WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/ddi/ddi.c


/*
 * Copyright (C) 2006 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.
 */
 
/**
 * @file    ddi.c
 * @brief   Device Driver Interface functions.
 *
 * This file contains functions that comprise the Device Driver Interface.
 * These are the functions for mapping physical memory and enabling I/O
 * space to tasks.
 */
 
#include <ddi/ddi.h>
#include <ddi/ddi_arg.h>
#include <proc/task.h>
#include <security/cap.h>
#include <mm/frame.h>
#include <mm/as.h>
#include <synch/spinlock.h>
#include <syscall/copy.h>
#include <arch.h>
#include <align.h>
#include <errno.h>
 
/** Map piece of physical memory into virtual address space of specified task.
 *
 * @param id Task ID of the destination task.
 * @param pf Physical frame address of the starting frame.
 * @param vp Virtual page address of the starting page.
 * @param pages Number of pages to map.
 * @param writable If true, the mapping will be created writable.
 *
 * @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,
 *     ENOENT if there is no task matching the specified ID and ENOMEM if
 *     there was a problem in creating address space area.
 */
static int ddi_physmem_map(task_id_t id, __address pf, __address vp, count_t pages, bool writable)
{
    ipl_t ipl;
    cap_t caps;
    task_t *t;
    int flags;
    mem_backend_data_t backend_data = { .d1 = (__native) pf, .d2 = (__native) pages };
   
    /*
     * Make sure the caller is authorised to make this syscall.
     */
    caps = cap_get(TASK);
    if (!(caps & CAP_MEM_MANAGER))
        return EPERM;
   
    ipl = interrupts_disable();
    spinlock_lock(&tasks_lock);
   
    t = task_find_by_id(id);
   
    if (!t) {
        /*
         * There is no task with the specified ID.
         */
        spinlock_unlock(&tasks_lock);
        interrupts_restore(ipl);
        return ENOENT;
    }
 
    /*
     * TODO: We are currently lacking support for task destroying.
     * Once it is added to the kernel, we must take care to
     * synchronize in a way that prevents race conditions here.
     */
   
    /* Lock the task and release the lock protecting tasks_btree. */
    spinlock_lock(&t->lock);
    spinlock_unlock(&tasks_lock);
   
    flags = AS_AREA_READ;
    if (writable)
        flags |= AS_AREA_WRITE;
    if (!as_area_create(t->as, flags, pages * PAGE_SIZE, vp, AS_AREA_ATTR_NONE,
        &phys_backend, &backend_data)) {
        /*
         * The address space area could not have been created.
         * We report it using ENOMEM.
         */
        spinlock_unlock(&t->lock);
        interrupts_restore(ipl);
        return ENOMEM;
    }
   
    /*
 
     * Mapping is created on-demand during page fault.
     */
   
    spinlock_unlock(&t->lock);
    interrupts_restore(ipl);
    return 0;
}
 
/** Enable range of I/O space for task.
 *
 * @param id Task ID of the destination task.
 * @param ioaddr Starting I/O address.
 * @param size Size of the enabled I/O space..
 *
 * @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,
 *     ENOENT if there is no task matching the specified ID.
 */
static int ddi_iospace_enable(task_id_t id, __address ioaddr, size_t size)
{
    ipl_t ipl;
    cap_t caps;
    task_t *t;
    int rc;
   
    /*
     * Make sure the caller is authorised to make this syscall.
     */
    caps = cap_get(TASK);
    if (!(caps & CAP_IO_MANAGER))
        return EPERM;
   
    ipl = interrupts_disable();
    spinlock_lock(&tasks_lock);
   
    t = task_find_by_id(id);
   
    if (!t) {
        /*
         * There is no task with the specified ID.
         */
        spinlock_unlock(&tasks_lock);
        interrupts_restore(ipl);
        return ENOENT;
    }
 
    /*
     * TODO: We are currently lacking support for task destroying.
     * Once it is added to the kernel, we must take care to
     * synchronize in a way that prevents race conditions here.
     */
   
