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78fa51503f
size_t in cma_alloc is confusing since it makes people think it's byte
count, not pages. Change it to unsigned long[1].
The unsigned int in cma_release is also not right so change it. Since we
have unsigned long in cma_release, free_contig_range should also respect
it.
[1] 67a2e213e7
, mm: cma: fix incorrect type conversion for size during dma allocation
Link: https://lore.kernel.org/linux-mm/20210324043434.GP1719932@casper.infradead.org/
Link: https://lkml.kernel.org/r/20210331164018.710560-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
574 lines
15 KiB
C
574 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Contiguous Memory Allocator
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*
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* Copyright (c) 2010-2011 by Samsung Electronics.
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* Copyright IBM Corporation, 2013
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* Copyright LG Electronics Inc., 2014
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* Written by:
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* Marek Szyprowski <m.szyprowski@samsung.com>
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* Michal Nazarewicz <mina86@mina86.com>
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* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
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* Joonsoo Kim <iamjoonsoo.kim@lge.com>
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*/
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#define pr_fmt(fmt) "cma: " fmt
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#ifdef CONFIG_CMA_DEBUG
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#ifndef DEBUG
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# define DEBUG
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#endif
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#endif
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#define CREATE_TRACE_POINTS
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#include <linux/memblock.h>
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#include <linux/err.h>
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#include <linux/mm.h>
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#include <linux/sizes.h>
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#include <linux/slab.h>
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#include <linux/log2.h>
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#include <linux/cma.h>
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#include <linux/highmem.h>
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#include <linux/io.h>
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#include <linux/kmemleak.h>
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#include <trace/events/cma.h>
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#include "cma.h"
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struct cma cma_areas[MAX_CMA_AREAS];
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unsigned cma_area_count;
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phys_addr_t cma_get_base(const struct cma *cma)
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{
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return PFN_PHYS(cma->base_pfn);
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}
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unsigned long cma_get_size(const struct cma *cma)
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{
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return cma->count << PAGE_SHIFT;
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}
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const char *cma_get_name(const struct cma *cma)
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{
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return cma->name;
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}
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static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
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unsigned int align_order)
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{
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if (align_order <= cma->order_per_bit)
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return 0;
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return (1UL << (align_order - cma->order_per_bit)) - 1;
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}
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/*
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* Find the offset of the base PFN from the specified align_order.
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* The value returned is represented in order_per_bits.
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*/
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static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
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unsigned int align_order)
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{
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return (cma->base_pfn & ((1UL << align_order) - 1))
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>> cma->order_per_bit;
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}
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static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
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unsigned long pages)
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{
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return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
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}
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static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
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unsigned long count)
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{
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unsigned long bitmap_no, bitmap_count;
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unsigned long flags;
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bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
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bitmap_count = cma_bitmap_pages_to_bits(cma, count);
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spin_lock_irqsave(&cma->lock, flags);
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bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
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spin_unlock_irqrestore(&cma->lock, flags);
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}
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static void __init cma_activate_area(struct cma *cma)
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{
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unsigned long base_pfn = cma->base_pfn, pfn;
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struct zone *zone;
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cma->bitmap = bitmap_zalloc(cma_bitmap_maxno(cma), GFP_KERNEL);
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if (!cma->bitmap)
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goto out_error;
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/*
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* alloc_contig_range() requires the pfn range specified to be in the
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* same zone. Simplify by forcing the entire CMA resv range to be in the
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* same zone.
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*/
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WARN_ON_ONCE(!pfn_valid(base_pfn));
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zone = page_zone(pfn_to_page(base_pfn));
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for (pfn = base_pfn + 1; pfn < base_pfn + cma->count; pfn++) {
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WARN_ON_ONCE(!pfn_valid(pfn));
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if (page_zone(pfn_to_page(pfn)) != zone)
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goto not_in_zone;
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}
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for (pfn = base_pfn; pfn < base_pfn + cma->count;
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pfn += pageblock_nr_pages)
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init_cma_reserved_pageblock(pfn_to_page(pfn));
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spin_lock_init(&cma->lock);
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#ifdef CONFIG_CMA_DEBUGFS
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INIT_HLIST_HEAD(&cma->mem_head);
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spin_lock_init(&cma->mem_head_lock);
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#endif
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return;
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not_in_zone:
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bitmap_free(cma->bitmap);
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out_error:
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/* Expose all pages to the buddy, they are useless for CMA. */
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for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++)
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free_reserved_page(pfn_to_page(pfn));
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totalcma_pages -= cma->count;
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cma->count = 0;
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pr_err("CMA area %s could not be activated\n", cma->name);
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return;
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}
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static int __init cma_init_reserved_areas(void)
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{
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int i;
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for (i = 0; i < cma_area_count; i++)
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cma_activate_area(&cma_areas[i]);
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return 0;
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}
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core_initcall(cma_init_reserved_areas);
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/**
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* cma_init_reserved_mem() - create custom contiguous area from reserved memory
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* @base: Base address of the reserved area
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* @size: Size of the reserved area (in bytes),
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* @order_per_bit: Order of pages represented by one bit on bitmap.
