linux/mm/cma.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Contiguous Memory Allocator
 *
 * Copyright (c) 2010-2011 by Samsung Electronics.
 * Copyright IBM Corporation, 2013
 * Copyright LG Electronics Inc., 2014
 * Written by:
 *	Marek Szyprowski <[email protected]>
 *	Michal Nazarewicz <[email protected]>
 *	Aneesh Kumar K.V <[email protected]>
 *	Joonsoo Kim <[email protected]>
 */

#define pr_fmt(fmt) …

#define CREATE_TRACE_POINTS

#include <linux/memblock.h>
#include <linux/err.h>
#include <linux/mm.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 <linux/kmemleak.h>
#include <trace/events/cma.h>

#include "internal.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)
{ … }

unsigned long cma_get_size(const struct cma *cma)
{ … }

const char *cma_get_name(const struct cma *cma)
{ … }

static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
					     unsigned int align_order)
{ … }

/*
 * Find the offset of the base PFN from the specified align_order.
 * The value returned is represented in order_per_bits.
 */
static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
					       unsigned int align_order)
{ … }

static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
					      unsigned long pages)
{ … }

static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
			     unsigned long count)
{ … }

static void __init cma_activate_area(struct cma *cma)
{ … }

static int __init cma_init_reserved_areas(void)
{ … }
core_initcall(cma_init_reserved_areas);

void __init cma_reserve_pages_on_error(struct cma *cma)
{ … }

/**
 * 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.
 * @name: The name of the area. If this parameter is NULL, the name of
 *        the area will be set to "cmaN", where N is a running counter of
 *        used areas.
 * @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,
				 const char *name,
				 struct cma **res_cma)
{ … }

/**
 * cma_declare_contiguous_nid() - 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
 * @name: The name of the area. See function cma_init_reserved_mem()
 * @res_cma: Pointer to store the created cma region.
 * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
 *
 * 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_nid(phys_addr_t base,
			phys_addr_t size, phys_addr_t limit,
			phys_addr_t alignment, unsigned int order_per_bit,
			bool fixed, const char *name, struct cma **res_cma,
			int nid)
{ … }

static void cma_debug_show_areas(struct cma *cma)
{ … }

/**
 * 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).
 * @no_warn: Avoid printing message about failed allocation
 *
 * This function allocates part of contiguous memory on specific
 * contiguous memory area.
 */
struct page *cma_alloc(struct cma *cma, unsigned long count,
		       unsigned int align, bool no_warn)
{ … }

bool cma_pages_valid(struct cma *cma, const struct page *pages,
		     unsigned long count)
{ … }

/**
 * 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)
{ … }

int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)
{ … }