Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 1 | /* |
| 2 | * File: arch/blackfin/kernel/process.c |
| 3 | * Based on: |
| 4 | * Author: |
| 5 | * |
| 6 | * Created: |
| 7 | * Description: Blackfin architecture-dependent process handling. |
| 8 | * |
| 9 | * Modified: |
| 10 | * Copyright 2004-2006 Analog Devices Inc. |
| 11 | * |
| 12 | * Bugs: Enter bugs at http://blackfin.uclinux.org/ |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * This program is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with this program; if not, see the file COPYING, or write |
| 26 | * to the Free Software Foundation, Inc., |
| 27 | * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 28 | */ |
| 29 | |
| 30 | #include <linux/module.h> |
| 31 | #include <linux/smp_lock.h> |
| 32 | #include <linux/unistd.h> |
| 33 | #include <linux/user.h> |
Mike Frysinger | 1f83b8f | 2007-07-12 22:58:21 +0800 | [diff] [blame] | 34 | #include <linux/uaccess.h> |
Bryan Wu | d31c5ab | 2007-08-10 13:00:42 -0700 | [diff] [blame] | 35 | #include <linux/fs.h> |
| 36 | #include <linux/err.h> |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 37 | |
| 38 | #include <asm/blackfin.h> |
Bernd Schmidt | 7adfb58 | 2007-06-21 11:34:16 +0800 | [diff] [blame] | 39 | #include <asm/fixed_code.h> |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 40 | |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 41 | asmlinkage void ret_from_fork(void); |
| 42 | |
| 43 | /* Points to the SDRAM backup memory for the stack that is currently in |
| 44 | * L1 scratchpad memory. |
| 45 | */ |
| 46 | void *current_l1_stack_save; |
| 47 | |
| 48 | /* The number of tasks currently using a L1 stack area. The SRAM is |
| 49 | * allocated/deallocated whenever this changes from/to zero. |
| 50 | */ |
| 51 | int nr_l1stack_tasks; |
| 52 | |
| 53 | /* Start and length of the area in L1 scratchpad memory which we've allocated |
| 54 | * for process stacks. |
| 55 | */ |
| 56 | void *l1_stack_base; |
| 57 | unsigned long l1_stack_len; |
| 58 | |
| 59 | /* |
| 60 | * Powermanagement idle function, if any.. |
| 61 | */ |
| 62 | void (*pm_idle)(void) = NULL; |
| 63 | EXPORT_SYMBOL(pm_idle); |
| 64 | |
| 65 | void (*pm_power_off)(void) = NULL; |
| 66 | EXPORT_SYMBOL(pm_power_off); |
| 67 | |
| 68 | /* |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 69 | * The idle loop on BFIN |
| 70 | */ |
| 71 | #ifdef CONFIG_IDLE_L1 |
| 72 | void default_idle(void)__attribute__((l1_text)); |
| 73 | void cpu_idle(void)__attribute__((l1_text)); |
| 74 | #endif |
| 75 | |
| 76 | void default_idle(void) |
| 77 | { |
| 78 | while (!need_resched()) { |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 79 | local_irq_disable(); |
| 80 | if (likely(!need_resched())) |
| 81 | idle_with_irq_disabled(); |
| 82 | local_irq_enable(); |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 83 | } |
| 84 | } |
| 85 | |
| 86 | void (*idle)(void) = default_idle; |
| 87 | |
| 88 | /* |
| 89 | * The idle thread. There's no useful work to be |
| 90 | * done, so just try to conserve power and have a |
| 91 | * low exit latency (ie sit in a loop waiting for |
| 92 | * somebody to say that they'd like to reschedule) |
| 93 | */ |
| 94 | void cpu_idle(void) |
| 95 | { |
| 96 | /* endless idle loop with no priority at all */ |
| 97 | while (1) { |
| 98 | idle(); |
| 99 | preempt_enable_no_resched(); |
| 100 | schedule(); |
| 101 | preempt_disable(); |
| 102 | } |
| 103 | } |
| 104 | |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 105 | /* Fill in the fpu structure for a core dump. */ |
| 106 | |
| 107 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs) |
| 108 | { |
| 109 | return 1; |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | * This gets run with P1 containing the |
| 114 | * function to call, and R1 containing |
| 115 | * the "args". Note P0 is clobbered on the way here. |
