diff options
Diffstat (limited to 'drivers/xen/xenbus/xenbus_client.c')
| -rw-r--r-- | drivers/xen/xenbus/xenbus_client.c | 165 |
1 files changed, 111 insertions, 54 deletions
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index e8bed1cb76ba..2dc874fb5506 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -116,14 +116,17 @@ EXPORT_SYMBOL_GPL(xenbus_strstate); * @dev: xenbus device * @path: path to watch * @watch: watch to register + * @will_handle: events queuing determine callback * @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. + * for storage, @will_handle function as the callback to determine if each + * event need to be queued, and the given @callback function as the callback. + * 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. + * + * Returns: %0 on success or -errno on error */ int xenbus_watch_path(struct xenbus_device *dev, const char *path, struct xenbus_watch *watch, @@ -156,16 +159,20 @@ EXPORT_SYMBOL_GPL(xenbus_watch_path); * xenbus_watch_pathfmt - register a watch on a sprintf-formatted path * @dev: xenbus device * @watch: watch to register + * @will_handle: events queuing determine callback * @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 + * structure for storage, @will_handle function as the callback to determine if + * each event need to be queued, and the given @callback function as the + * callback. 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. + * + * Returns: %0 on success or -errno on error */ int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, @@ -195,6 +202,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev, } EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt); +__printf(4, 5) static void xenbus_switch_fatal(struct xenbus_device *, int, int, const char *, ...); @@ -255,13 +263,15 @@ abort: } /** - * xenbus_switch_state + * xenbus_switch_state - save the new state of a driver * @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. + * On error, the device will switch to XenbusStateClosing, and the error + * will be saved in the store. + * + * Returns: %0 on success or -errno on error */ int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state state) { @@ -278,6 +288,7 @@ int xenbus_frontend_closed(struct xenbus_device *dev) } EXPORT_SYMBOL_GPL(xenbus_frontend_closed); +__printf(3, 0) static void xenbus_va_dev_error(struct xenbus_device *dev, int err, const char *fmt, va_list ap) { @@ -305,7 +316,7 @@ static void xenbus_va_dev_error(struct xenbus_device *dev, int err, } /** - * xenbus_dev_error + * xenbus_dev_error - place an error message into the store * @dev: xenbus device * @err: error to report * @fmt: error message format @@ -324,7 +335,7 @@ void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...) EXPORT_SYMBOL_GPL(xenbus_dev_error); /** - * xenbus_dev_fatal + * xenbus_dev_fatal - put an error messages into the store and then shutdown * @dev: xenbus device * @err: error to report * @fmt: error message format @@ -346,7 +357,7 @@ void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...) } EXPORT_SYMBOL_GPL(xenbus_dev_fatal); -/** +/* * Equivalent to xenbus_dev_fatal(dev, err, fmt, args), but helps * avoiding recursion within xenbus_switch_state. */ @@ -363,54 +374,97 @@ static void xenbus_switch_fatal(struct xenbus_device *dev, int depth, int err, __xenbus_switch_state(dev, XenbusStateClosing, 1); } -/** - * xenbus_grant_ring +/* + * xenbus_setup_ring * @dev: xenbus device - * @vaddr: starting virtual address of the ring + * @vaddr: pointer to 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. + * Allocate physically contiguous pages for a shared ring buffer and grant it + * to the peer of the given device. The ring buffer is initially filled with + * zeroes. The virtual address of the ring is stored at @vaddr and the + * grant references are stored in the @grefs array. In case of error @vaddr + * will be set to NULL and @grefs will be filled with INVALID_GRANT_REF. */ -int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr, +int xenbus_setup_ring(struct xenbus_device *dev, gfp_t gfp, void **vaddr, unsigned int nr_pages, grant_ref_t *grefs) { - int err; - int i, j; + unsigned long ring_size = nr_pages * XEN_PAGE_SIZE; + grant_ref_t gref_head; + unsigned int i; + void *addr; + int ret; + + addr = *vaddr = alloc_pages_exact(ring_size, gfp | __GFP_ZERO); + if (!