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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. /** @addtogroup genericddi
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Device Driver Interface functions.
  36.  *
  37.  * This file contains functions that comprise the Device Driver Interface.
  38.  * These are the functions for mapping physical memory and enabling I/O
  39.  * space to tasks.
  40.  */
  41.  
  42. #include <ddi/ddi.h>
  43. #include <ddi/ddi_arg.h>
  44. #include <proc/task.h>
  45. #include <security/cap.h>
  46. #include <mm/frame.h>
  47. #include <mm/as.h>
  48. #include <synch/spinlock.h>
  49. #include <syscall/copy.h>
  50. #include <adt/list.h>
  51. #include <arch.h>
  52. #include <align.h>
  53. #include <errno.h>
  54.  
  55. /** This lock protects the parea_btree. */
  56. SPINLOCK_INITIALIZE(parea_lock);
  57.  
  58. /** List with enabled physical memory areas. */
  59. static LIST_INITIALIZE(parea_head);
  60.  
  61. /** Physical memory area for devices. */
  62. static parea_t dev_area;
  63.  
  64. /** Initialize DDI. */
  65. void ddi_init(void)
  66. {
  67.     hw_area(&dev_area.pbase, &dev_area.frames);
  68.     ddi_parea_register(&dev_area);
  69. }
  70.  
  71. /** Enable piece of physical memory for mapping by physmem_map().
  72.  *
  73.  * @param parea Pointer to physical area structure.
  74.  *
  75.  * @todo This function doesn't check for overlaps. It depends on the kernel to
  76.  * create disjunct physical memory areas.
  77.  */
  78. void ddi_parea_register(parea_t *parea)
  79. {
  80.     ipl_t ipl;
  81.    
  82.     ipl = interrupts_disable();
  83.     spinlock_lock(&parea_lock);
  84.    
  85.     /*
  86.      * TODO: we should really check for overlaps here.
  87.      * However, we should be safe because the kernel is pretty sane.
  88.      */
  89.     link_initialize(&parea->link);
  90.     list_append(&parea->link, &parea_head);
  91.    
  92.     spinlock_unlock(&parea_lock);
  93.     interrupts_restore(ipl);
  94. }
  95.  
  96. /** Map piece of physical memory into virtual address space of current task.
  97.  *
  98.  * @param pf Physical address of the starting frame.
  99.  * @param vp Virtual address of the starting page.
  100.  * @param pages Number of pages to map.
  101.  * @param flags Address space area flags for the mapping.
  102.  *
  103.  * @return 0 on success, EPERM if the caller lacks capabilities to use this
  104.  *  syscall, ENOENT if there is no task matching the specified ID or the
  105.  *  physical address space is not enabled for mapping and ENOMEM if there
  106.  *  was a problem in creating address space area.
  107.  */
  108. static int ddi_physmem_map(uintptr_t pf, uintptr_t vp, pfn_t pages, int flags)
  109. {
  110.     ipl_t ipl;
  111.     cap_t caps;
  112.     mem_backend_data_t backend_data;
  113.    
  114.     backend_data.base = pf;
  115.     backend_data.frames = pages;
  116.    
  117.     /*
  118.      * Make sure the caller is authorised to make this syscall.
  119.      */
  120.     caps = cap_get(TASK);
  121.     if (!(caps & CAP_MEM_MANAGER))
  122.         return EPERM;
  123.    
  124.     ipl = interrupts_disable();
  125.    
  126.     /*
  127.      * Check if the physical memory area is enabled for mapping.
  128.      */
  129.     spinlock_lock(&parea_lock);
  130.    
  131.     bool fnd = false;
  132.     link_t *cur;
  133.    
  134.     for (cur = parea_head.next; cur != &parea_head; cur = cur->next) {
  135.         parea_t *parea = list_get_instance(cur, parea_t, link);
  136.         if ((parea->pbase <= pf) && (ADDR2PFN(pf - parea->pbase) + pages <= parea->frames)) {
  137.             fnd = true;
  138.             break;
  139.         }
  140.     }
  141.    
  142.     spinlock_unlock(&parea_lock);
  143.    
  144.     if (!fnd) {
  145.         /*
  146.          * Physical memory area cannot be mapped.
  147.          */
  148.         interrupts_restore(ipl);
  149.         return ENOENT;
  150.     }
  151.    
  152.     spinlock_lock(&TASK->lock);
  153.    
  154.     if (!as_area_create(TASK->as, flags, pages * PAGE_SIZE, vp, AS_AREA_ATTR_NONE,
  155.         &phys_backend, &backend_data)) {
  156.         /*
  157.          * The address space area could not have been created.
  158.          * We report it using ENOMEM.
