Release 4.11 mm/cma.c

/*
 * Contiguous Memory Allocator
 *
 * Copyright (c) 2010-2011 by Samsung Electronics.
 * Copyright IBM Corporation, 2013
 * Copyright LG Electronics Inc., 2014
 * Written by:
 *      Marek Szyprowski <m.szyprowski@samsung.com>
 *      Michal Nazarewicz <mina86@mina86.com>
 *      Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
 *      Joonsoo Kim <iamjoonsoo.kim@lge.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License or (at your optional) any later version of the license.
 */


#define pr_fmt(fmt) "cma: " fmt

#ifdef CONFIG_CMA_DEBUG
#ifndef DEBUG

#  define DEBUG
#endif
#endif

#define CREATE_TRACE_POINTS

#include <linux/memblock.h>
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/log2.h>
#include <linux/cma.h>
#include <linux/highmem.h>
#include <linux/io.h>
#include <trace/events/cma.h>

#include "cma.h"


struct cma cma_areas[MAX_CMA_AREAS];

unsigned cma_area_count;
static DEFINE_MUTEX(cma_mutex);



phys_addr_t cma_get_base(const struct cma *cma)
{
	return PFN_PHYS(cma->base_pfn);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
18
94.74%
1
50.00%
Sasha Levin
1
5.26%
1
50.00%
Total
19
100.00%
2
100.00%



unsigned long cma_get_size(const struct cma *cma)
{
	return cma->count << PAGE_SHIFT;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
18
94.74%
1
50.00%
Sasha Levin
1
5.26%
1
50.00%
Total
19
100.00%
2
100.00%



static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
					     int align_order)
{
	if (align_order <= cma->order_per_bit)
		return 0;
	return (1UL << (align_order - cma->order_per_bit)) - 1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
29
69.05%
1
33.33%
Weijie Yang
12
28.57%
1
33.33%
Sasha Levin
1
2.38%
1
33.33%
Total
42
100.00%
3
100.00%

/*
 * Find a PFN aligned to the specified order and return an offset represented in
 * order_per_bits.
 */


static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
					       int align_order)
{
	if (align_order <= cma->order_per_bit)
		return 0;

	return (ALIGN(cma->base_pfn, (1UL << align_order))
		- cma->base_pfn) >> cma->order_per_bit;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Gregory Fong
43
84.31%
1
33.33%
Danesh Petigara
7
13.73%
1
33.33%
Sasha Levin
1
1.96%
1
33.33%
Total
51
100.00%
3
100.00%



static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
					      unsigned long pages)
{
	return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
32
96.97%
1
50.00%
Sasha Levin
1
3.03%
1
50.00%
Total
33
100.00%
2
100.00%



static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
			     unsigned int count)
{
	unsigned long bitmap_no, bitmap_count;

	bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
	bitmap_count = cma_bitmap_pages_to_bits(cma, count);

	mutex_lock(&cma->lock);
	bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
	mutex_unlock(&cma->lock);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
74
98.67%
1
50.00%
Sasha Levin
1
1.33%
1
50.00%
Total
75
100.00%
2
100.00%



static int __init cma_activate_area(struct cma *cma)
{
	int bitmap_size = BITS_TO_LONGS(cma_bitmap_maxno(cma)) * sizeof(long);
	unsigned long base_pfn = cma->base_pfn, pfn = base_pfn;
	unsigned i = cma->count >> pageblock_order;
	struct zone *zone;

	cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL);

	if (!cma->bitmap)
		return -ENOMEM;

	WARN_ON_ONCE(!pfn_valid(pfn));
	zone = page_zone(pfn_to_page(pfn));

	do {
		unsigned j;

		base_pfn = pfn;
		for (j = pageblock_nr_pages; j; --j, pfn++) {
			WARN_ON_ONCE(!pfn_valid(pfn));
			/*
                         * alloc_contig_range requires the pfn range
                         * specified to be in the same zone. Make this
                         * simple by forcing the entire CMA resv range
                         * to be in the same zone.
                         */
			if (page_zone(pfn_to_page(pfn)) != zone)
				goto err;
		}
		init_cma_reserved_pageblock(pfn_to_page(base_pfn));
	} while (--i);

	mutex_init(&cma->lock);

