mca.c

linux2.6.16版本

	cmcv.cmcv_mask = 1; /* Mask/disable interrupt */
	ia64_setreg(_IA64_REG_CR_CMCV, cmcv.cmcv_regval);

	IA64_MCA_DEBUG("%s: CPU %d corrected "
		       "machine check vector %#x disabled.\n",
		       __FUNCTION__, smp_processor_id(), cmcv.cmcv_vector);
}

/*
 * ia64_mca_cmc_vector_enable
 *
 *  Unmask the corrected machine check vector register in the processor.
 *  This function is invoked on a per-processor basis.
 *
 * Inputs
 *      dummy(unused)
 *
 * Outputs
 *	None
 */
static void
ia64_mca_cmc_vector_enable (void *dummy)
{
	cmcv_reg_t	cmcv;

	cmcv.cmcv_regval = ia64_getreg(_IA64_REG_CR_CMCV);

	cmcv.cmcv_mask = 0; /* Unmask/enable interrupt */
	ia64_setreg(_IA64_REG_CR_CMCV, cmcv.cmcv_regval);

	IA64_MCA_DEBUG("%s: CPU %d corrected "
		       "machine check vector %#x enabled.\n",
		       __FUNCTION__, smp_processor_id(), cmcv.cmcv_vector);
}

/*
 * ia64_mca_cmc_vector_disable_keventd
 *
 * Called via keventd (smp_call_function() is not safe in interrupt context) to
 * disable the cmc interrupt vector.
 */
static void
ia64_mca_cmc_vector_disable_keventd(void *unused)
{
	on_each_cpu(ia64_mca_cmc_vector_disable, NULL, 1, 0);
}

/*
 * ia64_mca_cmc_vector_enable_keventd
 *
 * Called via keventd (smp_call_function() is not safe in interrupt context) to
 * enable the cmc interrupt vector.
 */
static void
ia64_mca_cmc_vector_enable_keventd(void *unused)
{
	on_each_cpu(ia64_mca_cmc_vector_enable, NULL, 1, 0);
}

/*
 * ia64_mca_wakeup
 *
 *	Send an inter-cpu interrupt to wake-up a particular cpu
 *	and mark that cpu to be out of rendez.
 *
 *  Inputs  :   cpuid
 *  Outputs :   None
 */
static void
ia64_mca_wakeup(int cpu)
{
	platform_send_ipi(cpu, IA64_MCA_WAKEUP_VECTOR, IA64_IPI_DM_INT, 0);
	ia64_mc_info.imi_rendez_checkin[cpu] = IA64_MCA_RENDEZ_CHECKIN_NOTDONE;

}

/*
 * ia64_mca_wakeup_all
 *
 *	Wakeup all the cpus which have rendez'ed previously.
 *
 *  Inputs  :   None
 *  Outputs :   None
 */
static void
ia64_mca_wakeup_all(void)
{
	int cpu;

	/* Clear the Rendez checkin flag for all cpus */
	for_each_online_cpu(cpu) {
		if (ia64_mc_info.imi_rendez_checkin[cpu] == IA64_MCA_RENDEZ_CHECKIN_DONE)
			ia64_mca_wakeup(cpu);
	}

}

/*
 * ia64_mca_rendez_interrupt_handler
 *
 *	This is handler used to put slave processors into spinloop
 *	while the monarch processor does the mca handling and later
 *	wake each slave up once the monarch is done.
 *
 *  Inputs  :   None
 *  Outputs :   None
 */
static irqreturn_t
ia64_mca_rendez_int_handler(int rendez_irq, void *arg, struct pt_regs *regs)
{
	unsigned long flags;
	int cpu = smp_processor_id();

	/* Mask all interrupts */
	local_irq_save(flags);
	if (notify_die(DIE_MCA_RENDZVOUS_ENTER, "MCA", regs, 0, 0, 0)
			== NOTIFY_STOP)
		ia64_mca_spin(__FUNCTION__);

	ia64_mc_info.imi_rendez_checkin[cpu] = IA64_MCA_RENDEZ_CHECKIN_DONE;
	/* Register with the SAL monarch that the slave has
	 * reached SAL
	 */
	ia64_sal_mc_rendez();

	if (notify_die(DIE_MCA_RENDZVOUS_PROCESS, "MCA", regs, 0, 0, 0)
			== NOTIFY_STOP)
		ia64_mca_spin(__FUNCTION__);

	/* Wait for the monarch cpu to exit. */
	while (monarch_cpu != -1)
	       cpu_relax();	/* spin until monarch leaves */

	if (notify_die(DIE_MCA_RENDZVOUS_LEAVE, "MCA", regs, 0, 0, 0)
			== NOTIFY_STOP)
		ia64_mca_spin(__FUNCTION__);

