diff options
Diffstat (limited to 'arch/tile/kernel/process.c')
| -rw-r--r-- | arch/tile/kernel/process.c | 598 |
1 files changed, 0 insertions, 598 deletions
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c deleted file mode 100644 index 8ac304484f98..000000000000 --- a/arch/tile/kernel/process.c +++ /dev/null @@ -1,598 +0,0 @@ -/* - * Copyright 2010 Tilera Corporation. All Rights Reserved. - * - * 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, version 2. - * - * 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, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for - * more details. - */ - -#include <linux/sched.h> -#include <linux/preempt.h> -#include <linux/module.h> -#include <linux/fs.h> -#include <linux/kprobes.h> -#include <linux/elfcore.h> -#include <linux/tick.h> -#include <linux/init.h> -#include <linux/mm.h> -#include <linux/compat.h> -#include <linux/hardirq.h> -#include <linux/syscalls.h> -#include <linux/kernel.h> -#include <linux/tracehook.h> -#include <linux/signal.h> -#include <asm/stack.h> -#include <asm/switch_to.h> -#include <asm/homecache.h> -#include <asm/syscalls.h> -#include <asm/traps.h> -#include <asm/setup.h> -#ifdef CONFIG_HARDWALL -#include <asm/hardwall.h> -#endif -#include <arch/chip.h> -#include <arch/abi.h> -#include <arch/sim_def.h> - -/* - * Use the (x86) "idle=poll" option to prefer low latency when leaving the - * idle loop over low power while in the idle loop, e.g. if we have - * one thread per core and we want to get threads out of futex waits fast. - */ -static int __init idle_setup(char *str) -{ - if (!str) - return -EINVAL; - - if (!strcmp(str, "poll")) { - pr_info("using polling idle threads.\n"); - cpu_idle_poll_ctrl(true); - return 0; - } else if (!strcmp(str, "halt")) { - return 0; - } - return -1; -} -early_param("idle", idle_setup); - -void arch_cpu_idle(void) -{ - __get_cpu_var(irq_stat).idle_timestamp = jiffies; - _cpu_idle(); -} - -/* - * Release a thread_info structure - */ -void arch_release_thread_info(struct thread_info *info) -{ - struct single_step_state *step_state = info->step_state; - -#ifdef CONFIG_HARDWALL - /* - * We free a thread_info from the context of the task that has - * been scheduled next, so the original task is already dead. - * Calling deactivate here just frees up the data structures. - * If the task we're freeing held the last reference to a - * hardwall fd, it would have been released prior to this point - * anyway via exit_files(), and the hardwall_task.info pointers - * would be NULL by now. - */ - hardwall_deactivate_all(info->task); -#endif - - if (step_state) { - - /* - * FIXME: we don't munmap step_state->buffer - * because the mm_struct for this process (info->task->mm) - * has already been zeroed in exit_mm(). Keeping a - * reference to it here seems like a bad move, so this - * means we can't munmap() the buffer, and therefore if we - * ptrace multiple threads in a process, we will slowly - * leak user memory. (Note that as soon as the last - * thread in a process dies, we will reclaim all user - * memory including single-step buffers in the usual way.) - * We should either assign a kernel VA to this buffer - * somehow, or we should associate the buffer(s) with the - * mm itself so we can clean them up that way. - */ - kfree(step_state); - } -} - -static void save_arch_state(struct thread_struct *t); - -int copy_thread(unsigned long clone_flags, unsigned long sp, - unsigned long arg, struct task_struct *p) -{ - struct pt_regs *childregs = task_pt_regs(p); - unsigned long ksp; - unsigned long *callee_regs; - - /* - * 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. - */ - 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; - - /* Record the pid of the task that created this one. */ - p->thread.creator_pid = current->pid; - - if (unlikely(p->flags & PF_KTHREAD)) { - /* 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 - * and then return from interrupt like the parent. - */ - 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; - - /* - * Copy the registers onto the kernel stack so the - * return-from-interrupt code will reload it into registers. - */ - *childregs = *current_pt_regs(); - childregs->regs[0] = 0; /* return value is zero */ - if (sp) - childregs->sp = sp; /* override with new user stack pointer */ - memcpy(callee_regs, &childregs->regs[CALLEE_SAVED_FIRST_REG], - CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long)); - - /* Save user stack top pointer so