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* @name: The name of the area. If this parameter is NULL, the name of
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* the area will be set to "cmaN", where N is a running counter of
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* used areas.
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* @res_cma: Pointer to store the created cma region.
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*
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* This function creates custom contiguous area from already reserved memory.
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*/
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int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
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unsigned int order_per_bit,
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const char *name,
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struct cma **res_cma)
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{
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struct cma *cma;
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phys_addr_t alignment;
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/* Sanity checks */
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if (cma_area_count == ARRAY_SIZE(cma_areas)) {
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pr_err("Not enough slots for CMA reserved regions!\n");
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return -ENOSPC;
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}
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if (!size || !memblock_is_region_reserved(base, size))
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return -EINVAL;
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/* ensure minimal alignment required by mm core */
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alignment = PAGE_SIZE <<
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max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
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/* alignment should be aligned with order_per_bit */
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if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit))
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return -EINVAL;
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if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size)
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return -EINVAL;
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/*
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* Each reserved area must be initialised later, when more kernel
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* subsystems (like slab allocator) are available.
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*/
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cma = &cma_areas[cma_area_count];
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if (name)
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snprintf(cma->name, CMA_MAX_NAME, name);
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else
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snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", cma_area_count);
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cma->base_pfn = PFN_DOWN(base);
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cma->count = size >> PAGE_SHIFT;
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cma->order_per_bit = order_per_bit;
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*res_cma = cma;
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cma_area_count++;
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totalcma_pages += (size / PAGE_SIZE);
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return 0;
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}
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/**
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* cma_declare_contiguous_nid() - reserve custom contiguous area
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* @base: Base address of the reserved area optional, use 0 for any
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* @size: Size of the reserved area (in bytes),
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* @limit: End address of the reserved memory (optional, 0 for any).
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* @alignment: Alignment for the CMA area, should be power of 2 or zero
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* @order_per_bit: Order of pages represented by one bit on bitmap.
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* @fixed: hint about where to place the reserved area
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* @name: The name of the area. See function cma_init_reserved_mem()
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* @res_cma: Pointer to store the created cma region.
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* @nid: nid of the free area to find, %NUMA_NO_NODE for any node
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*
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* This function reserves memory from early allocator. It should be
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* called by arch specific code once the early allocator (memblock or bootmem)
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* has been activated and all other subsystems have already allocated/reserved
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* memory. This function allows to create custom reserved areas.
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*
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* If @fixed is true, reserve contiguous area at exactly @base. If false,
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* reserve in range from @base to @limit.
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*/
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int __init cma_declare_contiguous_nid(phys_addr_t base,
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phys_addr_t size, phys_addr_t limit,
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phys_addr_t alignment, unsigned int order_per_bit,
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bool fixed, const char *name, struct cma **res_cma,
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int nid)
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{
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phys_addr_t memblock_end = memblock_end_of_DRAM();
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phys_addr_t highmem_start;
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int ret = 0;
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/*
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* We can't use __pa(high_memory) directly, since high_memory
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* isn't a valid direct map VA, and DEBUG_VIRTUAL will (validly)
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* complain. Find the boundary by adding one to the last valid
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* address.
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*/
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highmem_start = __pa(high_memory - 1) + 1;
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pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
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__func__, &size, &base, &limit, &alignment);
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if (cma_area_count == ARRAY_SIZE(cma_areas)) {
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pr_err("Not enough slots for CMA reserved regions!\n");
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return -ENOSPC;
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}
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if (!size)
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return -EINVAL;
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if (alignment && !is_power_of_2(alignment))
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return -EINVAL;
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/*
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* Sanitise input arguments.
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* Pages both ends in CMA area could be merged into adjacent unmovable
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* migratetype page by page allocator's buddy algorithm. In the case,
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* you couldn't get a contiguous memory, which is not what we want.
