mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
130 lines
3.2 KiB
130 lines
3.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* mm/percpu-km.c - kernel memory based chunk allocation |
|
* |
|
* Copyright (C) 2010 SUSE Linux Products GmbH |
|
* Copyright (C) 2010 Tejun Heo <[email protected]> |
|
* |
|
* Chunks are allocated as a contiguous kernel memory using gfp |
|
* allocation. This is to be used on nommu architectures. |
|
* |
|
* To use percpu-km, |
|
* |
|
* - define CONFIG_NEED_PER_CPU_KM from the arch Kconfig. |
|
* |
|
* - CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK must not be defined. It's |
|
* not compatible with PER_CPU_KM. EMBED_FIRST_CHUNK should work |
|
* fine. |
|
* |
|
* - NUMA is not supported. When setting up the first chunk, |
|
* @cpu_distance_fn should be NULL or report all CPUs to be nearer |
|
* than or at LOCAL_DISTANCE. |
|
* |
|
* - It's best if the chunk size is power of two multiple of |
|
* PAGE_SIZE. Because each chunk is allocated as a contiguous |
|
* kernel memory block using alloc_pages(), memory will be wasted if |
|
* chunk size is not aligned. percpu-km code will whine about it. |
|
*/ |
|
|
|
#if defined(CONFIG_SMP) && defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) |
|
#error "contiguous percpu allocation is incompatible with paged first chunk" |
|
#endif |
|
|
|
#include <linux/log2.h> |
|
|
|
static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk, |
|
int page_start, int page_end) |
|
{ |
|
/* nothing */ |
|
} |
|
|
|
static int pcpu_populate_chunk(struct pcpu_chunk *chunk, |
|
int page_start, int page_end, gfp_t gfp) |
|
{ |
|
return 0; |
|
} |
|
|
|
static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, |
|
int page_start, int page_end) |
|
{ |
|
/* nada */ |
|
} |
|
|
|
static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp) |
|
{ |
|
const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT; |
|
struct pcpu_chunk *chunk; |
|
struct page *pages; |
|
unsigned long flags; |
|
int i; |
|
|
|
chunk = pcpu_alloc_chunk(gfp); |
|
if (!chunk) |
|
return NULL; |
|
|
|
pages = alloc_pages(gfp, order_base_2(nr_pages)); |
|
if (!pages) { |
|
pcpu_free_chunk(chunk); |
|
return NULL; |
|
} |
|
|
|
for (i = 0; i < nr_pages; i++) |
|
pcpu_set_page_chunk(nth_page(pages, i), chunk); |
|
|
|
chunk->data = pages; |
|
chunk->base_addr = page_address(pages); |
|
|
|
spin_lock_irqsave(&pcpu_lock, flags); |
|
pcpu_chunk_populated(chunk, 0, nr_pages); |
|
spin_unlock_irqrestore(&pcpu_lock, flags); |
|
|
|
pcpu_stats_chunk_alloc(); |
|
trace_percpu_create_chunk(chunk->base_addr); |
|
|
|
return chunk; |
|
} |
|
|
|
static void pcpu_destroy_chunk(struct pcpu_chunk *chunk) |
|
{ |
|
const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT; |
|
|
|
if (!chunk) |
|
return; |
|
|
|
pcpu_stats_chunk_dealloc(); |
|
trace_percpu_destroy_chunk(chunk->base_addr); |
|
|
|
if (chunk->data) |
|
__free_pages(chunk->data, order_base_2(nr_pages)); |
|
pcpu_free_chunk(chunk); |
|
} |
|
|
|
static struct page *pcpu_addr_to_page(void *addr) |
|
{ |
|
return virt_to_page(addr); |
|
} |
|
|
|
static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai) |
|
{ |
|
size_t nr_pages, alloc_pages; |
|
|
|
/* all units must be in a single group */ |
|
if (ai->nr_groups != 1) { |
|
pr_crit("can't handle more than one group\n"); |
|
return -EINVAL; |
|
} |
|
|
|
nr_pages = (ai->groups[0].nr_units * ai->unit_size) >> PAGE_SHIFT; |
|
alloc_pages = roundup_pow_of_two(nr_pages); |
|
|
|
if (alloc_pages > nr_pages) |
|
pr_warn("wasting %zu pages per chunk\n", |
|
alloc_pages - nr_pages); |
|
|
|
return 0; |
|
} |
|
|
|
static bool pcpu_should_reclaim_chunk(struct pcpu_chunk *chunk) |
|
{ |
|
return false; |
|
}
|
|
|