xref: /freebsd/sys/dev/ioat/ioat.h (revision 3311ff84eac3b7e82f28e331df0586036c6d361c)
1 /*-
2  * Copyright (C) 2012 Intel Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 __FBSDID("$FreeBSD$");
28 
29 #ifndef __IOAT_H__
30 #define __IOAT_H__
31 
32 #include <sys/param.h>
33 #include <machine/bus.h>
34 
35 /*
36  * This file defines the public interface to the IOAT driver.
37  */
38 
39 /*
40  * Enables an interrupt for this operation. Typically, you would only enable
41  * this on the last operation in a group
42  */
43 #define	DMA_INT_EN	0x1
44 /*
45  * Like M_NOWAIT.  Operations will return NULL if they cannot allocate a
46  * descriptor without blocking.
47  */
48 #define	DMA_NO_WAIT	0x2
49 #define	DMA_ALL_FLAGS	(DMA_INT_EN | DMA_NO_WAIT)
50 
51 /*
52  * Hardware revision number.  Different hardware revisions support different
53  * features.  For example, 3.2 cannot read from MMIO space, while 3.3 can.
54  */
55 #define	IOAT_VER_3_0			0x30
56 #define	IOAT_VER_3_2			0x32
57 #define	IOAT_VER_3_3			0x33
58 
59 typedef void *bus_dmaengine_t;
60 struct bus_dmadesc;
61 typedef void (*bus_dmaengine_callback_t)(void *arg, int error);
62 
63 /*
64  * Called first to acquire a reference to the DMA channel
65  */
66 bus_dmaengine_t ioat_get_dmaengine(uint32_t channel_index);
67 
68 /* Release the DMA channel */
69 void ioat_put_dmaengine(bus_dmaengine_t dmaengine);
70 
71 /* Check the DMA engine's HW version */
72 int ioat_get_hwversion(bus_dmaengine_t dmaengine);
73 size_t ioat_get_max_io_size(bus_dmaengine_t dmaengine);
74 
75 /*
76  * Set interrupt coalescing on a DMA channel.
77  *
78  * The argument is in microseconds.  A zero value disables coalescing.  Any
79  * other value delays interrupt generation for N microseconds to provide
80  * opportunity to coalesce multiple operations into a single interrupt.
81  *
82  * Returns an error status, or zero on success.
83  *
84  * - ERANGE if the given value exceeds the delay supported by the hardware.
85  *   (All current hardware supports a maximum of 0x3fff microseconds delay.)
86  * - ENODEV if the hardware does not support interrupt coalescing.
87  */
88 int ioat_set_interrupt_coalesce(bus_dmaengine_t dmaengine, uint16_t delay);
89 
90 /*
91  * Return the maximum supported coalescing period, for use in
92  * ioat_set_interrupt_coalesce().  If the hardware does not support coalescing,
93  * returns zero.
94  */
95 uint16_t ioat_get_max_coalesce_period(bus_dmaengine_t dmaengine);
96 
97 /*
98  * Acquire must be called before issuing an operation to perform. Release is
99  * called after.  Multiple operations can be issued within the context of one
100  * acquire and release
101  */
102 void ioat_acquire(bus_dmaengine_t dmaengine);
103 void ioat_release(bus_dmaengine_t dmaengine);
104 
105 /*
106  * Acquire_reserve can be called to ensure there is room for N descriptors.  If
107  * it succeeds, the next N valid operations will successfully enqueue.
108  *
109  * It may fail with:
110  *   - ENXIO if the channel is in an errored state, or the driver is being
111  *     unloaded
112  *   - EAGAIN if mflags included M_NOWAIT
113  *
114  * On failure, the caller does not hold the dmaengine.
115  */
116 int ioat_acquire_reserve(bus_dmaengine_t dmaengine, unsigned n, int mflags);
117 
118 /*
119  * Issue a blockfill operation.  The 64-bit pattern 'fillpattern' is written to
120  * 'len' physically contiguous bytes at 'dst'.
121  *
122  * Only supported on devices with the BFILL capability.
123  */
124 struct bus_dmadesc *ioat_blockfill(bus_dmaengine_t dmaengine, bus_addr_t dst,
125     uint64_t fillpattern, bus_size_t len, bus_dmaengine_callback_t callback_fn,
126     void *callback_arg, uint32_t flags);
127 
128 /* Issues the copy data operation */
129 struct bus_dmadesc *ioat_copy(bus_dmaengine_t dmaengine, bus_addr_t dst,
130     bus_addr_t src, bus_size_t len, bus_dmaengine_callback_t callback_fn,
131     void *callback_arg, uint32_t flags);
132 
133 /*
134  * Issue a copy data operation, with constraints:
135  *  - src1, src2, dst1, dst2 are all page-aligned addresses
136  *  - The quantity to copy is exactly 2 pages;
137  *  - src1 -> dst1, src2 -> dst2
138  *
139  * Why use this instead of normal _copy()?  You can copy two non-contiguous
140  * pages (src, dst, or both) with one descriptor.
141  */
142 struct bus_dmadesc *ioat_copy_8k_aligned(bus_dmaengine_t dmaengine,
143     bus_addr_t dst1, bus_addr_t dst2, bus_addr_t src1, bus_addr_t src2,
144     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags);
145 
146 /*
147  * Issues a null operation. This issues the operation to the hardware, but the
148  * hardware doesn't do anything with it.
149  */
150 struct bus_dmadesc *ioat_null(bus_dmaengine_t dmaengine,
151     bus_dmaengine_callback_t callback_fn, void *callback_arg, uint32_t flags);
152 
153 
154 #endif /* __IOAT_H__ */
155 
156