| 116 | */ |
| 117 | void kernel_thread_helper(void); |
| 118 | __asm__(".section .text\n" |
| 119 | ".align 4\n" |
| 120 | "_kernel_thread_helper:\n\t" |
| 121 | "\tsp += -12;\n\t" |
| 122 | "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous"); |
| 123 | |
| 124 | /* |
| 125 | * Create a kernel thread. |
| 126 | */ |
| 127 | pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags) |
| 128 | { |
| 129 | struct pt_regs regs; |
| 130 | |
| 131 | memset(®s, 0, sizeof(regs)); |
| 132 | |
| 133 | regs.r1 = (unsigned long)arg; |
| 134 | regs.p1 = (unsigned long)fn; |
| 135 | regs.pc = (unsigned long)kernel_thread_helper; |
| 136 | regs.orig_p0 = -1; |
| 137 | /* Set bit 2 to tell ret_from_fork we should be returning to kernel |
| 138 | mode. */ |
| 139 | regs.ipend = 0x8002; |
| 140 | __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):); |
| 141 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, |
| 142 | NULL); |
| 143 | } |
| 144 | |
| 145 | void flush_thread(void) |
| 146 | { |
| 147 | } |
| 148 | |
| 149 | asmlinkage int bfin_vfork(struct pt_regs *regs) |
| 150 | { |
| 151 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, |
| 152 | NULL); |
| 153 | } |
| 154 | |
| 155 | asmlinkage int bfin_clone(struct pt_regs *regs) |
| 156 | { |
| 157 | unsigned long clone_flags; |
| 158 | unsigned long newsp; |
| 159 | |
| 160 | /* syscall2 puts clone_flags in r0 and usp in r1 */ |
| 161 | clone_flags = regs->r0; |
| 162 | newsp = regs->r1; |
| 163 | if (!newsp) |
| 164 | newsp = rdusp(); |
| 165 | else |
| 166 | newsp -= 12; |
| 167 | return do_fork(clone_flags, newsp, regs, 0, NULL, NULL); |
| 168 | } |
| 169 | |
| 170 | int |
| 171 | copy_thread(int nr, unsigned long clone_flags, |
| 172 | unsigned long usp, unsigned long topstk, |
| 173 | struct task_struct *p, struct pt_regs *regs) |
| 174 | { |
| 175 | struct pt_regs *childregs; |
| 176 | |
| 177 | childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1; |
| 178 | *childregs = *regs; |
| 179 | childregs->r0 = 0; |
| 180 | |
| 181 | p->thread.usp = usp; |
| 182 | p->thread.ksp = (unsigned long)childregs; |
| 183 | p->thread.pc = (unsigned long)ret_from_fork; |
| 184 | |
| 185 | return 0; |
| 186 | } |
| 187 | |
| 188 | /* |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 189 | * sys_execve() executes a new program. |
| 190 | */ |
| 191 | |
| 192 | asmlinkage int sys_execve(char *name, char **argv, char **envp) |
| 193 | { |
| 194 | int error; |
| 195 | char *filename; |
| 196 | struct pt_regs *regs = (struct pt_regs *)((&name) + 6); |
| 197 | |
| 198 | lock_kernel(); |
| 199 | filename = getname(name); |
| 200 | error = PTR_ERR(filename); |
| 201 | if (IS_ERR(filename)) |
| 202 | goto out; |
| 203 | error = do_execve(filename, argv, envp, regs); |
| 204 | putname(filename); |
Mike Frysinger | 1f83b8f | 2007-07-12 22:58:21 +0800 | [diff] [blame] | 205 | out: |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 206 | unlock_kernel(); |
| 207 | return error; |
| 208 | } |
| 209 | |
| 210 | unsigned long get_wchan(struct task_struct *p) |
| 211 | { |
| 212 | unsigned long fp, pc; |
| 213 | unsigned long stack_page; |
| 214 | int count = 0; |
| 215 | if (!p || p == current || p->state == TASK_RUNNING) |
| 216 | return 0; |
| 217 | |
| 218 | stack_page = (unsigned long)p; |
| 219 | fp = p->thread.usp; |
| 220 | do { |
| 221 | if (fp < stack_page + sizeof(struct thread_info) || |
| 222 | fp >= 8184 + stack_page) |
| 223 | return 0; |
| 224 | pc = ((unsigned long *)fp)[1]; |
| 225 | if (!in_sched_functions(pc)) |
| 226 | return pc; |
| 227 | fp = *(unsigned long *)fp; |
| 228 | } |
| 229 | while (count++ < 16); |
| 230 | return 0; |
| 231 | } |
| 232 | |
Bernd Schmidt | 7adfb58 | 2007-06-21 11:34:16 +0800 | [diff] [blame] | 233 | void finish_atomic_sections (struct pt_regs *regs) |
| 234 | { |
| 235 | if (regs->pc < ATOMIC_SEQS_START || regs->pc >= ATOMIC_SEQS_END) |
