--- /dev/null
+/*
+ * Copyright (C) 2017 Thomas Gleixner <tglx@linutronix.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+#include <linux/spinlock.h>
+#include <linux/seq_file.h>
+#include <linux/bitmap.h>
+#include <linux/percpu.h>
+#include <linux/cpu.h>
+#include <linux/irq.h>
+
+#define IRQ_MATRIX_SIZE (BITS_TO_LONGS(IRQ_MATRIX_BITS) * sizeof(unsigned long))
+
+struct cpumap {
+ unsigned int available;
+ unsigned int allocated;
+ unsigned int managed;
+ bool online;
+ unsigned long alloc_map[IRQ_MATRIX_SIZE];
+ unsigned long managed_map[IRQ_MATRIX_SIZE];
+};
+
+struct irq_matrix {
+ unsigned int matrix_bits;
+ unsigned int alloc_start;
+ unsigned int alloc_end;
+ unsigned int alloc_size;
+ unsigned int global_available;
+ unsigned int global_reserved;
+ unsigned int systembits_inalloc;
+ unsigned int total_allocated;
+ unsigned int online_maps;
+ struct cpumap __percpu *maps;
+ unsigned long scratch_map[IRQ_MATRIX_SIZE];
+ unsigned long system_map[IRQ_MATRIX_SIZE];
+};
+
+/**
+ * irq_alloc_matrix - Allocate a irq_matrix structure and initialize it
+ * @matrix_bits: Number of matrix bits must be <= IRQ_MATRIX_BITS
+ * @alloc_start: From which bit the allocation search starts
+ * @alloc_end: At which bit the allocation search ends, i.e first
+ * invalid bit
+ */
+__init struct irq_matrix *irq_alloc_matrix(unsigned int matrix_bits,
+ unsigned int alloc_start,
+ unsigned int alloc_end)
+{
+ struct irq_matrix *m;
+
+ if (matrix_bits > IRQ_MATRIX_BITS)
+ return NULL;
+
+ m = kzalloc(sizeof(*m), GFP_KERNEL);
+ if (!m)
+ return NULL;
+
+ m->matrix_bits = matrix_bits;
+ m->alloc_start = alloc_start;
+ m->alloc_end = alloc_end;
+ m->alloc_size = alloc_end - alloc_start;
+ m->maps = alloc_percpu(*m->maps);
+ if (!m->maps) {
+ kfree(m);
+ return NULL;
+ }
+ return m;
+}
+
+/**
+ * irq_matrix_online - Bring the local CPU matrix online
+ * @m: Matrix pointer
+ */
+void irq_matrix_online(struct irq_matrix *m)
+{
+ struct cpumap *cm = this_cpu_ptr(m->maps);
+
+ BUG_ON(cm->online);
+
+ bitmap_zero(cm->alloc_map, m->matrix_bits);
+ cm->available = m->alloc_size - (cm->managed + m->systembits_inalloc);
+ cm->allocated = 0;
+ m->global_available += cm->available;
+ cm->online = true;
+ m->online_maps++;
+}
+
+/**
+ * irq_matrix_offline - Bring the local CPU matrix offline
+ * @m: Matrix pointer
+ */
+void irq_matrix_offline(struct irq_matrix *m)
+{
+ struct cpumap *cm = this_cpu_ptr(m->maps);
+
+ /* Update the global available size */
+ m->global_available -= cm->available;
+ cm->online = false;
+ m->online_maps--;
+}
+
+static unsigned int matrix_alloc_area(struct irq_matrix *m, struct cpumap *cm,
+ unsigned int num, bool managed)
+{
+ unsigned int area, start = m->alloc_start;
+ unsigned int end = m->alloc_end;
+
+ bitmap_or(m->scratch_map, cm->managed_map, m->system_map, end);
+ bitmap_or(m->scratch_map, m->scratch_map, cm->alloc_map, end);
+ area = bitmap_find_next_zero_area(m->scratch_map, end, start, num, 0);
+ if (area >= end)
+ return area;
+ if (managed)
+ bitmap_set(cm->managed_map, area, num);
+ else
+ bitmap_set(cm->alloc_map, area, num);
+ return area;
+}
+
+/**
+ * irq_matrix_assign_system - Assign system wide entry in the matrix
+ * @m: Matrix pointer
+ * @bit: Which bit to reserve
+ * @replace: Replace an already allocated vector with a system
+ * vector at the same bit position.
+ *
+ * The BUG_ON()s below are on purpose. If this goes wrong in the
+ * early boot process, then the chance to survive is about zero.
+ * If this happens when the system is life, it's not much better.
+ */
+void irq_matrix_assign_system(struct irq_matrix *m, unsigned int bit,
+ bool replace)
+{
+ struct cpumap *cm = this_cpu_ptr(m->maps);
+
+ BUG_ON(bit > m->matrix_bits);
+ BUG_ON(m->online_maps > 1 || (m->online_maps && !replace));
+
+ set_bit(bit, m->system_map);
+ if (replace) {
+ BUG_ON(!test_and_clear_bit(bit, cm->alloc_map));
+ cm->allocated--;
+ m->total_allocated--;
+ }
+ if (bit >= m->alloc_start && bit < m->alloc_end)
+ m->systembits_inalloc++;
+}
+
+/**
+ * irq_matrix_reserve_managed - Reserve a managed interrupt in a CPU map
+ * @m: Matrix pointer
+ * @msk: On which CPUs the bits should be reserved.
