/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2012 EMC Corp. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _SYS_MEMDESC_H_ #define _SYS_MEMDESC_H_ struct bio; struct bus_dma_segment; struct uio; struct mbuf; struct vm_page; union ccb; /* * struct memdesc encapsulates various memory descriptors and provides * abstract access to them. */ struct memdesc { union { void *md_vaddr; vm_paddr_t md_paddr; struct bus_dma_segment *md_list; struct uio *md_uio; struct mbuf *md_mbuf; struct vm_page **md_ma; } u; union { /* type specific data. */ size_t md_len; /* VADDR, PADDR, VMPAGES */ int md_nseg; /* VLIST, PLIST */ }; union { uint32_t md_offset; /* VMPAGES */ }; uint32_t md_type; /* Type of memory. */ }; #define MEMDESC_VADDR 1 /* Contiguous virtual address. */ #define MEMDESC_PADDR 2 /* Contiguous physical address. */ #define MEMDESC_VLIST 3 /* scatter/gather list of kva addresses. */ #define MEMDESC_PLIST 4 /* scatter/gather list of physical addresses. */ #define MEMDESC_UIO 6 /* Pointer to a uio (any io). */ #define MEMDESC_MBUF 7 /* Pointer to a mbuf (network io). */ #define MEMDESC_VMPAGES 8 /* Pointer to array of VM pages. */ static inline struct memdesc memdesc_vaddr(void *vaddr, size_t len) { struct memdesc mem; mem.u.md_vaddr = vaddr; mem.md_len = len; mem.md_type = MEMDESC_VADDR; return (mem); } static inline struct memdesc memdesc_paddr(vm_paddr_t paddr, size_t len) { struct memdesc mem; mem.u.md_paddr = paddr; mem.md_len = len; mem.md_type = MEMDESC_PADDR; return (mem); } static inline struct memdesc memdesc_vlist(struct bus_dma_segment *vlist, int sglist_cnt) { struct memdesc mem; mem.u.md_list = vlist; mem.md_nseg = sglist_cnt; mem.md_type = MEMDESC_VLIST; return (mem); } static inline struct memdesc memdesc_plist(struct bus_dma_segment *plist, int sglist_cnt) { struct memdesc mem; mem.u.md_list = plist; mem.md_nseg = sglist_cnt; mem.md_type = MEMDESC_PLIST; return (mem); } static inline struct memdesc memdesc_uio(struct uio *uio) { struct memdesc mem; mem.u.md_uio = uio; mem.md_type = MEMDESC_UIO; return (mem); } static inline struct memdesc memdesc_mbuf(struct mbuf *mbuf) { struct memdesc mem; mem.u.md_mbuf = mbuf; mem.md_type = MEMDESC_MBUF; return (mem); } static inline struct memdesc memdesc_vmpages(struct vm_page **ma, size_t len, u_int ma_offset) { struct memdesc mem; mem.u.md_ma = ma; mem.md_len = len; mem.md_type = MEMDESC_VMPAGES; mem.md_offset = ma_offset; return (mem); } struct memdesc memdesc_bio(struct bio *bio); struct memdesc memdesc_ccb(union ccb *ccb); /* * Similar to m_copyback/data, *_copyback copy data from the 'src' * buffer into the memory descriptor's data buffer while *_copydata * copy data from the memory descriptor's data buffer into the the * 'dst' buffer. */ void memdesc_copyback(struct memdesc *mem, int off, int size, const void *src); void memdesc_copydata(struct memdesc *mem, int off, int size, void *dst); /* * This routine constructs a chain of M_EXT mbufs backed by a data * buffer described by a memory descriptor. Some buffers may require * multiple mbufs. For memory descriptors using unmapped storage * (e.g. memdesc_vmpages), M_EXTPG mbufs are used. * * Since memory descriptors are not an actual buffer, just a * description of the buffer, the caller is required to supply a * couple of helper routines to manage allocation of the raw mbufs and * associate them with a reference to the underlying buffer. * * The memdesc_alloc_ext_mbuf_t callback is passed the callback * argument as its first argument, the how flag as its second * argument, and the pointer and length of a KVA buffer. This * callback should allocate an mbuf for the KVA buffer, either by * making a copy of the data or using m_extaddref(). * * The memdesc_alloc_extpg_mbuf_t callback is passed the callback * argument as its first argument and the how flag as its second * argument. It should return an empty mbuf allocated by * mb_alloc_ext_pgs. * * If either of the callbacks returns NULL, any partially allocated * chain is freed and this routine returns NULL. * * If can_truncate is true, then this function might return a short * chain to avoid gratuitously splitting up a page. */ typedef struct mbuf *memdesc_alloc_ext_mbuf_t(void *, int, void *, size_t); typedef struct mbuf *memdesc_alloc_extpg_mbuf_t(void *, int); struct mbuf *memdesc_alloc_ext_mbufs(struct memdesc *mem, memdesc_alloc_ext_mbuf_t *ext_alloc, memdesc_alloc_extpg_mbuf_t *extpg_alloc, void *cb_arg, int how, size_t offset, size_t len, size_t *actual_len, bool can_truncate); #endif /* _SYS_MEMDESC_H_ */
