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authorDan Williams <dan.j.williams@intel.com>2011-06-07 21:50:55 -0400
committerDan Williams <dan.j.williams@intel.com>2011-07-03 07:04:51 -0400
commitac668c69709c7d927015c5cf3d9e87bf4eaaf57d (patch)
tree16a42117d260a86b8217d266ab65b25438c48e06
parent9b917987fd16d0687afe550a02f68099419f5d43 (diff)
isci: cleanup/optimize pool implementation
The circ_buf macros are ~6% faster, as measured by perf, because they take advantage of power-of-two math assumptions i.e. no test and branch for rollover. Their semantics are clearer than the hidden side effects in pool.h (like sci_pool_get() which hides an assignment). Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--drivers/scsi/isci/host.c75
-rw-r--r--drivers/scsi/isci/host.h12
-rw-r--r--drivers/scsi/isci/isci.h1
-rw-r--r--drivers/scsi/isci/pool.h199
4 files changed, 56 insertions, 231 deletions
diff --git a/drivers/scsi/isci/host.c b/drivers/scsi/isci/host.c
index 41a7c5099dea..343655bd1a6a 100644
--- a/drivers/scsi/isci/host.c
+++ b/drivers/scsi/isci/host.c
@@ -52,6 +52,7 @@
52 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 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. 53 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54 */ 54 */
55#include <linux/circ_buf.h>
55#include <linux/device.h> 56#include <linux/device.h>
56#include <scsi/sas.h> 57#include <scsi/sas.h>
57#include "host.h" 58#include "host.h"
@@ -1054,6 +1055,33 @@ done:
1054 spin_unlock_irqrestore(&ihost->scic_lock, flags); 1055 spin_unlock_irqrestore(&ihost->scic_lock, flags);
1055} 1056}
1056 1057
1058static void isci_tci_free(struct isci_host *ihost, u16 tci)
1059{
1060 u16 tail = ihost->tci_tail & (SCI_MAX_IO_REQUESTS-1);
1061
1062 ihost->tci_pool[tail] = tci;
1063 ihost->tci_tail = tail + 1;
1064}
1065
1066static u16 isci_tci_alloc(struct isci_host *ihost)
1067{
1068 u16 head = ihost->tci_head & (SCI_MAX_IO_REQUESTS-1);
1069 u16 tci = ihost->tci_pool[head];
1070
1071 ihost->tci_head = head + 1;
1072 return tci;
1073}
1074
1075static u16 isci_tci_active(struct isci_host *ihost)
1076{
1077 return CIRC_CNT(ihost->tci_head, ihost->tci_tail, SCI_MAX_IO_REQUESTS);
1078}
1079
1080static u16 isci_tci_space(struct isci_host *ihost)
1081{
1082 return CIRC_SPACE(ihost->tci_head, ihost->tci_tail, SCI_MAX_IO_REQUESTS);
1083}
1084
1057static enum sci_status scic_controller_start(struct scic_sds_controller *scic, 1085static enum sci_status scic_controller_start(struct scic_sds_controller *scic,
1058 u32 timeout) 1086 u32 timeout)
1059{ 1087{
@@ -1069,9 +1097,11 @@ static enum sci_status scic_controller_start(struct scic_sds_controller *scic,
1069 } 1097 }
1070 1098
1071 /* Build the TCi free pool */ 1099 /* Build the TCi free pool */
1072 sci_pool_initialize(scic->tci_pool); 1100 BUILD_BUG_ON(SCI_MAX_IO_REQUESTS > 1 << sizeof(ihost->tci_pool[0]) * 8);
1101 ihost->tci_head = 0;
1102 ihost->tci_tail = 0;
1073 for (index = 0; index < scic->task_context_entries; index++) 1103 for (index = 0; index < scic->task_context_entries; index++)
1074 sci_pool_put(scic->tci_pool, index); 1104 isci_tci_free(ihost, index);
1075 1105
1076 /* Build the RNi free pool */ 1106 /* Build the RNi free pool */
1077 scic_sds_remote_node_table_initialize( 1107 scic_sds_remote_node_table_initialize(
@@ -3063,18 +3093,17 @@ enum sci_task_status scic_controller_start_task(
3063 * currently available tags to be allocated. All return other values indicate a 3093 * currently available tags to be allocated. All return other values indicate a
3064 * legitimate tag. 3094 * legitimate tag.
