arch/blackfin/kernel/process.c

   1 /*
   2  * Blackfin architecture-dependent process handling
   3  *
   4  * Copyright 2004-2009 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/unistd.h>
  11 #include <linux/user.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/slab.h>
  14 #include <linux/sched.h>
  15 #include <linux/sched/debug.h>
  16 #include <linux/sched/task.h>
  17 #include <linux/sched/task_stack.h>
  18 #include <linux/mm_types.h>
  19 #include <linux/tick.h>
  20 #include <linux/fs.h>
  21 #include <linux/err.h>
  22
  23 #include <asm/blackfin.h>
  24 #include <asm/fixed_code.h>
  25 #include <asm/mem_map.h>
  26 #include <asm/irq.h>
  27
  28 asmlinkage void ret_from_fork(void);
  29
  30 /* Points to the SDRAM backup memory for the stack that is currently in
  31  * L1 scratchpad memory.
  32  */
  33 void *current_l1_stack_save;
  34
  35 /* The number of tasks currently using a L1 stack area.  The SRAM is
  36  * allocated/deallocated whenever this changes from/to zero.
  37  */
  38 int nr_l1stack_tasks;
  39
  40 /* Start and length of the area in L1 scratchpad memory which we've allocated
  41  * for process stacks.
  42  */
  43 void *l1_stack_base;
  44 unsigned long l1_stack_len;
  45
  46 void (*pm_power_off)(void) = NULL;
  47 EXPORT_SYMBOL(pm_power_off);
  48
  49 /*
  50  * The idle loop on BFIN
  51  */
  52 #ifdef CONFIG_IDLE_L1
  53 void arch_cpu_idle(void)__attribute__((l1_text));
  54 #endif
  55
  56 /*
  57  * This is our default idle handler.  We need to disable
  58  * interrupts here to ensure we don't miss a wakeup call.
  59  */
  60 void arch_cpu_idle(void)
  61 {
  62 #ifdef CONFIG_IPIPE
  63         ipipe_suspend_domain();
  64 #endif
  65         hard_local_irq_disable();
  66         if (!need_resched())
  67                 idle_with_irq_disabled();
  68
  69         hard_local_irq_enable();
  70 }
  71
  72 #ifdef CONFIG_HOTPLUG_CPU
  73 void arch_cpu_idle_dead(void)
  74 {
  75         cpu_die();
  76 }
  77 #endif
  78
  79 /*
  80  * Do necessary setup to start up a newly executed thread.
  81  *
  82  * pass the data segment into user programs if it exists,
  83  * it can't hurt anything as far as I can tell
  84  */
  85 void start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
  86 {
  87         regs->pc = new_ip;
  88         if (current->mm)
  89                 regs->p5 = current->mm->start_data;
  90 #ifndef CONFIG_SMP
  91         task_thread_info(current)->l1_task_info.stack_start =
  92                 (void *)current->mm->context.stack_start;
  93         task_thread_info(current)->l1_task_info.lowest_sp = (void *)new_sp;
  94         memcpy(L1_SCRATCH_TASK_INFO, &task_thread_info(current)->l1_task_info,
  95                sizeof(*L1_SCRATCH_TASK_INFO));
  96 #endif
  97         wrusp(new_sp);
  98 }
  99 EXPORT_SYMBOL_GPL(start_thread);
 100
 101 void flush_thread(void)
 102 {
 103 }
 104
 105 asmlinkage int bfin_clone(unsigned long clone_flags, unsigned long newsp)
 106 {
 107 #ifdef __ARCH_SYNC_CORE_DCACHE
 108         if (current->nr_cpus_allowed == num_possible_cpus())
 109                 set_cpus_allowed_ptr(current, cpumask_of(smp_processor_id()));
 110 #endif
 111         if (newsp)
 112                 newsp -= 12;
 113         return do_fork(clone_flags, newsp, 0, NULL, NULL);
 114 }
 115
 116 int
 117 copy_thread(unsigned long clone_flags,
 118             unsigned long usp, unsigned long topstk,
 119             struct task_struct *p)
 120 {
 121         struct pt_regs *childregs;
 122         unsigned long *v;
 123
 124         childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 125         v = ((unsigned long *)childregs) - 2;