  159.          */
  160.         spinlock_unlock(&TASK->lock);
  161.         interrupts_restore(ipl);
  162.         return ENOMEM;
  163.     }
  164.    
  165.     /*
  166.      * Mapping is created on-demand during page fault.
  167.      */
  168.    
  169.     spinlock_unlock(&TASK->lock);
  170.     interrupts_restore(ipl);
  171.     return 0;
  172. }
  173.  
  174. /** Enable range of I/O space for task.
  175.  *
  176.  * @param id Task ID of the destination task.
  177.  * @param ioaddr Starting I/O address.
  178.  * @param size Size of the enabled I/O space..
  179.  *
  180.  * @return 0 on success, EPERM if the caller lacks capabilities to use this
  181.  *  syscall, ENOENT if there is no task matching the specified ID.
  182.  */
  183. static int ddi_iospace_enable(task_id_t id, uintptr_t ioaddr, size_t size)
  184. {
  185.     ipl_t ipl;
  186.     cap_t caps;
  187.     task_t *t;
  188.     int rc;
  189.    
  190.     /*
  191.      * Make sure the caller is authorised to make this syscall.
  192.      */
  193.     caps = cap_get(TASK);
  194.     if (!(caps & CAP_IO_MANAGER))
  195.         return EPERM;
  196.    
  197.     ipl = interrupts_disable();
  198.     spinlock_lock(&tasks_lock);
  199.    
  200.     t = task_find_by_id(id);
  201.    
  202.     if ((!t) || (!context_check(CONTEXT, t->context))) {
  203.         /*
  204.          * There is no task with the specified ID
  205.          * or the task belongs to a different security
  206.          * context.
  207.          */
  208.         spinlock_unlock(&tasks_lock);
  209.         interrupts_restore(ipl);
  210.         return ENOENT;
  211.     }
  212.  
  213.     /* Lock the task and release the lock protecting tasks_btree. */
  214.     spinlock_lock(&t->lock);
  215.     spinlock_unlock(&tasks_lock);
  216.  
  217.     rc = ddi_iospace_enable_arch(t, ioaddr, size);
  218.    
  219.     spinlock_unlock(&t->lock);
  220.     interrupts_restore(ipl);
  221.     return rc;
  222. }
  223.  
  224. /** Wrapper for SYS_PHYSMEM_MAP syscall.
  225.  *
  226.  * @param phys_base Physical base address to map
  227.  * @param virt_base Destination virtual address
  228.  * @param pages Number of pages
  229.  * @param flags Flags of newly mapped pages
  230.  *
  231.  * @return 0 on success, otherwise it returns error code found in errno.h
  232.  */
  233. unative_t sys_physmem_map(unative_t phys_base, unative_t virt_base,
  234.     unative_t pages, unative_t flags)
  235. {
  236.     return (unative_t) ddi_physmem_map(ALIGN_DOWN((uintptr_t) phys_base,
  237.         FRAME_SIZE), ALIGN_DOWN((uintptr_t) virt_base, PAGE_SIZE),
  238.         (pfn_t) pages, (int) flags);
  239. }
  240.  
  241. /** Wrapper for SYS_ENABLE_IOSPACE syscall.
  242.  *
  243.  * @param uspace_io_arg User space address of DDI argument structure.
  244.  *
  245.  * @return 0 on success, otherwise it returns error code found in errno.h
  246.  */
  247. unative_t sys_iospace_enable(ddi_ioarg_t *uspace_io_arg)
  248. {
  249.     ddi_ioarg_t arg;
  250.     int rc;
  251.    
  252.     rc = copy_from_uspace(&arg, uspace_io_arg, sizeof(ddi_ioarg_t));
  253.     if (rc != 0)
  254.         return (unative_t) rc;
  255.        
  256.     return (unative_t) ddi_iospace_enable((task_id_t) arg.task_id,
  257.         (uintptr_t) arg.ioaddr, (size_t) arg.size);
  258. }
  259.  
  260. /** Disable or enable preemption.
  261.  *
  262.  * @param enable If non-zero, the preemption counter will be decremented,
  263.  *  leading to potential enabling of preemption. Otherwise the preemption
  264.  *  counter will be incremented, preventing preemption from occurring.
  265.  *
  266.  * @return Zero on success or EPERM if callers capabilities are not sufficient.
  267.  */
  268. unative_t sys_preempt_control(int enable)
  269. {
  270.     if (!cap_get(TASK) & CAP_PREEMPT_CONTROL)
  271.         return EPERM;
  272.     if (enable)
  273.         preemption_enable();
  274.     else
  275.         preemption_disable();
  276.     return 0;
  277. }
  278.  
  279. /** @}
  280.  */
  281.