diff options
Diffstat (limited to 'drivers/xen/grant-table.c')
-rw-r--r-- | drivers/xen/grant-table.c | 610 |
1 files changed, 404 insertions, 206 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 7b36b51cdb9f..e1ec725c2819 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -33,6 +33,7 @@ #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt +#include <linux/bitmap.h> #include <linux/memblock.h> #include <linux/sched.h> #include <linux/mm.h> @@ -64,18 +65,38 @@ #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> -#include <asm/pgtable.h> #include <asm/sync_bitops.h> -/* External tools reserve first few grant table entries. */ -#define NR_RESERVED_ENTRIES 8 #define GNTTAB_LIST_END 0xffffffff static grant_ref_t **gnttab_list; static unsigned int nr_grant_frames; + +/* + * Handling of free grants: + * + * Free grants are in a simple list anchored in gnttab_free_head. They are + * linked by grant ref, the last element contains GNTTAB_LIST_END. The number + * of free entries is stored in gnttab_free_count. + * Additionally there is a bitmap of free entries anchored in + * gnttab_free_bitmap. This is being used for simplifying allocation of + * multiple consecutive grants, which is needed e.g. for support of virtio. + * gnttab_last_free is used to add free entries of new frames at the end of + * the free list. + * gnttab_free_tail_ptr specifies the variable which references the start + * of consecutive free grants ending with gnttab_last_free. This pointer is + * updated in a rather defensive way, in order to avoid performance hits in + * hot paths. + * All those variables are protected by gnttab_list_lock. + */ static int gnttab_free_count; -static grant_ref_t gnttab_free_head; +static unsigned int gnttab_size; +static grant_ref_t gnttab_free_head = GNTTAB_LIST_END; +static grant_ref_t gnttab_last_free = GNTTAB_LIST_END; +static grant_ref_t *gnttab_free_tail_ptr; +static unsigned long *gnttab_free_bitmap; static DEFINE_SPINLOCK(gnttab_list_lock); + struct grant_frames xen_auto_xlat_grant_frames; static unsigned int xen_gnttab_version; module_param_named(version, xen_gnttab_version, uint, 0); @@ -110,7 +131,7 @@ struct gnttab_ops { void (*unmap_frames)(void); /* * Introducing a valid entry into the grant table, granting the frame of - * this grant entry to domain for accessing or transfering. Ref + * this grant entry to domain for accessing. Ref * parameter is reference of this introduced grant entry, domid is id of * granted domain, frame is the page frame to be granted, and flags is * status of the grant entry to be updated. @@ -119,28 +140,16 @@ struct gnttab_ops { unsigned long frame, unsigned flags); /* * Stop granting a grant entry to domain for accessing. Ref parameter is - * reference of a grant entry whose grant access will be stopped, - * readonly is not in use in this function. If the grant entry is - * currently mapped for reading or writing, just return failure(==0) - * directly and don't tear down the grant access. Otherwise, stop grant - * access for this entry and return success(==1). - */ - int (*end_foreign_access_ref)(grant_ref_t ref, int readonly); - /* - * Stop granting a grant entry to domain for transfer. Ref parameter is - * reference of a grant entry whose grant transfer will be stopped. If - * tranfer has not started, just reclaim the grant entry and return - * failure(==0). Otherwise, wait for the transfer to complete and then - * return the frame. + * reference of a grant entry whose grant access will be stopped. + * If the grant entry is currently mapped for reading or writing, just + * return failure(==0) directly and