	/* Enable all interrupts */
	local_irq_restore(flags);
	return IRQ_HANDLED;
}

/*
 * ia64_mca_wakeup_int_handler
 *
 *	The interrupt handler for processing the inter-cpu interrupt to the
 *	slave cpu which was spinning in the rendez loop.
 *	Since this spinning is done by turning off the interrupts and
 *	polling on the wakeup-interrupt bit in the IRR, there is
 *	nothing useful to be done in the handler.
 *
 *  Inputs  :   wakeup_irq  (Wakeup-interrupt bit)
 *	arg		(Interrupt handler specific argument)
 *	ptregs		(Exception frame at the time of the interrupt)
 *  Outputs :   None
 *
 */
static irqreturn_t
ia64_mca_wakeup_int_handler(int wakeup_irq, void *arg, struct pt_regs *ptregs)
{
	return IRQ_HANDLED;
}

/* Function pointer for extra MCA recovery */
int (*ia64_mca_ucmc_extension)
	(void*,struct ia64_sal_os_state*)
	= NULL;

int
ia64_reg_MCA_extension(int (*fn)(void *, struct ia64_sal_os_state *))
{
	if (ia64_mca_ucmc_extension)
		return 1;

	ia64_mca_ucmc_extension = fn;
	return 0;
}

void
ia64_unreg_MCA_extension(void)
{
	if (ia64_mca_ucmc_extension)
		ia64_mca_ucmc_extension = NULL;
}

EXPORT_SYMBOL(ia64_reg_MCA_extension);
EXPORT_SYMBOL(ia64_unreg_MCA_extension);


static inline void
copy_reg(const u64 *fr, u64 fnat, u64 *tr, u64 *tnat)
{
	u64 fslot, tslot, nat;
	*tr = *fr;
	fslot = ((unsigned long)fr >> 3) & 63;
	tslot = ((unsigned long)tr >> 3) & 63;
	*tnat &= ~(1UL << tslot);
	nat = (fnat >> fslot) & 1;
	*tnat |= (nat << tslot);
}

/* On entry to this routine, we are running on the per cpu stack, see
 * mca_asm.h.  The original stack has not been touched by this event.  Some of
 * the original stack's registers will be in the RBS on this stack.  This stack
 * also contains a partial pt_regs and switch_stack, the rest of the data is in
 * PAL minstate.
 *
 * The first thing to do is modify the original stack to look like a blocked
 * task so we can run backtrace on the original task.  Also mark the per cpu
 * stack as current to ensure that we use the correct task state, it also means
 * that we can do backtrace on the MCA/INIT handler code itself.
 */

static task_t *
ia64_mca_modify_original_stack(struct pt_regs *regs,
		const struct switch_stack *sw,
		struct ia64_sal_os_state *sos,
		const char *type)
{
	char *p, comm[sizeof(current->comm)];
	ia64_va va;
	extern char ia64_leave_kernel[];	/* Need asm address, not function descriptor */
	const pal_min_state_area_t *ms = sos->pal_min_state;
	task_t *previous_current;
	struct pt_regs *old_regs;
	struct switch_stack *old_sw;
	unsigned size = sizeof(struct pt_regs) +
			sizeof(struct switch_stack) + 16;
	u64 *old_bspstore, *old_bsp;
	u64 *new_bspstore, *new_bsp;
	u64 old_unat, old_rnat, new_rnat, nat;
	u64 slots, loadrs = regs->loadrs;
	u64 r12 = ms->pmsa_gr[12-1], r13 = ms->pmsa_gr[13-1];
	u64 ar_bspstore = regs->ar_bspstore;
	u64 ar_bsp = regs->ar_bspstore + (loadrs >> 16);
	const u64 *bank;
	const char *msg;
	int cpu = smp_processor_id();

	previous_current = curr_task(cpu);
	set_curr_task(cpu, current);
	if ((p = strchr(current->comm, ' ')))
		*p = '\0';

	/* Best effort attempt to cope with MCA/INIT delivered while in
	 * physical mode.
	 */
	regs->cr_ipsr = ms->pmsa_ipsr;
	if (ia64_psr(regs)->dt == 0) {
		va.l = r12;
		if (va.f.reg == 0) {
			va.f.reg = 7;
			r12 = va.l;
		}
		va.l = r13;
		if (va.f.reg == 0) {
			va.f.reg = 7;
			r13 = va.l;
		}
	}
	if (ia64_psr(regs)->rt == 0) {
		va.l = ar_bspstore;
		if (va.f.reg == 0) {
			va.f.reg = 7;
			ar_bspstore = va.l;
		}
		va.l = ar_bsp;
		if (va.f.reg == 0) {
			va.f.reg = 7;
			ar_bsp = va.l;
		}
	}