we can ID the stack vm area later. */ - p->thread.usp0 = childregs->sp; - - /* - * If CLONE_SETTLS is set, set "tp" in the new task to "r4", - * which is passed in as arg #5 to sys_clone(). - */ - if (clone_flags & CLONE_SETTLS) - childregs->tp = childregs->regs[4]; - - -#if CHIP_HAS_TILE_DMA() - /* - * No DMA in the new thread. We model this on the fact that - * fork() clears the pending signals, alarms, and aio for the child. - */ - memset(&p->thread.tile_dma_state, 0, sizeof(struct tile_dma_state)); - memset(&p->thread.dma_async_tlb, 0, sizeof(struct async_tlb)); -#endif - -#if CHIP_HAS_SN_PROC() - /* Likewise, the new thread is not running static processor code. */ - p->thread.sn_proc_running = 0; - memset(&p->thread.sn_async_tlb, 0, sizeof(struct async_tlb)); -#endif - -#if CHIP_HAS_PROC_STATUS_SPR() - /* New thread has its miscellaneous processor state bits clear. */ - p->thread.proc_status = 0; -#endif - -#ifdef CONFIG_HARDWALL - /* New thread does not own any networks. */ - memset(&p->thread.hardwall[0], 0, - sizeof(struct hardwall_task) * HARDWALL_TYPES); -#endif - - - /* - * Start the new thread with the current architecture state - * (user interrupt masks, etc.). - */ - save_arch_state(&p->thread); - - return 0; -} - -/* - * Return "current" if it looks plausible, or else a pointer to a dummy. - * This can be helpful if we are just trying to emit a clean panic. - */ -struct task_struct *validate_current(void) -{ - static struct task_struct corrupt = { .comm = "<corrupt>" }; - struct task_struct *tsk = current; - if (unlikely((unsigned long)tsk < PAGE_OFFSET || - (high_memory && (void *)tsk > high_memory) || - ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) { - pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer); - tsk = &corrupt; - } - return tsk; -} - -/* Take and return the pointer to the previous task, for schedule_tail(). */ -struct task_struct *sim_notify_fork(struct task_struct *prev) -{ - struct task_struct *tsk = current; - __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK_PARENT | - (tsk->thread.creator_pid << _SIM_CONTROL_OPERATOR_BITS)); - __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK | - (tsk->pid << _SIM_CONTROL_OPERATOR_BITS)); - return prev; -} - -int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) -{ - struct pt_regs *ptregs = task_pt_regs(tsk); - elf_core_copy_regs(regs, ptregs); - return 1; -} - -#if CHIP_HAS_TILE_DMA() - -/* Allow user processes to access the DMA SPRs */ -void grant_dma_mpls(void) -{ -#if CONFIG_KERNEL_PL == 2 - __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); - __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); -#else - __insn_mtspr(SPR_MPL_DMA_CPL_SET_0, 1); - __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0, 1); -#endif -} - -/* Forbid user processes from accessing the DMA SPRs */ -void restrict_dma_mpls(void) -{ -#if CONFIG_KERNEL_PL == 2 - __insn_mtspr(SPR_MPL_DMA_CPL_SET_2, 1); - __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_2, 1); -#else - __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); - __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); -#endif -} - -/* Pause the DMA engine, then save off its state registers. */ -static void save_tile_dma_state(struct tile_dma_state *dma) -{ - unsigned long state = __insn_mfspr(SPR_DMA_USER_STATUS); - unsigned long post_suspend_state; - - /* If we're running, suspend the engine. */ - if ((state & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) - __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK); - - /* - * Wait for the engine to idle, then save regs. Note that we - * want to record the "running" bit from before suspension, - * and the "done" bit from after, so that we can properly - * distinguish a case where the user suspended the engine from - * the case where the kernel suspended as part of the context - * swap. - */ - do { - post_suspend_state = __insn_mfspr(SPR_DMA_USER_STATUS); - } while (post_suspend_state & SPR_DMA_STATUS__BUSY_MASK); - - dma->src = __insn_mfspr(SPR_DMA_SRC_ADDR); - dma->src_chunk = __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR); - dma->dest = __insn_mfspr(SPR_DMA_DST_ADDR); - dma->dest_chunk = __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR); - dma->strides = __insn_mfspr(SPR_DMA_STRIDE); - dma->chunk_size = __insn_mfspr(SPR_DMA_CHUNK_SIZE); - dma->byte = __insn_mfspr(SPR_DMA_BYTE); - dma->status = (state & SPR_DMA_STATUS__RUNNING_MASK) | - (post_suspend_state & SPR_DMA_STATUS__DONE_MASK); -} - -/* Restart a DMA that was running before we were context-switched out. */ -static void restore_tile_dma_state(struct thread_struct *t) -{ - const struct tile_dma_state *dma = &t->tile_dma_state; - - /* - * The only way to restore the done bit is to run a zero - * length transaction. - */ - if ((dma->status & SPR_DMA_STATUS__DONE_MASK) && - !