don't tear down the grant access. + * Otherwise, stop grant access for this entry and return success(==1). */ - unsigned long (*end_foreign_transfer_ref)(grant_ref_t ref); + int (*end_foreign_access_ref)(grant_ref_t ref); /* - * Query the status of a grant entry. Ref parameter is reference of - * queried grant entry, return value is the status of queried entry. - * Detailed status(writing/reading) can be gotten from the return value - * by bit operations. + * Read the frame number related to a given grant reference. */ - int (*query_foreign_access)(grant_ref_t ref); + unsigned long (*read_frame)(grant_ref_t ref); }; struct unmap_refs_callback_data { @@ -183,16 +192,116 @@ static int get_free_entries(unsigned count) ref = head = gnttab_free_head; gnttab_free_count -= count; - while (count-- > 1) - head = gnttab_entry(head); + while (count--) { + bitmap_clear(gnttab_free_bitmap, head, 1); + if (gnttab_free_tail_ptr == __gnttab_entry(head)) + gnttab_free_tail_ptr = &gnttab_free_head; + if (count) + head = gnttab_entry(head); + } gnttab_free_head = gnttab_entry(head); gnttab_entry(head) = GNTTAB_LIST_END; + if (!gnttab_free_count) { + gnttab_last_free = GNTTAB_LIST_END; + gnttab_free_tail_ptr = NULL; + } + spin_unlock_irqrestore(&gnttab_list_lock, flags); return ref; } +static int get_seq_entry_count(void) +{ + if (gnttab_last_free == GNTTAB_LIST_END || !gnttab_free_tail_ptr || + *gnttab_free_tail_ptr == GNTTAB_LIST_END) + return 0; + + return gnttab_last_free - *gnttab_free_tail_ptr + 1; +} + +/* Rebuilds the free grant list and tries to find count consecutive entries. */ +static int get_free_seq(unsigned int count) +{ + int ret = -ENOSPC; + unsigned int from, to; + grant_ref_t *last; + + gnttab_free_tail_ptr = &gnttab_free_head; + last = &gnttab_free_head; + + for (from = find_first_bit(gnttab_free_bitmap, gnttab_size); + from < gnttab_size; + from = find_next_bit(gnttab_free_bitmap, gnttab_size, to + 1)) { + to = find_next_zero_bit(gnttab_free_bitmap, gnttab_size, + from + 1); + if (ret < 0 && to - from >= count) { + ret = from; + bitmap_clear(gnttab_free_bitmap, ret, count); + from += count; + gnttab_free_count -= count; + if (from == to) + continue; + } + + /* + * Recreate the free list in order to have it properly sorted. + * This is needed to make sure that the free tail has the maximum + * possible size. + */ + while (from < to) { + *last = from; + last = __gnttab_entry(from); + gnttab_last_free = from; + from++; + } + if (to < gnttab_size) + gnttab_free_tail_ptr = __gnttab_entry(to - 1); + } + + *last = GNTTAB_LIST_END; + if (gnttab_last_free != gnttab_size - 1) + gnttab_free_tail_ptr = NULL; + + return ret; +} + +static int get_free_entries_seq(unsigned int count) +{ + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&gnttab_list_lock, flags); + + if (gnttab_free_count < count) { + ret = gnttab_expand(count - gnttab_free_count); + if (ret < 0) + goto out; + } + + if (get_seq_entry_count() < count) { + ret = get_free_seq(count); + if (ret >= 0) + goto out; + ret = gnttab_expand(count - get_seq_entry_count()); + if (ret < 0) + goto out; + } + + ret = *gnttab_free_tail_ptr; + *gnttab_free_tail_ptr = gnttab_entry(ret + count - 1); + gnttab_free_count -= count; + if (!gnttab_free_count) + gnttab_free_tail_ptr = NULL; + bitmap_clear(gnttab_free_bitmap, ret, count); + + out: + spin_unlock_irqrestore(&gnttab_list_lock, flags); + + return ret; +} + static void do_free_callbacks(void) { struct gnttab_free_callback *callback, *next; @@ -219,25 +328,56 @@ static inline void check_free_callbacks(void) do_free_callbacks(); } -static void put_free_entry(grant_ref_t