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*/
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alignment = max(alignment, (phys_addr_t)PAGE_SIZE <<
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max_t(unsigned long, MAX_ORDER - 1, pageblock_order));
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if (fixed && base & (alignment - 1)) {
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ret = -EINVAL;
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pr_err("Region at %pa must be aligned to %pa bytes\n",
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&base, &alignment);
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goto err;
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}
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base = ALIGN(base, alignment);
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size = ALIGN(size, alignment);
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limit &= ~(alignment - 1);
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if (!base)
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fixed = false;
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/* size should be aligned with order_per_bit */
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if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
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return -EINVAL;
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/*
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* If allocating at a fixed base the request region must not cross the
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* low/high memory boundary.
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*/
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if (fixed && base < highmem_start && base + size > highmem_start) {
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ret = -EINVAL;
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pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
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&base, &highmem_start);
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goto err;
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}
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/*
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* If the limit is unspecified or above the memblock end, its effective
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* value will be the memblock end. Set it explicitly to simplify further
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* checks.
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*/
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if (limit == 0 || limit > memblock_end)
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limit = memblock_end;
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if (base + size > limit) {
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ret = -EINVAL;
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pr_err("Size (%pa) of region at %pa exceeds limit (%pa)\n",
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&size, &base, &limit);
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goto err;
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}
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/* Reserve memory */
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if (fixed) {
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if (memblock_is_region_reserved(base, size) ||
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memblock_reserve(base, size) < 0) {
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ret = -EBUSY;
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goto err;
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}
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} else {
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phys_addr_t addr = 0;
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/*
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* All pages in the reserved area must come from the same zone.
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* If the requested region crosses the low/high memory boundary,
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* try allocating from high memory first and fall back to low
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* memory in case of failure.
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*/
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if (base < highmem_start && limit > highmem_start) {
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addr = memblock_alloc_range_nid(size, alignment,
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highmem_start, limit, nid, true);
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limit = highmem_start;
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}
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/*
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* If there is enough memory, try a bottom-up allocation first.
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* It will place the new cma area close to the start of the node
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* and guarantee that the compaction is moving pages out of the
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* cma area and not into it.
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* Avoid using first 4GB to not interfere with constrained zones
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* like DMA/DMA32.
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*/
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#ifdef CONFIG_PHYS_ADDR_T_64BIT
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if (!memblock_bottom_up() && memblock_end >= SZ_4G + size) {
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memblock_set_bottom_up(true);
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addr = memblock_alloc_range_nid(size, alignment, SZ_4G,
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limit, nid, true);
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memblock_set_bottom_up(false);
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}
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#endif
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if (!addr) {
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addr = memblock_alloc_range_nid(size, alignment, base,
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limit, nid, true);
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if (!addr) {
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ret = -ENOMEM;
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goto err;
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}
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}
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/*
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* kmemleak scans/reads tracked objects for pointers to other
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* objects but this address isn't mapped and accessible
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*/
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kmemleak_ignore_phys(addr);
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base = addr;
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}
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ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
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if (ret)
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goto free_mem;
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pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
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&base);
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return 0;
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free_mem:
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memblock_free(base, size);
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err:
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pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
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return ret;
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}
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#ifdef CONFIG_CMA_DEBUG
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static void cma_debug_show_areas(struct cma *cma)
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{
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unsigned long next_zero_bit, next_set_bit, nr_zero;
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unsigned long start = 0;
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unsigned long nr_part, nr_total = 0;
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unsigned long nbits = cma_bitmap_maxno(cma);
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spin_lock_irq(&cma->lock);
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pr_info("number of available pages: ");
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for (;;) {
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next_zero_bit = find_next_zero_bit(cma->bitmap, nbits, start);
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if (next_zero_bit >= nbits)
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break;
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next_set_bit = find_next_bit(cma->bitmap, nbits, next_zero_bit);
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nr_zero = next_set_bit - next_zero_bit;
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nr_part = nr_zero << cma->order_per_bit;
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pr_cont("%s%lu@%lu", nr_total ? "+" : "", nr_part,
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next_zero_bit);
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nr_total += nr_part;
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start = next_zero_bit + nr_zero;
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}
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pr_cont("=> %lu free of %lu total pages\n", nr_total, cma->count);
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spin_unlock_irq(&cma->lock);
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}
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#else
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static inline void cma_debug_show_areas(struct cma *cma) { }
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#endif
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/**
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* cma_alloc() - allocate pages from contiguous area
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* @cma: Contiguous memory region for which the allocation is performed.
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* @count: Requested number of pages.
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* @align: Requested alignment of pages (in PAGE_SIZE order).
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* @no_warn: Avoid printing message about failed allocation
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*
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* This function allocates part of contiguous memory on specific
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* contiguous memory area.
