| 0,0 → 1,120 |
|---|
| /* |
| * Copyright (C) 2005 Martin Decky |
| * Copyright (C) 2005 Jakub Jermar |
| * 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. |
| * - 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 ``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 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 <arch/mm/asid.h> |
| #include <synch/spinlock.h> |
| #include <arch.h> |
| #include <debug.h> |
| #include <typedefs.h> |
| |
| static spinlock_t asid_usage_lock; |
| static count_t asid_usage[ASIDS]; /**< Usage tracking array for ASIDs */ |
| |
| /** Get ASID |
| * |
| * Get the least used ASID. |
| * |
| * @return ASID |
| */ |
| asid_t asid_get(void) |
| { |
| ipl_t ipl; |
| int i, j; |
| count_t min; |
| |
| min = (unsigned) -1; |
| |
| ipl = interrupts_disable(); |
| spinlock_lock(&asid_usage_lock); |
| |
| for (i = ASID_START, j = ASID_START; i < ASIDS; i++) { |
| if (asid_usage[i] < min) { |
| j = i; |
| min = asid_usage[i]; |
| if (!min) |
| break; |
| } |
| } |
| |
| asid_usage[j]++; |
| |
| spinlock_unlock(&asid_usage_lock); |
| interrupts_restore(ipl); |
| |
| return i; |
| } |
| |
| /** Release ASID |
| * |
| * Release ASID by decrementing its usage count. |
| * |
| * @param asid ASID. |
| */ |
| void asid_put(asid_t asid) |
| { |
| ipl_t ipl; |
| |
| ipl = interrupts_disable(); |
| spinlock_lock(&asid_usage_lock); |
| |
| ASSERT(asid != ASID_INVALID); |
| |
| ASSERT(asid_usage[asid] > 0); |
| asid_usage[asid]--; |
| |
| spinlock_unlock(&asid_usage_lock); |
| interrupts_restore(ipl); |
| } |
| |
| /** Find out whether ASID is used by more address spaces |
| * |
| * Find out whether ASID is used by more address spaces. |
| * |
| * @param asid ASID in question. |
| * |
| * @return True if 'asid' is used by more address spaces, false otherwise. |
| */ |
| bool asid_has_conflicts(asid_t asid) |
| { |
| bool has_conflicts = false; |
| ipl_t ipl; |
| |
| ASSERT(asid != ASID_INVALID); |
| |
| ipl = interrupts_disable(); |
| spinlock_lock(&asid_usage_lock); |
| |
| if (asid_usage[asid] > 1) |
| has_conflicts = true; |
| |
| spinlock_unlock(&asid_usage_lock); |
| interrupts_restore(ipl); |
| |
| return has_conflicts; |
| } |