aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/isci/unsolicited_frame_control.c
blob: 04a6d0d59a225340c38c5b82c97f1ffe6d78e3ed (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 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.
 */

#include "host.h"
#include "unsolicited_frame_control.h"
#include "registers.h"

void sci_unsolicited_frame_control_construct(struct isci_host *ihost)
{
	struct sci_unsolicited_frame_control *uf_control = &ihost->uf_control;
	struct sci_unsolicited_frame *uf;
	dma_addr_t dma = ihost->ufi_dma;
	void *virt = ihost->ufi_buf;
	int i;

	/*
	 * The Unsolicited Frame buffers are set at the start of the UF
	 * memory descriptor entry. The headers and address table will be
	 * placed after the buffers.
	 */

	/*
	 * Program the location of the UF header table into the SCU.
	 * Notes:
	 * - The address must align on a 64-byte boundary. Guaranteed to be
	 *   on 64-byte boundary already 1KB boundary for unsolicited frames.
	 * - Program unused header entries to overlap with the last
	 *   unsolicited frame.  The silicon will never DMA to these unused
	 *   headers, since we program the UF address table pointers to
	 *   NULL.
	 */
	uf_control->headers.physical_address = dma + SCI_UFI_BUF_SIZE;
	uf_control->headers.array = virt + SCI_UFI_BUF_SIZE;

	/*
	 * Program the location of the UF address table into the SCU.
	 * Notes:
	 * - The address must align on a 64-bit boundary. Guaranteed to be on 64
	 *   byte boundary already due to above programming headers being on a
	 *   64-bit boundary and headers are on a 64-bytes in size.
	 */
	uf_control->address_table.physical_address = dma + SCI_UFI_BUF_SIZE + SCI_UFI_HDR_SIZE;
	uf_control->address_table.array = virt + SCI_UFI_BUF_SIZE + SCI_UFI_HDR_SIZE;
	uf_control->get = 0;

	/*
	 * UF buffer requirements are:
	 * - The last entry in the UF queue is not NULL.
	 * - There is a power of 2 number of entries (NULL or not-NULL)
	 *   programmed into the queue.
	 * - Aligned on a 1KB boundary. */

	/*
	 * Program the actual used UF buffers into the UF address table and
	 * the controller's array of UFs.
	 */
	for (i = 0; i < SCU_MAX_UNSOLICITED_FRAMES; i++) {
		uf = &uf_control->buffers.array[i];

		uf_control->address_table.array[i] = dma;

		uf->buffer = virt;
		uf->header = &uf_control->headers.array[i];
		uf->state  = UNSOLICITED_FRAME_EMPTY;

		/*
		 * Increment the address of the physical and virtual memory
		 * pointers. Everything is aligned on 1k boundary with an
		 * increment of 1k.
		 */
		virt += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
		dma += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
	}
}

enum sci_status sci_unsolicited_frame_control_get_header(struct sci_unsolicited_frame_control *uf_control,
							 u32 frame_index,
							 void **frame_header)
{
	if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
		/* Skip the first word in the frame since this is a controll word used
		 * by the hardware.
		 */
		*frame_header = &uf_control->buffers.array[frame_index].header->data;

		return SCI_SUCCESS;
	}

	return SCI_FAILURE_INVALID_PARAMETER_VALUE;
}

enum sci_status sci_unsolicited_frame_control_get_buffer(struct sci_unsolicited_frame_control *uf_control,
							 u32 frame_index,
							 void **frame_buffer)
{
	if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
		*frame_buffer = uf_control->buffers.array[frame_index].buffer;

		return SCI_SUCCESS;
	}

	return SCI_FAILURE_INVALID_PARAMETER_VALUE;
}

bool sci_unsolicited_frame_control_release_frame(struct sci_unsolicited_frame_control *uf_control,
						 u32 frame_index)
{
	u32 frame_get;
	u32 frame_cycle;

	frame_get   = uf_control->get & (SCU_MAX_UNSOLICITED_FRAMES - 1);
	frame_cycle = uf_control->get & SCU_MAX_UNSOLICITED_FRAMES;

	/*
	 * In the event there are NULL entries in the UF table, we need to
	 * advance the get pointer in order to find out if this frame should
	 * be released (i.e. update the get pointer)
	 */
	while (lower_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
	       upper_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
	       frame_get < SCU_MAX_UNSOLICITED_FRAMES)
		frame_get++;

	/*
	 * The table has a NULL entry as it's last element.  This is
	 * illegal.
	 */
	BUG_ON(frame_get >= SCU_MAX_UNSOLICITED_FRAMES);
	if (frame_index >= SCU_MAX_UNSOLICITED_FRAMES)
		return false;

	uf_control->buffers.array[frame_index].state = UNSOLICITED_FRAME_RELEASED;

	if (frame_get != frame_index) {
		/*
		 * Frames remain in use until we advance the get pointer
		 * so there is nothing we can do here
		 */
		return false;
	}

	/*
	 * The frame index is equal to the current get pointer so we
	 * can now free up all of the frame entries that
	 */
	while (uf_control->buffers.array[frame_get].state == UNSOLICITED_FRAME_RELEASED) {
		uf_control->buffers.array[frame_get].state = UNSOLICITED_FRAME_EMPTY;

		if (frame_get+1 == SCU_MAX_UNSOLICITED_FRAMES-1) {
			frame_cycle ^= SCU_MAX_UNSOLICITED_FRAMES;
			frame_get = 0;
		} else
			frame_get++;
	}

	uf_control->get = SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get;

	return true;
}