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-rw-r--r--arch/blackfin/kernel/process.c394
1 files changed, 394 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
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+/*
+ * File: arch/blackfin/kernel/process.c
+ * Based on:
+ * Author:
+ *
+ * Created:
+ * Description: Blackfin architecture-dependent process handling.
+ *
+ * Modified:
+ * Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs: Enter bugs at http://blackfin.uclinux.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <linux/module.h>
+#include <linux/smp_lock.h>
+#include <linux/unistd.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+
+#include <asm/blackfin.h>
+#include <asm/uaccess.h>
+
+#define LED_ON 0
+#define LED_OFF 1
+
+asmlinkage void ret_from_fork(void);
+
+/* Points to the SDRAM backup memory for the stack that is currently in
+ * L1 scratchpad memory.
+ */
+void *current_l1_stack_save;
+
+/* The number of tasks currently using a L1 stack area. The SRAM is
+ * allocated/deallocated whenever this changes from/to zero.
+ */
+int nr_l1stack_tasks;
+
+/* Start and length of the area in L1 scratchpad memory which we've allocated
+ * for process stacks.
+ */
+void *l1_stack_base;
+unsigned long l1_stack_len;
+
+/*
+ * Powermanagement idle function, if any..
+ */
+void (*pm_idle)(void) = NULL;
+EXPORT_SYMBOL(pm_idle);
+
+void (*pm_power_off)(void) = NULL;
+EXPORT_SYMBOL(pm_power_off);
+
+/*
+ * We are using a different LED from the one used to indicate timer interrupt.
+ */
+#if defined(CONFIG_BFIN_IDLE_LED)
+static inline void leds_switch(int flag)
+{
+ unsigned short tmp = 0;
+
+ tmp = bfin_read_CONFIG_BFIN_IDLE_LED_PORT();
+ SSYNC();
+
+ if (flag == LED_ON)
+ tmp &= ~CONFIG_BFIN_IDLE_LED_PIN; /* light on */
+ else
+ tmp |= CONFIG_BFIN_IDLE_LED_PIN; /* light off */
+
+ bfin_write_CONFIG_BFIN_IDLE_LED_PORT(tmp);
+ SSYNC();
+
+}
+#else
+static inline void leds_switch(int flag)
+{
+}
+#endif
+
+/*
+ * The idle loop on BFIN
+ */
+#ifdef CONFIG_IDLE_L1
+void default_idle(void)__attribute__((l1_text));
+void cpu_idle(void)__attribute__((l1_text));
+#endif
+
+void default_idle(void)
+{
+ while (!need_resched()) {
+ leds_switch(LED_OFF);
+ local_irq_disable();
+ if (likely(!need_resched()))
+ idle_with_irq_disabled();
+ local_irq_enable();
+ leds_switch(LED_ON);
+ }
+}
+
+void (*idle)(void) = default_idle;
+
+/*
+ * The idle thread. There's no useful work to be
+ * done, so just try to conserve power and have a
+ * low exit latency (ie sit in a loop waiting for
+ * somebody to say that they'd like to reschedule)
+ */
+void cpu_idle(void)
+{
+ /* endless idle loop with no priority at all */
+ while (1) {
+ idle();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+}
+
+void machine_restart(char *__unused)
+{
+#if defined(CONFIG_BLKFIN_CACHE)
+ bfin_write_IMEM_CONTROL(0x01);
+ SSYNC();
+#endif
+ bfin_reset();
+ /* Dont do anything till the reset occurs */
