2 * File: arch/blackfin/kernel/process.c
7 * Description: Blackfin architecture-dependent process handling.
10 * Copyright 2004-2006 Analog Devices Inc.
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
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.
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.
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
30 #include <linux/module.h>
31 #include <linux/smp_lock.h>
32 #include <linux/unistd.h>
33 #include <linux/user.h>
34 #include <linux/uaccess.h>
35 #include <linux/sched.h>
36 #include <linux/tick.h>
38 #include <linux/err.h>
40 #include <asm/blackfin.h>
41 #include <asm/fixed_code.h>
43 asmlinkage void ret_from_fork(void);
45 /* Points to the SDRAM backup memory for the stack that is currently in
46 * L1 scratchpad memory.
48 void *current_l1_stack_save;
50 /* The number of tasks currently using a L1 stack area. The SRAM is
51 * allocated/deallocated whenever this changes from/to zero.
55 /* Start and length of the area in L1 scratchpad memory which we've allocated
59 unsigned long l1_stack_len;
62 * Powermanagement idle function, if any..
64 void (*pm_idle)(void) = NULL;
65 EXPORT_SYMBOL(pm_idle);
67 void (*pm_power_off)(void) = NULL;
68 EXPORT_SYMBOL(pm_power_off);
71 * The idle loop on BFIN
74 static void default_idle(void)__attribute__((l1_text));
75 void cpu_idle(void)__attribute__((l1_text));
79 * This is our default idle handler. We need to disable
80 * interrupts here to ensure we don't miss a wakeup call.
82 static void default_idle(void)
86 idle_with_irq_disabled();
92 * The idle thread. We try to conserve power, while trying to keep
93 * overall latency low. The architecture specific idle is passed
94 * a value to indicate the level of "idleness" of the system.
98 /* endless idle loop with no priority at all */
100 void (*idle)(void) = pm_idle;
102 #ifdef CONFIG_HOTPLUG_CPU
103 if (cpu_is_offline(smp_processor_id()))
108 tick_nohz_stop_sched_tick(1);
109 while (!need_resched())
111 tick_nohz_restart_sched_tick();
112 preempt_enable_no_resched();
118 /* Fill in the fpu structure for a core dump. */
120 int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
126 * This gets run with P1 containing the
127 * function to call, and R1 containing
128 * the "args". Note P0 is clobbered on the way here.
130 void kernel_thread_helper(void);
131 __asm__(".section .text\n"
133 "_kernel_thread_helper:\n\t"
135 "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
138 * Create a kernel thread.
140 pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
144 memset(®s, 0, sizeof(regs));
146 regs.r1 = (unsigned long)arg;
147 regs.p1 = (unsigned long)fn;
148 regs.pc = (unsigned long)kernel_thread_helper;
150 /* Set bit 2 to tell ret_from_fork we should be returning to kernel
153 __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
154 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL,
157 EXPORT_SYMBOL(kernel_thread);
159 void flush_thread(void)
163 asmlinkage int bfin_vfork(struct pt_regs *regs)
165 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
169 asmlinkage int bfin_clone(struct pt_regs *regs)
171 unsigned long clone_flags;
174 #ifdef __ARCH_SYNC_CORE_DCACHE
175 if (current->rt.nr_cpus_allowed == num_possible_cpus()) {
176 current->cpus_allowed = cpumask_of_cpu(smp_processor_id());
177 current->rt.nr_cpus_allowed = 1;
181 /* syscall2 puts clone_flags in r0 and usp in r1 */
182 clone_flags = regs->r0;
188 return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
192 copy_thread(int nr, unsigned long clone_flags,
193 unsigned long usp, unsigned long topstk,
194 struct task_struct *p, struct pt_regs *regs)
196 struct pt_regs *childregs;
198 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
203 p->thread.ksp = (unsigned long)childregs;
204 p->thread.pc = (unsigned long)ret_from_fork;
210 * sys_execve() executes a new program.
