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  1. /*
  2.  * Copyright (c) 2008 Jakub Jermar
  3.  * Copyright (c) 2005-2006 Ondrej Palkovsky
  4.  * All rights reserved.
  5.  *
  6.  * Redistribution and use in source and binary forms, with or without
  7.  * modification, are permitted provided that the following conditions
  8.  * are met:
  9.  *
  10.  * - Redistributions of source code must retain the above copyright
  11.  *   notice, this list of conditions and the following disclaimer.
  12.  * - Redistributions in binary form must reproduce the above copyright
  13.  *   notice, this list of conditions and the following disclaimer in the
  14.  *   documentation and/or other materials provided with the distribution.
  15.  * - The name of the author may not be used to endorse or promote products
  16.  *   derived from this software without specific prior written permission.
  17.  *
  18.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28.  */
  29.  
  30. /** @addtogroup amd64  
  31.  * @{
  32.  */
  33. /** @file
  34.  */
  35.  
  36. #include <arch.h>
  37. #include <arch/pm.h>
  38. #include <arch/asm.h>
  39. #include <mm/as.h>
  40. #include <mm/frame.h>
  41. #include <memstr.h>
  42. #include <mm/slab.h>
  43.  
  44. /*
  45.  * There is no segmentation in long mode so we set up flat mode. In this
  46.  * mode, we use, for each privilege level, two segments spanning the
  47.  * whole memory. One is for code and one is for data.
  48.  */
  49.  
  50. descriptor_t gdt[GDT_ITEMS] = {
  51.     /* NULL descriptor */
  52.     { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
  53.     /* KTEXT descriptor */
  54.     { .limit_0_15  = 0xffff,
  55.       .base_0_15   = 0,
  56.       .base_16_23  = 0,
  57.       .access      = AR_PRESENT | AR_CODE | DPL_KERNEL | AR_READABLE,
  58.       .limit_16_19 = 0xf,
  59.       .available   = 0,
  60.       .longmode    = 1,
  61.       .special     = 0,
  62.       .granularity = 1,
  63.       .base_24_31  = 0 },
  64.     /* KDATA descriptor */
  65.     { .limit_0_15  = 0xffff,
  66.       .base_0_15   = 0,
  67.       .base_16_23  = 0,
  68.       .access      = AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_KERNEL,
  69.       .limit_16_19 = 0xf,
  70.       .available   = 0,
  71.       .longmode    = 0,
  72.       .special     = 0,
  73.       .granularity = 1,
  74.       .base_24_31  = 0 },
  75.     /* UDATA descriptor */
  76.     { .limit_0_15  = 0xffff,
  77.       .base_0_15   = 0,
  78.       .base_16_23  = 0,
  79.       .access      = AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_USER,
  80.       .limit_16_19 = 0xf,
  81.       .available   = 0,
  82.       .longmode    = 0,
  83.       .special     = 1,
  84.       .granularity = 1,
  85.       .base_24_31  = 0 },
  86.     /* UTEXT descriptor */
  87.     { .limit_0_15  = 0xffff,
  88.       .base_0_15   = 0,
  89.       .base_16_23  = 0,
  90.       .access      = AR_PRESENT | AR_CODE | DPL_USER,
  91.       .limit_16_19 = 0xf,
  92.       .available   = 0,
  93.       .longmode    = 1,
  94.       .special     = 0,
  95.       .granularity = 1,
  96.       .base_24_31  = 0 },
  97.     /* KTEXT 32-bit protected, for protected mode before long mode */
  98.     { .limit_0_15  = 0xffff,
  99.       .base_0_15   = 0,
  100.       .base_16_23  = 0,
  101.       .access      = AR_PRESENT | AR_CODE | DPL_KERNEL | AR_READABLE,
  102.       .limit_16_19 = 0xf,
  103.       .available   = 0,
  104.       .longmode    = 0,
  105.       .special     = 1,
  106.       .granularity = 1,
  107.       .base_24_31  = 0 },
  108.     /* TSS descriptor - set up will be completed later,
  109.      * on AMD64 it is 64-bit - 2 items in table */
  110.     { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
  111.     { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
  112.     /* VESA Init descriptor */
  113. #ifdef CONFIG_FB   
  114.     { 0xffff, 0, VESA_INIT_SEGMENT >> 12, AR_PRESENT | AR_CODE | DPL_KERNEL,
  115.       0xf, 0, 0, 0, 0, 0
  116.     }
  117. #endif
  118. };
  119.  
