kernel/arch/earm/pg_utils.c

   1 #include <minix/cpufeature.h>
   2
   3 #include <minix/type.h>
   4 #include <assert.h>
   5 #include "kernel/kernel.h"
   6 #include "arch_proto.h"
   7 #include <machine/cpu.h>
   8 #include <arm/armreg.h>
   9
  10 #include <string.h>
  11 #include <minix/type.h>
  12
  13 /* These are set/computed in kernel.lds. */
  14 extern char _kern_vir_base, _kern_phys_base, _kern_size;
  15
  16 /* Retrieve the absolute values to something we can use. */
  17 static phys_bytes kern_vir_start = (phys_bytes) &_kern_vir_base;
  18 static phys_bytes kern_phys_start = (phys_bytes) &_kern_phys_base;
  19 static phys_bytes kern_kernlen = (phys_bytes) &_kern_size;
  20
  21 /* page directory we can use to map things */
  22 static u32_t pagedir[4096]  __aligned(16384);
  23
  24 void print_memmap(kinfo_t *cbi)
  25 {
  26         int m;
  27         assert(cbi->mmap_size < MAXMEMMAP);
  28         for(m = 0; m < cbi->mmap_size; m++) {
  29                 phys_bytes addr = cbi->memmap[m].mm_base_addr, endit = cbi->memmap[m].mm_base_addr + cbi->memmap[m].mm_length;
  30                 printf("%08lx-%08lx ",addr, endit);
  31         }
  32         printf("\nsize %08lx\n", cbi->mmap_size);
  33 }
  34
  35 void cut_memmap(kinfo_t *cbi, phys_bytes start, phys_bytes end)
  36 {
  37         int m;
  38         phys_bytes o;
  39
  40         if((o=start % ARM_PAGE_SIZE))
  41                 start -= o;
  42         if((o=end % ARM_PAGE_SIZE))
  43                 end += ARM_PAGE_SIZE - o;
  44
  45         assert(kernel_may_alloc);
  46
  47         for(m = 0; m < cbi->mmap_size; m++) {
  48                 phys_bytes substart = start, subend = end;
  49                 phys_bytes memaddr = cbi->memmap[m].mm_base_addr,
  50                     memend = cbi->memmap[m].mm_base_addr + cbi->memmap[m].mm_length;
  51
  52                 /* adjust cut range to be a subset of the free memory */
  53                 if(substart < memaddr) substart = memaddr;
  54                 if(subend > memend) subend = memend;
  55                 if(substart >= subend) continue;
  56
  57                 /* if there is any overlap, forget this one and add
  58                  * 1-2 subranges back
  59                  */
  60                 cbi->memmap[m].mm_base_addr = cbi->memmap[m].mm_length = 0;
  61                 if(substart > memaddr)
  62                         add_memmap(cbi, memaddr, substart-memaddr);
  63                 if(subend < memend)
  64                         add_memmap(cbi, subend, memend-subend);
  65         }
  66 }
  67
  68 void add_memmap(kinfo_t *cbi, u64_t addr, u64_t len)
  69 {
  70         int m;
  71 #define LIMIT 0xFFFFF000
  72         /* Truncate available memory at 4GB as the rest of minix
  73          * currently can't deal with any bigger.