 126         if (unlikely(p->flags & PF_KTHREAD)) {
 127                 memset(childregs, 0, sizeof(struct pt_regs));
 128                 v[0] = usp;
 129                 v[1] = topstk;
 130                 childregs->orig_p0 = -1;
 131                 childregs->ipend = 0x8000;
 132                 __asm__ __volatile__("%0 = syscfg;":"=da"(childregs->syscfg):);
 133                 p->thread.usp = 0;
 134         } else {
 135                 *childregs = *current_pt_regs();
 136                 childregs->r0 = 0;
 137                 p->thread.usp = usp ? : rdusp();
 138                 v[0] = v[1] = 0;
 139         }
 140
 141         p->thread.ksp = (unsigned long)v;
 142         p->thread.pc = (unsigned long)ret_from_fork;
 143
 144         return 0;
 145 }
 146
 147 unsigned long get_wchan(struct task_struct *p)
 148 {
 149         unsigned long fp, pc;
 150         unsigned long stack_page;
 151         int count = 0;
 152         if (!p || p == current || p->state == TASK_RUNNING)
 153                 return 0;
 154
 155         stack_page = (unsigned long)p;
 156         fp = p->thread.usp;
 157         do {
 158                 if (fp < stack_page + sizeof(struct thread_info) ||
 159                     fp >= 8184 + stack_page)
 160                         return 0;
 161                 pc = ((unsigned long *)fp)[1];
 162                 if (!in_sched_functions(pc))
 163                         return pc;
 164                 fp = *(unsigned long *)fp;
 165         }
 166         while (count++ < 16);
 167         return 0;
 168 }
 169
 170 void finish_atomic_sections (struct pt_regs *regs)
 171 {
 172         int __user *up0 = (int __user *)regs->p0;
 173
 174         switch (regs->pc) {
 175         default:
 176                 /* not in middle of an atomic step, so resume like normal */
 177                 return;
 178
 179         case ATOMIC_XCHG32 + 2:
 180                 put_user(regs->r1, up0);
 181                 break;
 182
 183         case ATOMIC_CAS32 + 2:
 184         case ATOMIC_CAS32 + 4:
 185                 if (regs->r0 == regs->r1)
 186         case ATOMIC_CAS32 + 6:
 187                         put_user(regs->r2, up0);
 188                 break;
 189
 190         case ATOMIC_ADD32 + 2:
 191                 regs->r0 = regs->r1 + regs->r0;
 192                 /* fall through */
 193         case ATOMIC_ADD32 + 4:
 194                 put_user(regs->r0, up0);
 195                 break;
 196
 197         case ATOMIC_SUB32 + 2:
 198                 regs->r0 = regs->r1 - regs->r0;
 199                 /* fall through */
 200         case ATOMIC_SUB32 + 4:
 201                 put_user(regs->r0, up0);
 202                 break;
 203
 204         case ATOMIC_IOR32 + 2:
 205                 regs->r0 = regs->r1 | regs->r0;
 206                 /* fall through */
 207         case ATOMIC_IOR32 + 4:
 208                 put_user(regs->r0, up0);
 209                 break;
 210
 211         case ATOMIC_AND32 + 2:
 212                 regs->r0 = regs->r1 & regs->r0;
 213                 /* fall through */
 214         case ATOMIC_AND32 + 4:
 215                 put_user(regs->r0, up0);
 216                 break;
 217
 218         case ATOMIC_XOR32 + 2:
 219                 regs->r0 = regs->r1 ^ regs->r0;
 220                 /* fall through */
 221         case ATOMIC_XOR32 + 4:
 222                 put_user(regs->r0, up0);
 223                 break;
 224         }
 225
 226         /*
 227          * We've finished the atomic section, and the only thing left for
 228          * userspace is to do a RTS, so we might as well handle that too
 229          * since we need to update the PC anyways.
