arch/arm/src/armv7-a: Port the SMP change by Masayuki Ishikawa to the ARMv7-A family.
This commit is contained in:
Gregory Nutt
parent
d7fae340c1
commit
3ddea73dc1
@ -1,7 +1,7 @@
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/****************************************************************************
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* arch/arm/src/armv7-a/arm_schedulesigaction.c
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*
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* Copyright (C) 2013, 2015-2017 Gregory Nutt. All rights reserved.
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* Copyright (C) 2013, 2015-2018 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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@ -116,7 +116,7 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
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if (tcb == this_task())
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{
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/* CASE 1: We are not in an interrupt handler and a task is
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* signalling itself for some reason.
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* signaling itself for some reason.
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*/
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if (!CURRENT_REGS)
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@ -133,7 +133,7 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
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*
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* Hmmm... there looks like a latent bug here: The following logic
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* would fail in the strange case where we are in an interrupt
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* handler, the thread is signalling itself, but a context switch
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* handler, the thread is signaling itself, but a context switch
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* to another task has occurred so that CURRENT_REGS does not
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* refer to the thread of this_task()!
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*/
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@ -166,7 +166,7 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
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/* Otherwise, we are (1) signaling a task is not running from an
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* interrupt handler or (2) we are not in an interrupt handler and the
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* running task is signalling some other non-running task.
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* running task is signaling some other non-running task.
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*/
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else
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@ -222,7 +222,7 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
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cpu = tcb->cpu;
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/* CASE 1: We are not in an interrupt handler and a task is
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* signalling itself for some reason.
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* signaling itself for some reason.
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*/
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if (cpu == me && !CURRENT_REGS)
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@ -238,51 +238,36 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
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* CPU. In the former case, we will have to PAUSE the other CPU
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* first. But in either case, we will have to modify the return
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* state as well as the state in the TCB.
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*
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* Hmmm... there looks like a latent bug here: The following logic
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* would fail in the strange case where we are in an interrupt
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* handler, the thread is signalling itself, but a context switch
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* to another task has occurred so that CURRENT_REGS does not
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* refer to the thread of this_task()!
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*/
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else
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{
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/* If we signalling a task running on the other CPU, we have
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/* If we signaling a task running on the other CPU, we have
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* to PAUSE the other CPU.
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*/
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if (cpu != me)
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{
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/* Pause the CPU */
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up_cpu_pause(cpu);
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}
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/* Save the return lr and cpsr and one scratch register
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* These will be restored by the signal trampoline after
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* the signals have been delivered.
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*/
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/* Wait while the pause request is pending */
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tcb->xcp.sigdeliver = sigdeliver;
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tcb->xcp.saved_pc = CURRENT_REGS[REG_PC];
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tcb->xcp.saved_cpsr = CURRENT_REGS[REG_CPSR];
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while (up_cpu_pausereq(cpu))
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{
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}
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/* Increment the IRQ lock count so that when the task is restarted,
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* it will hold the IRQ spinlock.
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*/
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/* Now tcb on the other CPU can be accessed safely */
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DEBUGASSERT(tcb->irqcount < INT16_MAX);
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tcb->irqcount++;
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/* Copy tcb->xcp.regs to tcp.xcp.saved. These will be restored
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* by the signal trampoline after the signal has been delivered.
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*/
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/* Handle a possible race condition where the TCB was suspended
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* just before we paused the other CPU. The critical section
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* established above will prevent new threads from running on
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* that CPU, but it will not guarantee that the running thread
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* did not suspend itself (allowing any threads "assigned" to
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* the CPU to run).
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*/
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tcb->xcp.sigdeliver = sigdeliver;
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tcb->xcp.saved_pc = tcb->xcp.regs[REG_PC];
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tcb->xcp.saved_cpsr = tcb->xcp.regs[REG_CPSR];
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if (tcb->task_state != TSTATE_TASK_RUNNING)
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{
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/* Then set up to vector to the trampoline with interrupts
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* disabled
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*/
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@ -292,23 +277,26 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
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}
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else
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{
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/* Then set up to vector to the trampoline with interrupts
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* disabled
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/* tcb is running on the same CPU */
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/* Save the return PC, CPSR and either the BASEPRI or PRIMASK
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* registers (and perhaps also the LR). These will be
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* restored by the signal trampoline after the signal has been
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* delivered.
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*/
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tcb->xcp.sigdeliver = (FAR void *)sigdeliver;
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tcb->xcp.saved_pc = CURRENT_REGS[REG_PC];
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tcb->xcp.saved_cpsr = CURRENT_REGS[REG_CPSR];
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/* Then set up vector to the trampoline with interrupts
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* disabled. The kernel-space trampoline must run in
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* privileged thread mode.
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*/
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CURRENT_REGS[REG_PC] = (uint32_t)up_sigdeliver;
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CURRENT_REGS[REG_CPSR] = (PSR_MODE_SVC | PSR_I_BIT | PSR_F_BIT);
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/* In an SMP configuration, the interrupt disable logic also
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* involves spinlocks that are configured per the TCB irqcount
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* field. This is logically equivalent to enter_critical_section().
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* The matching call to leave_critical_section() will be
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* performed in up_sigdeliver().
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*/
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spin_setbit(&g_cpu_irqset, cpu, &g_cpu_irqsetlock,
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&g_cpu_irqlock);
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/* And make sure that the saved context in the TCB is the same
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* as the interrupt return context.
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*/
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@ -316,6 +304,23 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
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up_savestate(tcb->xcp.regs);
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}
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/* Increment the IRQ lock count so that when the task is restarted,
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* it will hold the IRQ spinlock.
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*/
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DEBUGASSERT(tcb->irqcount < INT16_MAX);
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tcb->irqcount++;
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/* In an SMP configuration, the interrupt disable logic also
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* involves spinlocks that are configured per the TCB irqcount
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* field. This is logically equivalent to enter_critical_section().
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* The matching call to leave_critical_section() will be
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* performed in up_sigdeliver().
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*/
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spin_setbit(&g_cpu_irqset, cpu, &g_cpu_irqsetlock,
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&g_cpu_irqlock);
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/* RESUME the other CPU if it was PAUSED */
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if (cpu != me)
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@ -327,7 +332,7 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
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/* Otherwise, we are (1) signaling a task is not running from an
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* interrupt handler or (2) we are not in an interrupt handler and the
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* running task is signalling some other non-running task.
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* running task is signaling some other non-running task.
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*/
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else
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@ -413,7 +413,7 @@ int nxsig_tcbdispatch(FAR struct tcb_s *stcb, siginfo_t *info)
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* Description:
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* This is the front-end for nxsig_tcbdispatch that should be typically
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* be used to dispatch a signal. If HAVE_GROUP_MEMBERS is defined,
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* then function will follow the group signal delivery algorthrims:
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* then function will follow the group signal delivery algorithms:
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*
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* This front-end does the following things before calling
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* nxsig_tcbdispatch.
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