diff options
| -rw-r--r-- | arch/tile/Kconfig | 2 | ||||
| -rw-r--r-- | arch/tile/include/asm/switch_to.h | 5 | ||||
| -rw-r--r-- | arch/tile/kernel/entry.S | 11 | ||||
| -rw-r--r-- | arch/tile/kernel/intvec_32.S | 15 | ||||
| -rw-r--r-- | arch/tile/kernel/intvec_64.S | 15 | ||||
| -rw-r--r-- | arch/tile/kernel/process.c | 103 |
6 files changed, 75 insertions, 76 deletions
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig index 875d008828b..ea7f61e8bc9 100644 --- a/arch/tile/Kconfig +++ b/arch/tile/Kconfig @@ -21,6 +21,8 @@ config TILE select ARCH_HAVE_NMI_SAFE_CMPXCHG select GENERIC_CLOCKEVENTS select MODULES_USE_ELF_RELA + select GENERIC_KERNEL_THREAD + select GENERIC_KERNEL_EXECVE # FIXME: investigate whether we need/want these options. # select HAVE_IOREMAP_PROT diff --git a/arch/tile/include/asm/switch_to.h b/arch/tile/include/asm/switch_to.h index 1d48c5fee8b..b8f888cbe6b 100644 --- a/arch/tile/include/asm/switch_to.h +++ b/arch/tile/include/asm/switch_to.h @@ -68,7 +68,10 @@ extern unsigned long get_switch_to_pc(void); /* Support function for forking a new task. */ void ret_from_fork(void); -/* Called from ret_from_fork() when a new process starts up. */ +/* Support function for forking a new kernel thread. */ +void ret_from_kernel_thread(void *fn, void *arg); + +/* Called from ret_from_xxx() when a new process starts up. */ struct task_struct *sim_notify_fork(struct task_struct *prev); #endif /* !__ASSEMBLY__ */ diff --git a/arch/tile/kernel/entry.S b/arch/tile/kernel/entry.S index c31637baff2..f116cb0bce2 100644 --- a/arch/tile/kernel/entry.S +++ b/arch/tile/kernel/entry.S @@ -28,17 +28,6 @@ STD_ENTRY(current_text_addr) STD_ENDPROC(current_text_addr) /* - * Implement execve(). The i386 code has a note that forking from kernel - * space results in no copy on write until the execve, so we should be - * careful not to write to the stack here. - */ -STD_ENTRY(kernel_execve) - moveli TREG_SYSCALL_NR_NAME, __NR_execve - swint1 - jrp lr - STD_ENDPROC(kernel_execve) - -/* * We don't run this function directly, but instead copy it to a page * we map into every user process. See vdso_setup(). * diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S index 6943515100f..58aad519b7d 100644 --- a/arch/tile/kernel/intvec_32.S +++ b/arch/tile/kernel/intvec_32.S @@ -1291,6 +1291,21 @@ STD_ENTRY(ret_from_fork) } STD_ENDPROC(ret_from_fork) +STD_ENTRY(ret_from_kernel_thread) + jal sim_notify_fork + jal schedule_tail + FEEDBACK_REENTER(ret_from_fork) + { + move r0, r31 + jalr r30 + } + FEEDBACK_REENTER(ret_from_kernel_thread) + { + movei r30, 0 /* not an NMI */ + j .Lresume_userspace /* jump into middle of interrupt_return */ + } + STD_ENDPROC(ret_from_kernel_thread) + /* * Code for ill interrupt. */ diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S index 73f6c0a648c..f66bd5f67d4 100644 --- a/arch/tile/kernel/intvec_64.S +++ b/arch/tile/kernel/intvec_64.S @@ -1150,6 +1150,21 @@ STD_ENTRY(ret_from_fork) } STD_ENDPROC(ret_from_fork) +STD_ENTRY(ret_from_kernel_thread) + jal sim_notify_fork + jal schedule_tail + FEEDBACK_REENTER(ret_from_fork) + { + move r0, r31 + jalr r30 + } + FEEDBACK_REENTER(ret_from_kernel_thread) + { + movei r30, 0 /* not an NMI */ + j .Lresume_userspace /* jump into middle of interrupt_return */ + } + STD_ENDPROC(ret_from_kernel_thread) + /* Various stub interrupt handlers and syscall handlers */ STD_ENTRY_LOCAL(_kernel_double_fault) diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c index 9dc139127f8..da6e4d78da6 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -157,24 +157,44 @@ void arch_release_thread_info(struct thread_info *info) static void save_arch_state(struct thread_struct *t); int copy_thread(unsigned long clone_flags, unsigned long sp, - unsigned long stack_size, + unsigned long arg, struct task_struct *p, struct pt_regs *regs) { - struct pt_regs *childregs; + struct pt_regs *childregs = task_pt_regs(p); unsigned long ksp; + unsigned long *callee_regs; /* - * When creating a new kernel thread we pass sp as zero. - * Assign it to a reasonable value now that we have the stack. + * Set up the stack and stack pointer appropriately for the + * new child to find itself woken up in __switch_to(). + * The callee-saved registers must be on the stack to be read; + * the new task will then jump to assembly