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-rw-r--r--arch/powerpc/kernel/irq.c394
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diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Derived from arch/i386/kernel/irq.c
+ * Copyright (C) 1992 Linus Torvalds
+ * Adapted from arch/i386 by Gary Thomas
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ * Updated and modified by Cort Dougan <cort@fsmlabs.com>
+ * Copyright (C) 1996-2001 Cort Dougan
+ * Adapted for Power Macintosh by Paul Mackerras
+ * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
+ *
+ * This file contains the code used by various IRQ handling routines:
+ * asking for different IRQ's should be done through these routines
+ * instead of just grabbing them. Thus setups with different IRQ numbers
+ * shouldn't result in any weird surprises, and installing new handlers
+ * should be easier.
+ *
+ * The MPC8xx has an interrupt mask in the SIU. If a bit is set, the
+ * interrupt is _enabled_. As expected, IRQ0 is bit 0 in the 32-bit
+ * mask register (of which only 16 are defined), hence the weird shifting
+ * and complement of the cached_irq_mask. I want to be able to stuff
+ * this right into the SIU SMASK register.
+ * Many of the prep/chrp functions are conditional compiled on CONFIG_PPC_8xx
+ * to reduce code space and undefined function references.
+ */
+
+#undef DEBUG
+
+#include <linux/export.h>
+#include <linux/threads.h>
+#include <linux/kernel_stat.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/timex.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/seq_file.h>
+#include <linux/cpumask.h>
+#include <linux/profile.h>
+#include <linux/bitops.h>
+#include <linux/list.h>
+#include <linux/radix-tree.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/debugfs.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/vmalloc.h>
+#include <linux/pgtable.h>
+#include <linux/static_call.h>
+
+#include <linux/uaccess.h>
+#include <asm/interrupt.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/cache.h>
+#include <asm/ptrace.h>
+#include <asm/machdep.h>
+#include <asm/udbg.h>
+#include <asm/smp.h>
+#include <asm/hw_irq.h>
+#include <asm/softirq_stack.h>
+#include <asm/ppc_asm.h>
+
+#define CREATE_TRACE_POINTS
+#include <asm/trace.h>
+#include <asm/cpu_has_feature.h>
+
+DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+EXPORT_PER_CPU_SYMBOL(irq_stat);
+
+#ifdef CONFIG_PPC32
+atomic_t ppc_n_lost_interrupts;
+
+#ifdef CONFIG_TAU_INT
+extern int tau_initialized;
+u32 tau_interrupts(unsigned long cpu);
+#endif
+#endif /* CONFIG_PPC32 */
+
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+ int j;
+
+#if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
+ if (tau_initialized) {
+ seq_printf(p, "%*s: ", prec, "TAU");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", tau_interrupts(j));
+ seq_puts(p, " PowerPC Thermal Assist (cpu temp)\n");
+ }
+#endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
+
+ seq_printf(p, "%*s: ", prec, "LOC");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_event);
+ seq_printf(p, " Local timer interrupts for timer event device\n");
+
+ seq_printf(p, "%*s: ", prec, "BCT");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).broadcast_irqs_event);
+ seq_printf(p, " Broadcast timer interrupts for timer event device\n");
+
