Current Path : /sys/cam/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/cam/cam_queue.c |
/*- * CAM request queue management functions. * * Copyright (c) 1997 Justin T. Gibbs. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions, and the following disclaimer, * without modification, immediately at the beginning of the file. * 2. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. */ #include <sys/cdefs.h> __FBSDID("$FreeBSD: release/9.1.0/sys/cam/cam_queue.c 199281 2009-11-14 20:30:42Z mav $"); #include <sys/param.h> #include <sys/systm.h> #include <sys/types.h> #include <sys/malloc.h> #include <sys/kernel.h> #include <cam/cam.h> #include <cam/cam_ccb.h> #include <cam/cam_queue.h> #include <cam/cam_debug.h> MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers"); MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers"); MALLOC_DEFINE(M_CAMCCBQ, "CAM ccb queue", "CAM ccb queue buffers"); static __inline int queue_cmp(cam_pinfo **queue_array, int i, int j); static __inline void swap(cam_pinfo **queue_array, int i, int j); static void heap_up(cam_pinfo **queue_array, int new_index); static void heap_down(cam_pinfo **queue_array, int index, int last_index); struct camq * camq_alloc(int size) { struct camq *camq; camq = (struct camq *)malloc(sizeof(*camq), M_CAMQ, M_NOWAIT); if (camq != NULL) { if (camq_init(camq, size) != 0) { free(camq, M_CAMQ); camq = NULL; } } return (camq); } int camq_init(struct camq *camq, int size) { bzero(camq, sizeof(*camq)); camq->array_size = size; if (camq->array_size != 0) { camq->queue_array = (cam_pinfo**)malloc(size*sizeof(cam_pinfo*), M_CAMQ, M_NOWAIT); if (camq->queue_array == NULL) { printf("camq_init: - cannot malloc array!\n"); return (1); } /* * Heap algorithms like everything numbered from 1, so * offset our pointer into the heap array by one element. */ camq->queue_array--; } return (0); } /* * Free a camq structure. This should only be called if a controller * driver failes somehow during its attach routine or is unloaded and has * obtained a camq structure. The XPT should ensure that the queue * is empty before calling this routine. */ void camq_free(struct camq *queue) { if (queue != NULL) { camq_fini(queue); free(queue, M_CAMQ); } } void camq_fini(struct camq *queue) { if (queue->queue_array != NULL) { /* * Heap algorithms like everything numbered from 1, so * our pointer into the heap array is offset by one element. */ queue->queue_array++; free(queue->queue_array, M_CAMQ); } } u_int32_t camq_resize(struct camq *queue, int new_size) { cam_pinfo **new_array; #ifdef DIAGNOSTIC if (new_size < queue->entries) panic("camq_resize: New queue size can't accomodate " "queued entries."); #endif new_array = (cam_pinfo **)malloc(new_size * sizeof(cam_pinfo *), M_CAMQ, M_NOWAIT); if (new_array == NULL) { /* Couldn't satisfy request */ return (CAM_RESRC_UNAVAIL); } /* * Heap algorithms like everything numbered from 1, so * remember that our pointer into the heap array is offset * by one element. */ if (queue->queue_array != NULL) { queue->queue_array++; bcopy(queue->queue_array, new_array, queue->entries * sizeof(cam_pinfo *)); free(queue->queue_array, M_CAMQ); } queue->queue_array = new_array-1; queue->array_size = new_size; return (CAM_REQ_CMP); } /* * camq_insert: Given an array of cam_pinfo* elememnts with * the Heap(1, num_elements) property and array_size - num_elements >= 1, * output Heap(1, num_elements+1) including new_entry in the array. */ void camq_insert(struct camq *queue, cam_pinfo *new_entry) { #ifdef DIAGNOSTIC if (queue->entries >= queue->array_size) panic("camq_insert: Attempt to insert into a full queue"); #endif queue->entries++; queue->queue_array[queue->entries] = new_entry; new_entry->index = queue->entries; if (queue->entries != 0) heap_up(queue->queue_array, queue->entries); } /* * camq_remove: Given an array of cam_pinfo* elevements with the * Heap(1, num_elements) property and an index such that 1 <= index <= * num_elements, remove that entry and restore the Heap(1, num_elements-1) * property. */ cam_pinfo * camq_remove(struct camq *queue, int index) { cam_pinfo *removed_entry; if (index == 0 || index > queue->entries) return (NULL); removed_entry = queue->queue_array[index]; if (queue->entries != index) { queue->queue_array[index] = queue->queue_array[queue->entries]; queue->queue_array[index]->index = index; heap_down(queue->queue_array, index, queue->entries - 1); } removed_entry->index = CAM_UNQUEUED_INDEX; queue->entries--; return (removed_entry); } /* * camq_change_priority: Given an array of cam_pinfo* elements with the * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements, * and a new priority for the element at index, change the priority of * element index and restore the Heap(0, num_elements) property. */ void camq_change_priority(struct camq *queue, int index, u_int32_t new_priority) { if (new_priority > queue->queue_array[index]->priority) { queue->queue_array[index]->priority = new_priority; heap_down(queue->queue_array, index, queue->entries); } else { /* new_priority <= old_priority */ queue->queue_array[index]->priority = new_priority; heap_up(queue->queue_array, index); } } struct cam_devq * cam_devq_alloc(int devices, int openings) { struct cam_devq *devq; devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT); if (devq == NULL) { printf("cam_devq_alloc: - cannot malloc!