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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-12 10:02:03 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-12 10:02:03 -0800 |
commit | b53966ffd4c0676c02987d4fc33b99bdfc548cf0 (patch) | |
tree | 551926f0b9bfe27ecc4c609d10192e0cf447ace7 /drivers/xen/grant-table.c | |
parent | b01deddb8d3cb779ac250978afd200931fd91dcd (diff) | |
parent | ee32f32335e8c7f6154bf397f4ac9b6175b488a8 (diff) | |
download | linux-b53966ffd4c0676c02987d4fc33b99bdfc548cf0.tar.bz2 |
Merge tag 'for-linus-5.10c-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"A short series fixing a regression introduced in 5.9 for running as
Xen dom0 on a system with NVMe backed storage"
* tag 'for-linus-5.10c-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: don't use page->lru for ZONE_DEVICE memory
xen: add helpers for caching grant mapping pages
Diffstat (limited to 'drivers/xen/grant-table.c')
-rw-r--r-- | drivers/xen/grant-table.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 523dcdf39cc9..3729bea0c989 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -813,6 +813,129 @@ 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; |