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  1. /*
  2.  * Copyright (c) 2001-2004 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, 0xf, 0, 0, 0, 0, 0 }
  115. #endif
  116. };
  117.  
  118. idescriptor_t idt[IDT_ITEMS];
  119.  
  120. ptr_16_64_t gdtr = {.limit = sizeof(gdt), .base= (uint64_t) gdt };
  121. ptr_16_64_t idtr = {.limit = sizeof(idt), .base= (uint64_t) idt };
  122.  
  123. static tss_t tss;
  124. tss_t *tss_p = NULL;
  125.  
  126. void gdt_tss_setbase(descriptor_t *d, uintptr_t base)
  127. {
  128.     tss_descriptor_t *td = (tss_descriptor_t *) d;
  129.  
  130.     td->base_0_15 = base & 0xffff;
  131.     td->base_16_23 = ((base) >> 16) & 0xff;
  132.     td->base_24_31 = ((base) >> 24) & 0xff;
  133.     td->base_32_63 = ((base) >> 32);
  134. }
  135.  
  136. void gdt_tss_setlimit(descriptor_t *d, uint32_t limit)
  137. {
  138.     struct tss_descriptor *td = (tss_descriptor_t *) d;
  139.  
  140.     td->limit_0_15 = limit & 0xffff;
  141.     td->limit_16_19 = (limit >> 16) & 0xf;
  142. }
  143.  
  144. void idt_setoffset(idescriptor_t *d, uintptr_t offset)
  145. {
  146.     /*
  147.      * Offset is a linear address.
  148.      */
  149.     d->offset_0_15 = offset & 0xffff;
  150.     d->offset_16_31 = offset >> 16 & 0xffff;
  151.     d->offset_32_63 = offset >> 32;
  152. }
  153.  
  154. void tss_initialize(tss_t *t)
  155. {
  156.     memsetb((uintptr_t) t, sizeof(tss_t), 0);
  157. }
  158.  
  159. /*
  160.  * This function takes care of proper setup of IDT and IDTR.
  161.  */
  162. void idt_init(void)
  163. {
  164.     idescriptor_t *d;
  165.     int i;
  166.  
  167.     for (i = 0; i < IDT_ITEMS; i++) {
  168.         d = &idt[i];
  169.  
  170.         d->unused = 0;
  171.         d->selector = gdtselector(KTEXT_DES);
  172.  
  173.         d->present = 1;
  174.         d->type = AR_INTERRUPT; /* masking interrupt */
  175.  
  176.         idt_setoffset(d, ((uintptr_t) interrupt_handlers) + i*interrupt_handler_size);
  177.     }
  178. }
  179.  
  180. /** Initialize segmentation - code/data/idt tables
  181.  *
  182.  */
  183. void pm_init(void)
  184. {
  185.     descriptor_t *gdt_p = (struct descriptor *) gdtr.base;
  186.     tss_descriptor_t *tss_desc;
  187.  
  188.     /*
  189.      * Each CPU has its private GDT and TSS.
  190.      * All CPUs share one IDT.
  191.      */
  192.  
  193.     if (config.cpu_active == 1) {
  194.         idt_init();
  195.         /*
  196.          * NOTE: bootstrap CPU has statically allocated TSS, because
  197.          * the heap hasn't been initialized so far.
  198.          */
  199.         tss_p = &tss;
  200.     }
  201.     else {
  202.         /* We are going to use malloc, which may return
  203.          * non boot-mapped pointer, initialize the CR3 register
  204.          * ahead of page_init */
  205.         write_cr3((uintptr_t) AS_KERNEL->genarch.page_table);
  206.  
  207.         tss_p = (struct tss *) malloc(sizeof(tss_t), FRAME_ATOMIC);
  208.         if (!tss_p)
  209.             panic("could not allocate TSS\n");
  210.     }
  211.  
  212.     tss_initialize(tss_p);
  213.  
  214.     tss_desc = (tss_descriptor_t *) (&gdt_p[TSS_DES]);
  215.     tss_desc->present = 1;
  216.     tss_desc->type = AR_TSS;
  217.     tss_desc->dpl = PL_KERNEL;
  218.    
  219.     gdt_tss_setbase(&gdt_p[TSS_DES], (uintptr_t) tss_p);
  220.     gdt_tss_setlimit(&gdt_p[TSS_DES], TSS_BASIC_SIZE - 1);
  221.  
  222.     gdtr_load(&gdtr);
  223.     idtr_load(&idtr);
  224.     /*
  225.      * As of this moment, the current CPU has its own GDT pointing
  226.      * to its own TSS. We just need to load the TR register.
  227.      */
  228.     tr_load(gdtselector(TSS_DES));
  229. }
  230.  
  231. /* Reboot the machine by initiating
  232.  * a triple fault
  233.  */
  234. void arch_reboot(void)
  235. {
  236.     preemption_disable();
  237.     ipl_t ipl = interrupts_disable();
  238.    
  239.     memsetb((uintptr_t) idt, sizeof(idt), 0);
  240.     idtr_load(&idtr);
  241.    
  242.     interrupts_restore(ipl);
  243.     asm volatile (
  244.         "int $0x03\n"
  245.         "hlt\n"
  246.     );
  247. }
  248.  
  249. /** @}
  250.  */
  251.