	/* mca_asm.S ia64_old_stack() cannot assume that the dirty registers
	 * have been copied to the old stack, the old stack may fail the
	 * validation tests below.  So ia64_old_stack() must restore the dirty
	 * registers from the new stack.  The old and new bspstore probably
	 * have different alignments, so loadrs calculated on the old bsp
	 * cannot be used to restore from the new bsp.  Calculate a suitable
	 * loadrs for the new stack and save it in the new pt_regs, where
	 * ia64_old_stack() can get it.
	 */
	old_bspstore = (u64 *)ar_bspstore;
	old_bsp = (u64 *)ar_bsp;
	slots = ia64_rse_num_regs(old_bspstore, old_bsp);
	new_bspstore = (u64 *)((u64)current + IA64_RBS_OFFSET);
	new_bsp = ia64_rse_skip_regs(new_bspstore, slots);
	regs->loadrs = (new_bsp - new_bspstore) * 8 << 16;

	/* Verify the previous stack state before we change it */
	if (user_mode(regs)) {
		msg = "occurred in user space";
		goto no_mod;
	}
	if (r13 != sos->prev_IA64_KR_CURRENT) {
		msg = "inconsistent previous current and r13";
		goto no_mod;
	}
	if ((r12 - r13) >= KERNEL_STACK_SIZE) {
		msg = "inconsistent r12 and r13";
		goto no_mod;
	}
	if ((ar_bspstore - r13) >= KERNEL_STACK_SIZE) {
		msg = "inconsistent ar.bspstore and r13";
		goto no_mod;
	}
	va.p = old_bspstore;
	if (va.f.reg < 5) {
		msg = "old_bspstore is in the wrong region";
		goto no_mod;
	}
	if ((ar_bsp - r13) >= KERNEL_STACK_SIZE) {
		msg = "inconsistent ar.bsp and r13";
		goto no_mod;
	}
	size += (ia64_rse_skip_regs(old_bspstore, slots) - old_bspstore) * 8;
	if (ar_bspstore + size > r12) {
		msg = "no room for blocked state";
		goto no_mod;
	}

	/* Change the comm field on the MCA/INT task to include the pid that
	 * was interrupted, it makes for easier debugging.  If that pid was 0
	 * (swapper or nested MCA/INIT) then use the start of the previous comm
	 * field suffixed with its cpu.
	 */
	if (previous_current->pid)
		snprintf(comm, sizeof(comm), "%s %d",
			current->comm, previous_current->pid);
	else {
		int l;
		if ((p = strchr(previous_current->comm, ' ')))
			l = p - previous_current->comm;
		else
			l = strlen(previous_current->comm);
		snprintf(comm, sizeof(comm), "%s %*s %d",
			current->comm, l, previous_current->comm,
			task_thread_info(previous_current)->cpu);
	}
	memcpy(current->comm, comm, sizeof(current->comm));