+ seq_printf(p, "%*s: ", prec, "LOC");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_others);
+ seq_printf(p, " Local timer interrupts for others\n");
+
+ seq_printf(p, "%*s: ", prec, "SPU");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
+ seq_printf(p, " Spurious interrupts\n");
+
+ seq_printf(p, "%*s: ", prec, "PMI");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
+ seq_printf(p, " Performance monitoring interrupts\n");
+
+ seq_printf(p, "%*s: ", prec, "MCE");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
+ seq_printf(p, " Machine check exceptions\n");
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
+ seq_printf(p, "%*s: ", prec, "HMI");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", paca_ptrs[j]->hmi_irqs);
+ seq_printf(p, " Hypervisor Maintenance Interrupts\n");
+ }
+#endif
+
+ seq_printf(p, "%*s: ", prec, "NMI");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).sreset_irqs);
+ seq_printf(p, " System Reset interrupts\n");
+
+#ifdef CONFIG_PPC_WATCHDOG
+ seq_printf(p, "%*s: ", prec, "WDG");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).soft_nmi_irqs);
+ seq_printf(p, " Watchdog soft-NMI interrupts\n");
+#endif
+
+#ifdef CONFIG_PPC_DOORBELL
+ if (cpu_has_feature(CPU_FTR_DBELL)) {
+ seq_printf(p, "%*s: ", prec, "DBL");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).doorbell_irqs);
+ seq_printf(p, " Doorbell interrupts\n");
+ }
+#endif
+
+ return 0;
+}
+
+/*
+ * /proc/stat helpers
+ */
+u64 arch_irq_stat_cpu(unsigned int cpu)
+{
+ u64 sum = per_cpu(irq_stat, cpu).timer_irqs_event;
+
+ sum += per_cpu(irq_stat, cpu).broadcast_irqs_event;
+ sum += per_cpu(irq_stat, cpu).pmu_irqs;
+ sum += per_cpu(irq_stat, cpu).mce_exceptions;
+ sum += per_cpu(irq_stat, cpu).spurious_irqs;
+ sum += per_cpu(irq_stat, cpu).timer_irqs_others;
+#ifdef CONFIG_PPC_BOOK3S_64
+ sum += paca_ptrs[cpu]->hmi_irqs;
+#endif
+ sum += per_cpu(irq_stat, cpu).sreset_irqs;
+#ifdef CONFIG_PPC_WATCHDOG
+ sum += per_cpu(irq_stat, cpu).soft_nmi_irqs;
+#endif
+#ifdef CONFIG_PPC_DOORBELL
+ sum += per_cpu(irq_stat, cpu).doorbell_irqs;
+#endif
+
+ return sum;
+}
+
+static inline void check_stack_overflow(unsigned long sp)
+{
+ if (!IS_ENABLED(CONFIG_DEBUG_STACKOVERFLOW))
+ return;
+
+ sp &= THREAD_SIZE - 1;
+
+ /* check for stack overflow: is there less than 1/4th free? */
+ if (unlikely(sp < THREAD_SIZE / 4)) {
+ pr_err("do_IRQ: stack overflow: %ld\n", sp);
+ dump_stack();
+ }
+}
+
+#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
+static __always_inline void call_do_softirq(const void *sp)
+{
+ /* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */
+ asm volatile (
+ PPC_STLU " %%r1, %[offset](%[sp]) ;"
+ "mr %%r1, %[sp] ;"
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ "bl %[callee]@notoc ;"
+#else
+ "bl %[callee] ;"
+#endif
+ PPC_LL " %%r1, 0(%%r1) ;"
+ : // Outputs
+ : // Inputs
+ [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_MIN_SIZE),
+ [callee] "i" (__do_softirq)
+ : // Clobbers
+ "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
+ "cr7", "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
+ "r11", "r12"
+ );
+}
+#endif
+
+DEFINE_STATIC_CALL_RET0(ppc_get_irq, *ppc_md.get_irq);
+
+static void __do_irq(struct pt_regs *regs, unsigned long oldsp)
+{
+ unsigned int irq;
+
+ trace_irq_entry(regs);
+
+ check_stack_overflow(oldsp);
+
+ /*
+ * Query the platform PIC for the interrupt & ack it.
