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