https://github.com/torvalds/linux
Tip revision: 219d54332a09e8d8741c1e1982f5eae56099de85 authored by Linus Torvalds on 25 November 2019, 00:32:01 UTC
Linux 5.4
Linux 5.4
Tip revision: 219d543
packer.c
/*
* Copyright (c) 2004 Topspin Corporation. All rights reserved.
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - 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.
*
* 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.
*/
#include <linux/export.h>
#include <linux/string.h>
#include <rdma/ib_pack.h>
static u64 value_read(int offset, int size, void *structure)
{
switch (size) {
case 1: return *(u8 *) (structure + offset);
case 2: return be16_to_cpup((__be16 *) (structure + offset));
case 4: return be32_to_cpup((__be32 *) (structure + offset));
case 8: return be64_to_cpup((__be64 *) (structure + offset));
default:
pr_warn("Field size %d bits not handled\n", size * 8);
return 0;
}
}
/**
* ib_pack - Pack a structure into a buffer
* @desc:Array of structure field descriptions
* @desc_len:Number of entries in @desc
* @structure:Structure to pack from
* @buf:Buffer to pack into
*
* ib_pack() packs a list of structure fields into a buffer,
* controlled by the array of fields in @desc.
*/
void ib_pack(const struct ib_field *desc,
int desc_len,
void *structure,
void *buf)
{
int i;
for (i = 0; i < desc_len; ++i) {
if (desc[i].size_bits <= 32) {
int shift;
u32 val;
__be32 mask;
__be32 *addr;
shift = 32 - desc[i].offset_bits - desc[i].size_bits;
if (desc[i].struct_size_bytes)
val = value_read(desc[i].struct_offset_bytes,
desc[i].struct_size_bytes,
structure) << shift;
else
val = 0;
mask = cpu_to_be32(((1ull << desc[i].size_bits) - 1) << shift);
addr = (__be32 *) buf + desc[i].offset_words;
*addr = (*addr & ~mask) | (cpu_to_be32(val) & mask);
} else if (desc[i].size_bits <= 64) {
int shift;
u64 val;
__be64 mask;
__be64 *addr;
shift = 64 - desc[i].offset_bits - desc[i].size_bits;
if (desc[i].struct_size_bytes)
val = value_read(desc[i].struct_offset_bytes,
desc[i].struct_size_bytes,
structure) << shift;
else
val = 0;
mask = cpu_to_be64((~0ull >> (64 - desc[i].size_bits)) << shift);
addr = (__be64 *) ((__be32 *) buf + desc[i].offset_words);
*addr = (*addr & ~mask) | (cpu_to_be64(val) & mask);
} else {
if (desc[i].offset_bits % 8 ||
desc[i].size_bits % 8) {
pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
desc[i].field_name, desc[i].size_bits);
}
if (desc[i].struct_size_bytes)
memcpy(buf + desc[i].offset_words * 4 +
desc[i].offset_bits / 8,
structure + desc[i].struct_offset_bytes,
desc[i].size_bits / 8);
else
memset(buf + desc[i].offset_words * 4 +
desc[i].offset_bits / 8,
0,
desc[i].size_bits / 8);
}
}
}
EXPORT_SYMBOL(ib_pack);
static void value_write(int offset, int size, u64 val, void *structure)
{
switch (size * 8) {
case 8: *( u8 *) (structure + offset) = val; break;
case 16: *(__be16 *) (structure + offset) = cpu_to_be16(val); break;
case 32: *(__be32 *) (structure + offset) = cpu_to_be32(val); break;
case 64: *(__be64 *) (structure + offset) = cpu_to_be64(val); break;
default:
pr_warn("Field size %d bits not handled\n", size * 8);
}
}
/**
* ib_unpack - Unpack a buffer into a structure
* @desc:Array of structure field descriptions
* @desc_len:Number of entries in @desc
* @buf:Buffer to unpack from
* @structure:Structure to unpack into
*
* ib_pack() unpacks a list of structure fields from a buffer,
* controlled by the array of fields in @desc.
*/
void ib_unpack(const struct ib_field *desc,
int desc_len,
void *buf,
void *structure)
{
int i;
for (i = 0; i < desc_len; ++i) {
if (!desc[i].struct_size_bytes)
continue;
if (desc[i].size_bits <= 32) {
int shift;
u32 val;
u32 mask;
__be32 *addr;
shift = 32 - desc[i].offset_bits - desc[i].size_bits;
mask = ((1ull << desc[i].size_bits) - 1) << shift;
addr = (__be32 *) buf + desc[i].offset_words;
val = (be32_to_cpup(addr) & mask) >> shift;
value_write(desc[i].struct_offset_bytes,
desc[i].struct_size_bytes,
val,
structure);
} else if (desc[i].size_bits <= 64) {
int shift;
u64 val;
u64 mask;
__be64 *addr;
shift = 64 - desc[i].offset_bits - desc[i].size_bits;
mask = (~0ull >> (64 - desc[i].size_bits)) << shift;
addr = (__be64 *) buf + desc[i].offset_words;
val = (be64_to_cpup(addr) & mask) >> shift;
value_write(desc[i].struct_offset_bytes,
desc[i].struct_size_bytes,
val,
structure);
} else {
if (desc[i].offset_bits % 8 ||
desc[i].size_bits % 8) {
pr_warn("Structure field %s of size %d bits is not byte-aligned\n",
desc[i].field_name, desc[i].size_bits);
}
memcpy(structure + desc[i].struct_offset_bytes,
buf + desc[i].offset_words * 4 +
desc[i].offset_bits / 8,
desc[i].size_bits / 8);
}
}
}
EXPORT_SYMBOL(ib_unpack);