->idx] = vaddr; |
| info->addrs[info->idx] = vaddr; |
| |
| info->idx++; |
| } |
| |
| static int xenbus_map_ring_hvm(struct xenbus_device *dev, |
| struct map_ring_valloc *info, |
| grant_ref_t *gnt_ref, |
| unsigned int nr_grefs, |
| void **vaddr) |
| { |
| struct xenbus_map_node *node = info->node; |
| int err; |
| void *addr; |
| bool leaked = false; |
| unsigned int nr_pages = XENBUS_PAGES(nr_grefs); |
| |
| err = xen_alloc_unpopulated_pages(nr_pages, node->hvm.pages); |
| if (err) |
| goto out_err; |
| |
| gnttab_foreach_grant(node->hvm.pages, nr_grefs, |
| xenbus_map_ring_setup_grant_hvm, |
| info); |
| |
| err = __xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handles, |
| info, GNTMAP_host_map, &leaked); |
| node->nr_handles = nr_grefs; |
| |
| if (err) |
| goto out_free_ballooned_pages; |
| |
| addr = vmap(node->hvm.pages, nr_pages, VM_MAP | VM_IOREMAP, |
| PAGE_KERNEL); |
| if (!addr) { |
| err = -ENOMEM; |
| goto out_xenbus_unmap_ring; |
| } |
| |
| node->hvm.addr = addr; |
| |
| spin_lock(&xenbus_valloc_lock); |
| list_add(&node->next, &xenbus_valloc_pages); |
| spin_unlock(&xenbus_valloc_lock); |
| |
| *vaddr = addr; |
| info->node = NULL; |
| |
| return 0; |
| |
| out_xenbus_unmap_ring: |
| if (!leaked) |
| xenbus_unmap_ring(dev, node->handles, nr_grefs, info->addrs); |
| else |
| pr_alert("leaking %p size %u page(s)", |
| addr, nr_pages); |
| out_free_ballooned_pages: |
| if (!leaked) |
| xen_free_unpopulated_pages(nr_pages, node->hvm.pages); |
| out_err: |
| return err; |
| } |
| |
| /** |
| * 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) |
| { |
| return ring_ops->unmap(dev, vaddr); |
| } |
| EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree); |
| |
| #ifdef CONFIG_XEN_PV |
| static int xenbus_map_ring_pv(struct xenbus_device *dev, |
| struct map_ring_valloc *info, |
| grant_ref_t *gnt_refs, |
| unsigned int nr_grefs, |
| void **vaddr) |
| { |
| struct xenbus_map_node *node = info->node; |
| struct vm_struct *area; |
| int err = GNTST_okay; |
| int i; |
| bool leaked; |
| |
| area = alloc_vm_area(XEN_PAGE_SIZE * nr_grefs, info->ptes); |
| if (!area) |
| return -ENOMEM; |
| |
| for (i = 0; i < nr_grefs; i++) |
| info->phys_addrs[i] = |
| arbitrary_virt_to_machine(info->ptes[i]).maddr; |
| |
| err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles, |
| info, GNTMAP_host_map | GNTMAP_contains_pte, |
| &leaked); |
| if (err) |
| goto failed; |
| |
| node->nr_handles = nr_grefs; |
| node->pv.area = area; |
| |
| spin_lock(&xenbus_valloc_lock); |
| list_add(&node->next, &xenbus_valloc_pages); |
| spin_unlock(&xenbus_valloc_lock); |
| |
| *vaddr = area->addr; |
| info->node = NULL; |
| |
| return 0; |
| |
| failed: |
| if (!leaked) |
| free_vm_area(area); |
| else |
| pr_alert("leaking VM area %p size %u page(s)", area, nr_grefs); |
| |
| return err; |
| } |
| |
| static int xenbus_unmap_ring_pv(struct xenbus_device *dev, void *vaddr) |
| { |
| struct xenbus_map_node *node; |
| struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS]; |
| unsigned int level; |
| int i; |
| bool leaked = false; |
| int err; |
| |
| spin_lock(&xenbus_valloc_lock); |
| list_for_each_entry(node, &xenbus_valloc_pages, next) { |
| if (node->pv.area->addr == vaddr) { |
| list_del(&node->next); |
