Differential D8645 Diff 22520 sys/dev/bhnd/nvram/bhnd_nvram_io.c

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sys/dev/bhnd/nvram/bhnd_nvram_io.c

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				/*-
				* Copyright (c) 2016 Landon Fuller <landonf@FreeBSD.org>
				* 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,
				* without modification.
				* 2. Redistributions in binary form must reproduce at minimum a disclaimer
				* similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
				* redistribution must be conditioned upon including a substantially
				* similar Disclaimer requirement for further binary redistribution.
				*
				* NO WARRANTY
				* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
				* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
				* LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
				* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
				* THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
				*/

				#include <sys/cdefs.h>
				__FBSDID("$FreeBSD$");

				#ifdef _KERNEL
				#include <sys/param.h>
				#else /* !_KERNEL */
				#include <errno.h>
				#include <stdint.h>
				#include <stdlib.h>
				#endif /* _KERNEL */

				#include "bhnd_nvram_io.h"
				#include "bhnd_nvram_iovar.h"

				/**
				* Read exactly @p nbytes from @p io at @p offset.
				*
				* @param io NVRAM I/O context.
				* @param offset The offset within @p io at which to perform the read.
				* @param[out] buffer Output buffer to which @p nbytes from @p io will be
				* written.
				* @param nbytes The maximum number of bytes to be read from @p io.
				*
				* @retval 0 success
				* @retval EIO if an input error occured reading @p io.
				* @retval ENXIO if the request for @p offset or @p nbytes exceeds the size
				* of @p io.
				* @retval EFAULT if @p io requires I/O request alignment and @p offset is
				* misaligned.
				* @retval EFAULT if @p io requires I/O request alignment and @p nbytes is
				* misaligned and cannot be rounded down to an aligned non-zero value.
				*/
				int
				bhnd_nvram_io_read(struct bhnd_nvram_io io, size_t offset, void buffer,
				size_t nbytes)
				{
				return (io->iops->read(io, offset, buffer, nbytes));
				}


				/**
				* Attempt to fetch a pointer to @p io's internal read buffer, if
				* supported by @p io.
				*
				* The returned pointer is only gauranteed to be valid until the next I/O
				* operation performed on @p io; concrete implementations of bhnd_nvram_io
				* may provide stronger gaurantees.
				*
				* @param io NVRAM I/O context.
				* @param offset The offset within @p io for which to return a buffer pointer.
				* @param[out] ptr On success, will be initialized with a pointer to @p io's
				* internal read buffer.
				* @param nbytes The minimum number of bytes that must be readable at @p offset.
				* @param[out] navail The actual number of readable bytes, which may be greater
				* than @p nbytes. If this value is not required, a NULL pointer may be
				* provided.
				*
				* @retval 0 success
				* @retval EIO if an input error occured reading @p io.
				* @retval ENODEV if @p io does not support direct access to its backing read
				* buffer.
				* @retval ENXIO if the request exceeds the size of @p io.
				* @retval EFAULT if @p io requires I/O request alignment and @p offset or
				* @p nbytes are misaligned.
				*/
				int
				bhnd_nvram_io_read_ptr(struct bhnd_nvram_io *io, size_t offset,
				const void *ptr, size_t nbytes, size_t navail)
				{
				return (io->iops->read_ptr(io, offset, ptr, nbytes, navail));
				}

				/**
				* Write @p nbytes to @p io at @p offset.
				*
				* @param io NVRAM I/O context.
				* @param offset The offset within @p io at which to perform the write.
				* @param buffer Data to be written to @p io.
				* @param nbytes The number of bytes to be written from @p buffer.
				*
				* @retval 0 success
				* @retval EIO if an output error occurs writing to @p io.
				* @retval ENODEV if @p io does not support writing.
				* @retval ENXIO if @p io does not support writes beyond the existing
				* end-of-file, and a write at @p offset would exceed the size of the @p io
				* backing data store.
				* @retval EFAULT if @p io requires I/O request alignment and @p offset or
				* @p nbytes are misaligned.
				*/
				int
				bhnd_nvram_io_write(struct bhnd_nvram_io io, size_t offset, void buffer,
				size_t nbytes)
				{
				return (io->iops->write(io, offset, buffer, nbytes));
				}

				/**
				* Attempt to fetch a writable pointer to @p io's internal write buffer, if
				* supported by @p io.
				*
				* The returned pointer is only gauranteed to be valid until the next I/O
				* operation performed on @p io; concrete implementations of bhnd_nvram_io
				* may provide stronger gaurantees.
				*
				* @param io NVRAM I/O context.
				* @param offset The offset within @p io for which to return a buffer pointer.
				* @param[in,out] ptr On success, will be initialized with a pointer to @p io's
				* internal buffer at which up to @p nbytes may be written.
				* @param nbytes The minimum number of bytes that must be writable at @p offset.
				* @param[out] navail The actual number of writable bytes, which may be greater
				* than @p nbytes. If this value is not required, a NULL pointer may be
				* provided.
				*
				* @retval 0 success
				* @retval EIO if an output error occurs preparing @p io's write buffer.
				* @retval ENODEV if @p io does not support direct access to its backing write
				* buffer.
				* @retval ENXIO if @p io does not support writes beyond the existing
				* end-of-file, and a write at @p offset of @p nbytes would exceed the size of
				* the @p io backing data store.
				* @retval EFAULT if @p io requires I/O request alignment and @p offset or
				* @p nbytes are misaligned.
				*/
				int
				bhnd_nvram_io_write_ptr(struct bhnd_nvram_io io, size_t offset, void *ptr,
				size_t nbytes, size_t *navail)
				{
				return (io->iops->write_ptr(io, offset, ptr, nbytes, navail));
				}

				/**
				* Return the total number of bytes readable via @p io.
				*
				* @param io NVRAM I/O context.
				*/
				size_t
				bhnd_nvram_io_getsize(struct bhnd_nvram_io *io)
				{
				return (io->iops->getsize(io));
				}

				/**
				* Attempt to set the size of @p io to @p size.
				*
				* If the total size of @p io is increased, the contents of the newly mapped
				* bytes are undefined; concrete implementations of bhnd_nvram_io may
				* provide stronger gaurantees.
				*
				* @param io NVRAM I/O context.
				* @param size The new size.
				*
				* @retval 0 success
				* @retval EIO if an I/O error occurs resizing @p io.
				* @retval ENODEV if @p io does not support resizing.
				* @retval ENXIO if @p size exceeds the capacity or other limits of @p io.
				* @retval EFAULT if @p io requires I/O request alignment and @p size is
				* misaligned.
				*/
				int
				bhnd_nvram_io_setsize(struct bhnd_nvram_io *io, size_t size)
				{
				return (io->iops->setsize(io, size));
				}

				/**
				* Free a previously allocated I/O context, releasing all associated
				* resources.
				*
				* @param io The I/O context to be freed.
				*/
				void
				bhnd_nvram_io_free(struct bhnd_nvram_io *io)
				{
				return (io->iops->free(io));
				}