diff options
Diffstat (limited to 'arch/blackfin/kernel/process.c')
| -rw-r--r-- | arch/blackfin/kernel/process.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c new file mode 100644 index 00000000..c0f4fe28 --- /dev/null +++ b/arch/blackfin/kernel/process.c @@ -0,0 +1,513 @@ +/* + * Blackfin architecture-dependent process handling + * + * Copyright 2004-2009 Analog Devices Inc. + * + * Licensed under the GPL-2 or later + */ + +#include <linux/module.h> +#include <linux/unistd.h> +#include <linux/user.h> +#include <linux/uaccess.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/tick.h> +#include <linux/fs.h> +#include <linux/err.h> + +#include <asm/blackfin.h> +#include <asm/fixed_code.h> +#include <asm/mem_map.h> +#include <asm/irq.h> + +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); + +/* + * The idle loop on BFIN + */ +#ifdef CONFIG_IDLE_L1 +static void default_idle(void)__attribute__((l1_text)); +void cpu_idle(void)__attribute__((l1_text)); +#endif + +/* + * This is our default idle handler. We need to disable + * interrupts here to ensure we don't miss a wakeup call. + */ +static void default_idle(void) +{ +#ifdef CONFIG_IPIPE + ipipe_suspend_domain(); +#endif + hard_local_irq_disable(); + if (!need_resched()) + idle_with_irq_disabled(); + + hard_local_irq_enable(); +} + +/* + * The idle thread. We try to conserve power, while trying to keep + * overall latency low. The architecture specific idle is passed + * a value to indicate the level of "idleness" of the system. + */ +void cpu_idle(void) +{ + /* endless idle loop with no priority at all */ + while (1) { + void (*idle)(void) = pm_idle; + +#ifdef CONFIG_HOTPLUG_CPU + if (cpu_is_offline(smp_processor_id())) + cpu_die(); +#endif + if (!idle) + idle = default_idle; + tick_nohz_idle_enter(); + rcu_idle_enter(); + while (!need_resched()) + idle(); + rcu_idle_exit(); + tick_nohz_idle_exit(); + schedule_preempt_disabled(); + } +} + +/* + * 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(®s, 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, ®s, 0, NULL, + NULL); +} +EXPORT_SYMBOL(kernel_thread); + +/* + * Do necessary setup to start up a newly executed thread. + * + * pass the data segment into user programs if it exists, + * it can't hurt anything as far as I can tell + */ +void start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) +{ + regs->pc = new_ip; + if (current->mm) + regs->p5 = current->mm->start_data; +#ifndef CONFIG_SMP + task_thread_info(current)->l1_task_info.stack_start = + (void *)current->mm->context.stack_start; + task_thread_info(current)->l1_task_info.lowest_sp = (void *)new_sp; + memcpy(L1_SCRATCH_TASK_INFO, &task_thread_info(current)->l1_task_info, + sizeof(*L1_SCRATCH_TASK_INFO)); +#endif + wrusp(new_sp); +} +EXPORT_SYMBOL_GPL(start_thread); + +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; + +#ifdef __ARCH_SYNC_CORE_DCACHE + if (current->rt.nr_cpus_allowed == num_possible_cpus()) + set_cpus_allowed_ptr(current, cpumask_of(smp_processor_id())); +#endif + + /* 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(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; +} + +/* + * sys_execve() executes a new program. + */ +asmlinkage int sys_execve(const char __user *name, + const char __user *const __user *argv, + const char __user *const __user *envp) +{ + int error; + char *filename; + struct pt_regs *regs = (struct pt_regs *)((&name) + 6); + + filename = getname(name); + error = PTR_ERR(filename); + if (IS_ERR(filename)) + return error; + error = do_execve(filename, argv, envp, regs); + putname(filename); + 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; +} + +void finish_atomic_sections (struct pt_regs *regs) +{ + int __user *up0 = (int __user *)regs->p0; + + switch (regs->pc) { + default: + /* not in middle of an atomic step, so resume like normal */ + return; + + case ATOMIC_XCHG32 + 2: + put_user(regs->r1, up0); + break; + + case ATOMIC_CAS32 + 2: + case ATOMIC_CAS32 + 4: + if (regs->r0 == regs->r1) + case ATOMIC_CAS32 + 6: + put_user(regs->r2, up0); + break; + + case ATOMIC_ADD32 + 2: + regs->r0 = regs->r1 + regs->r0; + /* fall through */ + case ATOMIC_ADD32 + 4: + put_user(regs->r0, up0); + break; + + case ATOMIC_SUB32 + 2: + regs->r0 = regs->r1 - regs->r0; + /* fall through */ + case ATOMIC_SUB32 + 4: + put_user(regs->r0, up0); + break; + + case ATOMIC_IOR32 + 2: + regs->r0 = regs->r1 | regs->r0; + /* fall through */ + case ATOMIC_IOR32 + 4: + put_user(regs->r0, up0); + break; + + case ATOMIC_AND32 + 2: + regs->r0 = regs->r1 & regs->r0; + /* fall through */ + case ATOMIC_AND32 + 4: + put_user(regs->r0, up0); + break; + + case ATOMIC_XOR32 + 2: + regs->r0 = regs->r1 ^ regs->r0; + /* fall through */ + case ATOMIC_XOR32 + 4: + put_user(regs->r0, up0); + break; + } + + /* + * We've finished the atomic section, and the only thing left for + * userspace is to do a RTS, so we might as well handle that too + * since we need to update the PC anyways. + */ + regs->pc = regs->rets; +} + +static inline +int in_mem(unsigned long addr, unsigned long size, + unsigned long start, unsigned long end) +{ + return addr >= start && addr + size <= end; +} +static inline +int in_mem_const_off(unsigned long addr, unsigned long size, unsigned long off, + unsigned long const_addr, unsigned long const_size) +{ + return const_size && + in_mem(addr, size, const_addr + off, const_addr + const_size); +} +static inline +int in_mem_const(unsigned long addr, unsigned long size, + unsigned long const_addr, unsigned long const_size) +{ + return in_mem_const_off(addr, size, 0, const_addr, const_size); +} +#define ASYNC_ENABLED(bnum, bctlnum) \ +({ \ + (bfin_read_EBIU_AMGCTL() & 0xe) < ((bnum + 1) << 1) ? 0 : \ + bfin_read_EBIU_AMBCTL##bctlnum() & B##bnum##RDYEN ? 0 : \ + 1; \ +}) +/* + * We can't read EBIU banks that aren't enabled or we end up hanging + * on the access to the async space. Make sure we validate accesses + * that cross async banks too. + * 0 - found, but unusable + * 1 - found & usable + * 2 - not found + */ +static +int in_async(unsigned long addr, unsigned long size) +{ + if (addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE) { + if (!ASYNC_ENABLED(0, 0)) + return 0; + if (addr + size <= ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE) + return 1; + size -= ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE - addr; + addr = ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE; + } + if (addr >= ASYNC_BANK1_BASE && addr < ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE) { + if (!ASYNC_ENABLED(1, 0)) + return 0; + if (addr + size <= ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE) + return 1; + size -= ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE - addr; + addr = ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE; + } + if (addr >= ASYNC_BANK2_BASE && addr < ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE) { + if (!ASYNC_ENABLED(2, 1)) + return 0; + if (addr + size <= ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE) + return 1; + size -= ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE - addr; + addr = ASYNC_BANK2_BASE + ASYNC_BANK2_SIZE; + } + if (addr >= ASYNC_BANK3_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) { + if (ASYNC_ENABLED(3, 1)) + return 0; + if (addr + size <= ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE) + return 1; + return 0; + } + + /* not within async bounds */ + return 2; +} + +int bfin_mem_access_type(unsigned long addr, unsigned long size) +{ + int cpu = raw_smp_processor_id(); + + /* Check that things do not wrap around */ + if (addr > ULONG_MAX - size) + return -EFAULT; + + if (in_mem(addr, size, FIXED_CODE_START, physical_mem_end)) + return