xref: /linux/drivers/scsi/isci/unsolicited_frame_control.c (revision 4be5e8648b0c287aefc6ac3f3a0b12c696054f43)
1 /*
2  * This file is provided under a dual BSD/GPLv2 license.  When using or
3  * redistributing this file, you may do so under either license.
4  *
5  * GPL LICENSE SUMMARY
6  *
7  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of version 2 of the GNU General Public License as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
21  * The full GNU General Public License is included in this distribution
22  * in the file called LICENSE.GPL.
23  *
24  * BSD LICENSE
25  *
26  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
27  * All rights reserved.
28  *
29  * Redistribution and use in source and binary forms, with or without
30  * modification, are permitted provided that the following conditions
31  * are met:
32  *
33  *   * Redistributions of source code must retain the above copyright
34  *     notice, this list of conditions and the following disclaimer.
35  *   * Redistributions in binary form must reproduce the above copyright
36  *     notice, this list of conditions and the following disclaimer in
37  *     the documentation and/or other materials provided with the
38  *     distribution.
39  *   * Neither the name of Intel Corporation nor the names of its
40  *     contributors may be used to endorse or promote products derived
41  *     from this software without specific prior written permission.
42  *
43  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
44  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
45  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
46  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
47  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
48  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
49  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
50  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
51  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
52  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
53  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54  */
55 
56 #include "host.h"
57 #include "unsolicited_frame_control.h"
58 #include "registers.h"
59 
60 void sci_unsolicited_frame_control_construct(struct isci_host *ihost)
61 {
62 	struct sci_unsolicited_frame_control *uf_control = &ihost->uf_control;
63 	struct sci_unsolicited_frame *uf;
64 	dma_addr_t dma = ihost->ufi_dma;
65 	void *virt = ihost->ufi_buf;
66 	int i;
67 
68 	/*
69 	 * The Unsolicited Frame buffers are set at the start of the UF
70 	 * memory descriptor entry. The headers and address table will be
71 	 * placed after the buffers.
72 	 */
73 
74 	/*
75 	 * Program the location of the UF header table into the SCU.
76 	 * Notes:
77 	 * - The address must align on a 64-byte boundary. Guaranteed to be
78 	 *   on 64-byte boundary already 1KB boundary for unsolicited frames.
79 	 * - Program unused header entries to overlap with the last
80 	 *   unsolicited frame.  The silicon will never DMA to these unused
81 	 *   headers, since we program the UF address table pointers to
82 	 *   NULL.
83 	 */
84 	uf_control->headers.physical_address = dma + SCI_UFI_BUF_SIZE;
85 	uf_control->headers.array = virt + SCI_UFI_BUF_SIZE;
86 
87 	/*
88 	 * Program the location of the UF address table into the SCU.
89 	 * Notes:
90 	 * - The address must align on a 64-bit boundary. Guaranteed to be on 64
91 	 *   byte boundary already due to above programming headers being on a
92 	 *   64-bit boundary and headers are on a 64-bytes in size.
93 	 */
94 	uf_control->address_table.physical_address = dma + SCI_UFI_BUF_SIZE + SCI_UFI_HDR_SIZE;
95 	uf_control->address_table.array = virt + SCI_UFI_BUF_SIZE + SCI_UFI_HDR_SIZE;
96 	uf_control->get = 0;
97 
98 	/*
99 	 * UF buffer requirements are:
100 	 * - The last entry in the UF queue is not NULL.
101 	 * - There is a power of 2 number of entries (NULL or not-NULL)
102 	 *   programmed into the queue.
103 	 * - Aligned on a 1KB boundary. */
104 
105 	/*
106 	 * Program the actual used UF buffers into the UF address table and
107 	 * the controller's array of UFs.
108 	 */
109 	for (i = 0; i < SCU_MAX_UNSOLICITED_FRAMES; i++) {
110 		uf = &uf_control->buffers.array[i];
111 
112 		uf_control->address_table.array[i] = dma;
113 
114 		uf->buffer = virt;
115 		uf->header = &uf_control->headers.array[i];
116 		uf->state  = UNSOLICITED_FRAME_EMPTY;
117 
118 		/*
119 		 * Increment the address of the physical and virtual memory
120 		 * pointers. Everything is aligned on 1k boundary with an
121 		 * increment of 1k.
122 		 */
123 		virt += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
124 		dma += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
125 	}
126 }
127 
128 enum sci_status sci_unsolicited_frame_control_get_header(struct sci_unsolicited_frame_control *uf_control,
129 							 u32 frame_index,
130 							 void **frame_header)
131 {
132 	if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
133 		/* Skip the first word in the frame since this is a controll word used
134 		 * by the hardware.
135 		 */
136 		*frame_header = &uf_control->buffers.array[frame_index].header->data;
137 
138 		return SCI_SUCCESS;
139 	}
140 
141 	return SCI_FAILURE_INVALID_PARAMETER_VALUE;
142 }
143 
144 enum sci_status sci_unsolicited_frame_control_get_buffer(struct sci_unsolicited_frame_control *uf_control,
145 							 u32 frame_index,
146 							 void **frame_buffer)
147 {
148 	if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
149 		*frame_buffer = uf_control->buffers.array[frame_index].buffer;
150 
151 		return SCI_SUCCESS;
152 	}
153 
154 	return SCI_FAILURE_INVALID_PARAMETER_VALUE;
155 }
156 
157 bool sci_unsolicited_frame_control_release_frame(struct sci_unsolicited_frame_control *uf_control,
158 						 u32 frame_index)
159 {
160 	u32 frame_get;
161 	u32 frame_cycle;
162 
163 	frame_get   = uf_control->get & (SCU_MAX_UNSOLICITED_FRAMES - 1);
164 	frame_cycle = uf_control->get & SCU_MAX_UNSOLICITED_FRAMES;
165 
166 	/*
167 	 * In the event there are NULL entries in the UF table, we need to
168 	 * advance the get pointer in order to find out if this frame should
169 	 * be released (i.e. update the get pointer)
170 	 */
171 	while (lower_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
172 	       upper_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
173 	       frame_get < SCU_MAX_UNSOLICITED_FRAMES)
174 		frame_get++;
175 
176 	/*
177 	 * The table has a NULL entry as it's last element.  This is
178 	 * illegal.
179 	 */
180 	BUG_ON(frame_get >= SCU_MAX_UNSOLICITED_FRAMES);
181 	if (frame_index >= SCU_MAX_UNSOLICITED_FRAMES)
182 		return false;
183 
184 	uf_control->buffers.array[frame_index].state = UNSOLICITED_FRAME_RELEASED;
185 
186 	if (frame_get != frame_index) {
187 		/*
188 		 * Frames remain in use until we advance the get pointer
189 		 * so there is nothing we can do here
190 		 */
191 		return false;
192 	}
193 
194 	/*
195 	 * The frame index is equal to the current get pointer so we
196 	 * can now free up all of the frame entries that
197 	 */
198 	while (uf_control->buffers.array[frame_get].state == UNSOLICITED_FRAME_RELEASED) {
199 		uf_control->buffers.array[frame_get].state = UNSOLICITED_FRAME_EMPTY;
200 
201 		if (frame_get+1 == SCU_MAX_UNSOLICITED_FRAMES-1) {
202 			frame_cycle ^= SCU_MAX_UNSOLICITED_FRAMES;
203 			frame_get = 0;
204 		} else
205 			frame_get++;
206 	}
207 
208 	uf_control->get = SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get;
209 
210 	return true;
211 }
212