src/cpu/x86/pae/pgtbl.c

   1 /*
   2         2005.12 yhlu add coreboot_ram cross the vga font buffer handling
   3 */
   4
   5 #include <console/console.h>
   6 #include <cpu/cpu.h>
   7 #include <cpu/x86/pae.h>
   8 #include <string.h>
   9
  10 static void paging_off(void)
  11 {
  12         __asm__ __volatile__ (
  13                 /* Disable paging */
  14                 "movl   %%cr0, %%eax\n\t"
  15                 "andl   $0x7FFFFFFF, %%eax\n\t"
  16                 "movl   %%eax, %%cr0\n\t"
  17                 /* Disable pae */
  18                 "movl   %%cr4, %%eax\n\t"
  19                 "andl   $0xFFFFFFDF, %%eax\n\t"
  20                 "movl   %%eax, %%cr4\n\t"
  21                 :
  22                 :
  23                 : "eax"
  24                 );
  25 }
  26
  27 static void paging_on(void *pdp)
  28 {
  29         __asm__ __volatile__(
  30                 /* Load the page table address */
  31                 "movl   %0, %%cr3\n\t"
  32                 /* Enable pae */
  33                 "movl   %%cr4, %%eax\n\t"
  34                 "orl    $0x00000020, %%eax\n\t"
  35                 "movl   %%eax, %%cr4\n\t"
  36                 /* Enable paging */
  37                 "movl   %%cr0, %%eax\n\t"
  38                 "orl    $0x80000000, %%eax\n\t"
  39                 "movl   %%eax, %%cr0\n\t"
  40                 :
  41                 : "r" (pdp)
  42                 : "eax"
  43                 );
  44 }
  45
  46 void *map_2M_page(unsigned long page)
  47 {
  48         struct pde {
  49                 uint32_t addr_lo;
  50                 uint32_t addr_hi;
  51         } __attribute__ ((packed));
  52         struct pg_table {
  53                 struct pde pd[2048];
  54                 struct pde pdp[512];
  55         } __attribute__ ((packed));
  56
  57         static struct pg_table pgtbl[CONFIG_MAX_CPUS] __attribute__ ((aligned(4096)));
  58         static unsigned long mapped_window[CONFIG_MAX_CPUS];
  59         unsigned long index;
  60         unsigned long window;
  61         void *result;
  62         int i;
  63         index = cpu_index();
  64         if ((index < 0) || (index >= CONFIG_MAX_CPUS)) {
  65                 return MAPPING_ERROR;
  66         }
  67         window = page >> 10;
  68         if (window != mapped_window[index]) {
  69                 paging_off();
  70                 if (window > 1) {
  71                         struct pde *pd, *pdp;
  72                         /* Point the page directory pointers at the page directories */
  73                         memset(&pgtbl[index].pdp, 0, sizeof(pgtbl[index].pdp));
  74                         pd = pgtbl[index].pd;
  75                         pdp = pgtbl[index].pdp;
  76                         pdp[0].addr_lo = ((uint32_t)&pd[512*0])|1;
  77                         pdp[1].addr_lo = ((uint32_t)&pd[512*1])|1;
  78                         pdp[2].addr_lo = ((uint32_t)&pd[512*2])|1;
  79                         pdp[3].addr_lo = ((uint32_t)&pd[512*3])|1;
  80                         /* The first half of the page table is identity mapped */
  81                         for(i = 0; i < 1024; i++) {
  82                                 pd[i].addr_lo = ((i & 0x3ff) << 21)| 0xE3;
  83                                 pd[i].addr_hi = 0;
  84                         }
  85                         /* The second half of the page table holds the mapped page */
  86                         for(i = 1024; i < 2048; i++) {
  87                                 pd[i].addr_lo = ((window & 1) << 31) | ((i & 0x3ff) << 21) | 0xE3;
  88                                 pd[i].addr_hi = (window >> 1);
  89                         }
  90                         paging_on(pdp);
  91                 }
  92                 mapped_window[index] = window;
  93         }
  94         if (window == 0) {
  95                 result = (void *)(page << 21);
  96         } else {
  97                 result = (void *)(0x80000000 | ((page & 0x3ff) << 21));
  98         }
  99         return result;
 100 }