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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/kmem.h>
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/ioat.h>
/* structure used to keep track of resources */
typedef struct ioat_rs_s {
/*
* Bounds of resource allocation. We will start allocating at rs_min
* and rollover at rs_max+1 (rs_max is included). e.g. for rs_min=0
* and rs_max=7, we will have 8 total resources which can be alloced.
*/
uint_t rs_min;
uint_t rs_max;
/*
* rs_free points to an array of 64-bit values used to track resource
* allocation. rs_free_size is the free buffer size in bytes.
*/
uint64_t *rs_free;
uint_t rs_free_size;
/*
* last tracks the last alloc'd resource. This allows us to do a round
* robin allocation.
*/
uint_t rs_last;
kmutex_t rs_mutex;
} ioat_rs_t;
/*
* ioat_rs_init()
* Initialize the resource structure. This structure will be protected
* by a mutex at the iblock_cookie passed in. init() returns a handle to be
* used for the rest of the resource functions. This code is written assuming
* that min_val will be close to 0. Therefore, we will allocate the free
* buffer only taking max_val into account.
*/
void
ioat_rs_init(ioat_state_t *state, uint_t min_val, uint_t max_val,
ioat_rs_hdl_t *handle)
{
ioat_rs_t *rstruct;
uint_t array_size;
uint_t index;
ASSERT(handle != NULL);
ASSERT(min_val < max_val);
/* alloc space for resource structure */
rstruct = kmem_alloc(sizeof (ioat_rs_t), KM_SLEEP);
/*
* Test to see if the max value is 64-bit aligned. If so, we don't need
* to allocate an extra 64-bit word. alloc space for free buffer
* (8 bytes per uint64_t).
*/
if ((max_val & 0x3F) == 0) {
rstruct->rs_free_size = (max_val >> 6) * 8;
} else {
rstruct->rs_free_size = ((max_val >> 6) + 1) * 8;
}
rstruct->rs_free = kmem_alloc(rstruct->rs_free_size, KM_SLEEP);
/* Initialize resource structure */
rstruct->rs_min = min_val;
rstruct->rs_last = min_val;
rstruct->rs_max = max_val;
mutex_init(&rstruct->rs_mutex, NULL, MUTEX_DRIVER,
state->is_iblock_cookie);
/* Mark all resources as free */
array_size = rstruct->rs_free_size >> 3;
for (index = 0; index < array_size; index++) {
rstruct->rs_free[index] = (uint64_t)0xFFFFFFFFFFFFFFFF;
}
/* setup handle which is returned from this function */
*handle = rstruct;
}
/*
* ioat_rs_fini()
* Frees up the space allocated in init(). Notice that a pointer to the
* handle is used for the parameter. fini() will set the handle to NULL
* before returning.
*/
void
ioat_rs_fini(ioat_rs_hdl_t *handle)
{
ioat_rs_t *rstruct;
ASSERT(handle != NULL);
rstruct = (ioat_rs_t *)*handle;
mutex_destroy(&rstruct->rs_mutex);
kmem_free(rstruct->rs_free, rstruct->rs_free_size);
kmem_free(rstruct, sizeof (ioat_rs_t));
/* set handle to null. This helps catch bugs. */
*handle = NULL;
}
/*
* ioat_rs_alloc()
* alloc a resource. If alloc fails, we are out of resources.
*/
int
ioat_rs_alloc(ioat_rs_hdl_t handle, uint_t *resource)
{
ioat_rs_t *rstruct;
uint_t array_idx;
uint64_t free;
uint_t index;
uint_t last;
uint_t min;
uint_t max;
ASSERT(handle != NULL);
ASSERT(resource != NULL);
rstruct = (ioat_rs_t *)handle;
mutex_enter(&rstruct->rs_mutex);
min = rstruct->rs_min;
max = rstruct->rs_max;
/*
* Find a free resource. This will return out of the loop once it finds
* a free resource. There are a total of 'max'-'min'+1 resources.
* Performs a round robin allocation.
*/
for (index = min; index <= max; index++) {
array_idx = rstruct->rs_last >> 6;
free = rstruct->rs_free[array_idx];
last = rstruct->rs_last & 0x3F;
/* if the next resource to check is free */
if ((free & ((uint64_t)1 << last)) != 0) {
/* we are using this resource */
*resource = rstruct->rs_last;
/* take it out of the free list */
rstruct->rs_free[array_idx] &= ~((uint64_t)1 << last);
/*
* increment the last count so we start checking the
* next resource on the next alloc(). Note the rollover
* at 'max'+1.
*/
rstruct->rs_last++;
if (rstruct->rs_last > max) {
rstruct->rs_last = rstruct->rs_min;
}
/* unlock the resource structure */
mutex_exit(&rstruct->rs_mutex);
return (DDI_SUCCESS);
}
/*
* This resource is not free, lets go to the next one. Note the
* rollover at 'max'.
*/
rstruct->rs_last++;
if (rstruct->rs_last > max) {
rstruct->rs_last = rstruct->rs_min;
}
}
mutex_exit(&rstruct->rs_mutex);
return (DDI_FAILURE);
}
/*
* ioat_rs_free()
* Free the previously alloc'd resource. Once a resource has been free'd,
* it can be used again when alloc is called.
*/
void
ioat_rs_free(ioat_rs_hdl_t handle, uint_t resource)
{
ioat_rs_t *rstruct;
uint_t array_idx;
uint_t offset;
ASSERT(handle != NULL);
rstruct = (ioat_rs_t *)handle;
ASSERT(resource >= rstruct->rs_min);
ASSERT(resource <= rstruct->rs_max);
mutex_enter(&rstruct->rs_mutex);
/* Put the resource back in the free list */
array_idx = resource >> 6;
offset = resource & 0x3F;
rstruct->rs_free[array_idx] |= ((uint64_t)1 << offset);
mutex_exit(&rstruct->rs_mutex);
}
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