\n"); return (NULL); } if (cam_devq_init(devq, devices, openings) != 0) { free(devq, M_CAMDEVQ); return (NULL); } return (devq); } int cam_devq_init(struct cam_devq *devq, int devices, int openings) { bzero(devq, sizeof(*devq)); if (camq_init(&devq->alloc_queue, devices) != 0) { return (1); } if (camq_init(&devq->send_queue, devices) != 0) { camq_fini(&devq->alloc_queue); return (1); } devq->alloc_openings = openings; devq->alloc_active = 0; devq->send_openings = openings; devq->send_active = 0; return (0); } void cam_devq_free(struct cam_devq *devq) { camq_fini(&devq->alloc_queue); camq_fini(&devq->send_queue); free(devq, M_CAMDEVQ); } u_int32_t cam_devq_resize(struct cam_devq *camq, int devices) { u_int32_t retval; retval = camq_resize(&camq->alloc_queue, devices); if (retval == CAM_REQ_CMP) retval = camq_resize(&camq->send_queue, devices); return (retval); } struct cam_ccbq * cam_ccbq_alloc(int openings) { struct cam_ccbq *ccbq; ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT); if (ccbq == NULL) { printf("cam_ccbq_alloc: - cannot malloc!\n"); return (NULL); } if (cam_ccbq_init(ccbq, openings) != 0) { free(ccbq, M_CAMCCBQ); return (NULL); } return (ccbq); } void cam_ccbq_free(struct cam_ccbq *ccbq) { if (ccbq) { cam_ccbq_fini(ccbq); free(ccbq, M_CAMCCBQ); } } u_int32_t cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size) { int delta; int space_left; delta = new_size - (ccbq->dev_active + ccbq->dev_openings); space_left = new_size - ccbq->queue.entries - ccbq->held - ccbq->dev_active; /* * Only attempt to change the underlying queue size if we are * shrinking it and there is space for all outstanding entries * in the new array or we have been requested to grow the array. * We don't fail in the case where we can't reduce the array size, * but clients that care that the queue be "garbage collected" * should detect this condition and call us again with the * same size once the outstanding entries have been processed. */ if (space_left < 0 || camq_resize(&ccbq->queue, new_size) == CAM_REQ_CMP) { ccbq->devq_openings += delta; ccbq->dev_openings += delta; return (CAM_REQ_CMP); } else { return (CAM_RESRC_UNAVAIL); } } int cam_ccbq_init(struct cam_ccbq *ccbq, int openings) { bzero(ccbq, sizeof(*ccbq)); if (camq_init(&ccbq->queue, openings) != 0) { return (1); } ccbq->devq_openings = openings; ccbq->dev_openings = openings; return (0); } void cam_ccbq_fini(struct cam_ccbq *ccbq) { camq_fini(&ccbq->queue); } /* * Heap routines for manipulating CAM queues. */ /* * queue_cmp: Given an array of cam_pinfo* elements and indexes i * and j, return less than 0, 0, or greater than 0 if i is less than, * equal too, or greater than j respectively. */ static __inline int queue_cmp(cam_pinfo **queue_array, int i, int j) { if (queue_array[i]->priority == queue_array[j]->priority) return ( queue_array[i]->generation - queue_array[j]->generation ); else return ( queue_array[i]->priority - queue_array[j]->priority ); } /* * swap: Given an array of cam_pinfo* elements and indexes i and j, * exchange elements i and j. */ static __inline void swap(cam_pinfo **queue_array, int i, int j) { cam_pinfo *temp_qentry; temp_qentry = queue_array[j]; queue_array[j] = queue_array[i]; queue_array[i] = temp_qentry; queue_array[j]->index = j; queue_array[i]->index = i; } /* * heap_up: Given an array of cam_pinfo* elements with the * Heap(1, new_index-1) property and a new element in location * new_index, output Heap(1, new_index). */ static void heap_up(cam_pinfo **queue_array, int new_index) { int child; int parent; child = new_index; while (child != 1) { parent = child >> 1; if (queue_cmp(queue_array, parent, child) <= 0) break; swap(queue_array, parent, child); child = parent; } } /* * heap_down: Given an array of cam_pinfo* elements with the * Heap(index + 1, num_entries) property with index containing * an unsorted entry, output Heap(index, num_entries). */ static void heap_down(cam_pinfo **queue_array, int index, int num_entries) { int child; int parent; parent = index; child = parent << 1; for (; child <= num_entries; child = parent << 1) { if (child < num_entries) { /* child+1 is the right child of parent */ if (queue_cmp(queue_array, child + 1, child) < 0) child++; } /* child is now the least child of parent */ if (queue_cmp(queue_array, parent, child) <= 0) break; swap(queue_array, child, parent); parent = child; } }