3065 */ 3095 */
3066u16 scic_controller_allocate_io_tag( 3096u16 scic_controller_allocate_io_tag(struct scic_sds_controller *scic)
3067 struct scic_sds_controller *scic)
3068{ 3097{
3069 u16 task_context; 3098 struct isci_host *ihost = scic_to_ihost(scic);
3070 u16 sequence_count; 3099 u16 tci;
3071 3100 u16 seq;
3072 if (!sci_pool_empty(scic->tci_pool)) {
3073 sci_pool_get(scic->tci_pool, task_context);
3074 3101
3075 sequence_count = scic->io_request_sequence[task_context]; 3102 if (isci_tci_space(ihost)) {
3103 tci = isci_tci_alloc(ihost);
3104 seq = scic->io_request_sequence[tci];
3076 3105
3077 return scic_sds_io_tag_construct(sequence_count, task_context); 3106 return scic_sds_io_tag_construct(seq, tci);
3078 } 3107 }
3079 3108
3080 return SCI_CONTROLLER_INVALID_IO_TAG; 3109 return SCI_CONTROLLER_INVALID_IO_TAG;
@@ -3105,10 +3134,10 @@ u16 scic_controller_allocate_io_tag(
3105 * tags. SCI_FAILURE_INVALID_IO_TAG This value is returned if the supplied tag 3134 * tags. SCI_FAILURE_INVALID_IO_TAG This value is returned if the supplied tag
3106 * is not a valid IO tag value. 3135 * is not a valid IO tag value.
3107 */ 3136 */
3108enum sci_status scic_controller_free_io_tag( 3137enum sci_status scic_controller_free_io_tag(struct scic_sds_controller *scic,
3109 struct scic_sds_controller *scic, 3138 u16 io_tag)
3110 u16 io_tag)
3111{ 3139{
3140 struct isci_host *ihost = scic_to_ihost(scic);
3112 u16 sequence; 3141 u16 sequence;
3113 u16 index; 3142 u16 index;
3114 3143
@@ -3117,18 +3146,16 @@ enum sci_status scic_controller_free_io_tag(
3117 sequence = scic_sds_io_tag_get_sequence(io_tag); 3146 sequence = scic_sds_io_tag_get_sequence(io_tag);
3118 index = scic_sds_io_tag_get_index(io_tag); 3147 index = scic_sds_io_tag_get_index(io_tag);
3119 3148
3120 if (!sci_pool_full(scic->tci_pool)) { 3149 /* prevent tail from passing head */
3121 if (sequence == scic->io_request_sequence[index]) { 3150 if (isci_tci_active(ihost) == 0)
3122 scic_sds_io_sequence_increment( 3151 return SCI_FAILURE_INVALID_IO_TAG;
3123 scic->io_request_sequence[index]);
3124 3152
3125 sci_pool_put(scic->tci_pool, index); 3153 if (sequence == scic->io_request_sequence[index]) {
3154 scic_sds_io_sequence_increment(scic->io_request_sequence[index]);
3126 3155
3127 return SCI_SUCCESS; 3156 isci_tci_free(ihost, index);
3128 }
3129 }
3130 3157
3158 return SCI_SUCCESS;
3159 }
3131 return SCI_FAILURE_INVALID_IO_TAG; 3160 return SCI_FAILURE_INVALID_IO_TAG;
3132} 3161}
3133
3134
diff --git a/drivers/scsi/isci/host.h b/drivers/scsi/isci/host.h
index 740350043d89..c61a9fa130b7 100644
--- a/drivers/scsi/isci/host.h
+++ b/drivers/scsi/isci/host.h
@@ -57,7 +57,6 @@
57 57
58#include "remote_device.h" 58#include "remote_device.h"
59#include "phy.h" 59#include "phy.h"
60#include "pool.h"
61#include "isci.h" 60#include "isci.h"
62#include "remote_node_table.h" 61#include "remote_node_table.h"
63#include "registers.h" 62#include "registers.h"
@@ -180,11 +179,6 @@ struct scic_sds_controller {
180 struct scic_remote_node_table available_remote_nodes; 179 struct scic_remote_node_table available_remote_nodes;
181 180
182 /** 181 /**
183 * This field is the TCi pool used to manage the task context index.
