ceph/src/spdk/include/spdk/mmio.h

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright (c) Intel Corporation.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /** \file
  35  * Memory-mapped I/O utility functions
  36  */
  37
  38 #ifndef SPDK_MMIO_H
  39 #define SPDK_MMIO_H
  40
  41 #include "spdk/stdinc.h"
  42
  43 #ifdef __cplusplus
  44 extern "C" {
  45 #endif
  46
  47 #include "spdk/barrier.h"
  48
  49 #ifdef __x86_64__
  50 #define SPDK_MMIO_64BIT 1 /* Can do atomic 64-bit memory read/write (over PCIe) */
  51 #else
  52 #define SPDK_MMIO_64BIT 0
  53 #endif
  54
  55 static inline uint8_t
  56 spdk_mmio_read_1(const volatile uint8_t *addr)
  57 {
  58         spdk_compiler_barrier();
  59         return *addr;
  60 }
  61
  62 static inline void
  63 spdk_mmio_write_1(volatile uint8_t *addr, uint8_t val)
  64 {
  65         spdk_compiler_barrier();
  66         *addr = val;
  67 }
  68
  69 static inline uint16_t
  70 spdk_mmio_read_2(const volatile uint16_t *addr)
  71 {
  72         spdk_compiler_barrier();
  73         return *addr;
  74 }
  75
  76 static inline void
  77 spdk_mmio_write_2(volatile uint16_t *addr, uint16_t val)
  78 {
  79         spdk_compiler_barrier();
  80         *addr = val;
  81 }
  82
  83 static inline uint32_t
  84 spdk_mmio_read_4(const volatile uint32_t *addr)
  85 {
  86         spdk_compiler_barrier();
  87         return *addr;
  88 }
  89
  90 static inline void
  91 spdk_mmio_write_4(volatile uint32_t *addr, uint32_t val)
  92 {
  93         spdk_compiler_barrier();
  94         *addr = val;
  95 }
  96
  97 static inline uint64_t
  98 spdk_mmio_read_8(volatile uint64_t *addr)
  99 {
 100         uint64_t val;
 101         volatile uint32_t *addr32 = (volatile uint32_t *)addr;
 102
 103         spdk_compiler_barrier();
 104
 105         if (SPDK_MMIO_64BIT) {
 106                 val = *addr;
 107         } else {
 108                 /*
 109                  * Read lower 4 bytes before upper 4 bytes.
 110                  * This particular order is required by I/OAT.
 111                  * If the other order is required, use a pair of spdk_mmio_read_4() calls.
 112                  */
 113                 val = addr32[0];
 114                 val |= (uint64_t)addr32[1] << 32;
 115         }
 116
 117         return val;
 118 }
 119
 120 static inline void
 121 spdk_mmio_write_8(volatile uint64_t *addr, uint64_t val)
 122 {
 123         volatile uint32_t *addr32 = (volatile uint32_t *)addr;
 124
 125         spdk_compiler_barrier();
 126
 127         if (SPDK_MMIO_64BIT) {
 128                 *addr = val;
 129         } else {
 130                 addr32[0] = (uint32_t)val;
 131                 addr32[1] = (uint32_t)(val >> 32);
 132         }
 133 }
 134
 135 #ifdef __cplusplus
 136 }
 137 #endif
 138
 139 #endif