numam-spdk/include/spdk/mmio.h
Daniel Verkamp 460327ea5c ioat, nvme: factor out MMIO helper functions
NVMe doesn't require the specific 64-bit MMIO ordering on 32-bit
platforms performed in spdk_mmio_read_8(), but it doesn't hurt.
We have to pick one of the two possible orderings, so pick the one
required by I/OAT.

Change-Id: I2b909d64d0c077b797d0f64a11d78d1ecc55eec7
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
2015-12-10 17:05:08 -07:00

92 lines
2.7 KiB
C

/*-
* BSD LICENSE
*
* Copyright(c) 2015 Intel Corporation. All rights reserved.
* All rights reserved.
*
* 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.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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 MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER 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 SPDK_MMIO_H
#define SPDK_MMIO_H
#include <inttypes.h>
#ifdef __x86_64__
#define SPDK_MMIO_64BIT 1 /* Can do atomic 64-bit memory read/write (over PCIe) */
#else
#define SPDK_MMIO_64BIT 0
#endif
static inline uint32_t
spdk_mmio_read_4(const volatile uint32_t *addr)
{
return *addr;
}
static inline void
spdk_mmio_write_4(volatile uint32_t *addr, uint32_t val)
{
*addr = val;
}
static inline uint64_t
spdk_mmio_read_8(volatile uint64_t *addr)
{
uint64_t val;
volatile uint32_t *addr32 = (volatile uint32_t *)addr;
if (SPDK_MMIO_64BIT) {
val = *addr;
} else {
/*
* Read lower 4 bytes before upper 4 bytes.
* This particular order is required by I/OAT.
* If the other order is required, use a pair of spdk_mmio_read_4() calls.
*/
val = addr32[0];
val |= (uint64_t)addr32[1] << 32;
}
return val;
}
static inline void
spdk_mmio_write_8(volatile uint64_t *addr, uint64_t val)
{
volatile uint32_t *addr32 = (volatile uint32_t *)addr;
if (SPDK_MMIO_64BIT) {
*addr = val;
} else {
addr32[0] = (uint32_t)val;
addr32[1] = (uint32_t)(val >> 32);
}
}
#endif