  120. idescriptor_t idt[IDT_ITEMS];
  121.  
  122. ptr_16_64_t gdtr = {.limit = sizeof(gdt), .base = (uint64_t) gdt };
  123. ptr_16_64_t idtr = {.limit = sizeof(idt), .base = (uint64_t) idt };
  124.  
  125. static tss_t tss;
  126. tss_t *tss_p = NULL;
  127.  
  128. void gdt_tss_setbase(descriptor_t *d, uintptr_t base)
  129. {
  130.     tss_descriptor_t *td = (tss_descriptor_t *) d;
  131.  
  132.     td->base_0_15 = base & 0xffff;
  133.     td->base_16_23 = ((base) >> 16) & 0xff;
  134.     td->base_24_31 = ((base) >> 24) & 0xff;
  135.     td->base_32_63 = ((base) >> 32);
  136. }
  137.  
  138. void gdt_tss_setlimit(descriptor_t *d, uint32_t limit)
  139. {
  140.     tss_descriptor_t *td = (tss_descriptor_t *) d;
  141.    
  142.     td->limit_0_15 = limit & 0xffff;
  143.     td->limit_16_19 = (limit >> 16) & 0xf;
  144. }
  145.  
  146. void idt_setoffset(idescriptor_t *d, uintptr_t offset)
  147. {
  148.     /*
  149.      * Offset is a linear address.
  150.      */
  151.     d->offset_0_15 = offset & 0xffff;
  152.     d->offset_16_31 = offset >> 16 & 0xffff;
  153.     d->offset_32_63 = offset >> 32;
  154. }
  155.  
  156. void tss_initialize(tss_t *t)
  157. {
  158.     memsetb(t, sizeof(tss_t), 0);
  159. }
  160.  
  161. /*
  162.  * This function takes care of proper setup of IDT and IDTR.
  163.  */
  164. void idt_init(void)
  165. {
  166.     idescriptor_t *d;
  167.     int i;
  168.  
  169.     for (i = 0; i < IDT_ITEMS; i++) {
  170.         d = &idt[i];
  171.  
  172.         d->unused = 0;
  173.         d->selector = gdtselector(KTEXT_DES);
  174.  
  175.         d->present = 1;
  176.         d->type = AR_INTERRUPT; /* masking interrupt */
  177.  
  178.         idt_setoffset(d, ((uintptr_t) interrupt_handlers) +
  179.             i * interrupt_handler_size);
  180.     }
  181. }
  182.  
  183. /** Initialize segmentation - code/data/idt tables
  184.  *
  185.  */
  186. void pm_init(void)
  187. {
  188.     descriptor_t *gdt_p = (descriptor_t *) gdtr.base;
  189.     tss_descriptor_t *tss_desc;
  190.    
  191.     /*
  192.      * Each CPU has its private GDT and TSS.
  193.      * All CPUs share one IDT.
  194.      */
  195.    
  196.     if (config.cpu_active == 1) {
  197.         idt_init();
  198.         /*
  199.          * NOTE: bootstrap CPU has statically allocated TSS, because
  200.          * the heap hasn't been initialized so far.
  201.          */
  202.         tss_p = &tss;
  203.     } else {
  204.         /* We are going to use malloc, which may return
  205.          * non boot-mapped pointer, initialize the CR3 register
  206.          * ahead of page_init */
  207.         write_cr3((uintptr_t) AS_KERNEL->genarch.page_table);
  208.        
  209.         tss_p = (tss_t *) malloc(sizeof(tss_t), FRAME_ATOMIC);
  210.         if (!tss_p)
  211.             panic("Cannot allocate TSS.");
  212.     }
  213.    
  214.     tss_initialize(tss_p);
  215.    
  216.     tss_desc = (tss_descriptor_t *) (&gdt_p[TSS_DES]);
  217.     tss_desc->present = 1;
  218.     tss_desc->type = AR_TSS;
  219.     tss_desc->dpl = PL_KERNEL;
  220.    
  221.     gdt_tss_setbase(&gdt_p[TSS_DES], (uintptr_t) tss_p);
  222.     gdt_tss_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE - 1);
  223.    
  224.     gdtr_load(&gdtr);
  225.     idtr_load(&idtr);
  226.     /*
  227.      * As of this moment, the current CPU has its own GDT pointing
  228.      * to its own TSS. We just need to load the TR register.
  229.      */
  230.     tr_load(gdtselector(TSS_DES));
  231. }
  232.  
  233. /** @}
  234.  */
  235.