BFIN_MEM_ACCESS_CORE; + + if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH)) + return cpu == 0 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA; + if (in_mem_const(addr, size, L1_SCRATCH_START, L1_SCRATCH_LENGTH)) + return cpu == 0 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT; + if (in_mem_const(addr, size, L1_DATA_A_START, L1_DATA_A_LENGTH)) + return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA; + if (in_mem_const(addr, size, L1_DATA_B_START, L1_DATA_B_LENGTH)) + return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA; +#ifdef COREB_L1_CODE_START + if (in_mem_const(addr, size, COREB_L1_CODE_START, COREB_L1_CODE_LENGTH)) + return cpu == 1 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA; + if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH)) + return cpu == 1 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT; + if (in_mem_const(addr, size, COREB_L1_DATA_A_START, COREB_L1_DATA_A_LENGTH)) + return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA; + if (in_mem_const(addr, size, COREB_L1_DATA_B_START, COREB_L1_DATA_B_LENGTH)) + return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA; +#endif + if (in_mem_const(addr, size, L2_START, L2_LENGTH)) + return BFIN_MEM_ACCESS_CORE; + + if (addr >= SYSMMR_BASE) + return BFIN_MEM_ACCESS_CORE_ONLY; + + switch (in_async(addr, size)) { + case 0: return -EFAULT; + case 1: return BFIN_MEM_ACCESS_CORE; + case 2: /* fall through */; + } + + if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH)) + return BFIN_MEM_ACCESS_CORE; + if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH)) + return BFIN_MEM_ACCESS_DMA; + + return -EFAULT; +} + +#if defined(CONFIG_ACCESS_CHECK) +#ifdef CONFIG_ACCESS_OK_L1 +__attribute__((l1_text)) +#endif +/* Return 1 if access to memory range is OK, 0 otherwise */ +int _access_ok(unsigned long addr, unsigned long size) +{ + int aret; + + if (size == 0) + return 1; + /* Check that things do not wrap around */ + if (addr > ULONG_MAX - size) + return 0; + if (segment_eq(get_fs(), KERNEL_DS)) + return 1; +#ifdef CONFIG_MTD_UCLINUX + if (1) +#else + if (0) +#endif + { + if (in_mem(addr, size, memory_start, memory_end)) + return 1; + if (in_mem(addr, size, memory_mtd_end, physical_mem_end)) + return 1; +# ifndef CONFIG_ROMFS_ON_MTD + if (0) +# endif + /* For XIP, allow user space to use pointers within the ROMFS. */ + if (in_mem(addr, size, memory_mtd_start, memory_mtd_end)) + return 1; + } else { + if (in_mem(addr, size, memory_start, physical_mem_end)) + return 1; + } + + if (in_mem(addr, size, (unsigned long)__init_begin, (unsigned long)__init_end)) + return 1; + + if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH)) + return 1; + if (in_mem_const_off(addr, size, _etext_l1 - _stext_l1, L1_CODE_START, L1_CODE_LENGTH)) + return 1; + if (in_mem_const_off(addr, size, _ebss_l1 - _sdata_l1, L1_DATA_A_START, L1_DATA_A_LENGTH)) + return 1; + if (in_mem_const_off(addr, size, _ebss_b_l1 - _sdata_b_l1, L1_DATA_B_START, L1_DATA_B_LENGTH)) + return 1; +#ifdef COREB_L1_CODE_START + if (in_mem_const(addr, size, COREB_L1_CODE_START, COREB_L1_CODE_LENGTH)) + return 1; + if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH)) + return 1; + if (in_mem_const(addr, size, COREB_L1_DATA_A_START, COREB_L1_DATA_A_LENGTH)) + return 1; + if (in_mem_const(addr, size, COREB_L1_DATA_B_START, COREB_L1_DATA_B_LENGTH)) + return 1; +#endif + +#ifndef CONFIG_EXCEPTION_L1_SCRATCH + if (in_mem_const(addr, size, (unsigned long)l1_stack_base, l1_stack_len)) + return 1; +#endif + + aret = in_async(addr, size); + if (aret < 2) + return aret; + + if (in_mem_const_off(addr, size, _ebss_l2 - _stext_l2, L2_START, L2_LENGTH)) + return 1; + + if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH)) + return 1; + if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH)) + return 1; + + return 0; +} +EXPORT_SYMBOL(_access_ok); +#endif /* CONFIG_ACCESS_CHECK */ |