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authorDan Williams <dan.j.williams@intel.com>2011-06-07 18:50:55 -0700
committerDan Williams <dan.j.williams@intel.com>2011-07-03 04:04:51 -0700
commitac668c69709c7d927015c5cf3d9e87bf4eaaf57d (patch)
tree16a42117d260a86b8217d266ab65b25438c48e06
parent9b917987fd16d0687afe550a02f68099419f5d43 (diff)
downloadlinux-sh-ac668c69709c7d927015c5cf3d9e87bf4eaaf57d.tar.gz
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 @@
* (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 <linux/circ_buf.h>
#include <linux/device.h>
#include <scsi/sas.h>
#include "host.h"
@@ -1054,6 +1055,33 @@ done:
spin_unlock_irqrestore(&ihost->scic_lock, flags);
}
+static void isci_tci_free(struct isci_host *ihost, u16 tci)
+{
+ u16 tail = ihost->tci_tail & (SCI_MAX_IO_REQUESTS-1);
+
+ ihost->tci_pool[tail] = tci;
+ ihost->tci_tail = tail + 1;
+}
+
+static u16 isci_tci_alloc(struct isci_host *ihost)
+{
+ u16 head = ihost->tci_head & (SCI_MAX_IO_REQUESTS-1);
+ u16 tci = ihost->tci_pool[head];
+
+ ihost->tci_head = head + 1;
+ return tci;
+}
+
+static u16 isci_tci_active(struct isci_host *ihost)
+{
+ return CIRC_CNT(ihost->tci_head, ihost->tci_tail, SCI_MAX_IO_REQUESTS);
+}
+
+static u16 isci_tci_space(struct isci_host *ihost)
+{
+ return CIRC_SPACE(ihost->tci_head, ihost->tci_tail, SCI_MAX_IO_REQUESTS);
+}
+
static enum sci_status scic_controller_start(struct scic_sds_controller *scic,
u32 timeout)
{
@@ -1069,9 +1097,11 @@ static enum sci_status scic_controller_start(struct scic_sds_controller *scic,
}
/* Build the TCi free pool */
- sci_pool_initialize(scic->tci_pool);
+ BUILD_BUG_ON(SCI_MAX_IO_REQUESTS > 1 << sizeof(ihost->tci_pool[0]) * 8);
+ ihost->tci_head = 0;
+ ihost->tci_tail = 0;
for (index = 0; index < scic->task_context_entries; index++)
- sci_pool_put(scic->tci_pool, index);
+ isci_tci_free(ihost, index);
/* Build the RNi free pool */
scic_sds_remote_node_table_initialize(
@@ -3063,18 +3093,17 @@ enum sci_task_status scic_controller_start_task(
* currently available tags to be allocated. All return other values indicate a
* legitimate tag.
*/
-u16 scic_controller_allocate_io_tag(
- struct scic_sds_controller *scic)
+u16 scic_controller_allocate_io_tag(struct scic_sds_controller *scic)
{
- u16 task_context;
- u16 sequence_count;
-
- if (!sci_pool_empty(scic->tci_pool)) {
- sci_pool_get(scic->tci_pool, task_context);
+ struct isci_host *ihost = scic_to_ihost(scic);
+ u16 tci;
+ u16 seq;
- sequence_count = scic->io_request_sequence[task_context];
+ if (isci_tci_space(ihost)) {
+ tci = isci_tci_alloc(ihost);
+ seq = scic->io_request_sequence[tci];
- return scic_sds_io_tag_construct(sequence_count, task_context);
+ return scic_sds_io_tag_construct(seq, tci);
}
return SCI_CONTROLLER_INVALID_IO_TAG;
@@ -3105,10 +3134,10 @@ u16 scic_controller_allocate_io_tag(
* tags. SCI_FAILURE_INVALID_IO_TAG This value is returned if the supplied tag
* is not a valid IO tag value.
*/
-enum sci_status scic_controller_free_io_tag(
- struct scic_sds_controller *scic,
- u16 io_tag)
+enum sci_status scic_controller_free_io_tag(struct scic_sds_controller *scic,
+ u16 io_tag)
{
+ struct isci_host *ihost = scic_to_ihost(scic);
u16 sequence;
u16 index;
@@ -3117,18 +3146,16 @@ enum sci_status scic_controller_free_io_tag(
sequence = scic_sds_io_tag_get_sequence(io_tag);
index = scic_sds_io_tag_get_index(io_tag);
- if (!sci_pool_full(scic->tci_pool)) {
- if (sequence == scic->io_request_sequence[index]) {
- scic_sds_io_sequence_increment(
- scic->io_request_sequence[index]);
+ /* prevent tail from passing head */
+ if (isci_tci_active(ihost) == 0)
+ return SCI_FAILURE_INVALID_IO_TAG;
- sci_pool_put(scic->tci_pool, index);
+ if (sequence == scic->io_request_sequence[index]) {
+ scic_sds_io_sequence_increment(scic->io_request_sequence[index]);
- return SCI_SUCCESS;
- }
- }
+ isci_tci_free(ihost, index);
+ return SCI_SUCCESS;
+ }
return SCI_FAILURE_INVALID_IO_TAG;
}
-
-
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 @@
#include "remote_device.h"
#include "phy.h"
-#include "pool.h"
#include "isci.h"
#include "remote_node_table.h"
#include "registers.h"
@@ -180,11 +179,6 @@ struct scic_sds_controller {
struct scic_remote_node_table available_remote_nodes;
/**
- * This field is the TCi pool used to manage the task context index.