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*/
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struct page *cma_alloc(struct cma *cma, unsigned long count,
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unsigned int align, bool no_warn)
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{
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unsigned long mask, offset;
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unsigned long pfn = -1;
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unsigned long start = 0;
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unsigned long bitmap_maxno, bitmap_no, bitmap_count;
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unsigned long i;
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struct page *page = NULL;
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int ret = -ENOMEM;
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if (!cma || !cma->count || !cma->bitmap)
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goto out;
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pr_debug("%s(cma %p, count %lu, align %d)\n", __func__, (void *)cma,
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count, align);
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if (!count)
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goto out;
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trace_cma_alloc_start(cma->name, count, align);
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mask = cma_bitmap_aligned_mask(cma, align);
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offset = cma_bitmap_aligned_offset(cma, align);
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bitmap_maxno = cma_bitmap_maxno(cma);
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bitmap_count = cma_bitmap_pages_to_bits(cma, count);
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if (bitmap_count > bitmap_maxno)
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goto out;
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for (;;) {
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spin_lock_irq(&cma->lock);
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bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
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bitmap_maxno, start, bitmap_count, mask,
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offset);
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if (bitmap_no >= bitmap_maxno) {
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spin_unlock_irq(&cma->lock);
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break;
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}
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bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
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/*
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* It's safe to drop the lock here. We've marked this region for
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* our exclusive use. If the migration fails we will take the
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* lock again and unmark it.
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*/
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spin_unlock_irq(&cma->lock);
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pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
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ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
|
|
GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
|
|
|
|
if (ret == 0) {
|
|
page = pfn_to_page(pfn);
|
|
break;
|
|
}
|
|
|
|
cma_clear_bitmap(cma, pfn, count);
|
|
if (ret != -EBUSY)
|
|
break;
|
|
|
|
pr_debug("%s(): memory range at %p is busy, retrying\n",
|
|
__func__, pfn_to_page(pfn));
|
|
|
|
trace_cma_alloc_busy_retry(cma->name, pfn, pfn_to_page(pfn),
|
|
count, align);
|
|
/* try again with a bit different memory target */
|
|
start = bitmap_no + mask + 1;
|
|
}
|
|
|
|
trace_cma_alloc_finish(cma->name, pfn, page, count, align);
|
|
|
|
/*
|
|
* CMA can allocate multiple page blocks, which results in different
|
|
* blocks being marked with different tags. Reset the tags to ignore
|
|
* those page blocks.
|
|
*/
|
|
if (page) {
|
|
for (i = 0; i < count; i++)
|
|
page_kasan_tag_reset(page + i);
|
|
}
|
|
|
|
if (ret && !no_warn) {
|
|
pr_err_ratelimited("%s: %s: alloc failed, req-size: %lu pages, ret: %d\n",
|
|
__func__, cma->name, count, ret);
|
|
cma_debug_show_areas(cma);
|
|
}
|
|
|
|
pr_debug("%s(): returned %p\n", __func__, page);
|
|
out:
|
|
if (page) {
|
|
count_vm_event(CMA_ALLOC_SUCCESS);
|
|
cma_sysfs_account_success_pages(cma, count);
|
|
} else {
|
|
count_vm_event(CMA_ALLOC_FAIL);
|
|
if (cma)
|
|
cma_sysfs_account_fail_pages(cma, count);
|
|
}
|
|
|
|
return page;
|
|
}
|
|
|
|
/**
|
|
* cma_release() - release allocated pages
|
|
* @cma: Contiguous memory region for which the allocation is performed.
|
|
* @pages: Allocated pages.
|
|
* @count: Number of allocated pages.
|
|
*
|
|
* This function releases memory allocated by cma_alloc().
|
|
* It returns false when provided pages do not belong to contiguous area and
|
|
* true otherwise.
|
|
*/
|
|
bool cma_release(struct cma *cma, const struct page *pages,
|
|
unsigned long count)
|
|
{
|
|
unsigned long pfn;
|
|
|
|
if (!cma || !pages)
|
|
return false;
|
|
|
|
pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count);
|
|
|
|
pfn = page_to_pfn(pages);
|
|
|
|
if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
|
|
return false;
|
|
|
|
VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
|
|
|
|
free_contig_range(pfn, count);
|
|
cma_clear_bitmap(cma, pfn, count);
|
|
trace_cma_release(cma->name, pfn, pages, count);
|
|
|
|
return true;
|
|
}
|
|
|
|
int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < cma_area_count; i++) {
|
|
int ret = it(&cma_areas[i], data);
|
|
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|