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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. #include <ddi/ddi.h>
  30. #include <arch/ddi/ddi.h>
  31. #include <proc/task.h>
  32. #include <arch/types.h>
  33. #include <typedefs.h>
  34. #include <adt/bitmap.h>
  35. #include <mm/slab.h>
  36. #include <arch/pm.h>
  37. #include <errno.h>
  38. #include <arch/cpu.h>
  39. #include <cpu.h>
  40. #include <arch.h>
  41. #include <align.h>
  42.  
  43. /** Enable I/O space range for task.
  44.  *
  45.  * Interrupts are disabled and task is locked.
  46.  *
  47.  * @param task Task.
  48.  * @param ioaddr Startign I/O space address.
  49.  * @param size Size of the enabled I/O range.
  50.  *
  51.  * @return 0 on success or an error code from errno.h.
  52.  */
  53. int ddi_iospace_enable_arch(task_t *task, __address ioaddr, size_t size)
  54. {
  55.     count_t bits;
  56.  
  57.     bits = ioaddr + size;
  58.     if (bits > IO_PORTS)
  59.         return ENOENT;
  60.  
  61.     if (task->arch.iomap.bits < bits) {
  62.         bitmap_t oldiomap;
  63.         __u8 *newmap;
  64.    
  65.         /*
  66.          * The I/O permission bitmap is too small and needs to be grown.
  67.          */
  68.        
  69.         newmap = (__u8 *) malloc(BITS2BYTES(bits), FRAME_ATOMIC);
  70.         if (!newmap)
  71.             return ENOMEM;
  72.        
  73.         bitmap_initialize(&oldiomap, task->arch.iomap.map, task->arch.iomap.bits);
  74.         bitmap_initialize(&task->arch.iomap, newmap, bits);
  75.  
  76.         /*
  77.          * Mark the new range inaccessible.
  78.          */
  79.         bitmap_set_range(&task->arch.iomap, oldiomap.bits, bits - oldiomap.bits);
  80.  
  81.         /*
  82.          * In case there really existed smaller iomap,
  83.          * copy its contents and deallocate it.
  84.          */    
  85.         if (oldiomap.bits) {
  86.             bitmap_copy(&task->arch.iomap, &oldiomap, oldiomap.bits);
  87.             free(oldiomap.map);
  88.         }
  89.     }
  90.  
  91.     /*
  92.      * Enable the range and we are done.
  93.      */
  94.     bitmap_clear_range(&task->arch.iomap, (index_t) ioaddr, (count_t) size);
  95.  
  96.     /*
  97.      * Increment I/O Permission bitmap generation counter.
  98.      */
  99.     task->arch.iomapver++;
  100.  
  101.     return 0;
  102. }
  103.  
  104. /** Install I/O Permission bitmap.
  105.  *
  106.  * Current task's I/O permission bitmap, if any, is installed
  107.  * in the current CPU's TSS.
  108.  *
  109.  * Interrupts must be disabled prior this call.
  110.  */
  111. void io_perm_bitmap_install(void)
  112. {
  113.     count_t bits;
  114.     ptr_16_32_t cpugdtr;
  115.     descriptor_t *gdt_p;
  116.     count_t ver;
  117.  
  118.     /* First, copy the I/O Permission Bitmap. */
  119.     spinlock_lock(&TASK->lock);
  120.     ver = TASK->arch.iomapver;
  121.     if ((bits = TASK->arch.iomap.bits)) {
  122.         bitmap_t iomap;
  123.    
  124.         ASSERT(TASK->arch.iomap.map);
  125.         bitmap_initialize(&iomap, CPU->arch.tss->iomap, TSS_IOMAP_SIZE * 8);
  126.         bitmap_copy(&iomap, &TASK->arch.iomap, TASK->arch.iomap.bits);
  127.         /*
  128.          * It is safe to set the trailing eight bits because of the extra
  129.          * convenience byte in TSS_IOMAP_SIZE.
  130.          */
  131.         bitmap_set_range(&iomap, ALIGN_UP(TASK->arch.iomap.bits, 8), 8);
  132.     }
  133.     spinlock_unlock(&TASK->lock);
  134.  
  135.     /*
  136.      * Second, adjust TSS segment limit.
  137.      * Take the extra ending byte with all bits set into account.
  138.      */
  139.     gdtr_store(&cpugdtr);
  140.     gdt_p = (descriptor_t *) cpugdtr.base;
  141.     gdt_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE + BITS2BYTES(bits));
  142.     gdtr_load(&cpugdtr);
  143.  
  144.     /*
  145.      * Before we load new TSS limit, the current TSS descriptor
  146.      * type must be changed to describe inactive TSS.
  147.      */
  148.     gdt_p[TSS_DES].access = AR_PRESENT | AR_TSS | DPL_KERNEL;
  149.     tr_load(selector(TSS_DES));
  150.    
  151.     /*
  152.      * Update the generation count so that faults caused by
  153.      * early accesses can be serviced.
  154.      */
  155.     CPU->arch.iomapver_copy = ver;
  156. }
  157.