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>
42 #include <asm/mem_map.h>
44 asmlinkage void ret_from_fork(void);
46 /* Points to the SDRAM backup memory for the stack that is currently in
47 * L1 scratchpad memory.
49 void *current_l1_stack_save;
51 /* The number of tasks currently using a L1 stack area. The SRAM is
52 * allocated/deallocated whenever this changes from/to zero.
56 /* Start and length of the area in L1 scratchpad memory which we've allocated
60 unsigned long l1_stack_len;
63 * Powermanagement idle function, if any..
65 void (*pm_idle)(void) = NULL;
66 EXPORT_SYMBOL(pm_idle);
68 void (*pm_power_off)(void) = NULL;
69 EXPORT_SYMBOL(pm_power_off);
72 * The idle loop on BFIN
75 static void default_idle(void)__attribute__((l1_text));
76 void cpu_idle(void)__attribute__((l1_text));
80 * This is our default idle handler. We need to disable
81 * interrupts here to ensure we don't miss a wakeup call.
83 static void default_idle(void)
87 idle_with_irq_disabled();
93 * The idle thread. We try to conserve power, while trying to keep
94 * overall latency low. The architecture specific idle is passed
95 * a value to indicate the level of "idleness" of the system.
99 /* endless idle loop with no priority at all */
101 void (*idle)(void) = pm_idle;
103 #ifdef CONFIG_HOTPLUG_CPU
104 if (cpu_is_offline(smp_processor_id()))
109 tick_nohz_stop_sched_tick(1);
110 while (!need_resched())
112 tick_nohz_restart_sched_tick();
113 preempt_enable_no_resched();
119 /* Fill in the fpu structure for a core dump. */
121 int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
127 * This gets run with P1 containing the
128 * function to call, and R1 containing
129 * the "args". Note P0 is clobbered on the way here.
131 void kernel_thread_helper(void);
132 __asm__(".section .text\n"
134 "_kernel_thread_helper:\n\t"
136 "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
139 * Create a kernel thread.
141 pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
145 memset(®s, 0, sizeof(regs));
147 regs.r1 = (unsigned long)arg;
148 regs.p1 = (unsigned long)fn;
149 regs.pc = (unsigned long)kernel_thread_helper;
151 /* Set bit 2 to tell ret_from_fork we should be returning to kernel
154 __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
155 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL,
158 EXPORT_SYMBOL(kernel_thread);
160 void flush_thread(void)
164 asmlinkage int bfin_vfork(struct pt_regs *regs)
166 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
170 asmlinkage int bfin_clone(struct pt_regs *regs)
172 unsigned long clone_flags;
175 #ifdef __ARCH_SYNC_CORE_DCACHE
176 if (current->rt.nr_cpus_allowed == num_possible_cpus()) {
177 current->cpus_allowed = cpumask_of_cpu(smp_processor_id());
178 current->rt.nr_cpus_allowed = 1;
182 /* syscall2 puts clone_flags in r0 and usp in r1 */
183 clone_flags = regs->r0;
189 return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
193 copy_thread(int nr, unsigned long clone_flags,
194 unsigned long usp, unsigned long topstk,
195 struct task_struct *p, struct pt_regs *regs)
197 struct pt_regs *childregs;
199 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
204 p->thread.ksp = (unsigned long)childregs;
205 p->thread.pc = (unsigned long)ret_from_fork;
211 * sys_execve() executes a new program.