 230          */
 231         regs->pc = regs->rets;
 232 }
 233
 234 static inline
 235 int in_mem(unsigned long addr, unsigned long size,
 236            unsigned long start, unsigned long end)
 237 {
 238         return addr >= start && addr + size <= end;
 239 }
 240 static inline
 241 int in_mem_const_off(unsigned long addr, unsigned long size, unsigned long off,
 242                      unsigned long const_addr, unsigned long const_size)
 243 {
 244         return const_size &&
 245                in_mem(addr, size, const_addr + off, const_addr + const_size);
 246 }
 247 static inline
 248 int in_mem_const(unsigned long addr, unsigned long size,
 249                  unsigned long const_addr, unsigned long const_size)
 250 {
 251         return in_mem_const_off(addr, size, 0, const_addr, const_size);
 252 }
 253 #ifdef CONFIG_BF60x
 254 #define ASYNC_ENABLED(bnum, bctlnum)    1
 255 #else
 256 #define ASYNC_ENABLED(bnum, bctlnum) \
 257 ({ \
 258         (bfin_read_EBIU_AMGCTL() & 0xe) < ((bnum + 1) << 1) ? 0 : \
 259         bfin_read_EBIU_AMBCTL##bctlnum() & B##bnum##RDYEN ? 0 : \
 260         1; \
 261 })
 262 #endif
 263 /*
 264  * We can't read EBIU banks that aren't enabled or we end up hanging
 265  * on the access to the async space.  Make sure we validate accesses
 266  * that cross async banks too.
 267  *      0 - found, but unusable
 268  *      1 - found & usable
 269  *      2 - not found
 270  */
 271 static
 272 int in_async(unsigned long addr, unsigned long size)
 273 {
 274         if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE) {
 275                 if (!ASYNC_ENABLED(0, 0))
 276                         return 0;
 277                 if (addr + size <= ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE)
 278                         return 1;
 279                 size -= ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE - addr;
 280                 addr = ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE;
 281         }
 282         if (addr >= ASYNC_BANK1_BASE && addr < ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE) {
 283                 if (!ASYNC_ENABLED(1, 0))
 284                         return 0;
 285                 if (addr + size <= ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE)
 286                         return 1;
 287                 size -= ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE - addr;
 288                 addr = ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE;
 289         }
 290         if (addr >= ASYNC_BANK2_BASE && addr < ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE) {
 291                 if (!ASYNC_ENABLED(2, 1))
 292                         return 0;
 293                 if (addr + size <= ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE)
 294                         return 1;
 295                 size -= ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE - addr;
 296                 addr = ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE;
 297         }
 298         if (addr >= ASYNC_BANK3_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) {
 299                 if (ASYNC_ENABLED(3, 1))
 300                         return 0;
 301                 if (addr + size <= ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE)
 302                         return 1;
 303                 return 0;
 304         }
 305
 306         /* not within async bounds */
 307         return 2;
 308 }
 309
 310 int bfin_mem_access_type(unsigned long addr, unsigned long size)
 311 {
 312         int cpu = raw_smp_processor_id();
 313
 314         /* Check that things do not wrap around */
 315         if (addr > ULONG_MAX - size)
 316                 return -EFAULT;
 317
 318         if (in_mem(addr, size, FIXED_CODE_START, physical_mem_end))
 319                 return BFIN_MEM_ACCESS_CORE;
 320
 321         if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH))
 322                 return cpu == 0 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA;
 323         if (in_mem_const(addr, size, L1_SCRATCH_START, L1_SCRATCH_LENGTH))
 324                 return cpu == 0 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT;
 325         if (in_mem_const(addr, size, L1_DATA_A_START, L1_DATA_A_LENGTH))
 326                 return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
 327         if (in_mem_const(addr, size, L1_DATA_B_START, L1_DATA_B_LENGTH))
 328                 return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
 329 #ifdef COREB_L1_CODE_START
