/****************************************************************************** * 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 … #define INVALID_GRANT_HANDLE … /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ #define NR_GRANT_FRAMES … struct gnttab_free_callback { … }; struct gntab_unmap_queue_data; gnttab_unmap_refs_done; struct gntab_unmap_queue_data { … }; 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) { … } 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) { … } static inline void gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, uint32_t flags, grant_handle_t handle) { … } 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 { … }; 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) … int gnttab_alloc_pages(int nr_pages, struct page **pages); void gnttab_free_pages(int nr_pages, struct page **pages); struct gnttab_page_cache { … }; 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 { … }; 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 { … }; static inline struct xen_page_foreign *xen_page_foreign(struct page *page) { … } /* 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 */ xen_grant_fn_t; 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) { … } /* 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) { … } #endif /* __ASM_GNTTAB_H__ */
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