freebsd-skq/sys/dev/bhnd/nvram/bhnd_nvram_io.c
landonf 7fa254ea43 bhnd(4): Unify NVRAM/SPROM parsing, implement compact SPROM layout encoding.
- Defined an abstract NVRAM I/O API (bhnd_nvram_io), decoupling NVRAM/SPROM
  parsing from the actual underlying NVRAM data provider (e.g. CFE firmware
  devices).
- Defined an abstract NVRAM data API (bhnd_nvram_data), decoupling
  higher-level NVRAM operations (indexed lookup, data conversion, etc) from
  the underlying NVRAM file format parsing/serialization.
- Implemented a new high-level bhnd_nvram_store API, providing indexed
  variable lookup, pending write tracking, etc on top of an arbitrary
  bhnd_nvram_data instance.
- Migrated all bhnd(4) NVRAM device drivers to the common bhnd_nvram_store
  API.
- Implemented a common bhnd_nvram_val API for parsing/encoding NVRAM
  variable values, including applying format-specific behavior when
  converting to/from the NVRAM string representations.
- Dropped the now unnecessary bhnd_nvram driver, and moved the
  broadcom/mips-specific CFE NVRAM driver out into sys/mips/broadcom.
- Implemented a new nvram_map file format:
        - Variable definitions are now defined separately from the SPROM
          layout. This will also allow us to define CIS tuple NVRAM
          mappings referencing the common NVRAM variable definitions.
        - Variables can now be defined within arbitrary named groups.
        - Textual descriptions and help information can be defined inline
          for both variables and variable groups.
        - Implemented a new, compact encoding of SPROM image layout
          offsets.
- Source-level (but not build system) support for building the NVRAM file
  format APIs (bhnd_nvram_io, bhnd_nvram_data, bhnd_nvram_store) as a
  userspace library.

The new compact SPROM image layout encoding is loosely modeled on Apple
dyld compressed LINKEDIT symbol binding opcodes; it provides a compact
state-machine encoding of the mapping between NVRAM variables and the SPROM
image offset, mask, and shift instructions necessary to decode or encode
the SPROM variable data.

The compact encoding reduces the size of the generated SPROM layout data
from roughly 60KB to 3KB. The sequential nature SPROM layout opcode tables
also simplify iteration of the SPROM variables, as it's no longer
neccessary to iterate the full NVRAM variable definition table, but
instead simply scan the SPROM revision's layout opcode table.

Approved by:    adrian (mentor)
Differential Revision:  https://reviews.freebsd.org/D8645
2016-11-26 23:22:32 +00:00

206 lines
7.1 KiB
C

/*-
* 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));
}