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/*
* 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);
}
unsigned long cma_get_size(const struct cma *cma)
{
return cma->count << PAGE_SHIFT;
}
const char *cma_get_name(const struct cma *cma)
{
return cma->name ? cma->name : "(undefined)";
}
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;
}
/*
* 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;
}
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;
}
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);
}
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;
}
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;
}
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,
const char *name,
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];
if (name) {
cma->name = name;
} else {
cma->name = kasprintf(GFP_KERNEL, "cma%d\n", cma_area_count);
if (!cma->name)
return -ENOMEM;
}
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;
}
/**
* 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, const char *name, 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 t
|