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Diffstat (limited to 'include/xen/grant_table.h')
| -rw-r--r-- | include/xen/grant_table.h | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h new file mode 100644 index 0000000000..e279be353e --- /dev/null +++ b/include/xen/grant_table.h @@ -0,0 +1,341 @@ +/****************************************************************************** + * grant_table.h + * + * Two sets of functionality: + * 1. Granting foreign access to our memory reservation. + * 2. Accessing others' memory reservations via grant references. + * (i.e., mechanisms for both sender and recipient of grant references) + * + * Copyright (c) 2004-2005, K A Fraser + * Copyright (c) 2005, Christopher Clark + * + * 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. + */ + +#ifndef __ASM_GNTTAB_H__ +#define __ASM_GNTTAB_H__ + +#include <asm/page.h> + +#include <xen/interface/xen.h> +#include <xen/interface/grant_table.h> + +#include <asm/xen/hypervisor.h> + +#include <xen/features.h> +#include <xen/page.h> +#include <linux/mm_types.h> +#include <linux/page-flags.h> +#include <linux/kernel.h> + +/* + * Technically there's no reliably invalid grant reference or grant handle, + * so pick the value that is the most unlikely one to be observed valid. + */ +#define INVALID_GRANT_REF ((grant_ref_t)-1) +#define INVALID_GRANT_HANDLE ((grant_handle_t)-1) + +/* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ +#define NR_GRANT_FRAMES 4 + +struct gnttab_free_callback { + struct gnttab_free_callback *next; + void (*fn)(void *); + void *arg; + u16 count; +}; + +struct gntab_unmap_queue_data; + +typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data); + +struct gntab_unmap_queue_data +{ + struct delayed_work gnttab_work; + void *data; + gnttab_unmap_refs_done done; + struct gnttab_unmap_grant_ref *unmap_ops; + struct gnttab_unmap_grant_ref *kunmap_ops; + struct page **pages; + unsigned int count; + unsigned int age; +}; + +int gnttab_init(void); +int gnttab_suspend(void); +int gnttab_resume(void); + +int gnttab_grant_foreign_access(domid_t domid, unsigned long frame, + int readonly); + +/* + * End access through the given grant reference, iff the grant entry is no + * longer in use. Return 1 if the grant entry was freed, 0 if it is still in + * use. + */ +int gnttab_end_foreign_access_ref(grant_ref_t ref); + +/* + * Eventually end access through the given grant reference, and once that + * access has been ended, free the given page too. Access will be ended + * immediately iff the grant entry is not in use, otherwise it will happen + * some time later. page may be NULL, in which case no freeing will occur. + * Note that the granted page might still be accessed (read or write) by the + * other side after gnttab_end_foreign_access() returns, so even if page was + * specified as NULL it is not allowed to just reuse the page for other + * purposes immediately. gnttab_end_foreign_access() will take an additional + * reference to the granted page in this case, which is dropped only after + * the grant is no longer in use. + * This requires that multi page allocations for areas subject to + * gnttab_end_foreign_access() are done via alloc_pages_exact() (and freeing + * via free_pages_exact()) in order to avoid high order pages. + */ +void gnttab_end_foreign_access(grant_ref_t ref, struct page *page); + +/* + * End access through the given grant reference, iff the grant entry is + * no longer in use. In case of success ending foreign access, the + * grant reference is deallocated. + * Return 1 if the grant entry was freed, 0 if it is still in use. + */ +int gnttab_try_end_foreign_access(grant_ref_t ref); + +/* + * operations on reserved batches of grant references + */ +int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head); + +int gnttab_alloc_grant_reference_seq(unsigned int count, grant_ref_t *first); + +void gnttab_free_grant_reference(grant_ref_t ref); + +void gnttab_free_grant_references(grant_ref_t head); + +void gnttab_free_grant_reference_seq(grant_ref_t head, unsigned int count); + +int gnttab_empty_grant_references(const grant_ref_t *pprivate_head); + +int gnttab_claim_grant_reference(grant_ref_t *pprivate_head); + +void gnttab_release_grant_reference(grant_ref_t *private_head, + grant_ref_t release); + +void gnttab_request_free_callback(struct gnttab_free_callback *callback, + void (*fn)(void *), void *arg, u16 count); +void gnttab_cancel_free_callback(struct gnttab_free_callback *callback); + +void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid, + unsigned long frame, int readonly); + +/* Give access to the first 4K of the page */ +static inline void gnttab_page_grant_foreign_access_ref_one( + grant_ref_t ref, domid_t domid, + struct page *page, int readonly) +{ + gnttab_grant_foreign_access_ref(ref, domid, xen_page_to_gfn(page), + readonly); +} + +static inline void +gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr, + uint32_t flags, grant_ref_t ref, domid_t domid) +{ + if (flags & GNTMAP_contains_pte) + map->host_addr = addr; + else if (xen_feature(XENFEAT_auto_translated_physmap)) + map->host_addr = __pa(addr); + else + map->host_addr = addr; + + map->flags = flags; + map->ref = ref; + map->dom = domid; + map->status = 1; /* arbitrary positive value */ +} + +static inline void +gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, + uint32_t flags, grant_handle_t handle) +{ + if (flags & GNTMAP_contains_pte) + unmap->host_addr = addr; + else if (xen_feature(XENFEAT_auto_translated_physmap)) + unmap->host_addr = __pa(addr); + else + unmap->host_addr = addr; + + unmap->handle = handle; + unmap->dev_bus_addr = 0; +} + +int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status); +int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes, + unsigned long max_nr_gframes, + void **__shared); +int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes, + unsigned long max_nr_gframes, + grant_status_t **__shared); +void arch_gnttab_unmap(void *shared, unsigned long nr_gframes); + +struct grant_frames { + xen_pfn_t *pfn; + unsigned int count; + void *vaddr; +}; +extern struct grant_frames xen_auto_xlat_grant_frames; +unsigned int gnttab_max_grant_frames(void); +int gnttab_setup_auto_xlat_frames(phys_addr_t addr); +void gnttab_free_auto_xlat_frames(void); + +#define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr)) + +int gnttab_alloc_pages(int nr_pages, struct page **pages); +void gnttab_free_pages(int nr_pages, struct page **pages); + +struct gnttab_page_cache { + spinlock_t lock; +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC + struct page *pages; +#else + struct list_head pages; +#endif + unsigned int num_pages; +}; + +void gnttab_page_cache_init(struct gnttab_page_cache *cache); +int gnttab_page_cache_get(struct gnttab_page_cache *cache, struct page **page); +void gnttab_page_cache_put(struct gnttab_page_cache *cache, struct page **page, + unsigned int num); +void gnttab_page_cache_shrink(struct gnttab_page_cache *cache, + unsigned int num); + +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC +struct gnttab_dma_alloc_args { + /* Device for which DMA memory will be/was allocated. */ + struct device *dev; + /* If set then DMA buffer is coherent and write-combine otherwise. */ + bool coherent; + + int nr_pages; + struct page **pages; + xen_pfn_t *frames; + void *vaddr; + dma_addr_t dev_bus_addr; +}; + +int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args); +int gnttab_dma_free_pages(struct gnttab_dma_alloc_args *args); +#endif + +int gnttab_pages_set_private(int nr_pages, struct page **pages); +void gnttab_pages_clear_private(int nr_pages, struct page **pages); + +int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, + struct gnttab_map_grant_ref *kmap_ops, + struct page **pages, unsigned int count); +int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_unmap_grant_ref *kunmap_ops, + struct page **pages, unsigned int count); +void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item); +int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item); + + +/* Perform a batch of grant map/copy operations. Retry every batch slot + * for which the hypervisor returns GNTST_eagain. This is typically due + * to paged out target frames. + * + * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds. + * + * Return value in each iand every status field of the batch guaranteed + * to not be GNTST_eagain. + */ +void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count); +void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count); + + +struct xen_page_foreign { + domid_t domid; + grant_ref_t gref; +}; + +static inline struct xen_page_foreign *xen_page_foreign(struct page *page) +{ + if (!PageForeign(page)) + return NULL; +#if BITS_PER_LONG < 64 + return (struct xen_page_foreign *)page->private; +#else + BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG); + return (struct xen_page_foreign *)&page->private; +#endif +} + +/* Split Linux page in chunk of the size of the grant and call fn + * + * Parameters of fn: + * gfn: guest frame number + * offset: offset in the grant + * len: length of the data in the grant. + * data: internal information + */ +typedef void (*xen_grant_fn_t)(unsigned long gfn, unsigned int offset, + unsigned int len, void *data); + +void gnttab_foreach_grant_in_range(struct page *page, + unsigned int offset, + unsigned int len, + xen_grant_fn_t fn, + void *data); + +/* Helper to get to call fn only on the first "grant chunk" */ +static inline void gnttab_for_one_grant(struct page *page, unsigned int offset, + unsigned len, xen_grant_fn_t fn, + void *data) +{ + /* The first request is limited to the size of one grant */ + len = min_t(unsigned int, XEN_PAGE_SIZE - (offset & ~XEN_PAGE_MASK), + len); + + gnttab_foreach_grant_in_range(page, offset, len, fn, data); +} + +/* Get @nr_grefs grants from an array of page and call fn for each grant */ +void gnttab_foreach_grant(struct page **pages, + unsigned int nr_grefs, + xen_grant_fn_t fn, + void *data); + +/* Get the number of grant in a specified region + * + * start: Offset from the beginning of the first page + * len: total length of data (can cross multiple page) + */ +static inline unsigned int gnttab_count_grant(unsigned int start, + unsigned int len) +{ + return XEN_PFN_UP(xen_offset_in_page(start) + len); +} + +#endif /* __ASM_GNTTAB_H__ */ |