f4cea5da70
This commit introduces driver for granting access for own grant table and for mapping/unmapping foreign gref. Grant tables are used for data exchange between Xen domains via shared memory page(s) (e.g. for sharing ring buffer with driver data) This functionality is widely used and needed for implementing PV backend/frontend drivers. Signed-off-by: Dmytro Firsov <dmytro_firsov@epam.com>
36 lines
1.1 KiB
C
36 lines
1.1 KiB
C
/*
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* Copyright (c) 2021 EPAM Systems
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef __XEN_GENERIC_H__
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#define __XEN_GENERIC_H__
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#include <zephyr/xen/public/xen.h>
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#define XEN_PAGE_SIZE 4096
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#define XEN_PAGE_SHIFT 12
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#define XEN_PFN_UP(x) (unsigned long)(((x) + XEN_PAGE_SIZE-1) >> XEN_PAGE_SHIFT)
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#define XEN_PFN_DOWN(x) (unsigned long)((x) >> XEN_PAGE_SHIFT)
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#define XEN_PFN_PHYS(x) ((unsigned long)(x) << XEN_PAGE_SHIFT)
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#define XEN_PHYS_PFN(x) (unsigned long)((x) >> XEN_PAGE_SHIFT)
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#define xen_to_phys(x) ((unsigned long) (x))
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#define xen_to_virt(x) ((void *) (x))
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#define xen_virt_to_gfn(_virt) (XEN_PFN_DOWN(xen_to_phys(_virt)))
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#define xen_gfn_to_virt(_gfn) (xen_to_virt(XEN_PFN_PHYS(_gfn)))
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/*
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* Atomically exchange value on "ptr" position. If value on "ptr" contains
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* "old", then store and return "new". Otherwise, return the "old" value.
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*/
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#define synch_cmpxchg(ptr, old, new) \
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({ __typeof__(*ptr) stored = old; \
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__atomic_compare_exchange_n(ptr, &stored, new, 0, __ATOMIC_SEQ_CST, \
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__ATOMIC_SEQ_CST) ? new : old; \
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})
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#endif /* __XEN_GENERIC_H__ */
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