| goto found; |
| } |
| } |
| node = NULL; |
| found: |
| spin_unlock(&xenbus_valloc_lock); |
| |
| if (!node) { |
| xenbus_dev_error(dev, -ENOENT, |
| "can't find mapped virtual address %p", vaddr); |
| return GNTST_bad_virt_addr; |
| } |
| |
| for (i = 0; i < node->nr_handles; i++) { |
| unsigned long addr; |
| |
| memset(&unmap[i], 0, sizeof(unmap[i])); |
| addr = (unsigned long)vaddr + (XEN_PAGE_SIZE * i); |
| unmap[i].host_addr = arbitrary_virt_to_machine( |
| lookup_address(addr, &level)).maddr; |
| unmap[i].dev_bus_addr = 0; |
| unmap[i].handle = node->handles[i]; |
| } |
| |
| if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap, i)) |
| BUG(); |
| |
| err = GNTST_okay; |
| leaked = false; |
| for (i = 0; i < node->nr_handles; i++) { |
| if (unmap[i].status != GNTST_okay) { |
| leaked = true; |
| xenbus_dev_error(dev, unmap[i].status, |
| "unmapping page at handle %d error %d", |
| node->handles[i], unmap[i].status); |
| err = unmap[i].status; |
| break; |
| } |
| } |
| |
| if (!leaked) |
| free_vm_area(node->pv.area); |
| else |
| pr_alert("leaking VM area %p size %u page(s)", |
| node->pv.area, node->nr_handles); |
| |
| kfree(node); |
| return err; |
| } |
| |
| static const struct xenbus_ring_ops ring_ops_pv = { |
| .map = xenbus_map_ring_pv, |
| .unmap = xenbus_unmap_ring_pv, |
| }; |
| #endif |
| |
| struct unmap_ring_hvm |
| { |
| unsigned int idx; |
| unsigned long addrs[XENBUS_MAX_RING_GRANTS]; |
| }; |
| |
| static void xenbus_unmap_ring_setup_grant_hvm(unsigned long gfn, |
| unsigned int goffset, |
| unsigned int len, |
| void *data) |
| { |
| struct unmap_ring_hvm *info = data; |
| |
| info->addrs[info->idx] = (unsigned long)gfn_to_virt(gfn); |
| |
| info->idx++; |
| } |
| |
| static int xenbus_unmap_ring_hvm(struct xenbus_device *dev, void *vaddr) |
| { |
| int rv; |
| struct xenbus_map_node *node; |
| void *addr; |
| struct unmap_ring_hvm info = { |
| .idx = 0, |
| }; |
| unsigned int nr_pages; |
| |
| spin_lock(&xenbus_valloc_lock); |
| list_for_each_entry(node, &xenbus_valloc_pages, next) { |
| addr = node->hvm.addr; |
| if (addr == vaddr) { |
| list_del(&node->next); |
| goto found; |
| } |
| } |
| node = addr = NULL; |
| found: |
| spin_unlock(&xenbus_valloc_lock); |
| |
| if (!node) { |
| xenbus_dev_error(dev, -ENOENT, |
| "can't find mapped virtual address %p", vaddr); |
| return GNTST_bad_virt_addr; |
| } |
| |
| nr_pages = XENBUS_PAGES(node->nr_handles); |
| |
| gnttab_foreach_grant(node->hvm.pages, node->nr_handles, |
| xenbus_unmap_ring_setup_grant_hvm, |
| &info); |
| |
| rv = xenbus_unmap_ring(dev, node->handles, node->nr_handles, |
| info.addrs); |
| if (!rv) { |
| vunmap(vaddr); |
| xen_free_unpopulated_pages(nr_pages, node->hvm.pages); |
| } |
| else |
| WARN(1, "Leaking %p, size %u page(s)\n", vaddr, nr_pages); |
| |
| kfree(node); |
| return rv; |
| } |
| |
| /** |
| * 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); |
| |
| static const struct xenbus_ring_ops ring_ops_hvm = { |
| .map = xenbus_map_ring_hvm, |
| .unmap = xenbus_unmap_ring_hvm, |
| }; |
| |
| void __init xenbus_ring_ops_init(void) |
| { |
| #ifdef CONFIG_XEN_PV |
| if (!xen_feature(XENFEAT_auto_translated_physmap)) |
| ring_ops = &ring_ops_pv; |
| else |
| #endif |
| ring_ops = &ring_ops_hvm; |
| } |