 330         if (in_mem_const(addr, size, COREB_L1_CODE_START, COREB_L1_CODE_LENGTH))
 331                 return cpu == 1 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA;
 332         if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH))
 333                 return cpu == 1 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT;
 334         if (in_mem_const(addr, size, COREB_L1_DATA_A_START, COREB_L1_DATA_A_LENGTH))
 335                 return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
 336         if (in_mem_const(addr, size, COREB_L1_DATA_B_START, COREB_L1_DATA_B_LENGTH))
 337                 return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
 338 #endif
 339         if (in_mem_const(addr, size, L2_START, L2_LENGTH))
 340                 return BFIN_MEM_ACCESS_CORE;
 341
 342         if (addr >= SYSMMR_BASE)
 343                 return BFIN_MEM_ACCESS_CORE_ONLY;
 344
 345         switch (in_async(addr, size)) {
 346         case 0: return -EFAULT;
 347         case 1: return BFIN_MEM_ACCESS_CORE;
 348         case 2: /* fall through */;
 349         }
 350
 351         if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH))
 352                 return BFIN_MEM_ACCESS_CORE;
 353         if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH))
 354                 return BFIN_MEM_ACCESS_DMA;
 355
 356         return -EFAULT;
 357 }
 358
 359 #if defined(CONFIG_ACCESS_CHECK)
 360 #ifdef CONFIG_ACCESS_OK_L1
 361 __attribute__((l1_text))
 362 #endif
 363 /* Return 1 if access to memory range is OK, 0 otherwise */
 364 int _access_ok(unsigned long addr, unsigned long size)
 365 {
 366         int aret;
 367
 368         if (size == 0)
 369                 return 1;
 370         /* Check that things do not wrap around */
 371         if (addr > ULONG_MAX - size)
 372                 return 0;
 373         if (segment_eq(get_fs(), KERNEL_DS))
 374                 return 1;
 375 #ifdef CONFIG_MTD_UCLINUX
 376         if (1)
 377 #else
 378         if (0)
 379 #endif
 380         {
 381                 if (in_mem(addr, size, memory_start, memory_end))
 382                         return 1;
 383                 if (in_mem(addr, size, memory_mtd_end, physical_mem_end))
 384                         return 1;
 385 # ifndef CONFIG_ROMFS_ON_MTD
 386                 if (0)
 387 # endif
 388                         /* For XIP, allow user space to use pointers within the ROMFS.  */
 389                         if (in_mem(addr, size, memory_mtd_start, memory_mtd_end))
 390                                 return 1;
 391         } else {
 392                 if (in_mem(addr, size, memory_start, physical_mem_end))
 393                         return 1;
 394         }
 395
 396         if (in_mem(addr, size, (unsigned long)__init_begin, (unsigned long)__init_end))
 397                 return 1;
 398
 399         if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH))
 400                 return 1;
 401         if (in_mem_const_off(addr, size, _etext_l1 - _stext_l1, L1_CODE_START, L1_CODE_LENGTH))
 402                 return 1;
 403         if (in_mem_const_off(addr, size, _ebss_l1 - _sdata_l1, L1_DATA_A_START, L1_DATA_A_LENGTH))
 404                 return 1;
 405         if (in_mem_const_off(addr, size, _ebss_b_l1 - _sdata_b_l1, L1_DATA_B_START, L1_DATA_B_LENGTH))
 406                 return 1;
 407 #ifdef COREB_L1_CODE_START
 408         if (in_mem_const(addr, size, COREB_L1_CODE_START, COREB_L1_CODE_LENGTH))
 409                 return 1;
 410         if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH))
 411                 return 1;
 412         if (in_mem_const(addr, size, COREB_L1_DATA_A_START, COREB_L1_DATA_A_LENGTH))
 413                 return 1;
 414         if (in_mem_const(addr, size, COREB_L1_DATA_B_START, COREB_L1_DATA_B_LENGTH))
 415                 return 1;
 416 #endif
 417
 418 #ifndef CONFIG_EXCEPTION_L1_SCRATCH
 419         if (in_mem_const(addr, size, (unsigned long)l1_stack_base, l1_stack_len))
 420                 return 1;
 421 #endif
 422
 423         aret = in_async(addr, size);
 424         if (aret < 2)
 425                 return aret;
 426
 427         if (in_mem_const_off(addr, size, _ebss_l2 - _stext_l2, L2_START, L2_LENGTH))
 428                 return 1;
 429
 430         if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH))
 431                 return 1;
 432         if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH))
 433                 return 1;
 434
 435         return 0;
 436 }
 437 EXPORT_SYMBOL(_access_ok);
 438 #endif /* CONFIG_ACCESS_CHECK */