#ifdef CONFIG_CMA_DEBUGFS
	INIT_HLIST_HEAD(&cma->mem_head);
	spin_lock_init(&cma->mem_head_lock);
#endif

	return 0;

err:
	kfree(cma->bitmap);
	cma->count = 0;
	return -EINVAL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
184
87.20%
1
33.33%
Sasha Levin
21
9.95%
1
33.33%
Laurent Pinchart
6
2.84%
1
33.33%
Total
211
100.00%
3
100.00%



static int __init cma_init_reserved_areas(void)
{
	int i;

	for (i = 0; i < cma_area_count; i++) {
		int ret = cma_activate_area(&cma_areas[i]);

		if (ret)
			return ret;
	}

	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
49
100.00%
1
100.00%
Total
49
100.00%
1
100.00%


core_initcall(cma_init_reserved_areas);

/**
 * cma_init_reserved_mem() - create custom contiguous area from reserved memory
 * @base: Base address of the reserved area
 * @size: Size of the reserved area (in bytes),
 * @order_per_bit: Order of pages represented by one bit on bitmap.
 * @res_cma: Pointer to store the created cma region.
 *
 * This function creates custom contiguous area from already reserved memory.
 */


int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
				 unsigned int order_per_bit,
				 struct cma **res_cma)
{
	struct cma *cma;
	phys_addr_t alignment;

	/* Sanity checks */
	if (cma_area_count == ARRAY_SIZE(cma_areas)) {
		pr_err("Not enough slots for CMA reserved regions!\n");
		return -ENOSPC;
	}

	if (!size || !memblock_is_region_reserved(base, size))
		return -EINVAL;

	/* ensure minimal alignment required by mm core */
	alignment = PAGE_SIZE <<
			max_t(unsigned long, MAX_ORDER - 1, pageblock_order);

	/* alignment should be aligned with order_per_bit */
	if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit))
		return -EINVAL;

	if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size)
		return -EINVAL;

	/*
         * Each reserved area must be initialised later, when more kernel
         * subsystems (like slab allocator) are available.
         */
	cma = &cma_areas[cma_area_count];
	cma->base_pfn = PFN_DOWN(base);
	cma->count = size >> PAGE_SHIFT;
	cma->order_per_bit = order_per_bit;
	*res_cma = cma;
	cma_area_count++;
	totalcma_pages += (size / PAGE_SIZE);

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Marek Szyprowski
162
91.53%
1
20.00%
George G. Davis
8
4.52%
1
20.00%
Stephen Rothwell
5
2.82%
1
20.00%
Shailendra Verma
1
0.56%
1
20.00%
Sasha Levin
1
0.56%
1
20.00%
Total
177
100.00%
5
100.00%

/**
 * cma_declare_contiguous() - reserve custom contiguous area
 * @base: Base address of the reserved area optional, use 0 for any
 * @size: Size of the reserved area (in bytes),
 * @limit: End address of the reserved memory (optional, 0 for any).
 * @alignment: Alignment for the CMA area, should be power of 2 or zero
 * @order_per_bit: Order of pages represented by one bit on bitmap.
 * @fixed: hint about where to place the reserved area
 * @res_cma: Pointer to store the created cma region.
 *
 * This function reserves memory from early allocator. It should be
 * called by arch specific code once the early allocator (memblock or bootmem)
 * has been activated and all other subsystems have already allocated/reserved
 * memory. This function allows to create custom reserved areas.
 *
 * If @fixed is true, reserve contiguous area at exactly @base.  If false,
 * reserve in range from @base to @limit.
 */


int __init cma_declare_contiguous(phys_addr_t base,
			phys_addr_t size, phys_addr_t limit,
			phys_addr_t alignment, unsigned int order_per_bit,
			bool fixed, struct cma **res_cma)
{
	phys_addr_t memblock_end = memblock_end_of_DRAM();
	phys_addr_t highmem_start;
	int ret = 0;

	/*
         * We can't use __pa(high_memory) directly, since high_memory
         * isn't a valid direct map VA, and DEBUG_VIRTUAL will (validly)
         * complain. Find the boundary by adding one to the last valid
         * address.
         */
	highmem_start = __pa(high_memory - 1) + 1;
	pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
		__func__, &size, &base, &limit, &alignment);

	if (cma_area_count == ARRAY_SIZE(cma_areas)) {
		pr_err("Not enough slots for CMA reserved regions!\n");
		return -ENOSPC;
	}

	if (!size)
		return -EINVAL;

	if (alignment && !is_power_of_2(alignment))
		return -EINVAL;