ref) +static void put_free_entry_locked(grant_ref_t ref) { - unsigned long flags; - spin_lock_irqsave(&gnttab_list_lock, flags); + if (unlikely(ref < GNTTAB_NR_RESERVED_ENTRIES)) + return; + gnttab_entry(ref) = gnttab_free_head; gnttab_free_head = ref; + if (!gnttab_free_count) + gnttab_last_free = ref; + if (gnttab_free_tail_ptr == &gnttab_free_head) + gnttab_free_tail_ptr = __gnttab_entry(ref); gnttab_free_count++; + bitmap_set(gnttab_free_bitmap, ref, 1); +} + +static void put_free_entry(grant_ref_t ref) +{ + unsigned long flags; + + spin_lock_irqsave(&gnttab_list_lock, flags); + put_free_entry_locked(ref); check_free_callbacks(); spin_unlock_irqrestore(&gnttab_list_lock, flags); } +static void gnttab_set_free(unsigned int start, unsigned int n) +{ + unsigned int i; + + for (i = start; i < start + n - 1; i++) + gnttab_entry(i) = i + 1; + + gnttab_entry(i) = GNTTAB_LIST_END; + if (!gnttab_free_count) { + gnttab_free_head = start; + gnttab_free_tail_ptr = &gnttab_free_head; + } else { + gnttab_entry(gnttab_last_free) = start; + } + gnttab_free_count += n; + gnttab_last_free = i; + + bitmap_set(gnttab_free_bitmap, start, n); +} + /* * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2. * Introducing a valid entry into the grant table: * 1. Write ent->domid. - * 2. Write ent->frame: - * GTF_permit_access: Frame to which access is permitted. - * GTF_accept_transfer: Pseudo-phys frame slot being filled by new - * frame, or zero if none. + * 2. Write ent->frame: Frame to which access is permitted. * 3. Write memory barrier (WMB). * 4. Write ent->flags, inc. valid type. */ @@ -285,23 +425,7 @@ int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, } EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access); -static int gnttab_query_foreign_access_v1(grant_ref_t ref) -{ - return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); -} - -static int gnttab_query_foreign_access_v2(grant_ref_t ref) -{ - return grstatus[ref] & (GTF_reading|GTF_writing); -} - -int gnttab_query_foreign_access(grant_ref_t ref) -{ - return gnttab_interface->query_foreign_access(ref); -} -EXPORT_SYMBOL_GPL(gnttab_query_foreign_access); - -static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) +static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref) { u16 flags, nflags; u16 *pflags; @@ -317,7 +441,7 @@ static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) return 1; } -static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) +static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref) { gnttab_shared.v2[ref].hdr.flags = 0; mb(); /* Concurrent access by hypervisor. */ @@ -340,24 +464,33 @@ static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) return 1; } -static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) +static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref) { - return gnttab_interface->end_foreign_access_ref(ref, readonly); + return gnttab_interface->end_foreign_access_ref(ref); } -int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) +int gnttab_end_foreign_access_ref(grant_ref_t ref) { - if (_gnttab_end_foreign_access_ref(ref, readonly)) + if (_gnttab_end_foreign_access_ref(ref)) return 1; pr_warn("WARNING: g.e. %#x still in use!