*vaddr) { + ret = -ENOMEM; + goto err; + } + + ret = gnttab_alloc_grant_references(nr_pages, &gref_head); + if (ret) { + xenbus_dev_fatal(dev, ret, "granting access to %u ring pages", + nr_pages); + goto err; + } for (i = 0; i < nr_pages; i++) { unsigned long gfn; - if (is_vmalloc_addr(vaddr)) - gfn = pfn_to_gfn(vmalloc_to_pfn(vaddr)); + if (is_vmalloc_addr(*vaddr)) + gfn = pfn_to_gfn(vmalloc_to_pfn(addr)); else - gfn = virt_to_gfn(vaddr); + gfn = virt_to_gfn(addr); - 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; + grefs[i] = gnttab_claim_grant_reference(&gref_head); + gnttab_grant_foreign_access_ref(grefs[i], dev->otherend_id, + gfn, 0); - vaddr = vaddr + XEN_PAGE_SIZE; + addr += XEN_PAGE_SIZE; } return 0; -fail: - for (j = 0; j < i; j++) - gnttab_end_foreign_access_ref(grefs[j], 0); - return err; + err: + if (*vaddr) + free_pages_exact(*vaddr, ring_size); + for (i = 0; i < nr_pages; i++) + grefs[i] = INVALID_GRANT_REF; + *vaddr = NULL; + + return ret; } -EXPORT_SYMBOL_GPL(xenbus_grant_ring); +EXPORT_SYMBOL_GPL(xenbus_setup_ring); +/* + * xenbus_teardown_ring + * @vaddr: starting virtual address of the ring + * @nr_pages: number of pages + * @grefs: grant reference array + * + * Remove grants for the shared ring buffer and free the associated memory. + * On return the grant reference array is filled with INVALID_GRANT_REF. + */ +void xenbus_teardown_ring(void **vaddr, unsigned int nr_pages, + grant_ref_t *grefs) +{ + unsigned int i; -/** + for (i = 0; i < nr_pages; i++) { + if (grefs[i] != INVALID_GRANT_REF) { + gnttab_end_foreign_access(grefs[i], NULL); + grefs[i] = INVALID_GRANT_REF; + } + } + + if (*vaddr) + free_pages_exact(*vaddr, nr_pages * XEN_PAGE_SIZE); + *vaddr = NULL; +} +EXPORT_SYMBOL_GPL(xenbus_teardown_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 @@ -436,7 +490,7 @@ int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port) 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) @@ -456,7 +510,7 @@ EXPORT_SYMBOL_GPL(xenbus_free_evtchn); /** - * xenbus_map_ring_valloc + * xenbus_map_ring_valloc - allocate & map pages of VA space * @dev: xenbus device * @gnt_refs: grant reference array * @nr_grefs: number of grant references @@ -464,10 +518,11 @@ EXPORT_SYMBOL_GPL(xenbus_free_evtchn); * * 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 + * pages of virtual address space, maps the pages to that address, and sets + * *vaddr to that address. If an error is returned, device will switch to * XenbusStateClosing and the error message will be saved in XenStore. + * + * Returns: %0 on success or -errno on error */ int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, unsigned int nr_grefs, void **vaddr) @@ -556,14 +611,15 @@ static int __xenbus_map_ring(struct xenbus_device *dev, } /** - * xenbus_unmap_ring + * xenbus_unmap_ring - unmap memory from another domain * @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 + * + * Returns: %0 on success or GNTST_* on error * (see xen/include/interface/grant_table.h). */ static int xenbus_unmap_ring(struct xenbus_device *dev, grant_handle_t *handles, @@ -669,7 +725,7 @@ static int xenbus_map_ring_hvm(struct xenbus_device *dev, } /** - * xenbus_unmap_ring_vfree + * xenbus_unmap_ring_vfree - unmap a page of memory from another domain * @dev: xenbus device * @vaddr: addr to unmap * @@ -677,7 +733,8 @@ static int xenbus_map_ring_hvm(struct xenbus_device *dev, * 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 + * + * Returns: %0 on success or GNTST_* on error * (see xen/include/interface/grant_table.h). */ int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr) @@ -873,10 +930,10 @@ static int xenbus_unmap_ring_hvm(struct xenbus_device *dev, void *vaddr) } /** - * xenbus_read_driver_state + * xenbus_read_driver_state - read state from a store path * @path: path for driver * - * Return the state of the driver rooted at the given store path, or + * Returns: 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) @@ -898,7 +955,7 @@ static const struct xenbus_ring_ops ring_ops_hvm = { void __init xenbus_ring_ops_init(void) { #ifdef CONFIG_XEN_PV - if (!xen_feature(XENFEAT_auto_translated_physmap)) + if (xen_pv_domain()) ring_ops = &ring_ops_pv; else #endif |