    /* Lock the task and release the lock protecting tasks_btree. */
    spinlock_lock(&t->lock);
    spinlock_unlock(&tasks_lock);
 
    rc = ddi_iospace_enable_arch(t, ioaddr, size);
   
    spinlock_unlock(&t->lock);
    interrupts_restore(ipl);
    return rc;
}
 
/** Wrapper for SYS_MAP_PHYSMEM syscall.
 *
 * @param User space address of memory DDI argument structure.
 *
 * @return 0 on success, otherwise it returns error code found in errno.h
 */
__native sys_physmem_map(ddi_memarg_t *uspace_mem_arg)
{
    ddi_memarg_t arg;
    int rc;
   
    rc = copy_from_uspace(&arg, uspace_mem_arg, sizeof(ddi_memarg_t));
    if (rc != 0)
        return (__native) rc;
       
    return (__native) ddi_physmem_map((task_id_t) arg.task_id, ALIGN_DOWN((__address) arg.phys_base, FRAME_SIZE),
                      ALIGN_DOWN((__address) arg.virt_base, PAGE_SIZE), (count_t) arg.pages,
                      (bool) arg.writable);
}
 
/** Wrapper for SYS_ENABLE_IOSPACE syscall.
 *
 * @param User space address of DDI argument structure.
 *
 * @return 0 on success, otherwise it returns error code found in errno.h
 */
__native sys_iospace_enable(ddi_ioarg_t *uspace_io_arg)
{
    ddi_ioarg_t arg;
    int rc;
   
    rc = copy_from_uspace(&arg, uspace_io_arg, sizeof(ddi_ioarg_t));
    if (rc != 0)
        return (__native) rc;
       
    return (__native) ddi_iospace_enable((task_id_t) arg.task_id, (__address) arg.ioaddr, (size_t) arg.size);
}
 
/** Disable or enable preemption.
 *
 * @param enable If non-zero, the preemption counter will be decremented, leading to potential
 *       enabling of preemption. Otherwise the preemption counter will be incremented,
 *       preventing preemption from occurring.
 *
 * @return Zero on success or EPERM if callers capabilities are not sufficient.
 */
__native sys_preempt_control(int enable)
{
        if (! cap_get(TASK) & CAP_PREEMPT_CONTROL)
                return EPERM;
        if (enable)
                preemption_enable();
        else
                preemption_disable();
        return 0;
}
 

