From: Shanker Donthineni Date: Fri, 19 May 2023 13:49:02 +0000 (-0500) Subject: genirq: Use a maple tree for interrupt descriptor management X-Git-Tag: v6.6.7~2605^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=721255b9826bd11c7a38b585905fc2dd0fb94e52;p=platform%2Fkernel%2Flinux-starfive.git genirq: Use a maple tree for interrupt descriptor management The current implementation uses a static bitmap for interrupt descriptor allocation and a radix tree to pointer store the pointer for lookup. However, the size of the bitmap is constrained by the build time macro MAX_SPARSE_IRQS, which may not be sufficient to support high-end servers, particularly those with GICv4.1 hardware, which require a large interrupt space to cover LPIs and vSGIs. Replace the bitmap and the radix tree with a maple tree, which not only stores pointers for lookup, but also provides a mechanism to find free ranges. That removes the build time hardcoded upper limit. Signed-off-by: Shanker Donthineni Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230519134902.1495562-4-sdonthineni@nvidia.com --- diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index f3f2090..7bdb750 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -12,7 +12,7 @@ #include #ifdef CONFIG_SPARSE_IRQ -# define MAX_SPARSE_IRQS (NR_IRQS + 8196) +# define MAX_SPARSE_IRQS INT_MAX #else # define MAX_SPARSE_IRQS NR_IRQS #endif diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index e0d9dd9..27ca1c8 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -12,8 +12,7 @@ #include #include #include -#include -#include +#include #include #include @@ -131,17 +130,39 @@ int nr_irqs = NR_IRQS; EXPORT_SYMBOL_GPL(nr_irqs); static DEFINE_MUTEX(sparse_irq_lock); -static DECLARE_BITMAP(allocated_irqs, MAX_SPARSE_IRQS); +static struct maple_tree sparse_irqs = MTREE_INIT_EXT(sparse_irqs, + MT_FLAGS_ALLOC_RANGE | + MT_FLAGS_LOCK_EXTERN | + MT_FLAGS_USE_RCU, + sparse_irq_lock); static int irq_find_free_area(unsigned int from, unsigned int cnt) { - return bitmap_find_next_zero_area(allocated_irqs, MAX_SPARSE_IRQS, - from, cnt, 0); + MA_STATE(mas, &sparse_irqs, 0, 0); + + if (mas_empty_area(&mas, from, MAX_SPARSE_IRQS, cnt)) + return -ENOSPC; + return mas.index; } static unsigned int irq_find_at_or_after(unsigned int offset) { - return find_next_bit(allocated_irqs, nr_irqs, offset); + unsigned long index = offset; + struct irq_desc *desc = mt_find(&sparse_irqs, &index, nr_irqs); + + return desc ? irq_desc_get_irq(desc) : nr_irqs; +} + +static void irq_insert_desc(unsigned int irq, struct irq_desc *desc) +{ + MA_STATE(mas, &sparse_irqs, irq, irq); + WARN_ON(mas_store_gfp(&mas, desc, GFP_KERNEL) != 0); +} + +static void delete_irq_desc(unsigned int irq) +{ + MA_STATE(mas, &sparse_irqs, irq, irq); + mas_erase(&mas); } #ifdef CONFIG_SPARSE_IRQ @@ -355,26 +376,14 @@ static void irq_sysfs_del(struct irq_desc *desc) {} #endif /* CONFIG_SYSFS */ -static RADIX_TREE(irq_desc_tree, GFP_KERNEL); - -static void irq_insert_desc(unsigned int irq, struct irq_desc *desc) -{ - radix_tree_insert(&irq_desc_tree, irq, desc); -} - struct irq_desc *irq_to_desc(unsigned int irq) { - return radix_tree_lookup(&irq_desc_tree, irq); + return mtree_load(&sparse_irqs, irq); } #ifdef CONFIG_KVM_BOOK3S_64_HV_MODULE EXPORT_SYMBOL_GPL(irq_to_desc); #endif -static void delete_irq_desc(unsigned int irq) -{ - radix_tree_delete(&irq_desc_tree, irq); -} - #ifdef CONFIG_SMP static void free_masks(struct irq_desc *desc) { @@ -517,7 +526,6 @@ static int alloc_descs(unsigned int start, unsigned int cnt, int node, irq_sysfs_add(start + i, desc); irq_add_debugfs_entry(start + i, desc); } - bitmap_set(allocated_irqs, start, cnt); return start; err: @@ -557,7 +565,6 @@ int __init early_irq_init(void) for (i = 0; i < initcnt; i++) { desc = alloc_desc(i, node, 0, NULL, NULL); - set_bit(i, allocated_irqs); irq_insert_desc(i, desc); } return arch_early_irq_init(); @@ -612,6 +619,7 @@ static void free_desc(unsigned int irq) raw_spin_lock_irqsave(&desc->lock, flags); desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL); raw_spin_unlock_irqrestore(&desc->lock, flags); + delete_irq_desc(irq); } static inline int alloc_descs(unsigned int start, unsigned int cnt, int node, @@ -624,8 +632,8 @@ static inline int alloc_descs(unsigned int start, unsigned int cnt, int node, struct irq_desc *desc = irq_to_desc(start + i); desc->owner = owner; + irq_insert_desc(start + i, desc); } - bitmap_set(allocated_irqs, start, cnt); return start; } @@ -637,7 +645,7 @@ static int irq_expand_nr_irqs(unsigned int nr) void irq_mark_irq(unsigned int irq) { mutex_lock(&sparse_irq_lock); - bitmap_set(allocated_irqs, irq, 1); + irq_insert_desc(irq, irq_desc + irq); mutex_unlock(&sparse_irq_lock); } @@ -781,7 +789,6 @@ void irq_free_descs(unsigned int from, unsigned int cnt) for (i = 0; i < cnt; i++) free_desc(from + i); - bitmap_clear(allocated_irqs, from, cnt); mutex_unlock(&sparse_irq_lock); } EXPORT_SYMBOL_GPL(irq_free_descs); @@ -844,7 +851,7 @@ EXPORT_SYMBOL_GPL(__irq_alloc_descs); * irq_get_next_irq - get next allocated irq number * @offset: where to start the search * - * Returns next irq number at or after offset or nr_irqs if none is found. + * Returns next irq number after offset or nr_irqs if none is found. */ unsigned int irq_get_next_irq(unsigned int offset) {