+ *
+ * Can be called for offline CPUs. Note, this will only reserve one bit
+ * on all CPUs in @msk, but it's not guaranteed that the bits are at the
+ * same offset on all CPUs
+ */
+int irq_matrix_reserve_managed(struct irq_matrix *m, const struct cpumask *msk)
+{
+ unsigned int cpu, failed_cpu;
+
+ for_each_cpu(cpu, msk) {
+ struct cpumap *cm = per_cpu_ptr(m->maps, cpu);
+ unsigned int bit;
+
+ bit = matrix_alloc_area(m, cm, 1, true);
+ if (bit >= m->alloc_end)
+ goto cleanup;
+ cm->managed++;
+ if (cm->online) {
+ cm->available--;
+ m->global_available--;
+ }
+ }
+ return 0;
+cleanup:
+ failed_cpu = cpu;
+ for_each_cpu(cpu, msk) {
+ if (cpu == failed_cpu)
+ break;
+ irq_matrix_remove_managed(m, cpumask_of(cpu));
+ }
+ return -ENOSPC;
+}
+
+/**
+ * irq_matrix_remove_managed - Remove managed interrupts in a CPU map
+ * @m: Matrix pointer
+ * @msk: On which CPUs the bits should be removed
+ *
+ * Can be called for offline CPUs
+ *
+ * This removes not allocated managed interrupts from the map. It does
+ * not matter which one because the managed interrupts free their
+ * allocation when they shut down. If not, the accounting is screwed,
+ * but all what can be done at this point is warn about it.
+ */
+void irq_matrix_remove_managed(struct irq_matrix *m, const struct cpumask *msk)
+{
+ unsigned int cpu;
+
+ for_each_cpu(cpu, msk) {
+ struct cpumap *cm = per_cpu_ptr(m->maps, cpu);
+ unsigned int bit, end = m->alloc_end;
+
+ if (WARN_ON_ONCE(!cm->managed))
+ continue;
+
+ /* Get managed bit which are not allocated */
+ bitmap_andnot(m->scratch_map, cm->managed_map, cm->alloc_map, end);
+
+ bit = find_first_bit(m->scratch_map, end);
+ if (WARN_ON_ONCE(bit >= end))
+ continue;
+
+ clear_bit(bit, cm->managed_map);
+
+ cm->managed--;
+ if (cm->online) {
+ cm->available++;
+ m->global_available++;
+ }
+ }
+}
+
+/**
+ * irq_matrix_alloc_managed - Allocate a managed interrupt in a CPU map
+ * @m: Matrix pointer
+ * @cpu: On which CPU the interrupt should be allocated
+ */
+int irq_matrix_alloc_managed(struct irq_matrix *m, unsigned int cpu)
+{
+ struct cpumap *cm = per_cpu_ptr(m->maps, cpu);
+ unsigned int bit, end = m->alloc_end;
+
+ /* Get managed bit which are not allocated */
+ bitmap_andnot(m->scratch_map, cm->managed_map, cm->alloc_map, end);
+ bit = find_first_bit(m->scratch_map, end);
+ if (bit >= end)
+ return -ENOSPC;
+ set_bit(bit, cm->alloc_map);
+ cm->allocated++;
+ m->total_allocated++;
+ return bit;
+}
+
+/**
+ * irq_matrix_assign - Assign a preallocated interrupt in the local CPU map
+ * @m: Matrix pointer
+ * @bit: Which bit to mark
+ *
+ * This should only be used to mark preallocated vectors
+ */
+void irq_matrix_assign(struct irq_matrix *m, unsigned int bit)
+{
+ struct cpumap *cm = this_cpu_ptr(m->maps);
+
+ if (WARN_ON_ONCE(bit < m->alloc_start || bit >= m->alloc_end))
+ return;
+ if (WARN_ON_ONCE(test_and_set_bit(bit, cm->alloc_map)))
+ return;
+ cm->allocated++;
+ m->total_allocated++;
+ cm->available--;
+ m->global_available--;
+}
+
+/**
+ * irq_matrix_reserve - Reserve interrupts
+ * @m: Matrix pointer
+ *
+ * This is merily a book keeping call. It increments the number of globally
+ * reserved interrupt bits w/o actually allocating them. This allows to
+ * setup interrupt descriptors w/o assigning low level resources to it.
+ * The actual allocation happens when the interrupt gets activated.
+ */
+void irq_matrix_reserve(struct irq_matrix *m)
+{
+ if (m->global_reserved <= m->global_available &&
+ m->global_reserved + 1 > m->global_available)
+ pr_warn("Interrupt reservation exceeds available resources\n");
+
+ m->global_reserved++;
+}
+
+/**
+ * irq_matrix_remove_reserved - Remove interrupt reservation
+ * @m: Matrix pointer
+ *
+ * This is merily a book keeping call. It decrements the number of globally
+ * reserved interrupt bits. This is used to undo irq_matrix_reserve() when the
+ * interrupt was never in use and a real vector allocated, which undid the
+ * reservation.