- */
- SCI_POOL_CREATE(tci_pool, u16, SCI_MAX_IO_REQUESTS);
-
- /**
* This filed is the struct scic_power_control data used to controll when direct
* attached devices can consume power.
*/
@@ -310,6 +304,10 @@ struct scic_sds_controller {
struct isci_host {
struct scic_sds_controller sci;
+ u16 tci_head;
+ u16 tci_tail;
+ u16 tci_pool[SCI_MAX_IO_REQUESTS];
+
union scic_oem_parameters oem_parameters;
int id; /* unique within a given pci device */
@@ -423,8 +421,6 @@ enum scic_sds_controller_states {
SCIC_FAILED,
};
-
-
/**
* struct isci_pci_info - This class represents the pci function containing the
* 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)
BUILD_BUG_ON_NOT_POWER_OF_2(SCU_MAX_UNSOLICITED_FRAMES);
BUILD_BUG_ON_NOT_POWER_OF_2(SCU_MAX_COMPLETION_QUEUE_ENTRIES);
BUILD_BUG_ON(SCU_MAX_UNSOLICITED_FRAMES > SCU_ABSOLUTE_MAX_UNSOLICITED_FRAMES);
+ BUILD_BUG_ON_NOT_POWER_OF_2(SCI_MAX_IO_REQUESTS);
}
/**
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 @@
-/*
- * 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.
- */
-
-/**
- * This file contains the interface to the pool class. This class allows two
- * different two different priority tasks to insert and remove items from
- * the free pool. The user of the pool is expected to evaluate the pool
- * condition empty before a get operation and pool condition full before a
- * put operation. Methods Provided: - sci_pool_create() -
- * sci_pool_initialize() - sci_pool_empty() - sci_pool_full() -
- * sci_pool_get() - sci_pool_put()
- *
- *
- */
-
-#ifndef _SCI_POOL_H_
-#define _SCI_POOL_H_
-
-/**
- * SCI_POOL_INCREMENT() -
- *
- * Private operation for the pool
- */
-#define SCI_POOL_INCREMENT(pool, index) \
- (((index) + 1) == (pool).size ? 0 : (index) + 1)
-
-/**
- * SCI_POOL_CREATE() -
- *
- * This creates a pool structure of pool_name. The members in the pool are of
- * type with number of elements equal to size.
- */
-#define SCI_POOL_CREATE(pool_name, type, pool_size) \
- struct \
- { \
- u32 size; \
- u32 get; \
- u32 put; \
- type array[(pool_size) + 1]; \
- } pool_name
-
-
-/**
- * sci_pool_empty() -
- *
- * This macro evaluates the pool and returns true if the pool is empty. If the
- * pool is empty the user should not perform any get operation on the pool.
- */
-#define sci_pool_empty(pool) \
- ((pool).get == (pool).put)
-
-/**
- * sci_pool_full() -
- *
- * This macro evaluates the pool and returns true if the pool is full. If the
- * pool is full the user should not perform any put operation.
- */
-#define sci_pool_full(pool) \
- (SCI_POOL_INCREMENT(pool, (pool).put) == (pool).get)
-
-/**
- * sci_pool_size() -
- *
- * This macro returns the size of the pool created. The internal size of the
- * pool is actually 1 larger then necessary in order to ensure get and put
- * pointers can be written simultaneously by different users. As a result,
- * this macro subtracts 1 from the internal size
- */
-#define sci_pool_size(pool) \
- ((pool).size - 1)
-
-/**
- * sci_pool_count() -
- *
- * This macro indicates the number of elements currently contained in the pool.
- */
-#define sci_pool_count(pool) \
- (\
- sci_pool_empty((pool)) \
- ? 0 \
- : (\
- sci_pool_full((pool)) \
- ? sci_pool_size((pool)) \
- : (\
- (pool).get > (pool).put \
- ? ((pool).size - (pool).get + (pool).put) \
- : ((pool).put - (pool).get) \
- ) \
- ) \
- )
-
-/**
- * sci_pool_initialize() -
- *
- * This macro initializes the pool to an empty condition.
- */
-#define sci_pool_initialize(pool) \
- { \
- (pool).size = (sizeof((pool).array) / sizeof((pool).array[0])); \
- (pool).get = 0; \
- (pool).put = 0; \
- }
-
-/**
- * sci_pool_get() -
- *
- * This macro will get the next free element from the pool. This should only be
- * called if the pool is not empty.
- */
-#define sci_pool_get(pool, my_value) \
- { \
- (my_value) = (pool).array[(pool).get]; \
- (pool).get = SCI_POOL_INCREMENT((pool), (pool).get); \
- }
-
-/**
- * sci_pool_put() -
- *
- * This macro will put the value into the pool. This should only be called if
- * the pool is not full.
- */
-#define sci_pool_put(pool, value) \
- { \
- (pool).array[(pool).put] = (value); \
- (pool).put = SCI_POOL_INCREMENT((pool), (pool).put); \
- }
-
-/**
- * sci_pool_erase() -
- *
- * This macro will search the pool and remove any elements in the pool matching
- * the supplied value. This method can only be utilized on pools
- */
-#define sci_pool_erase(pool, type, value) \
- { \
- type tmp_value; \
- u32 index; \
- u32 element_count = sci_pool_count((pool)); \
- \
- for (index = 0; index < element_count; index++) { \
- sci_pool_get((pool), tmp_value); \
- if (tmp_value != (value)) \
- sci_pool_put((pool), tmp_value); \
- } \
- }
-
-#endif /* _SCI_POOL_H_ */