184 */
185 SCI_POOL_CREATE(tci_pool, u16, SCI_MAX_IO_REQUESTS);
186
187 /**
188 * This filed is the struct scic_power_control data used to controll when direct 182 * This filed is the struct scic_power_control data used to controll when direct
189 * attached devices can consume power. 183 * attached devices can consume power.
190 */ 184 */
@@ -310,6 +304,10 @@ struct scic_sds_controller {
310 304
311struct isci_host { 305struct isci_host {
312 struct scic_sds_controller sci; 306 struct scic_sds_controller sci;
307 u16 tci_head;
308 u16 tci_tail;
309 u16 tci_pool[SCI_MAX_IO_REQUESTS];
310
313 union scic_oem_parameters oem_parameters; 311 union scic_oem_parameters oem_parameters;
314 312
315 int id; /* unique within a given pci device */ 313 int id; /* unique within a given pci device */
@@ -423,8 +421,6 @@ enum scic_sds_controller_states {
423 SCIC_FAILED, 421 SCIC_FAILED,
424}; 422};
425 423
426
427
428/** 424/**
429 * struct isci_pci_info - This class represents the pci function containing the 425 * struct isci_pci_info - This class represents the pci function containing the
430 * controllers. Depending on PCI SKU, there could be up to 2 controllers in 426 * controllers. Depending on PCI SKU, there could be up to 2 controllers in
diff --git a/drivers/scsi/isci/isci.h b/drivers/scsi/isci/isci.h
index 714ed926171b..84ba533ca51e 100644
--- a/drivers/scsi/isci/isci.h
+++ b/drivers/scsi/isci/isci.h
@@ -112,6 +112,7 @@ static inline void check_sizes(void)
112 BUILD_BUG_ON_NOT_POWER_OF_2(SCU_MAX_UNSOLICITED_FRAMES); 112 BUILD_BUG_ON_NOT_POWER_OF_2(SCU_MAX_UNSOLICITED_FRAMES);
113 BUILD_BUG_ON_NOT_POWER_OF_2(SCU_MAX_COMPLETION_QUEUE_ENTRIES); 113 BUILD_BUG_ON_NOT_POWER_OF_2(SCU_MAX_COMPLETION_QUEUE_ENTRIES);
114 BUILD_BUG_ON(SCU_MAX_UNSOLICITED_FRAMES > SCU_ABSOLUTE_MAX_UNSOLICITED_FRAMES); 114 BUILD_BUG_ON(SCU_MAX_UNSOLICITED_FRAMES > SCU_ABSOLUTE_MAX_UNSOLICITED_FRAMES);
115 BUILD_BUG_ON_NOT_POWER_OF_2(SCI_MAX_IO_REQUESTS);
115} 116}
116 117
117/** 118/**
diff --git a/drivers/scsi/isci/pool.h b/drivers/scsi/isci/pool.h
deleted file mode 100644
index 016ec832f74f..000000000000
--- a/drivers/scsi/isci/pool.h
+++ /dev/null
@@ -1,199 +0,0 @@
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/**
57 * This file contains the interface to the pool class. This class allows two
58 * different two different priority tasks to insert and remove items from
59 * the free pool. The user of the pool is expected to evaluate the pool
60 * condition empty before a get operation and pool condition full before a
61 * put operation. Methods Provided: - sci_pool_create() -
62 * sci_pool_initialize() - sci_pool_empty() - sci_pool_full() -
63 * sci_pool_get() - sci_pool_put()
64 *
65 *
66 */
67
68#ifndef _SCI_POOL_H_
69#define _SCI_POOL_H_
70
71/**
72 * SCI_POOL_INCREMENT() -
73 *
74 * Private operation for the pool
75 */
76#define SCI_POOL_INCREMENT(pool, index) \
77 (((index) + 1) == (pool).size ? 0 : (index) + 1)
78
79/**
80 * SCI_POOL_CREATE() -
81 *
82 * This creates a pool structure of pool_name. The members in the pool are of
83 * type with number of elements equal to size.
