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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 current task.
  51.  *
  52.  * @param pf Physical frame address of the starting frame.
  53.  * @param vp Virtual page address of the starting page.
  54.  * @param pages Number of pages to map.
  55.  * @param flags Address space area flags for the mapping.
  56.  *
  57.  * @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,
  58.  *     ENOENT if there is no task matching the specified ID and ENOMEM if
  59.  *     there was a problem in creating address space area.
  60.  */
  61. static int ddi_physmem_map(__address pf, __address vp, count_t pages, int flags)
  62. {
  63.     ipl_t ipl;
  64.     cap_t caps;
  65.     mem_backend_data_t backend_data;
  66.  
  67.     backend_data.base = pf;
  68.     backend_data.frames = pages;
  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.     /* Lock the task and release the lock protecting tasks_btree. */
  79.     spinlock_lock(&TASK->lock);
  80.    
  81.     if (!as_area_create(TASK->as, flags, pages * PAGE_SIZE, vp, AS_AREA_ATTR_NONE,
  82.         &phys_backend, &backend_data)) {
  83.         /*
  84.          * The address space area could not have been created.
  85.          * We report it using ENOMEM.
  86.          */
  87.         spinlock_unlock(&TASK->lock);
  88.         interrupts_restore(ipl);
  89.         return ENOMEM;
  90.     }
  91.    
  92.     /*
  93.      * Mapping is created on-demand during page fault.
  94.      */
  95.    
  96.     spinlock_unlock(&TASK->lock);
  97.     interrupts_restore(ipl);
  98.     return 0;
  99. }
  100.  
  101. /** Enable range of I/O space for task.
  102.  *
  103.  * @param id Task ID of the destination task.
  104.  * @param ioaddr Starting I/O address.
  105.  * @param size Size of the enabled I/O space..
  106.  *
  107.  * @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,
  108.  *     ENOENT if there is no task matching the specified ID.
  109.  */
  110. static int ddi_iospace_enable(task_id_t id, __address ioaddr, size_t size)
  111. {
  112.     ipl_t ipl;
  113.     cap_t caps;
  114.     task_t *t;
  115.     int rc;
  116.    
  117.     /*
  118.      * Make sure the caller is authorised to make this syscall.
  119.      */
  120.     caps = cap_get(TASK);
  121.     if (!(caps & CAP_IO_MANAGER))
  122.         return EPERM;
  123.    
  124.     ipl = interrupts_disable();
  125.     spinlock_lock(&tasks_lock);
  126.    
  127.     t = task_find_by_id(id);
  128.    
  129.     if (!t) {
  130.         /*
  131.          * There is no task with the specified ID.
  132.          */
  133.         spinlock_unlock(&tasks_lock);
  134.         interrupts_restore(ipl);
  135.         return ENOENT;
  136.     }
  137.  
  138.     /*
  139.      * TODO: We are currently lacking support for task destroying.
  140.      * Once it is added to the kernel, we must take care to
  141.      * synchronize in a way that prevents race conditions here.
  142.      */
  143.    
  144.     /* Lock the task and release the lock protecting tasks_btree. */
  145.     spinlock_lock(&t->lock);
  146.     spinlock_unlock(&tasks_lock);
  147.  
  148.     rc = ddi_iospace_enable_arch(t, ioaddr, size);
  149.    
  150.     spinlock_unlock(&t->lock);
  151.     interrupts_restore(ipl);
  152.     return rc;
  153. }
  154.  
  155. /** Wrapper for SYS_MAP_PHYSMEM syscall.
  156.  *
  157.  * @param phys_base Physical base address to map
  158.  * @param virt_base Destination virtual address
  159.  * @param pages Number of pages
  160.  * @param flags Flags of newly mapped pages
  161.  *
  162.  * @return 0 on success, otherwise it returns error code found in errno.h
  163.  */
  164. __native sys_physmem_map(__native phys_base, __native virt_base, __native pages,
  165.              __native flags)
  166. {
  167.     return (__native) ddi_physmem_map(ALIGN_DOWN((__address) phys_base, FRAME_SIZE),
  168.                       ALIGN_DOWN((__address) virt_base, PAGE_SIZE), (count_t) pages,
  169.                       (int) flags);
  170. }
  171.  
  172. /** Wrapper for SYS_ENABLE_IOSPACE syscall.
  173.  *
  174.  * @param User space address of DDI argument structure.
  175.  *
  176.  * @return 0 on success, otherwise it returns error code found in errno.h
  177.  */
  178. __native sys_iospace_enable(ddi_ioarg_t *uspace_io_arg)
  179. {
  180.     ddi_ioarg_t arg;
  181.     int rc;
  182.    
  183.     rc = copy_from_uspace(&arg, uspace_io_arg, sizeof(ddi_ioarg_t));
  184.     if (rc != 0)
  185.         return (__native) rc;
  186.        
  187.     return (__native) ddi_iospace_enable((task_id_t) arg.task_id, (__address) arg.ioaddr, (size_t) arg.size);
  188. }
  189.  
  190. /** Disable or enable preemption.
  191.  *
  192.  * @param enable If non-zero, the preemption counter will be decremented, leading to potential
  193.  *       enabling of preemption. Otherwise the preemption counter will be incremented,
  194.  *       preventing preemption from occurring.
  195.  *
  196.  * @return Zero on success or EPERM if callers capabilities are not sufficient.
  197.  */
  198. __native sys_preempt_control(int enable)
  199. {
  200.         if (! cap_get(TASK) & CAP_PREEMPT_CONTROL)
  201.                 return EPERM;
  202.         if (enable)
  203.                 preemption_enable();
  204.         else
  205.                 preemption_disable();
  206.         return 0;
  207. }
  208.