	/* Make the original task look blocked.  First stack a struct pt_regs,
	 * describing the state at the time of interrupt.  mca_asm.S built a
	 * partial pt_regs, copy it and fill in the blanks using minstate.
	 */
	p = (char *)r12 - sizeof(*regs);
	old_regs = (struct pt_regs *)p;
	memcpy(old_regs, regs, sizeof(*regs));
	/* If ipsr.ic then use pmsa_{iip,ipsr,ifs}, else use
	 * pmsa_{xip,xpsr,xfs}
	 */
	if (ia64_psr(regs)->ic) {
		old_regs->cr_iip = ms->pmsa_iip;
		old_regs->cr_ipsr = ms->pmsa_ipsr;
		old_regs->cr_ifs = ms->pmsa_ifs;
	} else {
		old_regs->cr_iip = ms->pmsa_xip;
		old_regs->cr_ipsr = ms->pmsa_xpsr;
		old_regs->cr_ifs = ms->pmsa_xfs;
	}
	old_regs->pr = ms->pmsa_pr;
	old_regs->b0 = ms->pmsa_br0;
	old_regs->loadrs = loadrs;
	old_regs->ar_rsc = ms->pmsa_rsc;
	old_unat = old_regs->ar_unat;
	copy_reg(&ms->pmsa_gr[1-1], ms->pmsa_nat_bits, &old_regs->r1, &old_unat);
	copy_reg(&ms->pmsa_gr[2-1], ms->pmsa_nat_bits, &old_regs->r2, &old_unat);
	copy_reg(&ms->pmsa_gr[3-1], ms->pmsa_nat_bits, &old_regs->r3, &old_unat);
	copy_reg(&ms->pmsa_gr[8-1], ms->pmsa_nat_bits, &old_regs->r8, &old_unat);
	copy_reg(&ms->pmsa_gr[9-1], ms->pmsa_nat_bits, &old_regs->r9, &old_unat);
	copy_reg(&ms->pmsa_gr[10-1], ms->pmsa_nat_bits, &old_regs->r10, &old_unat);
	copy_reg(&ms->pmsa_gr[11-1], ms->pmsa_nat_bits, &old_regs->r11, &old_unat);
	copy_reg(&ms->pmsa_gr[12-1], ms->pmsa_nat_bits, &old_regs->r12, &old_unat);
	copy_reg(&ms->pmsa_gr[13-1], ms->pmsa_nat_bits, &old_regs->r13, &old_unat);
	copy_reg(&ms->pmsa_gr[14-1], ms->pmsa_nat_bits, &old_regs->r14, &old_unat);
	copy_reg(&ms->pmsa_gr[15-1], ms->pmsa_nat_bits, &old_regs->r15, &old_unat);
	if (ia64_psr(old_regs)->bn)
		bank = ms->pmsa_bank1_gr;
	else
		bank = ms->pmsa_bank0_gr;
	copy_reg(&bank[16-16], ms->pmsa_nat_bits, &old_regs->r16, &old_unat);
	copy_reg(&bank[17-16], ms->pmsa_nat_bits, &old_regs->r17, &old_unat);
	copy_reg(&bank[18-16], ms->pmsa_nat_bits, &old_regs->r18, &old_unat);
	copy_reg(&bank[19-16], ms->pmsa_nat_bits, &old_regs->r19, &old_unat);
	copy_reg(&bank[20-16], ms->pmsa_nat_bits, &old_regs->r20, &old_unat);
	copy_reg(&bank[21-16], ms->pmsa_nat_bits, &old_regs->r21, &old_unat);
	copy_reg(&bank[22-16], ms->pmsa_nat_bits, &old_regs->r22, &old_unat);
	copy_reg(&bank[23-16], ms->pmsa_nat_bits, &old_regs->r23, &old_unat);
	copy_reg(&bank[24-16], ms->pmsa_nat_bits, &old_regs->r24, &old_unat);
	copy_reg(&bank[25-16], ms->pmsa_nat_bits, &old_regs->r25, &old_unat);
	copy_reg(&bank[26-16], ms->pmsa_nat_bits, &old_regs->r26, &old_unat);
	copy_reg(&bank[27-16], ms->pmsa_nat_bits, &old_regs->r27, &old_unat);
	copy_reg(&bank[28-16], ms->pmsa_nat_bits, &old_regs->r28, &old_unat);
	copy_reg(&bank[29-16], ms->pmsa_nat_bits, &old_regs->r29, &old_unat);
	copy_reg(&bank[30-16], ms->pmsa_nat_bits, &old_regs->r30, &old_unat);
	copy_reg(&bank[31-16], ms->pmsa_nat_bits, &old_regs->r31, &old_unat);

	/* Next stack a struct switch_stack.  mca_asm.S built a partial
	 * switch_stack, copy it and fill in the blanks using pt_regs and
	 * minstate.
	 *
	 * In the synthesized switch_stack, b0 points to ia64_leave_kernel,
	 * ar.pfs is set to 0.
	 *
	 * unwind.c::unw_unwind() does special processing for interrupt frames.
	 * It checks if the PRED_NON_SYSCALL predicate is set, if the predicate
	 * is clear then unw_unwind() does _not_ adjust bsp over pt_regs.  Not
	 * that this is documented, of course.  Set PRED_NON_SYSCALL in the
	 * switch_stack on the original stack so it will unwind correctly when
	 * unwind.c reads pt_regs.
	 *
	 * thread.ksp is updated to point to the synthesized switch_stack.
	 */
	p -= sizeof(struct switch_stack);
	old_sw = (struct switch_stack *)p;
	memcpy(old_sw, sw, sizeof(*sw));
	old_sw->caller_unat = old_unat;
	old_sw->ar_fpsr = old_regs->ar_fpsr;
	copy_reg(&ms->pmsa_gr[4-1], ms->pmsa_nat_bits, &old_sw->r4, &old_unat);
	copy_reg(&ms->pmsa_gr[5-1], ms->pmsa_nat_bits, &old_sw->r5, &old_unat);
	copy_reg(&ms->pmsa_gr[6-1], ms->pmsa_nat_bits, &old_sw->r6, &old_unat);
	copy_reg(&ms->pmsa_gr[7-1], ms->pmsa_nat_bits, &old_sw->r7, &old_unat);
	old_sw->b0 = (u64)ia64_leave_kernel;
	old_sw->b1 = ms->pmsa_br1;
	old_sw->ar_pfs = 0;
	old_sw->ar_unat = old_unat;
	old_sw->pr = old_regs->pr | (1UL << PRED_NON_SYSCALL);
	previous_current->thread.ksp = (u64)p - 16;

	/* Finally copy the original stack's registers back to its RBS.
	 * Registers from ar.bspstore through ar.bsp at the time of the event