	/*
         * Sanitise input arguments.
         * Pages both ends in CMA area could be merged into adjacent unmovable
         * migratetype page by page allocator's buddy algorithm. In the case,
         * you couldn't get a contiguous memory, which is not what we want.
         */
	alignment = max(alignment,  (phys_addr_t)PAGE_SIZE <<
			  max_t(unsigned long, MAX_ORDER - 1, pageblock_order));
	base = ALIGN(base, alignment);
	size = ALIGN(size, alignment);
	limit &= ~(alignment - 1);

	if (!base)
		fixed = false;

	/* size should be aligned with order_per_bit */
	if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
		return -EINVAL;

	/*
         * If allocating at a fixed base the request region must not cross the
         * low/high memory boundary.
         */
	if (fixed && base < highmem_start && base + size > highmem_start) {
		ret = -EINVAL;
		pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
			&base, &highmem_start);
		goto err;
	}

	/*
         * If the limit is unspecified or above the memblock end, its effective
         * value will be the memblock end. Set it explicitly to simplify further
         * checks.
         */
	if (limit == 0 || limit > memblock_end)
		limit = memblock_end;

	/* Reserve memory */
	if (fixed) {
		if (memblock_is_region_reserved(base, size) ||
		    memblock_reserve(base, size) < 0) {
			ret = -EBUSY;
			goto err;
		}
	} else {
		phys_addr_t addr = 0;

		/*
                 * All pages in the reserved area must come from the same zone.
                 * If the requested region crosses the low/high memory boundary,
                 * try allocating from high memory first and fall back to low
                 * memory in case of failure.
                 */
		if (base < highmem_start && limit > highmem_start) {
			addr = memblock_alloc_range(size, alignment,
						    highmem_start, limit,
						    MEMBLOCK_NONE);
			limit = highmem_start;
		}

		if (!addr) {
			addr = memblock_alloc_range(size, alignment, base,
						    limit,
						    MEMBLOCK_NONE);
			if (!addr) {
				ret = -ENOMEM;
				goto err;
			}
		}

		/*
                 * kmemleak scans/reads tracked objects for pointers to other
                 * objects but this address isn't mapped and accessible
                 */
		kmemleak_ignore_phys(addr);
		base = addr;
	}

	ret = cma_init_reserved_mem(base, size, order_per_bit, res_cma);
	if (ret)
		goto err;

	pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
		&base);
	return 0;

err:
	pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
276
64.64%
4
28.57%
Laurent Pinchart
77
18.03%
3
21.43%
Marek Szyprowski
54
12.65%
2
14.29%
Laura Abbott
5
1.17%
1
7.14%
Stephen Rothwell
5
1.17%
1
7.14%
Thierry Reding
5
1.17%
1
7.14%
Tony Luck
4
0.94%
1
7.14%
Catalin Marinas
1
0.23%
1
7.14%
Total
427
100.00%
14
100.00%

#ifdef CONFIG_CMA_DEBUG


static void cma_debug_show_areas(struct cma *cma)
{
	unsigned long next_zero_bit, next_set_bit;
	unsigned long start = 0;
	unsigned int nr_zero, nr_total = 0;

	mutex_lock(&cma->lock);
	pr_info("number of available pages: ");
	for (;;) {
		next_zero_bit = find_next_zero_bit(cma->bitmap, cma->count, start);
		if (next_zero_bit >= cma->count)
			break;
		next_set_bit = find_next_bit(cma->bitmap, cma->count, next_zero_bit);
		nr_zero = next_set_bit - next_zero_bit;
		pr_cont("%s%u@%lu", nr_total ? "+" : "", nr_zero, next_zero_bit);
		nr_total += nr_zero;
		start = next_zero_bit + nr_zero;
	}
	pr_cont("=> %u free of %lu total pages\n", nr_total, cma->count);
	mutex_unlock(&cma->lock);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Jaewon Kim
140
100.00%
1
100.00%
Total
140
100.00%
1
100.00%

#else


static inline void cma_debug_show_areas(struct cma *cma) { }
Contributors
Person
Tokens
Prop
Commits
CommitProp
Jaewon Kim
11
100.00%
1
100.00%
Total
11
100.00%
1
100.00%

