/******************************************************************************
* 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__ */
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