support to handle + * calling schedule_tail(), etc., and (for userspace tasks) + * returning to the context set up in the pt_regs. */ - if (sp == 0 && regs->ex1 == PL_ICS_EX1(KERNEL_PL, 0)) - sp = KSTK_TOP(p); + ksp = (unsigned long) childregs; + ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */ + ((long *)ksp)[0] = ((long *)ksp)[1] = 0; + ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long); + callee_regs = (unsigned long *)ksp; + ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */ + ((long *)ksp)[0] = ((long *)ksp)[1] = 0; + p->thread.ksp = ksp; - /* - * Do not clone step state from the parent; each thread - * must make its own lazily. - */ - task_thread_info(p)->step_state = NULL; + /* Record the pid of the task that created this one. */ + p->thread.creator_pid = current->pid; + + if (unlikely(!regs)) { + /* kernel thread */ + memset(childregs, 0, sizeof(struct pt_regs)); + memset(&callee_regs[2], 0, + (CALLEE_SAVED_REGS_COUNT - 2) * sizeof(unsigned long)); + callee_regs[0] = sp; /* r30 = function */ + callee_regs[1] = arg; /* r31 = arg */ + childregs->ex1 = PL_ICS_EX1(KERNEL_PL, 0); + p->thread.pc = (unsigned long) ret_from_kernel_thread; + return 0; + } /* * Start new thread in ret_from_fork so it schedules properly @@ -182,20 +202,24 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, */ p->thread.pc = (unsigned long) ret_from_fork; + /* + * Do not clone step state from the parent; each thread + * must make its own lazily. + */ + task_thread_info(p)->step_state = NULL; + /* Save user stack top pointer so we can ID the stack vm area later. */ p->thread.usp0 = sp; - /* Record the pid of the process that created this one. */ - p->thread.creator_pid = current->pid; - /* * Copy the registers onto the kernel stack so the * return-from-interrupt code will reload it into registers. */ - childregs = task_pt_regs(p); *childregs = *regs; childregs->regs[0] = 0; /* return value is zero */ childregs->sp = sp; /* override with new user stack pointer */ + memcpy(callee_regs, ®s->regs[CALLEE_SAVED_FIRST_REG], + CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long)); /* * If CLONE_SETTLS is set, set "tp" in the new task to "r4", @@ -204,24 +228,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, if (clone_flags & CLONE_SETTLS) childregs->tp = regs->regs[4]; - /* - * Copy the callee-saved registers from the passed pt_regs struct - * into the context-switch callee-saved registers area. - * This way when we start the interrupt-return sequence, the - * callee-save registers will be correctly in registers, which - * is how we assume the compiler leaves them as we start doing - * the normal return-from-interrupt path after calling C code. - * Zero out the C ABI save area to mark the top of the stack. - */ - ksp = (unsigned long) childregs; - ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */ - ((long *)ksp)[0] = ((long *)ksp)[1] = 0; - ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long); - memcpy((void *)ksp, ®s->regs[CALLEE_SAVED_FIRST_REG], - CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long)); - ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */ - ((long *)ksp)[0] = ((long *)ksp)[1] = 0; - p->thread.ksp = ksp; #if CHIP_HAS_TILE_DMA() /* @@ -650,37 +656,6 @@ unsigned long get_wchan(struct task_struct *p) return 0; } -/* - * We pass in lr as zero (cleared in kernel_thread) and the caller - * part of the backtrace ABI on the stack also zeroed (in copy_thread) - * so that backtraces will stop with this function. - * Note that we don't use r0, since copy_thread() clears it. - */ -static void start_kernel_thread(int dummy, int (*fn)(int), int arg) -{ - do_exit(fn(arg)); -} - -/* - * Create a kernel thread - */ -int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) -{ - struct pt_regs regs; - - memset(®s, 0, sizeof(regs)); - regs.ex1 = PL_ICS_EX1(KERNEL_PL, 0); /* run at kernel PL, no ICS */ - regs.pc = (long) start_kernel_thread; - regs.flags = PT_FLAGS_CALLER_SAVES; /* need to restore r1 and r2 */ - regs.regs[1] = (long) fn; /* function pointer */ - regs.regs[2] = (long) arg; /* parameter register */ - - /* Ok, create the new process.. */ - return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, - 0, NULL, NULL); -} -EXPORT_SYMBOL(kernel_thread); - /* Flush thread state. */ void flush_thread(void) { |