#endif

/**
 * cma_alloc() - allocate pages from contiguous area
 * @cma:   Contiguous memory region for which the allocation is performed.
 * @count: Requested number of pages.
 * @align: Requested alignment of pages (in PAGE_SIZE order).
 *
 * This function allocates part of contiguous memory on specific
 * contiguous memory area.
 */


struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
		       gfp_t gfp_mask)
{
	unsigned long mask, offset;
	unsigned long pfn = -1;
	unsigned long start = 0;
	unsigned long bitmap_maxno, bitmap_no, bitmap_count;
	struct page *page = NULL;
	int ret = -ENOMEM;

	if (!cma || !cma->count)
		return NULL;

	pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
		 count, align);

	if (!count)
		return NULL;

	mask = cma_bitmap_aligned_mask(cma, align);
	offset = cma_bitmap_aligned_offset(cma, align);
	bitmap_maxno = cma_bitmap_maxno(cma);
	bitmap_count = cma_bitmap_pages_to_bits(cma, count);

	if (bitmap_count > bitmap_maxno)
		return NULL;

	for (;;) {
		mutex_lock(&cma->lock);
		bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
				bitmap_maxno, start, bitmap_count, mask,
				offset);
		if (bitmap_no >= bitmap_maxno) {
			mutex_unlock(&cma->lock);
			break;
		}
		bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
		/*
                 * It's safe to drop the lock here. We've marked this region for
                 * our exclusive use. If the migration fails we will take the
                 * lock again and unmark it.
                 */
		mutex_unlock(&cma->lock);

		pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
		mutex_lock(&cma_mutex);
		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
					 gfp_mask);
		mutex_unlock(&cma_mutex);
		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));
		/* try again with a bit different memory target */
		start = bitmap_no + mask + 1;
	}

	trace_cma_alloc(pfn, page, count, align);

	if (ret) {
		pr_info("%s: alloc failed, req-size: %zu pages, ret: %d\n",
			__func__, count, ret);
		cma_debug_show_areas(cma);
	}

	pr_debug("%s(): returned %p\n", __func__, page);
	return page;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
280
79.10%
2
20.00%
Jaewon Kim
25
7.06%
1
10.00%
Gregory Fong
13
3.67%
1
10.00%
Stefan Strogin
11
3.11%
1
10.00%
Shiraz Hashim
9
2.54%
1
10.00%
Andrew Morton
9
2.54%
1
10.00%
Lucas Stach
5
1.41%
2
20.00%
Rohit Vaswani
2
0.56%
1
10.00%
Total
354
100.00%
10
100.00%

/**
 * 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 alloc_cma().
 * 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 int count)
{
	unsigned long pfn;

	if (!cma || !pages)
		return false;

	pr_debug("%s(page %p)\n", __func__, (void *)pages);

	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(pfn, pages, count);

	return true;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
108
90.76%
1
33.33%
Stefan Strogin
9
7.56%
1
33.33%
Sasha Levin
2
1.68%
1
33.33%
Total
119
100.00%
3
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
JoonSoo Kim
1137
62.47%
5
16.13%
Marek Szyprowski
220
12.09%
2
6.45%
Jaewon Kim
183
10.05%
1
3.23%
Laurent Pinchart
83
4.56%
4
12.90%
Gregory Fong
56
3.08%
1
3.23%
Sasha Levin
33
1.81%
3
9.68%
Stefan Strogin
26
1.43%
1
3.23%
Weijie Yang
12
0.66%
1
3.23%
Stephen Rothwell
10
0.55%
1
3.23%
Shiraz Hashim
9
0.49%
1
3.23%
Andrew Morton
9
0.49%
1
3.23%
Thierry Reding
8
0.44%
1
3.23%
Danesh Petigara
8
0.44%
1
3.23%
George G. Davis
8
0.44%
1
3.23%
Laura Abbott
5
0.27%
1
3.23%
Lucas Stach
5
0.27%
2
6.45%
Tony Luck
4
0.22%
1
3.23%
Rohit Vaswani
2
0.11%
1
3.23%
Catalin Marinas
1
0.05%
1
3.23%
Shailendra Verma
1
0.05%
1
3.23%
Total
1820
100.00%
31
100.00%
Directory: mm

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.