+ *
+ * This will typically lower the interrupt line to the CPU
+ */
+ irq = static_call(ppc_get_irq)();
+
+ /* We can hard enable interrupts now to allow perf interrupts */
+ if (should_hard_irq_enable(regs))
+ do_hard_irq_enable();
+
+ /* And finally process it */
+ if (unlikely(!irq))
+ __this_cpu_inc(irq_stat.spurious_irqs);
+ else
+ generic_handle_irq(irq);
+
+ trace_irq_exit(regs);
+}
+
+static __always_inline void call_do_irq(struct pt_regs *regs, void *sp)
+{
+ register unsigned long r3 asm("r3") = (unsigned long)regs;
+
+ /* Temporarily switch r1 to sp, call __do_irq() then restore r1. */
+ asm volatile (
+ PPC_STLU " %%r1, %[offset](%[sp]) ;"
+ "mr %%r4, %%r1 ;"
+ "mr %%r1, %[sp] ;"
+#ifdef CONFIG_PPC_KERNEL_PCREL
+ "bl %[callee]@notoc ;"
+#else
+ "bl %[callee] ;"
+#endif
+ PPC_LL " %%r1, 0(%%r1) ;"
+ : // Outputs
+ "+r" (r3)
+ : // Inputs
+ [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_MIN_SIZE),
+ [callee] "i" (__do_irq)
+ : // Clobbers
+ "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
+ "cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
+ "r11", "r12"
+ );
+}
+
+void __do_IRQ(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+ void *cursp, *irqsp, *sirqsp;
+
+ /* Switch to the irq stack to handle this */
+ cursp = (void *)(current_stack_pointer & ~(THREAD_SIZE - 1));
+ irqsp = hardirq_ctx[raw_smp_processor_id()];
+ sirqsp = softirq_ctx[raw_smp_processor_id()];
+
+ /* Already there ? If not switch stack and call */
+ if (unlikely(cursp == irqsp || cursp == sirqsp))
+ __do_irq(regs, current_stack_pointer);
+ else
+ call_do_irq(regs, irqsp);
+
+ set_irq_regs(old_regs);
+}
+
+DEFINE_INTERRUPT_HANDLER_ASYNC(do_IRQ)
+{
+ __do_IRQ(regs);
+}
+
+static void *__init alloc_vm_stack(void)
+{
+ return __vmalloc_node(THREAD_SIZE, THREAD_ALIGN, THREADINFO_GFP,
+ NUMA_NO_NODE, (void *)_RET_IP_);
+}
+
+static void __init vmap_irqstack_init(void)
+{
+ int i;
+
+ for_each_possible_cpu(i) {
+ softirq_ctx[i] = alloc_vm_stack();
+ hardirq_ctx[i] = alloc_vm_stack();
+ }
+}
+
+
+void __init init_IRQ(void)
+{
+ if (IS_ENABLED(CONFIG_VMAP_STACK))
+ vmap_irqstack_init();
+
+ if (ppc_md.init_IRQ)
+ ppc_md.init_IRQ();
+
+ if (!WARN_ON(!ppc_md.get_irq))
+ static_call_update(ppc_get_irq, ppc_md.get_irq);
+}
+
+#ifdef CONFIG_BOOKE_OR_40x
+void *critirq_ctx[NR_CPUS] __read_mostly;
+void *dbgirq_ctx[NR_CPUS] __read_mostly;
+void *mcheckirq_ctx[NR_CPUS] __read_mostly;
+#endif
+
+void *softirq_ctx[NR_CPUS] __read_mostly;
+void *hardirq_ctx[NR_CPUS] __read_mostly;
+
+#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
+void do_softirq_own_stack(void)
+{
+ call_do_softirq(softirq_ctx[smp_processor_id()]);
+}
+#endif
+
+irq_hw_number_t virq_to_hw(unsigned int virq)
+{
+ struct irq_data *irq_data = irq_get_irq_data(virq);
+ return WARN_ON(!irq_data) ? 0 : irq_data->hwirq;
+}
+EXPORT_SYMBOL_GPL(virq_to_hw);
+
+#ifdef CONFIG_SMP
+int irq_choose_cpu(const struct cpumask *mask)
+{
+ int cpuid;
+
+ if (cpumask_equal(mask, cpu_online_mask)) {
+ static int irq_rover;
+ static DEFINE_RAW_SPINLOCK(irq_rover_lock);
+ unsigned long flags;
+
+ /* Round-robin distribution... */
+do_round_robin:
+ raw_spin_lock_irqsave(&irq_rover_lock, flags);
+
+ irq_rover = cpumask_next(irq_rover, cpu_online_mask);
+ if (irq_rover >= nr_cpu_ids)
+ irq_rover = cpumask_first(cpu_online_mask);
+
+ cpuid = irq_rover;
+
+ raw_spin_unlock_irqrestore(&irq_rover_lock, flags);
+ } else {
+ cpuid = cpumask_first_and(mask, cpu_online_mask);
+ if (cpuid >= nr_cpu_ids)
+ goto do_round_robin;
+ }
+
+ return get_hard_smp_processor_id(cpuid);
+}
+#else
+int irq_choose_cpu(const struct cpumask *mask)
+{
+ return hard_smp_processor_id();
+}
+#endif