\n", ref); return 0; } EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref); +static unsigned long gnttab_read_frame_v1(grant_ref_t ref) +{ + return gnttab_shared.v1[ref].frame; +} + +static unsigned long gnttab_read_frame_v2(grant_ref_t ref) +{ + return gnttab_shared.v2[ref].full_page.frame; +} + struct deferred_entry { struct list_head list; grant_ref_t ref; - bool ro; uint16_t warn_delay; struct page *page; }; @@ -381,14 +514,11 @@ static void gnttab_handle_deferred(struct timer_list *unused) break; list_del(&entry->list); spin_unlock_irqrestore(&gnttab_list_lock, flags); - if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) { + if (_gnttab_end_foreign_access_ref(entry->ref)) { put_free_entry(entry->ref); - if (entry->page) { - pr_debug("freeing g.e. %#x (pfn %#lx)\n", - entry->ref, page_to_pfn(entry->page)); - put_page(entry->page); - } else - pr_info("freeing g.e. %#x\n", entry->ref); + pr_debug("freeing g.e. %#x (pfn %#lx)\n", + entry->ref, page_to_pfn(entry->page)); + put_page(entry->page); kfree(entry); entry = NULL; } else { @@ -410,17 +540,24 @@ static void gnttab_handle_deferred(struct timer_list *unused) spin_unlock_irqrestore(&gnttab_list_lock, flags); } -static void gnttab_add_deferred(grant_ref_t ref, bool readonly, - struct page *page) +static void gnttab_add_deferred(grant_ref_t ref, struct page *page) { - struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC); + struct deferred_entry *entry; + gfp_t gfp = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL; const char *what = KERN_WARNING "leaking"; + entry = kmalloc(sizeof(*entry), gfp); + if (!page) { + unsigned long gfn = gnttab_interface->read_frame(ref); + + page = pfn_to_page(gfn_to_pfn(gfn)); + get_page(page); + } + if (entry) { unsigned long flags; entry->ref = ref; - entry->ro = readonly; entry->page = page; entry->warn_delay = 60; spin_lock_irqsave(&gnttab_list_lock, flags); @@ -436,114 +573,26 @@ static void gnttab_add_deferred(grant_ref_t ref, bool readonly, what, ref, page ? page_to_pfn(page) : -1); } -void gnttab_end_foreign_access(grant_ref_t ref, int readonly, - unsigned long page) +int gnttab_try_end_foreign_access(grant_ref_t ref) { - if (gnttab_end_foreign_access_ref(ref, readonly)) { - put_free_entry(ref); - if (page != 0) - put_page(virt_to_page(page)); - } else - gnttab_add_deferred(ref, readonly, - page ? virt_to_page(page) : NULL); -} -EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); - -int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn) -{ - int ref; + int ret = _gnttab_end_foreign_access_ref(ref); - ref = get_free_entries(1); - if (unlikely(ref < 0)) - return -ENOSPC; - gnttab_grant_foreign_transfer_ref(ref, domid, pfn); - - return ref; -} -EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer); - -void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid, - unsigned long pfn) -{ - gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer); -} -EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref); - -static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) -{ - unsigned long frame; - u16 flags; - u16 *pflags; - - pflags = &gnttab_shared.v1[ref].flags; - - /* - * If a transfer is not even yet started, try to reclaim the grant - * reference and return failure (== 0). - */ - while (!((flags = *pflags) & GTF_transfer_committed)) { - if (sync_cmpxchg(pflags, flags, 0) == flags) - return 0; - cpu_relax(); - } - - /* If a transfer is in progress then wait until it is completed. */ - while (!(flags & GTF_transfer_completed)) { - flags = *pflags; - cpu_relax(); - } - - rmb(); /* Read the frame number /after/ reading completion status. */ - frame = gnttab_shared.v1[ref].frame; - BUG_ON(frame == 0); - - return frame; -} - -static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) -{ - unsigned long frame; - u16 flags; - u16 *pflags; - - pflags = &gnttab_shared.v2[ref].hdr.flags; - - /* - * If a transfer is not even yet started, try to reclaim the grant - * reference and return failure (== 0). - */ - while (!