cma.rar_V2

/* * 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 #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> struct cma { unsigned long base_pfn; unsigned long count; unsigned long *bitmap; unsigned int order_per_bit; /* Order of pages represented by one bit */ struct mutex lock; }; static struct cma cma_areas[MAX_CMA_AREAS]; static unsigned cma_area_count; static DEFINE_MUTEX(cma_mutex); phys_addr_t cma_get_base(struct cma *cma) { return PFN_PHYS(cma->base_pfn); } unsigned long cma_get_size(struct cma *cma) { return cma->count << PAGE_SHIFT; } static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order) { if (align_order <= cma->order_per_bit) return 0; return (1UL << (align_order - cma->order_per_bit)) - 1; } static unsigned long cma_bitmap_aligned_offset(struct cma *cma, int align_order) { unsigned int alignment; if (align_order <= cma->order_per_bit) return 0; alignment = 1UL << (align_order - cma->order_per_bit); return ALIGN(cma->base_pfn, alignment) - (cma->base_pfn >> cma->order_per_bit); } static unsigned long cma_bitmap_maxno(struct cma *cma) { return cma->count >> cma->order_per_bit; } static unsigned long cma_bitmap_pages_to_bits(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, 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); 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, 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 requied by mm core */ alignment = PAGE_SIZE << max(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++; 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, struct cma **res_cma) { phys_addr_t memblock_end = memblock_end_of_DRAM(); phys_addr_t highmem_start; int ret = 0; #ifdef CONFIG_X86 /* * high_memory isn't direct mapped memory so retrieving its physical * address isn't appropriate. But it would be useful to check the * physical address of the highmem boundary so it's justfiable to get * the physical address from it. On x86 there is a validation check for * this case, so the following workaround is needed to avoid it. */ highmem_start = __pa_nodebug(high_memory); #else highmem_start = __pa(high_memory); #endif 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(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 (%p