213 asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp)
217 struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
220 filename = getname(name);
221 error = PTR_ERR(filename);
222 if (IS_ERR(filename))
224 error = do_execve(filename, argv, envp, regs);
231 unsigned long get_wchan(struct task_struct *p)
233 unsigned long fp, pc;
234 unsigned long stack_page;
236 if (!p || p == current || p->state == TASK_RUNNING)
239 stack_page = (unsigned long)p;
242 if (fp < stack_page + sizeof(struct thread_info) ||
243 fp >= 8184 + stack_page)
245 pc = ((unsigned long *)fp)[1];
246 if (!in_sched_functions(pc))
248 fp = *(unsigned long *)fp;
250 while (count++ < 16);
254 void finish_atomic_sections (struct pt_regs *regs)
256 int __user *up0 = (int __user *)regs->p0;
258 if (regs->pc < ATOMIC_SEQS_START || regs->pc >= ATOMIC_SEQS_END)
262 case ATOMIC_XCHG32 + 2:
263 put_user(regs->r1, up0);
267 case ATOMIC_CAS32 + 2:
268 case ATOMIC_CAS32 + 4:
269 if (regs->r0 == regs->r1)
270 put_user(regs->r2, up0);
271 regs->pc = ATOMIC_CAS32 + 8;
273 case ATOMIC_CAS32 + 6:
274 put_user(regs->r2, up0);
278 case ATOMIC_ADD32 + 2:
279 regs->r0 = regs->r1 + regs->r0;
281 case ATOMIC_ADD32 + 4:
282 put_user(regs->r0, up0);
283 regs->pc = ATOMIC_ADD32 + 6;
286 case ATOMIC_SUB32 + 2:
287 regs->r0 = regs->r1 - regs->r0;
289 case ATOMIC_SUB32 + 4:
290 put_user(regs->r0, up0);
291 regs->pc = ATOMIC_SUB32 + 6;
294 case ATOMIC_IOR32 + 2:
295 regs->r0 = regs->r1 | regs->r0;
297 case ATOMIC_IOR32 + 4:
298 put_user(regs->r0, up0);
299 regs->pc = ATOMIC_IOR32 + 6;
302 case ATOMIC_AND32 + 2:
303 regs->r0 = regs->r1 & regs->r0;
305 case ATOMIC_AND32 + 4:
306 put_user(regs->r0, up0);
307 regs->pc = ATOMIC_AND32 + 6;
310 case ATOMIC_XOR32 + 2:
311 regs->r0 = regs->r1 ^ regs->r0;
313 case ATOMIC_XOR32 + 4:
314 put_user(regs->r0, up0);
315 regs->pc = ATOMIC_XOR32 + 6;
320 #if defined(CONFIG_ACCESS_CHECK)
321 /* Return 1 if access to memory range is OK, 0 otherwise */
322 int _access_ok(unsigned long addr, unsigned long size)
326 if (addr > (addr + size))
328 if (segment_eq(get_fs(), KERNEL_DS))
330 #ifdef CONFIG_MTD_UCLINUX
331 if (addr >= memory_start && (addr + size) <= memory_end)
333 if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
336 #ifdef CONFIG_ROMFS_MTD_FS
337 /* For XIP, allow user space to use pointers within the ROMFS. */
338 if (addr >= memory_mtd_start && (addr + size) <= memory_mtd_end)
342 if (addr >= memory_start && (addr + size) <= physical_mem_end)
345 if (addr >= (unsigned long)__init_begin &&
346 addr + size <= (unsigned long)__init_end)
348 if (addr >= get_l1_scratch_start()
349 && addr + size <= get_l1_scratch_start() + L1_SCRATCH_LENGTH)
351 #if L1_CODE_LENGTH != 0
352 if (addr >= get_l1_code_start() + (_etext_l1 - _stext_l1)
353 && addr + size <= get_l1_code_start() + L1_CODE_LENGTH)
356 #if L1_DATA_A_LENGTH != 0
357 if (addr >= get_l1_data_a_start() + (_ebss_l1 - _sdata_l1)
358 && addr + size <= get_l1_data_a_start() + L1_DATA_A_LENGTH)
361 #if L1_DATA_B_LENGTH != 0
362 if (addr >= get_l1_data_b_start() + (_ebss_b_l1 - _sdata_b_l1)
363 && addr + size <= get_l1_data_b_start() + L1_DATA_B_LENGTH)
367 if (addr >= L2_START + (_ebss_l2 - _stext_l2)
368 && addr + size <= L2_START + L2_LENGTH)
373 EXPORT_SYMBOL(_access_ok);
374 #endif /* CONFIG_ACCESS_CHECK */