+ while (1) {
+ SSYNC();
+ }
+}
+
+void machine_halt(void)
+{
+ for (;;)
+ asm volatile ("idle");
+}
+
+void machine_power_off(void)
+{
+ for (;;)
+ asm volatile ("idle");
+}
+
+void show_regs(struct pt_regs *regs)
+{
+ printk(KERN_NOTICE "\n");
+ printk(KERN_NOTICE
+ "PC: %08lu Status: %04lu SysStatus: %04lu RETS: %08lu\n",
+ regs->pc, regs->astat, regs->seqstat, regs->rets);
+ printk(KERN_NOTICE
+ "A0.x: %08lx A0.w: %08lx A1.x: %08lx A1.w: %08lx\n",
+ regs->a0x, regs->a0w, regs->a1x, regs->a1w);
+ printk(KERN_NOTICE "P0: %08lx P1: %08lx P2: %08lx P3: %08lx\n",
+ regs->p0, regs->p1, regs->p2, regs->p3);
+ printk(KERN_NOTICE "P4: %08lx P5: %08lx\n", regs->p4, regs->p5);
+ printk(KERN_NOTICE "R0: %08lx R1: %08lx R2: %08lx R3: %08lx\n",
+ regs->r0, regs->r1, regs->r2, regs->r3);
+ printk(KERN_NOTICE "R4: %08lx R5: %08lx R6: %08lx R7: %08lx\n",
+ regs->r4, regs->r5, regs->r6, regs->r7);
+
+ if (!(regs->ipend))
+ printk("USP: %08lx\n", rdusp());
+}
+
+/* Fill in the fpu structure for a core dump. */
+
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpregs)
+{
+ return 1;
+}
+
+/*
+ * This gets run with P1 containing the
+ * function to call, and R1 containing
+ * the "args". Note P0 is clobbered on the way here.
+ */
+void kernel_thread_helper(void);
+__asm__(".section .text\n"
+ ".align 4\n"
+ "_kernel_thread_helper:\n\t"
+ "\tsp += -12;\n\t"
+ "\tr0 = r1;\n\t" "\tcall (p1);\n\t" "\tcall _do_exit;\n" ".previous");
+
+/*
+ * Create a kernel thread.
+ */
+pid_t kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
+{
+ struct pt_regs regs;
+
+ memset(&regs, 0, sizeof(regs));
+
+ regs.r1 = (unsigned long)arg;
+ regs.p1 = (unsigned long)fn;
+ regs.pc = (unsigned long)kernel_thread_helper;
+ regs.orig_p0 = -1;
+ /* Set bit 2 to tell ret_from_fork we should be returning to kernel
+ mode. */
+ regs.ipend = 0x8002;
+ __asm__ __volatile__("%0 = syscfg;":"=da"(regs.syscfg):);
+ return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
+ NULL);
+}
+
+void flush_thread(void)
+{
+}
+
+asmlinkage int bfin_vfork(struct pt_regs *regs)
+{
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL,
+ NULL);
+}
+
+asmlinkage int bfin_clone(struct pt_regs *regs)
+{
+ unsigned long clone_flags;
+ unsigned long newsp;
+
+ /* syscall2 puts clone_flags in r0 and usp in r1 */
+ clone_flags = regs->r0;
+ newsp = regs->r1;
+ if (!newsp)
+ newsp = rdusp();
+ else
+ newsp -= 12;
+ return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
+}
+
+int
+copy_thread(int nr, unsigned long clone_flags,
+ unsigned long usp, unsigned long topstk,
+ struct task_struct *p, struct pt_regs *regs)
+{
+ struct pt_regs *childregs;
+
+ childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
+ *childregs = *regs;
+ childregs->r0 = 0;
+
+ p->thread.usp = usp;
+ p->thread.ksp = (unsigned long)childregs;
+ p->thread.pc = (unsigned long)ret_from_fork;
+
+ return 0;
+}
+
+/*
+ * fill in the user structure for a core dump..
