src/cpu/p6/pgtbl.c

   1 #include <console/console.h>
   2 #include <smp/start_stop.h>
   3 #include <cpu/p6/pgtbl.h>
   4
   5 static void paging_off(void)
   6 {
   7         __asm__ __volatile__ (
   8                 /* Disable paging */
   9                 "movl   %%cr0, %%eax\n\t"
  10                 "andl   $0x7FFFFFFF, %%eax\n\t"
  11                 "movl   %%eax, %%cr0\n\t"
  12                 /* Disable pae */
  13                 "movl   %%cr4, %%eax\n\t"
  14                 "andl   $0xFFFFFFDF, %%eax\n\t"
  15                 :
  16                 :
  17                 : "eax"
  18                 );
  19 }
  20
  21 static void paging_on(void *pdp)
  22 {
  23         __asm__ __volatile__(
  24                 /* Load the page table address */
  25                 "movl   %0, %%cr3\n\t"
  26                 /* Enable pae */
  27                 "movl   %%cr4, %%eax\n\t"
  28                 "orl    $0x00000020, %%eax\n\t"
  29                 "movl   %%eax, %%cr4\n\t"
  30                 /* Enable paging */
  31                 "movl   %%cr0, %%eax\n\t"
  32                 "orl    $0x80000000, %%eax\n\t"
  33                 "movl   %%eax, %%cr0\n\t"
  34                 :
  35                 : "r" (pdp)
  36                 : "eax"
  37                 );
  38 }
  39
  40 void *map_2M_page(int cpu_index, unsigned long page)
  41 {
  42         struct pde {
  43                 uint32_t addr_lo;
  44                 uint32_t addr_hi;
  45         } __attribute__ ((packed));
  46         struct pg_table {
  47                 struct pde pd[2048];
  48                 struct pde pdp[512];
  49         } __attribute__ ((packed));
  50         static struct pg_table pgtbl[CONFIG_MAX_CPUS] __attribute__ ((aligned(4096)));
  51         static unsigned long mapped_window[CONFIG_MAX_CPUS];
  52         unsigned long window;
  53         void *result;
  54         int i;
  55         if ((cpu_index < 0) || (cpu_index >= CONFIG_MAX_CPUS)) {
  56                 return MAPPING_ERROR;
  57         }
  58         window = page >> 10;
  59         if (window != mapped_window[cpu_index]) {
  60                 paging_off();
  61                 if (window > 1) {
  62                         struct pde *pd, *pdp;
  63                         /* Point the page directory pointers at the page directories */
  64                         memset(&pgtbl[cpu_index].pdp, 0, sizeof(pgtbl[cpu_index].pdp));
  65                         pd = pgtbl[cpu_index].pd;
  66                         pdp = pgtbl[cpu_index].pdp;
  67                         pdp[0].addr_lo = ((uint32_t)&pd[512*0])|1;
  68                         pdp[1].addr_lo = ((uint32_t)&pd[512*1])|1;
  69                         pdp[2].addr_lo = ((uint32_t)&pd[512*2])|1;
  70                         pdp[3].addr_lo = ((uint32_t)&pd[512*3])|1;
  71                         /* The first half of the page table is identity mapped */
  72                         for(i = 0; i < 1024; i++) {
  73                                 pd[i].addr_lo = ((i & 0x3ff) << 21)| 0xE3;
  74                                 pd[i].addr_hi = 0;
  75                         }
  76                         /* The second half of the page table holds the mapped page */
  77                         for(i = 1024; i < 2048; i++) {
  78                                 pd[i].addr_lo = ((window & 1) << 31) | ((i & 0x3ff) << 21) | 0xE3;
  79                                 pd[i].addr_hi = (window >> 1);
  80                         }
  81                         paging_on(pdp);
  82                 }
  83                 mapped_window[cpu_index] = window;
  84         }
  85         if (window == 0) {
  86                 result = (void *)(page << 21);
  87         } else {
  88                 result = (void *)(0x80000000 | ((page & 0x3ff) << 21));
  89         }
  90         return result;
  91 }