((flags = *pflags) & GTF_transfer_committed)) { - if (sync_cmpxchg(pflags, flags, 0) == flags) - return 0; - cpu_relax(); - } - - /* If a transfer is in progress then wait until it is completed. */ - while (!(flags & GTF_transfer_completed)) { - flags = *pflags; - cpu_relax(); - } - - rmb(); /* Read the frame number /after/ reading completion status. */ - frame = gnttab_shared.v2[ref].full_page.frame; - BUG_ON(frame == 0); - - return frame; -} + if (ret) + put_free_entry(ref); -unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) -{ - return gnttab_interface->end_foreign_transfer_ref(ref); + return ret; } -EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref); +EXPORT_SYMBOL_GPL(gnttab_try_end_foreign_access); -unsigned long gnttab_end_foreign_transfer(grant_ref_t ref) +void gnttab_end_foreign_access(grant_ref_t ref, struct page *page) { - unsigned long frame = gnttab_end_foreign_transfer_ref(ref); - put_free_entry(ref); - return frame; + if (gnttab_try_end_foreign_access(ref)) { + if (page) + put_page(page); + } else + gnttab_add_deferred(ref, page); } -EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer); +EXPORT_SYMBOL_GPL(gnttab_end_foreign_access); void gnttab_free_grant_reference(grant_ref_t ref) { @@ -555,23 +604,31 @@ void gnttab_free_grant_references(grant_ref_t head) { grant_ref_t ref; unsigned long flags; - int count = 1; - if (head == GNTTAB_LIST_END) - return; + spin_lock_irqsave(&gnttab_list_lock, flags); - ref = head; - while (gnttab_entry(ref) != GNTTAB_LIST_END) { - ref = gnttab_entry(ref); - count++; + while (head != GNTTAB_LIST_END) { + ref = gnttab_entry(head); + put_free_entry_locked(head); + head = ref; } - gnttab_entry(ref) = gnttab_free_head; - gnttab_free_head = head; - gnttab_free_count += count; check_free_callbacks(); spin_unlock_irqrestore(&gnttab_list_lock, flags); } EXPORT_SYMBOL_GPL(gnttab_free_grant_references); +void gnttab_free_grant_reference_seq(grant_ref_t head, unsigned int count) +{ + unsigned long flags; + unsigned int i; + + spin_lock_irqsave(&gnttab_list_lock, flags); + for (i = count; i > 0; i--) + put_free_entry_locked(head + i - 1); + check_free_callbacks(); + spin_unlock_irqrestore(&gnttab_list_lock, flags); +} +EXPORT_SYMBOL_GPL(gnttab_free_grant_reference_seq); + int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) { int h = get_free_entries(count); @@ -585,6 +642,24 @@ int gnttab_alloc_grant_references(u16 count, grant_ref_t *head) } EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references); +int gnttab_alloc_grant_reference_seq(unsigned int count, grant_ref_t *first) +{ + int h; + + if (count == 1) + h = get_free_entries(1); + else + h = get_free_entries_seq(count); + + if (h < 0) + return -ENOSPC; + + *first = h; + + return 0; +} +EXPORT_SYMBOL_GPL(gnttab_alloc_grant_reference_seq); + int gnttab_empty_grant_references(const grant_ref_t *private_head) { return (*private_head == GNTTAB_LIST_END); @@ -677,16 +752,13 @@ static int grow_gnttab_list(unsigned int more_frames) goto grow_nomem; } + gnttab_set_free(gnttab_size, extra_entries); - for (i = grefs_per_frame * nr_grant_frames; - i < grefs_per_frame * new_nr_grant_frames - 1; i++) - gnttab_entry(i) = i + 1; - - gnttab_entry(i) = gnttab_free_head; - gnttab_free_head = grefs_per_frame * nr_grant_frames; - gnttab_free_count += extra_entries; + if (!gnttab_free_tail_ptr) + gnttab_free_tail_ptr = __gnttab_entry(gnttab_size); nr_grant_frames = new_nr_grant_frames; + gnttab_size += extra_entries; check_free_callbacks(); @@ -737,7 +809,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) if (xen_auto_xlat_grant_frames.count) return -EINVAL; - vaddr = xen_remap(addr, XEN_PAGE_SIZE * max_nr_gframes); + vaddr = memremap(addr, XEN_PAGE_SIZE * max_nr_gframes, MEMREMAP_WB); if (vaddr == NULL) { pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n", &addr); @@ -745,7 +817,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) } pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL); if (!pfn) { - xen_unmap(vaddr); + memunmap(vaddr); return -ENOMEM; } for (i = 0; i < max_nr_gframes; i++) @@ -764,7 +836,7 @@ void gnttab_free_auto_xlat_frames(void) if (!xen_auto_xlat_grant_frames.count) return; kfree(xen_auto_xlat_grant_frames.pfn); - xen_unmap(xen_auto_xlat_grant_frames.vaddr); + memunmap(xen_auto_xlat_grant_frames.vaddr); xen_auto_xlat_grant_frames.pfn = NULL; xen_auto_xlat_grant_frames.count = 0; @@ -802,7 +874,7 @@ int gnttab_alloc_pages(int nr_pages, struct page **pages) { int ret; - ret = alloc_xenballooned_pages(nr_pages, pages); + ret = xen_alloc_unpopulated_pages(nr_pages, pages); if (ret < 0) return ret; @@ -814,6 +886,129 @@ int gnttab_alloc_pages(int nr_pages, struct page **pages) } EXPORT_SYMBOL_GPL(gnttab_alloc_pages); +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC +static inline void cache_init(struct gnttab_page_cache *cache) +{ + cache->pages = NULL; +} + +static inline bool cache_empty(struct gnttab_page_cache *cache) +{ + return !cache->pages; +} + +static inline struct page *cache_deq(struct gnttab_page_cache *cache) +{ + struct page *page; + + page = cache->pages; + cache->pages = page->zone_device_data; + + return page; +} + +static inline void cache_enq(struct gnttab_page_cache *cache, struct page *page) +{ + page->zone_device_data = cache->pages; + cache->pages = page; +} +#else +static inline void cache_init(struct gnttab_page_cache *cache) +{ + INIT_LIST_HEAD(&cache->pages); +} + +static inline bool cache_empty(struct gnttab_page_cache *cache) +{ + return list_empty(&cache->pages); +} + +static inline struct page *cache_deq(struct gnttab_page_cache *cache) +{ + struct page *page; + + page = list_first_entry(&cache->pages, struct page, lru); + list_del(&page->lru); + + return page; +} + +static inline void cache_enq(struct gnttab_page_cache *cache, struct page *page) +{ + list_add(&page->lru, &cache->pages); +} +#endif + +void gnttab_page_cache_init(struct gnttab_page_cache *cache) +{ + spin_lock_init(&cache->lock); + cache_init(cache); + cache->num_pages = 0; +} +EXPORT_SYMBOL_GPL(gnttab_page_cache_init); + +int gnttab_page_cache_get(struct gnttab_page_cache *cache, struct page **page) +{ + unsigned long flags; + + spin_lock_irqsave(&cache->lock, flags); + + if (cache_empty(cache)) { + spin_unlock_irqrestore(&cache->lock, flags); + return gnttab_alloc_pages(1, page); + } + + page[0] = cache_deq(cache); + cache->num_pages--; + + spin_unlock_irqrestore(&cache->lock, flags); + + return 0; +} +EXPORT_SYMBOL_GPL(gnttab_page_cache_get); + +void gnttab_page_cache_put(struct gnttab_page_cache *cache, struct page **page, + unsigned int num) +{ + unsigned long flags; + unsigned int i; + + spin_lock_irqsave(&cache->lock, flags); + + for (i = 0; i < num; i++) + cache_enq(cache, page[i]); + cache->num_pages += num; + + spin_unlock_irqrestore(&cache->lock, flags); +} +EXPORT_SYMBOL_GPL(gnttab_page_cache_put); + +void gnttab_page_cache_shrink(struct gnttab_page_cache *cache, unsigned int num) +{ + struct page *page[10]; + unsigned int i = 0; + unsigned long flags; + + spin_lock_irqsave(&cache->lock, flags); + + while (cache->num_pages > num) { + page[i] = cache_deq(cache); + cache->num_pages--; + if (++i == ARRAY_SIZE(page)) { + spin_unlock_irqrestore(&cache->lock, flags); + gnttab_free_pages(i, page); + i = 0; + spin_lock_irqsave(&cache->lock, flags); + } + } + + spin_unlock_irqrestore(&cache->lock, flags); + + if (i != 0) + gnttab_free_pages(i, page); +} +EXPORT_SYMBOL_GPL(gnttab_page_cache_shrink); + void gnttab_pages_clear_private(int nr_pages, struct page **pages) { int i; @@ -837,7 +1032,7 @@ EXPORT_SYMBOL_GPL(gnttab_pages_clear_private); void gnttab_free_pages(int nr_pages, struct page **pages) { gnttab_pages_clear_private(nr_pages, pages); - free_xenballooned_pages(nr_pages, pages); + xen_free_unpopulated_pages(nr_pages, pages); } EXPORT_SYMBOL_GPL(gnttab_free_pages); @@ -852,6 +1047,9 @@ int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args) size_t size; int i, ret; + if (args->nr_pages < 0 || args->nr_pages > (INT_MAX >> PAGE_SHIFT)) + return -ENOMEM; + size = args->nr_pages << PAGE_SHIFT; if (args->coherent) args->vaddr = dma_alloc_coherent(args->dev, size, @@ -1294,8 +1492,7 @@ static const struct gnttab_ops gnttab_v1_ops = { .unmap_frames = gnttab_unmap_frames_v1, .update_entry = gnttab_update_entry_v1, .end_foreign_access_ref = gnttab_end_foreign_access_ref_v1, - .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v1, - .query_foreign_access = gnttab_query_foreign_access_v1, + .read_frame = gnttab_read_frame_v1, }; static const struct gnttab_ops gnttab_v2_ops = { @@ -1306,8 +1503,7 @@ static const struct gnttab_ops gnttab_v2_ops = { .unmap_frames = gnttab_unmap_frames_v2, .update_entry = gnttab_update_entry_v2, .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, - .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, - .query_foreign_access = gnttab_query_foreign_access_v2, + .read_frame = gnttab_read_frame_v2, }; static bool gnttab_need_v2(void) @@ -1408,20 +1604,20 @@ static int gnttab_expand(unsigned int req_entries) int gnttab_init(void) { int i; - unsigned long max_nr_grant_frames; + unsigned long max_nr_grant_frames, max_nr_grefs; unsigned int max_nr_glist_frames, nr_glist_frames; - unsigned int nr_init_grefs; int ret; gnttab_request_version(); max_nr_grant_frames = gnttab_max_grant_frames(); + max_nr_grefs = max_nr_grant_frames * + gnttab_interface->grefs_per_grant_frame; nr_grant_frames = 1; /* Determine the maximum number of frames required for the * grant reference free list on the current hypervisor. */ - max_nr_glist_frames = (max_nr_grant_frames * - gnttab_interface->grefs_per_grant_frame / RPP); + max_nr_glist_frames = max_nr_grefs / RPP; gnttab_list = kmalloc_array(max_nr_glist_frames, sizeof(grant_ref_t *), @@ -1438,6 +1634,12 @@ int gnttab_init(void) } } + gnttab_free_bitmap = bitmap_zalloc(max_nr_grefs, GFP_KERNEL); + if (!gnttab_free_bitmap) { + ret = -ENOMEM; + goto ini_nomem; + } + ret = arch_gnttab_init(max_nr_grant_frames, nr_status_frames(max_nr_grant_frames)); if (ret < 0) @@ -1448,15 +1650,10 @@ int gnttab_init(void) goto ini_nomem; } - nr_init_grefs = nr_grant_frames * - gnttab_interface->grefs_per_grant_frame; - - for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) - gnttab_entry(i) = i + 1; + gnttab_size = nr_grant_frames * gnttab_interface->grefs_per_grant_frame; - gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; - gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; - gnttab_free_head = NR_RESERVED_ENTRIES; + gnttab_set_free(GNTTAB_NR_RESERVED_ENTRIES, + gnttab_size - GNTTAB_NR_RESERVED_ENTRIES); printk("Grant table initialized\n"); return 0; @@ -1465,6 +1662,7 @@ int gnttab_init(void) for (i--; i >= 0; i--) free_page((unsigned long)gnttab_list[i]); kfree(gnttab_list); + bitmap_free(gnttab_free_bitmap); return ret; } EXPORT_SYMBOL_GPL(gnttab_init); |