Rev 1409	Rev 1424
1	/*	1	/*
2	* Copyright (C) 2006 Jakub Jermar	2	* Copyright (C) 2006 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/**	29	/**
30	* @file ddi.c	30	* @file ddi.c
31	* @brief Device Driver Interface functions.	31	* @brief Device Driver Interface functions.
32	*	32	*
33	* This file contains functions that comprise the Device Driver Interface.	33	* This file contains functions that comprise the Device Driver Interface.
34	* These are the functions for mapping physical memory and enabling I/O	34	* These are the functions for mapping physical memory and enabling I/O
35	* space to tasks.	35	* space to tasks.
36	*/	36	*/
37		37
38	#include <ddi/ddi.h>	38	#include <ddi/ddi.h>
39	#include <ddi/ddi_arg.h>	39	#include <ddi/ddi_arg.h>
40	#include <proc/task.h>	40	#include <proc/task.h>
41	#include <security/cap.h>	41	#include <security/cap.h>
42	#include <mm/frame.h>	42	#include <mm/frame.h>
43	#include <mm/as.h>	43	#include <mm/as.h>
44	#include <synch/spinlock.h>	44	#include <synch/spinlock.h>
45	#include <syscall/copy.h>	45	#include <syscall/copy.h>
46	#include <arch.h>	46	#include <arch.h>
47	#include <align.h>	47	#include <align.h>
48	#include <errno.h>	48	#include <errno.h>
49		49
50	/** Map piece of physical memory into virtual address space of specified task.	50	/** Map piece of physical memory into virtual address space of specified task.
51	*	51	*
52	* @param id Task ID of the destination task.	52	* @param id Task ID of the destination task.
53	* @param pf Physical frame address of the starting frame.	53	* @param pf Physical frame address of the starting frame.
54	* @param vp Virtual page address of the starting page.	54	* @param vp Virtual page address of the starting page.
55	* @param pages Number of pages to map.	55	* @param pages Number of pages to map.
56	* @param writable If true, the mapping will be created writable.	56	* @param writable If true, the mapping will be created writable.
57	*	57	*
58	* @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,	58	* @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,
59	* ENOENT if there is no task matching the specified ID and ENOMEM if	59	* ENOENT if there is no task matching the specified ID and ENOMEM if
60	* there was a problem in creating address space area.	60	* there was a problem in creating address space area.
61	*/	61	*/
62	static int ddi_physmem_map(task_id_t id, __address pf, __address vp, count_t pages, bool writable)	62	static int ddi_physmem_map(task_id_t id, __address pf, __address vp, count_t pages, bool writable)
63	{	63	{
64	ipl_t ipl;	64	ipl_t ipl;
65	cap_t caps;	65	cap_t caps;
66	task_t *t;	66	task_t *t;
67	int flags;	67	int flags;
68	count_t i;	68	mem_backend_data_t backend_data = { .d1 = (__native) pf, .d2 = (__native) pages };
69		69
70	/*	70	/*
71	* Make sure the caller is authorised to make this syscall.	71	* Make sure the caller is authorised to make this syscall.
72	*/	72	*/
73	caps = cap_get(TASK);	73	caps = cap_get(TASK);
74	if (!(caps & CAP_MEM_MANAGER))	74	if (!(caps & CAP_MEM_MANAGER))
75	return EPERM;	75	return EPERM;
76		76
77	ipl = interrupts_disable();	77	ipl = interrupts_disable();
78	spinlock_lock(&tasks_lock);	78	spinlock_lock(&tasks_lock);
79		79
80	t = task_find_by_id(id);	80	t = task_find_by_id(id);
81		81
82	if (!t) {	82	if (!t) {
83	/*	83	/*
84	* There is no task with the specified ID.	84	* There is no task with the specified ID.
85	*/	85	*/
86	spinlock_unlock(&tasks_lock);	86	spinlock_unlock(&tasks_lock);
87	interrupts_restore(ipl);	87	interrupts_restore(ipl);
88	return ENOENT;	88	return ENOENT;
89	}	89	}
90		90
91	/*	91	/*
92	* TODO: We are currently lacking support for task destroying.	92	* TODO: We are currently lacking support for task destroying.
93	* Once it is added to the kernel, we must take care to	93	* Once it is added to the kernel, we must take care to
94	* synchronize in a way that prevents race conditions here.	94	* synchronize in a way that prevents race conditions here.
