xref: /linux/drivers/scsi/isci/remote_node_table.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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10  * it under the terms of version 2 of the GNU General Public License as
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55 
56 #ifndef _SCIC_SDS_REMOTE_NODE_TABLE_H_
57 #define _SCIC_SDS_REMOTE_NODE_TABLE_H_
58 
59 #include "isci.h"
60 
61 /**
62  *
63  *
64  * Remote node sets are sets of remote node index in the remtoe node table The
65  * SCU hardware requires that STP remote node entries take three consecutive
66  * remote node index so the table is arranged in sets of three. The bits are
67  * used as 0111 0111 to make a byte and the bits define the set of three remote
68  * nodes to use as a sequence.
69  */
70 #define SCIC_SDS_REMOTE_NODE_SETS_PER_BYTE 2
71 
72 /**
73  *
74  *
75  * Since the remote node table is organized as DWORDS take the remote node sets
76  * in bytes and represent them in DWORDs. The lowest ordered bits are the ones
77  * used in case full DWORD is not being used. i.e. 0000 0000 0000 0000 0111
78  * 0111 0111 0111 // if only a single WORD is in use in the DWORD.
79  */
80 #define SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD \
81 	(sizeof(u32) * SCIC_SDS_REMOTE_NODE_SETS_PER_BYTE)
82 /**
83  *
84  *
85  * This is a count of the numeber of remote nodes that can be represented in a
86  * byte
87  */
88 #define SCIC_SDS_REMOTE_NODES_PER_BYTE	\
89 	(SCU_STP_REMOTE_NODE_COUNT * SCIC_SDS_REMOTE_NODE_SETS_PER_BYTE)
90 
91 /**
92  *
93  *
94  * This is a count of the number of remote nodes that can be represented in a
95  * DWROD
96  */
97 #define SCIC_SDS_REMOTE_NODES_PER_DWORD	\
98 	(sizeof(u32) * SCIC_SDS_REMOTE_NODES_PER_BYTE)
99 
100 /**
101  *
102  *
103  * This is the number of bits in a remote node group
104  */
105 #define SCIC_SDS_REMOTE_NODES_BITS_PER_GROUP   4
106 
107 #define SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX      (0xFFFFFFFF)
108 #define SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE    (0x07)
109 #define SCIC_SDS_REMOTE_NODE_TABLE_EMPTY_SLOT_VALUE   (0x00)
110 
111 /**
112  *
113  *
114  * Expander attached sata remote node count
115  */
116 #define SCU_STP_REMOTE_NODE_COUNT        3
117 
118 /**
119  *
120  *
121  * Expander or direct attached ssp remote node count
122  */
123 #define SCU_SSP_REMOTE_NODE_COUNT        1
124 
125 /**
126  *
127  *
128  * Direct attached STP remote node count
129  */
130 #define SCU_SATA_REMOTE_NODE_COUNT       1
131 
132 /**
133  * struct sci_remote_node_table -
134  *
135  *
136  */
137 struct sci_remote_node_table {
138 	/**
139 	 * This field contains the array size in dwords
140 	 */
141 	u16 available_nodes_array_size;
142 
143 	/**
144 	 * This field contains the array size of the
145 	 */
146 	u16 group_array_size;
147 
148 	/**
149 	 * This field is the array of available remote node entries in bits.
150 	 * Because of the way STP remote node data is allocated on the SCU hardware
151 	 * the remote nodes must occupy three consecutive remote node context
152 	 * entries.  For ease of allocation and de-allocation we have broken the
153 	 * sets of three into a single nibble.  When the STP RNi is allocated all
154 	 * of the bits in the nibble are cleared.  This math results in a table size
155 	 * of MAX_REMOTE_NODES / CONSECUTIVE RNi ENTRIES for STP / 2 entries per byte.
156 	 */
157 	u32 available_remote_nodes[
158 		(SCI_MAX_REMOTE_DEVICES / SCIC_SDS_REMOTE_NODES_PER_DWORD)
159 		+ ((SCI_MAX_REMOTE_DEVICES % SCIC_SDS_REMOTE_NODES_PER_DWORD) != 0)];
160 
161 	/**
162 	 * This field is the nibble selector for the above table.  There are three
163 	 * possible selectors each for fast lookup when trying to find one, two or
164 	 * three remote node entries.
165 	 */
166 	u32 remote_node_groups[
167 		SCU_STP_REMOTE_NODE_COUNT][
168 		(SCI_MAX_REMOTE_DEVICES / (32 * SCU_STP_REMOTE_NODE_COUNT))
169 		+ ((SCI_MAX_REMOTE_DEVICES % (32 * SCU_STP_REMOTE_NODE_COUNT)) != 0)];
170 
171 };
172 
173 /* --------------------------------------------------------------------------- */
174 
175 void sci_remote_node_table_initialize(
176 	struct sci_remote_node_table *remote_node_table,
177 	u32 remote_node_entries);
178 
179 u16 sci_remote_node_table_allocate_remote_node(
180 	struct sci_remote_node_table *remote_node_table,
181 	u32 remote_node_count);
182 
183 void sci_remote_node_table_release_remote_node_index(
184 	struct sci_remote_node_table *remote_node_table,
185 	u32 remote_node_count,
186 	u16 remote_node_index);
187 
188 #endif /* _SCIC_SDS_REMOTE_NODE_TABLE_H_ */
189