(__insn_mfspr(SPR_DMA_USER_STATUS) & SPR_DMA_STATUS__DONE_MASK)) { - __insn_mtspr(SPR_DMA_BYTE, 0); - __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); - while (__insn_mfspr(SPR_DMA_USER_STATUS) & - SPR_DMA_STATUS__BUSY_MASK) - ; - } - - __insn_mtspr(SPR_DMA_SRC_ADDR, dma->src); - __insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR, dma->src_chunk); - __insn_mtspr(SPR_DMA_DST_ADDR, dma->dest); - __insn_mtspr(SPR_DMA_DST_CHUNK_ADDR, dma->dest_chunk); - __insn_mtspr(SPR_DMA_STRIDE, dma->strides); - __insn_mtspr(SPR_DMA_CHUNK_SIZE, dma->chunk_size); - __insn_mtspr(SPR_DMA_BYTE, dma->byte); - - /* - * Restart the engine if we were running and not done. - * Clear a pending async DMA fault that we were waiting on return - * to user space to execute, since we expect the DMA engine - * to regenerate those faults for us now. Note that we don't - * try to clear the TIF_ASYNC_TLB flag, since it's relatively - * harmless if set, and it covers both DMA and the SN processor. - */ - if ((dma->status & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) { - t->dma_async_tlb.fault_num = 0; - __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); - } -} - -#endif - -static void save_arch_state(struct thread_struct *t) -{ -#if CHIP_HAS_SPLIT_INTR_MASK() - t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0_0) | - ((u64)__insn_mfspr(SPR_INTERRUPT_MASK_0_1) << 32); -#else - t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0); -#endif - t->ex_context[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0); - t->ex_context[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1); - t->system_save[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0); - t->system_save[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1); - t->system_save[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2); - t->system_save[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3); - t->intctrl_0 = __insn_mfspr(SPR_INTCTRL_0_STATUS); -#if CHIP_HAS_PROC_STATUS_SPR() - t->proc_status = __insn_mfspr(SPR_PROC_STATUS); -#endif -#if !CHIP_HAS_FIXED_INTVEC_BASE() - t->interrupt_vector_base = __insn_mfspr(SPR_INTERRUPT_VECTOR_BASE_0); -#endif -#if CHIP_HAS_TILE_RTF_HWM() - t->tile_rtf_hwm = __insn_mfspr(SPR_TILE_RTF_HWM); -#endif -#if CHIP_HAS_DSTREAM_PF() - t->dstream_pf = __insn_mfspr(SPR_DSTREAM_PF); -#endif -} - -static void restore_arch_state(const struct thread_struct *t) -{ -#if CHIP_HAS_SPLIT_INTR_MASK() - __insn_mtspr(SPR_INTERRUPT_MASK_0_0, (u32) t->interrupt_mask); - __insn_mtspr(SPR_INTERRUPT_MASK_0_1, t->interrupt_mask >> 32); -#else - __insn_mtspr(SPR_INTERRUPT_MASK_0, t->interrupt_mask); -#endif - __insn_mtspr(SPR_EX_CONTEXT_0_0, t->ex_context[0]); - __insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]); - __insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]); - __insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]); - __insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]); - __insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]); - __insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0); -#if CHIP_HAS_PROC_STATUS_SPR() - __insn_mtspr(SPR_PROC_STATUS, t->proc_status); -#endif -#if !CHIP_HAS_FIXED_INTVEC_BASE() - __insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0, t->interrupt_vector_base); -#endif -#if CHIP_HAS_TILE_RTF_HWM() - __insn_mtspr(SPR_TILE_RTF_HWM, t->tile_rtf_hwm); -#endif -#if CHIP_HAS_DSTREAM_PF() - __insn_mtspr(SPR_DSTREAM_PF, t->dstream_pf); -#endif -} - - -void _prepare_arch_switch(struct task_struct *next) -{ -#if CHIP_HAS_SN_PROC() - int snctl; -#endif -#if CHIP_HAS_TILE_DMA() - struct tile_dma_state *dma = ¤t->thread.tile_dma_state; - if (dma->enabled) - save_tile_dma_state(dma); -#endif -#if CHIP_HAS_SN_PROC() - /* - * Suspend the static network processor if it was running. - * We do not suspend the fabric itself, just like we don't - * try to suspend the UDN. - */ - snctl = __insn_mfspr(SPR_SNCTL); - current->thread.sn_proc_running = - (snctl & SPR_SNCTL__FRZPROC_MASK) == 0; - if (current->thread.sn_proc_running) - __insn_mtspr(SPR_SNCTL, snctl | SPR_SNCTL__FRZPROC_MASK); -#endif -} - - -struct task_struct *__sched _switch_to(struct task_struct *prev, - struct task_struct *next) -{ - /* DMA state is already saved; save off other arch state. */ - save_arch_state(&prev->thread); - -#if CHIP_HAS_TILE_DMA() - /* - * Restore DMA in new task if desired. - * Note that it is only safe to restart here since interrupts - * are disabled, so we can't take any DMATLB miss or access - * interrupts before we have finished switching stacks. - */ - if (next->thread.tile_dma_state.enabled) { - restore_tile_dma_state(&next->thread); - grant_dma_mpls(); - } else { - restrict_dma_mpls(); - } -#endif - - /* Restore other arch state. */ - restore_arch_state(&next->thread); - -#if CHIP_HAS_SN_PROC() - /* - * Restart static network processor in the new process - * if it was running before. - */ - if (next->thread.sn_proc_running) { - int snctl = __insn_mfspr(SPR_SNCTL); - __insn_mtspr(SPR_SNCTL, snctl & ~SPR_SNCTL__FRZPROC_MASK); - } -#endif - -#ifdef CONFIG_HARDWALL - /* Enable or disable access to the network registers appropriately. */ - hardwall_switch_tasks(prev, next); -#endif - - /* - * Switch kernel SP, PC, and callee-saved registers. - * In the context of the new task, return the old task pointer - * (i.e. the task that actually called __switch_to). - * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp. - */ - return __switch_to(prev, next, next_current_ksp0(next)); -} - -/* - * This routine is called on return from interrupt if any of the - * TIF_WORK_MASK flags are set in thread_info->flags. It is - * entered with interrupts disabled so we don't miss an event - * that modified the thread_info flags. If any flag is set, we - * handle it and return, and the calling assembly code will - * re-disable interrupts, reload the thread flags, and call back - * if more flags need to be handled. - * - * We return whether we need to check the thread_info flags again - * or not. Note that we don't clear TIF_SINGLESTEP here, so it's - * important that it be tested last, and then claim that we don't - * need to recheck the flags. - */ -int do_work_pending(struct pt_regs *regs, u32 thread_info_flags) -{ - /* If we enter in kernel mode, do nothing and exit the caller loop. */ - if (!user_mode(regs)) - return 0; - - /* Enable interrupts; they are disabled again on return to caller. */ - local_irq_enable(); - - if (thread_info_flags & _TIF_NEED_RESCHED) { - schedule(); - return 1; - } -#if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC() - if (thread_info_flags & _TIF_ASYNC_TLB) { - do_async_page_fault(regs); - return 1; - } -#endif - if (thread_info_flags & _TIF_SIGPENDING) { - do_signal(regs); - return 1; - } - if (thread_info_flags & _TIF_NOTIFY_RESUME) { - clear_thread_flag(TIF_NOTIFY_RESUME); - tracehook_notify_resume(regs); - return 1; - } - if (thread_info_flags & _TIF_SINGLESTEP) { - single_step_once(regs); - return 0; - } - panic("work_pending: bad flags %#x\n", thread_info_flags); -} - -unsigned long get_wchan(struct task_struct *p) -{ - struct KBacktraceIterator kbt; - - if (!p || p == current || p->state == TASK_RUNNING) - return 0; - - for (KBacktraceIterator_init(&kbt, p, NULL); - !KBacktraceIterator_end(&kbt); - KBacktraceIterator_next(&kbt)) { - if (!in_sched_functions(kbt.it.pc)) - return kbt.it.pc; - } - - return 0; -} - -/* Flush thread state. */ -void flush_thread(void) -{ - /* Nothing */ -} - -/* - * Free current thread data structures etc.. - */ -void exit_thread(void) -{ - /* Nothing */ -} - -void show_regs(struct pt_regs *regs) -{ - struct task_struct *tsk = validate_current(); - int i; - - pr_err("\n"); - show_regs_print_info(KERN_ERR); -#ifdef __tilegx__ - for (i = 0; i < 51; i += 3) - pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n", - i, regs->regs[i], i+1, regs->regs[i+1], - i+2, regs->regs[i+2]); - pr_err(" r51: "REGFMT" r52: "REGFMT" tp : "REGFMT"\n", - regs->regs[51], regs->regs[52], regs->tp); - pr_err(" sp : "REGFMT" lr : "REGFMT"\n", regs->sp, regs->lr); -#else - for (i = 0; i < 52; i += 4) - pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT - " r%-2d: "REGFMT" r%-2d: "REGFMT"\n", - i, regs->regs[i], i+1, regs->regs[i+1], - i+2, regs->regs[i+2], i+3, regs->regs[i+3]); - pr_err(" r52: "REGFMT" tp : "REGFMT" sp : "REGFMT" lr : "REGFMT"\n", - regs->regs[52], regs->tp, regs->sp, regs->lr); -#endif - pr_err(" pc : "REGFMT" ex1: %ld faultnum: %ld\n", - regs->pc, regs->ex1, regs->faultnum); - - dump_stack_regs(regs); -} |