95	*/	95	*/
96		96
97	/* Lock the task and release the lock protecting tasks_btree. */	97	/* Lock the task and release the lock protecting tasks_btree. */
98	spinlock_lock(&t->lock);	98	spinlock_lock(&t->lock);
99	spinlock_unlock(&tasks_lock);	99	spinlock_unlock(&tasks_lock);
100		100
101	flags = AS_AREA_DEVICE \| AS_AREA_READ;	101	flags = AS_AREA_READ;
102	if (writable)	102	if (writable)
103	flags \|= AS_AREA_WRITE;	103	flags \|= AS_AREA_WRITE;
104	if (!as_area_create(t->as, flags, pages * PAGE_SIZE, vp, AS_AREA_ATTR_NONE, NULL, NULL)) {	104	if (!as_area_create(t->as, flags, pages * PAGE_SIZE, vp, AS_AREA_ATTR_NONE,
-		105	&phys_backend, &backend_data)) {
105	/*	106	/*
106	* The address space area could not have been created.	107	* The address space area could not have been created.
107	* We report it using ENOMEM.	108	* We report it using ENOMEM.
108	*/	109	*/
109	spinlock_unlock(&t->lock);	110	spinlock_unlock(&t->lock);
110	interrupts_restore(ipl);	111	interrupts_restore(ipl);
111	return ENOMEM;	112	return ENOMEM;
112	}	113	}
113		114
114	/* Initialize page tables. */	115	/*
115	for (i = 0; i < pages; i++)	-
116	as_set_mapping(t->as, vp + i * PAGE_SIZE, pf + i * FRAME_SIZE);	116	* Mapping is created on-demand during page fault.
-		117	*/
117		118
118	spinlock_unlock(&t->lock);	119	spinlock_unlock(&t->lock);
119	interrupts_restore(ipl);	120	interrupts_restore(ipl);
120	return 0;	121	return 0;
121	}	122	}
122		123
123	/** Enable range of I/O space for task.	124	/** Enable range of I/O space for task.
124	*	125	*
125	* @param id Task ID of the destination task.	126	* @param id Task ID of the destination task.
126	* @param ioaddr Starting I/O address.	127	* @param ioaddr Starting I/O address.
127	* @param size Size of the enabled I/O space..	128	* @param size Size of the enabled I/O space..
128	*	129	*
129	* @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,	130	* @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,
130	* ENOENT if there is no task matching the specified ID.	131	* ENOENT if there is no task matching the specified ID.
131	*/	132	*/
132	static int ddi_iospace_enable(task_id_t id, __address ioaddr, size_t size)	133	static int ddi_iospace_enable(task_id_t id, __address ioaddr, size_t size)
133	{	134	{
134	ipl_t ipl;	135	ipl_t ipl;
135	cap_t caps;	136	cap_t caps;
136	task_t *t;	137	task_t *t;
137	int rc;	138	int rc;
138		139
139	/*	140	/*
140	* Make sure the caller is authorised to make this syscall.	141	* Make sure the caller is authorised to make this syscall.
141	*/	142	*/
142	caps = cap_get(TASK);	143	caps = cap_get(TASK);
143	if (!(caps & CAP_IO_MANAGER))	144	if (!(caps & CAP_IO_MANAGER))
144	return EPERM;	145	return EPERM;
145		146
146	ipl = interrupts_disable();	147	ipl = interrupts_disable();
147	spinlock_lock(&tasks_lock);	148	spinlock_lock(&tasks_lock);
148		149
149	t = task_find_by_id(id);	150	t = task_find_by_id(id);
150		151
151	if (!t) {	152	if (!t) {
152	/*	153	/*
153	* There is no task with the specified ID.	154	* There is no task with the specified ID.
154	*/	155	*/
155	spinlock_unlock(&tasks_lock);	156	spinlock_unlock(&tasks_lock);
156	interrupts_restore(ipl);	157	interrupts_restore(ipl);
157	return ENOENT;	158	return ENOENT;
158	}	159	}
159		160
160	/*	161	/*
161	* TODO: We are currently lacking support for task destroying.	162	* TODO: We are currently lacking support for task destroying.
162	* Once it is added to the kernel, we must take care to	163	* Once it is added to the kernel, we must take care to
163	* synchronize in a way that prevents race conditions here.	164	* synchronize in a way that prevents race conditions here.
164	*/	165	*/
165		166
166	/* Lock the task and release the lock protecting tasks_btree. */	167	/* Lock the task and release the lock protecting tasks_btree. */
167	spinlock_lock(&t->lock);	168	spinlock_lock(&t->lock);
168	spinlock_unlock(&tasks_lock);	169	spinlock_unlock(&tasks_lock);
