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genirq/matrix: Dynamic bitmap allocation 

A future user of the matrix allocator, does not know the size of the matrix
bitmaps at compile time.

To avoid wasting memory on unnecessary large bitmaps, size the bitmap at
matrix allocation time.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240222094006.1030709-11-apatel@ventanamicro.com
This commit is contained in:
Björn Töpel 2024-02-22 15:09:58 +05:30 committed by Thomas Gleixner
parent 3c46fc5b55
commit 5b98d210ac
2 changed files with 17 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/include/asm/hw_irq.h
View File

@ -16,8 +16,6 @@
#include <asm/irq_vectors.h>
#define IRQ_MATRIX_BITS NR_VECTORS
#ifndef __ASSEMBLY__
#include <linux/percpu.h>

28
kernel/irq/matrix.c
View File

@ -8,8 +8,6 @@
#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;
@ -17,8 +15,8 @@ struct cpumap {
unsigned int managed_allocated;
bool initialized;
bool online;
unsigned long alloc_map[IRQ_MATRIX_SIZE];
unsigned long managed_map[IRQ_MATRIX_SIZE];
unsigned long *managed_map;
unsigned long alloc_map[];
};
struct irq_matrix {
@ -32,8 +30,8 @@ struct irq_matrix {
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];
unsigned long *system_map;
unsigned long scratch_map[];
};
#define CREATE_TRACE_POINTS
@ -50,24 +48,32 @@ __init struct irq_matrix *irq_alloc_matrix(unsigned int matrix_bits,
unsigned int alloc_start,
unsigned int alloc_end)
{
unsigned int cpu, matrix_size = BITS_TO_LONGS(matrix_bits);
struct irq_matrix *m;
if (matrix_bits > IRQ_MATRIX_BITS)
return NULL;
m = kzalloc(sizeof(*m), GFP_KERNEL);
m = kzalloc(struct_size(m, scratch_map, matrix_size * 2), GFP_KERNEL);
if (!m)
return NULL;
m->system_map = &m->scratch_map[matrix_size];
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);
m->maps = __alloc_percpu(struct_size(m->maps, alloc_map, matrix_size * 2),
__alignof__(*m->maps));
if (!m->maps) {
kfree(m);
return NULL;
}
for_each_possible_cpu(cpu) {
struct cpumap *cm = per_cpu_ptr(m->maps, cpu);
cm->managed_map = &cm->alloc_map[matrix_size];
}
return m;
}