214 asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp)
218 struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
221 filename = getname(name);
222 error = PTR_ERR(filename);
223 if (IS_ERR(filename))
225 error = do_execve(filename, argv, envp, regs);
232 unsigned long get_wchan(struct task_struct *p)
234 unsigned long fp, pc;
235 unsigned long stack_page;
237 if (!p || p == current || p->state == TASK_RUNNING)
240 stack_page = (unsigned long)p;
243 if (fp < stack_page + sizeof(struct thread_info) ||
244 fp >= 8184 + stack_page)
246 pc = ((unsigned long *)fp)[1];
247 if (!in_sched_functions(pc))
249 fp = *(unsigned long *)fp;
251 while (count++ < 16);
255 void finish_atomic_sections (struct pt_regs *regs)
257 int __user *up0 = (int __user *)regs->p0;
259 if (regs->pc < ATOMIC_SEQS_START || regs->pc >= ATOMIC_SEQS_END)
263 case ATOMIC_XCHG32 + 2:
264 put_user(regs->r1, up0);
268 case ATOMIC_CAS32 + 2:
269 case ATOMIC_CAS32 + 4:
270 if (regs->r0 == regs->r1)
271 put_user(regs->r2, up0);
272 regs->pc = ATOMIC_CAS32 + 8;
274 case ATOMIC_CAS32 + 6:
275 put_user(regs->r2, up0);
279 case ATOMIC_ADD32 + 2:
280 regs->r0 = regs->r1 + regs->r0;
282 case ATOMIC_ADD32 + 4:
283 put_user(regs->r0, up0);
284 regs->pc = ATOMIC_ADD32 + 6;
287 case ATOMIC_SUB32 + 2:
288 regs->r0 = regs->r1 - regs->r0;
290 case ATOMIC_SUB32 + 4:
291 put_user(regs->r0, up0);
292 regs->pc = ATOMIC_SUB32 + 6;
295 case ATOMIC_IOR32 + 2:
296 regs->r0 = regs->r1 | regs->r0;
298 case ATOMIC_IOR32 + 4:
299 put_user(regs->r0, up0);
300 regs->pc = ATOMIC_IOR32 + 6;
303 case ATOMIC_AND32 + 2:
304 regs->r0 = regs->r1 & regs->r0;
306 case ATOMIC_AND32 + 4:
307 put_user(regs->r0, up0);
308 regs->pc = ATOMIC_AND32 + 6;
311 case ATOMIC_XOR32 + 2:
312 regs->r0 = regs->r1 ^ regs->r0;
314 case ATOMIC_XOR32 + 4:
315 put_user(regs->r0, up0);
316 regs->pc = ATOMIC_XOR32 + 6;
321 #if defined(CONFIG_ACCESS_CHECK)
322 /* Return 1 if access to memory range is OK, 0 otherwise */
323 int _access_ok(unsigned long addr, unsigned long size)
327 if (addr > (addr + size))
329 if (segment_eq(get_fs(), KERNEL_DS))
331 #ifdef CONFIG_MTD_UCLINUX
332 if (addr >= memory_start && (addr + size) <= memory_end)
334 if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
337 #ifdef CONFIG_ROMFS_MTD_FS
338 /* For XIP, allow user space to use pointers within the ROMFS. */
339 if (addr >= memory_mtd_start && (addr + size) <= memory_mtd_end)
343 if (addr >= memory_start && (addr + size) <= physical_mem_end)
346 if (addr >= (unsigned long)__init_begin &&
347 addr + size <= (unsigned long)__init_end)
349 if (addr >= get_l1_scratch_start()
350 && addr + size <= get_l1_scratch_start() + L1_SCRATCH_LENGTH)
352 #if L1_CODE_LENGTH != 0
353 if (addr >= get_l1_code_start() + (_etext_l1 - _stext_l1)
354 && addr + size <= get_l1_code_start() + L1_CODE_LENGTH)
357 #if L1_DATA_A_LENGTH != 0
358 if (addr >= get_l1_data_a_start() + (_ebss_l1 - _sdata_l1)
359 && addr + size <= get_l1_data_a_start() + L1_DATA_A_LENGTH)
362 #if L1_DATA_B_LENGTH != 0
363 if (addr >= get_l1_data_b_start() + (_ebss_b_l1 - _sdata_b_l1)
364 && addr + size <= get_l1_data_b_start() + L1_DATA_B_LENGTH)
368 if (addr >= L2_START + (_ebss_l2 - _stext_l2)
369 && addr + size <= L2_START + L2_LENGTH)
374 EXPORT_SYMBOL(_access_ok);
375 #endif /* CONFIG_ACCESS_CHECK */