+ */
+void dump_thread(struct pt_regs *regs, struct user *dump)
+{
+ dump->magic = CMAGIC;
+ dump->start_code = 0;
+ dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
+ dump->u_tsize = ((unsigned long)current->mm->end_code) >> PAGE_SHIFT;
+ dump->u_dsize = ((unsigned long)(current->mm->brk +
+ (PAGE_SIZE - 1))) >> PAGE_SHIFT;
+ dump->u_dsize -= dump->u_tsize;
+ dump->u_ssize = 0;
+
+ if (dump->start_stack < TASK_SIZE)
+ dump->u_ssize =
+ ((unsigned long)(TASK_SIZE -
+ dump->start_stack)) >> PAGE_SHIFT;
+
+ dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump);
+
+ dump->regs.r0 = regs->r0;
+ dump->regs.r1 = regs->r1;
+ dump->regs.r2 = regs->r2;
+ dump->regs.r3 = regs->r3;
+ dump->regs.r4 = regs->r4;
+ dump->regs.r5 = regs->r5;
+ dump->regs.r6 = regs->r6;
+ dump->regs.r7 = regs->r7;
+ dump->regs.p0 = regs->p0;
+ dump->regs.p1 = regs->p1;
+ dump->regs.p2 = regs->p2;
+ dump->regs.p3 = regs->p3;
+ dump->regs.p4 = regs->p4;
+ dump->regs.p5 = regs->p5;
+ dump->regs.orig_p0 = regs->orig_p0;
+ dump->regs.a0w = regs->a0w;
+ dump->regs.a1w = regs->a1w;
+ dump->regs.a0x = regs->a0x;
+ dump->regs.a1x = regs->a1x;
+ dump->regs.rets = regs->rets;
+ dump->regs.astat = regs->astat;
+ dump->regs.pc = regs->pc;
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+
+asmlinkage int sys_execve(char *name, char **argv, char **envp)
+{
+ int error;
+ char *filename;
+ struct pt_regs *regs = (struct pt_regs *)((&name) + 6);
+
+ lock_kernel();
+ filename = getname(name);
+ error = PTR_ERR(filename);
+ if (IS_ERR(filename))
+ goto out;
+ error = do_execve(filename, argv, envp, regs);
+ putname(filename);
+ out:
+ unlock_kernel();
+ return error;
+}
+
+unsigned long get_wchan(struct task_struct *p)
+{
+ unsigned long fp, pc;
+ unsigned long stack_page;
+ int count = 0;
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+
+ stack_page = (unsigned long)p;
+ fp = p->thread.usp;
+ do {
+ if (fp < stack_page + sizeof(struct thread_info) ||
+ fp >= 8184 + stack_page)
+ return 0;
+ pc = ((unsigned long *)fp)[1];
+ if (!in_sched_functions(pc))
+ return pc;
+ fp = *(unsigned long *)fp;
+ }
+ while (count++ < 16);
+ return 0;
+}
+
+#if defined(CONFIG_ACCESS_CHECK)
+int _access_ok(unsigned long addr, unsigned long size)
+{
+
+ if (addr > (addr + size))
+ return 0;
+ if (segment_eq(get_fs(),KERNEL_DS))
+ return 1;
+#ifdef CONFIG_MTD_UCLINUX
+ if (addr >= memory_start && (addr + size) <= memory_end)
+ return 1;
+ if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
+ return 1;
+#else
+ if (addr >= memory_start && (addr + size) <= physical_mem_end)
+ return 1;
+#endif
+ if (addr >= (unsigned long)__init_begin &&
+ addr + size <= (unsigned long)__init_end)
+ return 1;
+ if (addr >= L1_SCRATCH_START
+ && addr + size <= L1_SCRATCH_START + L1_SCRATCH_LENGTH)
+ return 1;
+#if L1_CODE_LENGTH != 0
+ if (addr >= L1_CODE_START + (_etext_l1 - _stext_l1)
+ && addr + size <= L1_CODE_START + L1_CODE_LENGTH)
+ return 1;
+#endif
+#if L1_DATA_A_LENGTH != 0
+ if (addr >= L1_DATA_A_START + (_ebss_l1 - _sdata_l1)
+ && addr + size <= L1_DATA_A_START + L1_DATA_A_LENGTH)
+ return 1;
+#endif
+#if L1_DATA_B_LENGTH != 0
+ if (addr >= L1_DATA_B_START
+ && addr + size <= L1_DATA_B_START + L1_DATA_B_LENGTH)
+ return 1;
+#endif
+ return 0;
+}
+EXPORT_SYMBOL(_access_ok);
+#endif /* CONFIG_ACCESS_CHECK */