  74          */
  75         if(addr > LIMIT) {
  76                 return;
  77         }
  78
  79         if(addr + len > LIMIT) {
  80                 len -= (addr + len - LIMIT);
  81         }
  82
  83         assert(cbi->mmap_size < MAXMEMMAP);
  84         if(len == 0) {
  85                 return;
  86         }
  87         addr = roundup(addr, ARM_PAGE_SIZE);
  88         len = rounddown(len, ARM_PAGE_SIZE);
  89
  90         assert(kernel_may_alloc);
  91
  92         for(m = 0; m < MAXMEMMAP; m++) {
  93                 phys_bytes highmark;
  94                 if(cbi->memmap[m].mm_length) {
  95                         continue;
  96                 }
  97                 cbi->memmap[m].mm_base_addr = addr;
  98                 cbi->memmap[m].mm_length = len;
  99                 cbi->memmap[m].type = MULTIBOOT_MEMORY_AVAILABLE;
 100                 if(m >= cbi->mmap_size) {
 101                         cbi->mmap_size = m+1;
 102                 }
 103                 highmark = addr + len;
 104                 if(highmark > cbi->mem_high_phys) {
 105                         cbi->mem_high_phys = highmark;
 106                 }
 107                 return;
 108         }
 109
 110         panic("no available memmap slot");
 111 }
 112
 113 u32_t *alloc_pagetable(phys_bytes *ph)
 114 {
 115         u32_t *ret;
 116 #define PG_PAGETABLES 24
 117         static u32_t pagetables[PG_PAGETABLES][256]  __aligned(1024);
 118         static int pt_inuse = 0;
 119         if(pt_inuse >= PG_PAGETABLES) {
 120                 panic("no more pagetables");
 121         }
 122         assert(sizeof(pagetables[pt_inuse]) == 1024);
 123         ret = pagetables[pt_inuse++];
 124         *ph = vir2phys(ret);
 125         return ret;
 126 }
 127
 128 #define PAGE_KB (ARM_PAGE_SIZE / 1024)
 129
 130 phys_bytes pg_alloc_page(kinfo_t *cbi)
 131 {
 132         int m;
 133         multiboot_memory_map_t *mmap;
 134
 135         assert(kernel_may_alloc);
 136
 137         for(m = 0; m < cbi->mmap_size; m++) {
 138                 mmap = &cbi->memmap[m];
 139                 if(!mmap->mm_length) {
 140                         continue;
 141                 }
 142                 assert(mmap->mm_length > 0);
 143                 assert(!(mmap->mm_length % ARM_PAGE_SIZE));
 144                 assert(!(mmap->mm_base_addr % ARM_PAGE_SIZE));
 145
 146                 u32_t addr = mmap->mm_base_addr;
 147                 mmap->mm_base_addr += ARM_PAGE_SIZE;
 148                 mmap->mm_length  -= ARM_PAGE_SIZE;
 149
 150                 cbi->kernel_allocated_bytes_dynamic += ARM_PAGE_SIZE;
 151
 152                 return addr;
 153         }
 154
 155         panic("can't find free memory");
 156 }
 157
 158 void pg_identity(kinfo_t *cbi)
 159 {
 160         int i;
 161         phys_bytes phys;
 162
 163         /* We map memory that does not correspond to physical memory
 164          * as non-cacheable. Make sure we know what it is.
 165          */
 166         assert(cbi->mem_high_phys);
 167
 168         /* Set up an identity mapping page directory */
 169          for(i = 0; i < ARM_VM_DIR_ENTRIES; i++) {
 170                 u32_t flags = ARM_VM_SECTION
 171                         | ARM_VM_SECTION_USER
 172                         | ARM_VM_SECTION_DOMAIN;
 173
 174                 phys = i * ARM_SECTION_SIZE;
 175                 /* mark mormal memory as cacheable. TODO: fix hard coded values */
 176                 if (phys >= PHYS_MEM_BEGIN && phys <= PHYS_MEM_END) {
 177                         pagedir[i] =  phys | flags | ARM_VM_SECTION_CACHED;
 178                 } else {
 179                         pagedir[i] =  phys | flags | ARM_VM_SECTION_DEVICE;
 180                 }
 181         }
 182 }
 183
 184 int pg_mapkernel(void)
 185 {
 186         int pde;
 187         u32_t mapped = 0, kern_phys = kern_phys_start;
 188
 189         assert(!(kern_vir_start % ARM_SECTION_SIZE));
 190         assert(!(kern_phys_start % ARM_SECTION_SIZE));
 191         pde = kern_vir_start / ARM_SECTION_SIZE; /* start pde */
 192         while(mapped < kern_kernlen) {
 193                 pagedir[pde] = (kern_phys & ARM_VM_SECTION_MASK)
