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