169		170
170	rc = ddi_iospace_enable_arch(t, ioaddr, size);	171	rc = ddi_iospace_enable_arch(t, ioaddr, size);
171		172
172	spinlock_unlock(&t->lock);	173	spinlock_unlock(&t->lock);
173	interrupts_restore(ipl);	174	interrupts_restore(ipl);
174	return rc;	175	return rc;
175	}	176	}
176		177
177	/** Wrapper for SYS_MAP_PHYSMEM syscall.	178	/** Wrapper for SYS_MAP_PHYSMEM syscall.
178	*	179	*
179	* @param User space address of memory DDI argument structure.	180	* @param User space address of memory DDI argument structure.
180	*	181	*
181	* @return 0 on success, otherwise it returns error code found in errno.h	182	* @return 0 on success, otherwise it returns error code found in errno.h
182	*/	183	*/
183	__native sys_physmem_map(ddi_memarg_t *uspace_mem_arg)	184	__native sys_physmem_map(ddi_memarg_t *uspace_mem_arg)
184	{	185	{
185	ddi_memarg_t arg;	186	ddi_memarg_t arg;
186	int rc;	187	int rc;
187		188
188	rc = copy_from_uspace(&arg, uspace_mem_arg, sizeof(ddi_memarg_t));	189	rc = copy_from_uspace(&arg, uspace_mem_arg, sizeof(ddi_memarg_t));
189	if (rc != 0)	190	if (rc != 0)
190	return (__native) rc;	191	return (__native) rc;
191		192
192	return (__native) ddi_physmem_map((task_id_t) arg.task_id, ALIGN_DOWN((__address) arg.phys_base, FRAME_SIZE),	193	return (__native) ddi_physmem_map((task_id_t) arg.task_id, ALIGN_DOWN((__address) arg.phys_base, FRAME_SIZE),
193	ALIGN_DOWN((__address) arg.virt_base, PAGE_SIZE), (count_t) arg.pages,	194	ALIGN_DOWN((__address) arg.virt_base, PAGE_SIZE), (count_t) arg.pages,
194	(bool) arg.writable);	195	(bool) arg.writable);
195	}	196	}
196		197
197	/** Wrapper for SYS_ENABLE_IOSPACE syscall.	198	/** Wrapper for SYS_ENABLE_IOSPACE syscall.
198	*	199	*
199	* @param User space address of DDI argument structure.	200	* @param User space address of DDI argument structure.
200	*	201	*
201	* @return 0 on success, otherwise it returns error code found in errno.h	202	* @return 0 on success, otherwise it returns error code found in errno.h
202	*/	203	*/
203	__native sys_iospace_enable(ddi_ioarg_t *uspace_io_arg)	204	__native sys_iospace_enable(ddi_ioarg_t *uspace_io_arg)
204	{	205	{
205	ddi_ioarg_t arg;	206	ddi_ioarg_t arg;
206	int rc;	207	int rc;
207		208
208	rc = copy_from_uspace(&arg, uspace_io_arg, sizeof(ddi_ioarg_t));	209	rc = copy_from_uspace(&arg, uspace_io_arg, sizeof(ddi_ioarg_t));
209	if (rc != 0)	210	if (rc != 0)
210	return (__native) rc;	211	return (__native) rc;
211		212
212	return (__native) ddi_iospace_enable((task_id_t) arg.task_id, (__address) arg.ioaddr, (size_t) arg.size);	213	return (__native) ddi_iospace_enable((task_id_t) arg.task_id, (__address) arg.ioaddr, (size_t) arg.size);
213	}	214	}
214		215
215	/** Disable or enable preemption.	216	/** Disable or enable preemption.
216	*	217	*
217	* @param enable If non-zero, the preemption counter will be decremented, leading to potential	218	* @param enable If non-zero, the preemption counter will be decremented, leading to potential
218	* enabling of preemption. Otherwise the preemption counter will be incremented,	219	* enabling of preemption. Otherwise the preemption counter will be incremented,
219	* preventing preemption from occurring.	220	* preventing preemption from occurring.
220	*	221	*
221	* @return Zero on success or EPERM if callers capabilities are not sufficient.	222	* @return Zero on success or EPERM if callers capabilities are not sufficient.
222	*/	223	*/
223	__native sys_preempt_control(int enable)	224	__native sys_preempt_control(int enable)
224	{	225	{
225	if (! cap_get(TASK) & CAP_PREEMPT_CONTROL)	226	if (! cap_get(TASK) & CAP_PREEMPT_CONTROL)
226	return EPERM;	227	return EPERM;
227	if (enable)	228	if (enable)
228	preemption_enable();	229	preemption_enable();
229	else	230	else
230	preemption_disable();	231	preemption_disable();
231	return 0;	232	return 0;
232	}	233	}
233		234

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/ddi/ddi.c – Rev 1409 → 1424