 194                         | ARM_VM_SECTION
 195                         | ARM_VM_SECTION_SUPER
 196                         | ARM_VM_SECTION_DOMAIN
 197                         | ARM_VM_SECTION_CACHED;
 198                 mapped += ARM_SECTION_SIZE;
 199                 kern_phys += ARM_SECTION_SIZE;
 200                 pde++;
 201         }
 202         return pde;     /* free pde */
 203 }
 204
 205 void vm_enable_paging(void)
 206 {
 207         u32_t sctlr;
 208         u32_t actlr;
 209
 210         write_ttbcr(0);
 211
 212         /* Set all Domains to Client */
 213         write_dacr(0x55555555);
 214
 215         sctlr = read_sctlr();
 216
 217         /* Enable MMU */
 218         sctlr |= CPU_CONTROL_MMU_ENABLE;
 219
 220         /* TRE set to zero (default reset value): TEX[2:0] are used, plus C and B bits.*/
 221         sctlr &= ~CPU_CONTROL_TR_ENABLE;
 222
 223         /* AFE set to zero (default reset value): not using simplified model. */
 224         sctlr &= ~CPU_CONTROL_AF_ENABLE;
 225
 226         /* Enable instruction ,data cache and branch prediction */
 227         sctlr |= CPU_CONTROL_DC_ENABLE;
 228         sctlr |= CPU_CONTROL_IC_ENABLE;
 229         sctlr |= CPU_CONTROL_BPRD_ENABLE;
 230
 231         /* Enable barriers */
 232         sctlr |= CPU_CONTROL_32BD_ENABLE;
 233
 234         /* Enable L2 cache (cortex-a8) */
 235         #define CORTEX_A8_L2EN   (0x02)
 236         actlr = read_actlr();
 237         actlr |= CORTEX_A8_L2EN;
 238         write_actlr(actlr);
 239
 240         write_sctlr(sctlr);
 241 }
 242
 243 phys_bytes pg_load()
 244 {
 245         phys_bytes phpagedir = vir2phys(pagedir);
 246         write_ttbr0(phpagedir);
 247         return phpagedir;
 248 }
 249
 250 void pg_clear(void)
 251 {
 252         memset(pagedir, 0, sizeof(pagedir));
 253 }
 254
 255 phys_bytes pg_rounddown(phys_bytes b)
 256 {
 257         phys_bytes o;
 258         if(!(o = b % ARM_PAGE_SIZE)) {
 259                 return b;
 260         }
 261         return b  - o;
 262 }
 263
 264 void pg_map(phys_bytes phys, vir_bytes vaddr, vir_bytes vaddr_end,
 265         kinfo_t *cbi)
 266 {
 267         static int mapped_pde = -1;
 268         static u32_t *pt = NULL;
 269         int pde, pte;
 270
 271         assert(kernel_may_alloc);
 272
 273         if(phys == PG_ALLOCATEME) {
 274                 assert(!(vaddr % ARM_PAGE_SIZE));
 275         } else  {
 276                 assert((vaddr % ARM_PAGE_SIZE) == (phys % ARM_PAGE_SIZE));
 277                 vaddr = pg_rounddown(vaddr);
 278                 phys = pg_rounddown(phys);
 279         }
 280         assert(vaddr < kern_vir_start);
 281
 282         while(vaddr < vaddr_end) {
 283                 phys_bytes source = phys;
 284                 assert(!(vaddr % ARM_PAGE_SIZE));
 285                 if(phys == PG_ALLOCATEME) {
 286                         source = pg_alloc_page(cbi);
 287                 } else {
 288                         assert(!(phys % ARM_PAGE_SIZE));
 289                 }
 290                 assert(!(source % ARM_PAGE_SIZE));
 291                 pde = ARM_VM_PDE(vaddr);
 292                 pte = ARM_VM_PTE(vaddr);
 293                 if(mapped_pde < pde) {
 294                         phys_bytes ph;
 295                         pt = alloc_pagetable(&ph);
 296                         pagedir[pde] = (ph & ARM_VM_PDE_MASK)
 297                                         | ARM_VM_PAGEDIR
 298                                         | ARM_VM_PDE_DOMAIN;
 299                         mapped_pde = pde;
 300                 }
 301                 assert(pt);
 302                 pt[pte] = (source & ARM_VM_PTE_MASK)
 303                         | ARM_VM_PAGETABLE
 304                         | ARM_VM_PTE_CACHED
 305                         | ARM_VM_PTE_USER;
 306                 vaddr += ARM_PAGE_SIZE;
 307                 if(phys != PG_ALLOCATEME) {
 308                         phys += ARM_PAGE_SIZE;
 309                 }
 310         }
 311 }
 312
 313 void pg_info(reg_t *pagedir_ph, u32_t **pagedir_v)
 314 {
 315         *pagedir_ph = vir2phys(pagedir);
 316         *pagedir_v = pagedir;
 317 }