| /****************************************************************************** |
| * 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> |
| |
| #define GNTTAB_RESERVED_XENSTORE 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, int readonly); |
| |
| /* |
| * 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 0, 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 0 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, int readonly, |
| unsigned long 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); |
| |
| int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn); |
| |
| unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref); |
| unsigned long gnttab_end_foreign_transfer(grant_ref_t ref); |
| |
| /* |
| * operations on reserved batches of grant references |
| */ |
| int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head); |
| |
| void gnttab_free_grant_reference(grant_ref_t ref); |
| |
| void gnttab_free_grant_references(grant_ref_t head); |
| |
| 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); |
| } |
| |
| void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid, |
| unsigned long pfn); |
| |
| 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); |
| |
| #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__ */ |