84 */
85#define SCI_POOL_CREATE(pool_name, type, pool_size) \
86 struct \
87 { \
88 u32 size; \
89 u32 get; \
90 u32 put; \
91 type array[(pool_size) + 1]; \
92 } pool_name
93
94
95/**
96 * sci_pool_empty() -
97 *
98 * This macro evaluates the pool and returns true if the pool is empty. If the
99 * pool is empty the user should not perform any get operation on the pool.
100 */
101#define sci_pool_empty(pool) \
102 ((pool).get == (pool).put)
103
104/**
105 * sci_pool_full() -
106 *
107 * This macro evaluates the pool and returns true if the pool is full. If the
108 * pool is full the user should not perform any put operation.
109 */
110#define sci_pool_full(pool) \
111 (SCI_POOL_INCREMENT(pool, (pool).put) == (pool).get)
112
113/**
114 * sci_pool_size() -
115 *
116 * This macro returns the size of the pool created. The internal size of the
117 * pool is actually 1 larger then necessary in order to ensure get and put
118 * pointers can be written simultaneously by different users. As a result,
119 * this macro subtracts 1 from the internal size
120 */
121#define sci_pool_size(pool) \
122 ((pool).size - 1)
123
124/**
125 * sci_pool_count() -
126 *
127 * This macro indicates the number of elements currently contained in the pool.
128 */
129#define sci_pool_count(pool) \
130 (\
131 sci_pool_empty((pool)) \
132 ? 0 \
133 : (\
134 sci_pool_full((pool)) \
135 ? sci_pool_size((pool)) \
136 : (\
137 (pool).get > (pool).put \
138 ? ((pool).size - (pool).get + (pool).put) \
139 : ((pool).put - (pool).get) \
140 ) \
141 ) \
142 )
143
144/**
145 * sci_pool_initialize() -
146 *
147 * This macro initializes the pool to an empty condition.
148 */
149#define sci_pool_initialize(pool) \
150 { \
151 (pool).size = (sizeof((pool).array) / sizeof((pool).array[0])); \
152 (pool).get = 0; \
153 (pool).put = 0; \
154 }
155
156/**
157 * sci_pool_get() -
158 *
159 * This macro will get the next free element from the pool. This should only be
160 * called if the pool is not empty.
161 */
162#define sci_pool_get(pool, my_value) \
163 { \
164 (my_value) = (pool).array[(pool).get]; \
165 (pool).get = SCI_POOL_INCREMENT((pool), (pool).get); \
166 }
167
168/**
169 * sci_pool_put() -
170 *
171 * This macro will put the value into the pool. This should only be called if
172 * the pool is not full.
173 */
174#define sci_pool_put(pool, value) \
175 { \
176 (pool).array[(pool).put] = (value); \
177 (pool).put = SCI_POOL_INCREMENT((pool), (pool).put); \
178 }
179
180/**
181 * sci_pool_erase() -
182 *
183 * This macro will search the pool and remove any elements in the pool matching
184 * the supplied value. This method can only be utilized on pools
185 */
186#define sci_pool_erase(pool, type, value) \
187 { \
188 type tmp_value; \
189 u32 index; \
190 u32 element_count = sci_pool_count((pool)); \
191 \
192 for (index = 0; index < element_count; index++) { \
193 sci_pool_get((pool), tmp_value); \
194 if (tmp_value != (value)) \
195 sci_pool_put((pool), tmp_value); \
196 } \
197 }
198
199#endif /* _SCI_POOL_H_ */