/*
* 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.
*/
#include <ddi/ddi.h>
#include <ddi/ddi_arg.h>
#include <proc/task.h>
#include <security/cap.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <mm/as.h>
#include <synch/spinlock.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_map_physmem(task_id_t id, __address pf, __address vp, count_t pages, bool writable)
{
ipl_t ipl;
cap_t caps;
task_t *t;
int flags;
count_t i;
/*
* 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_DEVICE | AS_AREA_READ;
if (writable)
flags |= AS_AREA_WRITE;
if (!as_area_create(t->as, flags, pages * PAGE_SIZE, vp)) {
/*
* The address space area could not have been created.
* We report it using ENOMEM.
*/
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
return ENOMEM;
}
/* Initialize page tables. */
for (i = 0; i < pages; i++)
as_set_mapping(t->as, vp + i * PAGE_SIZE, pf + i * FRAME_SIZE);
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
return 0;
}
/** Wrapper for SYS_MAP_PHYSMEM syscall.
*
* @param User space address of DDI argument structure.
*
* @return 0 on success, otherwise it returns error code found in errno.h
*/
__native sys_map_physmem(ddi_arg_t *uspace_ddi_arg)
{
ddi_arg_t arg;
copy_from_uspace(&arg, uspace_ddi_arg, sizeof(ddi_arg_t));
return (__native) ddi_map_physmem((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);
}