+ */
+void irq_matrix_remove_reserved(struct irq_matrix *m)
+{
+ m->global_reserved--;
+}
+
+/**
+ * irq_matrix_alloc - Allocate a regular interrupt in a CPU map
+ * @m: Matrix pointer
+ * @msk: Which CPUs to search in
+ * @reserved: Allocate previously reserved interrupts
+ * @mapped_cpu: Pointer to store the CPU for which the irq was allocated
+ */
+int irq_matrix_alloc(struct irq_matrix *m, const struct cpumask *msk,
+ bool reserved, unsigned int *mapped_cpu)
+{
+ unsigned int cpu;
+
+ for_each_cpu(cpu, msk) {
+ struct cpumap *cm = per_cpu_ptr(m->maps, cpu);
+ unsigned int bit;
+
+ if (!cm->online)
+ continue;
+
+ bit = matrix_alloc_area(m, cm, 1, false);
+ if (bit < m->alloc_end) {
+ cm->allocated++;
+ cm->available--;
+ m->total_allocated++;
+ m->global_available--;
+ if (reserved)
+ m->global_reserved--;
+ *mapped_cpu = cpu;
+ return bit;
+ }
+ }
+ return -ENOSPC;
+}
+
+/**
+ * irq_matrix_free - Free allocated interrupt in the matrix
+ * @m: Matrix pointer
+ * @cpu: Which CPU map needs be updated
+ * @bit: The bit to remove
+ * @managed: If true, the interrupt is managed and not accounted
+ * as available.
+ */
+void irq_matrix_free(struct irq_matrix *m, unsigned int cpu,
+ unsigned int bit, bool managed)
+{
+ struct cpumap *cm = per_cpu_ptr(m->maps, cpu);
+
+ if (WARN_ON_ONCE(bit < m->alloc_start || bit >= m->alloc_end))
+ return;
+
+ if (cm->online) {
+ clear_bit(bit, cm->alloc_map);
+ cm->allocated--;
+ m->total_allocated--;
+ if (!managed) {
+ cm->available++;
+ m->global_available++;
+ }
+ }
+}
+
+/**
+ * irq_matrix_available - Get the number of globally available irqs
+ * @m: Pointer to the matrix to query
+ * @cpudown: If true, the local CPU is about to go down, adjust
+ * the number of available irqs accordingly
+ */
+unsigned int irq_matrix_available(struct irq_matrix *m, bool cpudown)
+{
+ struct cpumap *cm = this_cpu_ptr(m->maps);
+
+ return m->global_available - cpudown ? cm->available : 0;
+}
+
+/**
+ * irq_matrix_reserved - Get the number of globally reserved irqs
+ * @m: Pointer to the matrix to query
+ */
+unsigned int irq_matrix_reserved(struct irq_matrix *m)
+{
+ return m->global_reserved;
+}
+
+/**
+ * irq_matrix_allocated - Get the number of allocated irqs on the local cpu
+ * @m: Pointer to the matrix to search
+ *
+ * This returns number of allocated irqs
+ */
+unsigned int irq_matrix_allocated(struct irq_matrix *m)
+{
+ struct cpumap *cm = this_cpu_ptr(m->maps);
+
+ return cm->allocated;
+}
+
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+/**
+ * irq_matrix_debug_show - Show detailed allocation information
+ * @sf: Pointer to the seq_file to print to
+ * @m: Pointer to the matrix allocator
+ * @ind: Indentation for the print format
+ *
+ * Note, this is a lockless snapshot.
+ */
+void irq_matrix_debug_show(struct seq_file *sf, struct irq_matrix *m, int ind)
+{
+ unsigned int nsys = bitmap_weight(m->system_map, m->matrix_bits);
+ int cpu;
+
+ seq_printf(sf, "Online bitmaps: %6u\n", m->online_maps);
+ seq_printf(sf, "Global available: %6u\n", m->global_available);
+ seq_printf(sf, "Global reserved: %6u\n", m->global_reserved);
+ seq_printf(sf, "Total allocated: %6u\n", m->total_allocated);
+ seq_printf(sf, "System: %u: %*pbl\n", nsys, m->matrix_bits,
+ m->system_map);
+ seq_printf(sf, "%*s| CPU | avl | man | act | vectors\n", ind, " ");
+ cpus_read_lock();
+ for_each_online_cpu(cpu) {
+ struct cpumap *cm = per_cpu_ptr(m->maps, cpu);
+
+ seq_printf(sf, "%*s %4d %4u %4u %4u %*pbl\n", ind, " ",
+ cpu, cm->available, cm->managed, cm->allocated,
+ m->matrix_bits, cm->alloc_map);
+ }
+ cpus_read_unlock();
+}
+#endif
projects / platform / kernel / linux-rpi.git / commitdiff