| 236 | return; |
| 237 | |
| 238 | switch (regs->pc) { |
| 239 | case ATOMIC_XCHG32 + 2: |
| 240 | put_user(regs->r1, (int *)regs->p0); |
| 241 | regs->pc += 2; |
| 242 | break; |
| 243 | |
| 244 | case ATOMIC_CAS32 + 2: |
| 245 | case ATOMIC_CAS32 + 4: |
| 246 | if (regs->r0 == regs->r1) |
| 247 | put_user(regs->r2, (int *)regs->p0); |
| 248 | regs->pc = ATOMIC_CAS32 + 8; |
| 249 | break; |
| 250 | case ATOMIC_CAS32 + 6: |
| 251 | put_user(regs->r2, (int *)regs->p0); |
| 252 | regs->pc += 2; |
| 253 | break; |
| 254 | |
| 255 | case ATOMIC_ADD32 + 2: |
| 256 | regs->r0 = regs->r1 + regs->r0; |
| 257 | /* fall through */ |
| 258 | case ATOMIC_ADD32 + 4: |
| 259 | put_user(regs->r0, (int *)regs->p0); |
| 260 | regs->pc = ATOMIC_ADD32 + 6; |
| 261 | break; |
| 262 | |
| 263 | case ATOMIC_SUB32 + 2: |
| 264 | regs->r0 = regs->r1 - regs->r0; |
| 265 | /* fall through */ |
| 266 | case ATOMIC_SUB32 + 4: |
| 267 | put_user(regs->r0, (int *)regs->p0); |
| 268 | regs->pc = ATOMIC_SUB32 + 6; |
| 269 | break; |
| 270 | |
| 271 | case ATOMIC_IOR32 + 2: |
| 272 | regs->r0 = regs->r1 | regs->r0; |
| 273 | /* fall through */ |
| 274 | case ATOMIC_IOR32 + 4: |
| 275 | put_user(regs->r0, (int *)regs->p0); |
| 276 | regs->pc = ATOMIC_IOR32 + 6; |
| 277 | break; |
| 278 | |
| 279 | case ATOMIC_AND32 + 2: |
| 280 | regs->r0 = regs->r1 & regs->r0; |
| 281 | /* fall through */ |
| 282 | case ATOMIC_AND32 + 4: |
| 283 | put_user(regs->r0, (int *)regs->p0); |
| 284 | regs->pc = ATOMIC_AND32 + 6; |
| 285 | break; |
| 286 | |
| 287 | case ATOMIC_XOR32 + 2: |
| 288 | regs->r0 = regs->r1 ^ regs->r0; |
| 289 | /* fall through */ |
| 290 | case ATOMIC_XOR32 + 4: |
| 291 | put_user(regs->r0, (int *)regs->p0); |
| 292 | regs->pc = ATOMIC_XOR32 + 6; |
| 293 | break; |
| 294 | } |
| 295 | } |
| 296 | |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 297 | #if defined(CONFIG_ACCESS_CHECK) |
Robin Getz | b03b08b | 2007-12-23 22:57:01 +0800 | [diff] [blame] | 298 | /* Return 1 if access to memory range is OK, 0 otherwise */ |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 299 | int _access_ok(unsigned long addr, unsigned long size) |
| 300 | { |
Bernd Schmidt | bc41bb1 | 2007-10-10 17:54:19 +0800 | [diff] [blame] | 301 | if (size == 0) |
| 302 | return 1; |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 303 | if (addr > (addr + size)) |
| 304 | return 0; |
Mike Frysinger | 1f83b8f | 2007-07-12 22:58:21 +0800 | [diff] [blame] | 305 | if (segment_eq(get_fs(), KERNEL_DS)) |
Bryan Wu | 1394f03 | 2007-05-06 14:50:22 -0700 | [diff] [blame] | 306 | return 1; |
| 307 | #ifdef CONFIG_MTD_UCLINUX |
| 308 | if (addr >= memory_start && (addr + size) <= memory_end) |
| 309 | return 1; |
| 310 | if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end) |
| 311 | return 1; |
| 312 | #else |
| 313 | if (addr >= memory_start && (addr + size) <= physical_mem_end) |
| 314 | return 1; |
| 315 | #endif |
| 316 | if (addr >= (unsigned long)__init_begin && |
| 317 | addr + size <= (unsigned long)__init_end) |
| 318 | return 1; |
| 319 | if (addr >= L1_SCRATCH_START |
| 320 | && addr + size <= L1_SCRATCH_START + L1_SCRATCH_LENGTH) |
| 321 | return 1; |
| 322 | #if L1_CODE_LENGTH != 0 |
| 323 | if (addr >= L1_CODE_START + (_etext_l1 - _stext_l1) |
| 324 | && addr + size <= L1_CODE_START + L1_CODE_LENGTH) |
| 325 | return 1; |
| 326 | #endif |
| 327 | #if L1_DATA_A_LENGTH != 0 |
| 328 | if (addr >= L1_DATA_A_START + (_ebss_l1 - _sdata_l1) |
| 329 | && addr + size <= L1_DATA_A_START + L1_DATA_A_LENGTH) |
| 330 | return 1; |
| 331 | #endif |
| 332 | #if L1_DATA_B_LENGTH != 0 |
| 333 | if (addr >= L1_DATA_B_START |
| 334 | && addr + size <= L1_DATA_B_START + L1_DATA_B_LENGTH) |
| 335 | return 1; |
| 336 | #endif |
| 337 | return 0; |
| 338 | } |
| 339 | EXPORT_SYMBOL(_access_ok); |
| 340 | #endif /* CONFIG_ACCESS_CHECK */ |