Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 513 insertions, 0 deletions

diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c
new file mode 100644
index 000000000..8e586858b
--- /dev/null
+++ b/kernel/irq/matrix.c
@@ -0,0 +1,513 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2017 Thomas Gleixner <tglx@linutronix.de>
+
+#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))
+
+struct cpumap {
+	unsigned int		available;
+	unsigned int		allocated;
+	unsigned int		managed;
+	unsigned int		managed_allocated;
+	bool			initialized;
+	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];
+};
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/irq_matrix.h>
+
+/**
+ * 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);
+
+	if (!cm->initialized) {
+		cm->available = m->alloc_size;
+		cm->available -= cm->managed + m->systembits_inalloc;
+		cm->initialized = true;
+	}
+	m->global_available += cm->available;
+	cm->online = true;
+	m->online_maps++;
+	trace_irq_matrix_online(m);
+}
+
+/**
+ * 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--;
+	trace_irq_matrix_offline(m);
+}
+
+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;
+}
+
+/* Find the best CPU which has the lowest vector allocation count */
+static unsigned int matrix_find_best_cpu(struct irq_matrix *m,
+					const struct cpumask *msk)
+{
+	unsigned int cpu, best_cpu, maxavl = 0;
+	struct cpumap *cm;
+
+	best_cpu = UINT_MAX;
+
+	for_each_cpu(cpu, msk) {
+		cm = per_cpu_ptr(m->maps, cpu);
+
+		if (!cm->online || cm->available <= maxavl)
+			continue;
+
+		best_cpu = cpu;
+		maxavl = cm->available;
+	}
+	return best_cpu;
+}
+
+/* Find the best CPU which has the lowest number of managed IRQs allocated */
+static unsigned int matrix_find_best_cpu_managed(struct irq_matrix *m,
+						const struct cpumask *msk)
+{
+	unsigned int cpu, best_cpu, allocated = UINT_MAX;
+	struct cpumap *cm;
+
+	best_cpu = UINT_MAX;
+
+	for_each_cpu(cpu, msk) {
+		cm = per_cpu_ptr(m->maps, cpu);
+
+		if (!cm->online || cm->managed_allocated > allocated)
+			continue;
+
+		best_cpu = cpu;
+		allocated = cm->managed_allocated;
+	}
+	return best_cpu;
+}
+
+/**
+ * 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++;
+
+	trace_irq_matrix_assign_system(bit, m);
+}
+
+/**
+ * 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--;
+		}
+		trace_irq_matrix_reserve_managed(bit, cpu, m, cm);
+	}
+	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++;
+		}
+		trace_irq_matrix_remove_managed(bit, cpu, m, cm);
+	}
+}
+
+/**
+ * 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, const struct cpumask *msk,
+			     unsigned int *mapped_cpu)
+{
+	unsigned int bit, cpu, end = m->alloc_end;
+	struct cpumap *cm;
+
+	if (cpumask_empty(msk))
+		return -EINVAL;
+
+	cpu = matrix_find_best_cpu_managed(m, msk);
+	if (cpu == UINT_MAX)
+		return -ENOSPC;
+
+	cm = per_cpu_ptr(m->maps, cpu);
+	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++;
+	cm->managed_allocated++;
+	m->total_allocated++;
+	*mapped_cpu = cpu;
+	trace_irq_matrix_alloc_managed(bit, cpu, m, cm);
+	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--;
+	trace_irq_matrix_assign(bit, smp_processor_id(), m, cm);
+}
+
+/**
+ * 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++;
+	trace_irq_matrix_reserve(m);
+}
+
+/**
+ * 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--;
+	trace_irq_matrix_remove_reserved(m);
+}
+
+/**
+ * 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, bit;
+	struct cpumap *cm;
+
+	/*
+	 * Not required in theory, but matrix_find_best_cpu() uses
+	 * for_each_cpu() which ignores the cpumask on UP .
+	 */
+	if (cpumask_empty(msk))
+		return -EINVAL;
+
+	cpu = matrix_find_best_cpu(m, msk);
+	if (cpu == UINT_MAX)
+		return -ENOSPC;
+
+	cm = per_cpu_ptr(m->maps, cpu);
+	bit = matrix_alloc_area(m, cm, 1, false);
+	if (bit >= m->alloc_end)
+		return -ENOSPC;
+	cm->allocated++;
+	cm->available--;
+	m->total_allocated++;
+	m->global_available--;
+	if (reserved)
+		m->global_reserved--;
+	*mapped_cpu = cpu;
+	trace_irq_matrix_alloc(bit, cpu, m, cm);
+	return bit;
+
+}
+
+/**
+ * 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 (WARN_ON_ONCE(!test_and_clear_bit(bit, cm->alloc_map)))
+		return;
+
+	cm->allocated--;
+	if(managed)
+		cm->managed_allocated--;
+
+	if (cm->online)
+		m->total_allocated--;
+
+	if (!managed) {
+		cm->available++;
+		if (cm->online)
+			m->global_available++;
+	}
+	trace_irq_matrix_free(bit, cpu, m, cm);
+}
+
+/**
+ * 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);
+
+	if (!cpudown)
+		return m->global_available;
+	return m->global_available - cm->available;
+}
+
+/**
+ * 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 | mac | 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 %4u  %*pbl\n", ind, " ",
+			   cpu, cm->available, cm->managed,
+			   cm->managed_allocated, cm->allocated,
+			   m->matrix_bits, cm->alloc_map);
+	}
+	cpus_read_unlock();
+}
+#endif