// 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 * Michal Nazarewicz * Aneesh Kumar K.V * Joonsoo Kim */ #define pr_fmt(fmt) "cma: " fmt #define CREATE_TRACE_POINTS #include #include #include #include #include #include #include #include #include #include #include #include #include "internal.h" #include "cma.h" struct cma cma_areas[MAX_CMA_AREAS]; unsigned int cma_area_count; static int __init __cma_declare_contiguous_nid(phys_addr_t *basep, 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); phys_addr_t cma_get_base(const struct cma *cma) { WARN_ON_ONCE(cma->nranges != 1); return PFN_PHYS(cma->ranges[0].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; } static unsigned long cma_bitmap_aligned_mask(const struct cma *cma, unsigned int align_order) { if (align_order <= cma->order_per_bit) return 0; return (1UL << (align_order - cma->order_per_bit)) - 1; } /* * 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, const struct cma_memrange *cmr, unsigned int align_order) { return (cmr->base_pfn & ((1UL << align_order) - 1)) >> 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, const struct cma_memrange *cmr, unsigned long pfn, unsigned long count) { unsigned long bitmap_no, bitmap_count; unsigned long flags; bitmap_no = (pfn - cmr->base_pfn) >> cma->order_per_bit; bitmap_count = cma_bitmap_pages_to_bits(cma, count); spin_lock_irqsave(&cma->lock, flags); bitmap_clear(cmr->bitmap, bitmap_no, bitmap_count); cma->available_count += count; spin_unlock_irqrestore(&cma->lock, flags); } /* * Check if a CMA area contains no ranges that intersect with * multiple zones. Store the result in the flags in case * this gets called more than once. */ bool cma_validate_zones(struct cma *cma) { int r; unsigned long base_pfn; struct cma_memrange *cmr; bool valid_bit_set; /* * If already validated, return result of previous check. * Either the valid or invalid bit will be set if this * check has already been done. If neither is set, the * check has not been performed yet. */ valid_bit_set = test_bit(CMA_ZONES_VALID, &cma->flags); if (valid_bit_set || test_bit(CMA_ZONES_INVALID, &cma->flags)) return valid_bit_set; for (r = 0; r < cma->nranges; r++) { cmr = &cma->ranges[r]; base_pfn = cmr->base_pfn; /* * alloc_contig_range() requires the pfn range specified * to be in the same zone. Simplify by forcing the entire * CMA resv range to be in the same zone. */ WARN_ON_ONCE(!pfn_valid(base_pfn)); if (pfn_range_intersects_zones(cma->nid, base_pfn, cmr->count)) { set_bit(CMA_ZONES_INVALID, &cma->flags); return false; } } set_bit(CMA_ZONES_VALID, &cma->flags); return true; } static void __init cma_activate_area(struct cma *cma) { unsigned long pfn, end_pfn; int allocrange, r; struct cma_memrange *cmr; unsigned long bitmap_count, count; for (allocrange = 0; allocrange < cma->nranges; allocrange++) { cmr = &cma->ranges[allocrange]; cmr->bitmap = bitmap_zalloc(cma_bitmap_maxno(cma, cmr), GFP_KERNEL); if (!cmr->bitmap) goto cleanup; } if (!cma_validate_zones(cma)) goto cleanup; for (r = 0; r < cma->nranges; r++) { cmr = &cma->ranges[r]; if (cmr->early_pfn != cmr->base_pfn) { count = cmr->early_pfn - cmr->base_pfn; bitmap_count = cma_bitmap_pages_to_bits(cma, count); bitmap_set(cmr->bitmap, 0, bitmap_count); } for (pfn = cmr->early_pfn; pfn < cmr->base_pfn + cmr->count; pfn += pageblock_nr_pages) init_cma_reserved_pageblock(pfn_to_page(pfn)); } spin_lock_init(&cma->lock); mutex_init(&cma->alloc_mutex); #ifdef CONFIG_CMA_DEBUGFS INIT_HLIST_HEAD(&cma->mem_head); spin_lock_init(&cma->mem_head_lock); #endif set_bit(CMA_ACTIVATED, &cma->flags); return; cleanup: for (r = 0; r < allocrange; r++) bitmap_free(cma->ranges[r].bitmap); /* Expose all pages to the buddy, they are useless for CMA. */ if (!test_bit(CMA_RESERVE_PAGES_ON_ERROR, &cma->flags)) { for (r = 0; r < allocrange; r++) { cmr = &cma->ranges[r]; end_pfn = cmr->base_pfn + cmr->count; for (pfn = cmr->early_pfn; pfn < end_pfn; pfn++) free_reserved_page(pfn_to_page(pfn)); } } totalcma_pages -= cma->count; cma->available_count = cma->count = 0; pr_err("CMA area %s could not be activated\n", cma->name); } static int __init cma_init_reserved_areas(void) { int i; for (i = 0; i < cma_area_count; i++) cma_activate_area(&cma_areas[i]); return 0; } core_initcall(cma_init_reserved_areas); void __init cma_reserve_pages_on_error(struct cma *cma) { set_bit(CMA_RESERVE_PAGES_ON_ERROR, &cma->flags); } static int __init cma_new_area(const char *name, phys_addr_t size, unsigned int order_per_bit, struct cma **res_cma) { struct cma *cma; if (cma_area_count == ARRAY_SIZE(cma_areas)) { pr_err("Not enough slots for CMA reserved regions!\n"); return -ENOSPC; } /* * Each reserved area must be initialised later, when more kernel * subsystems (like slab allocator) are available. */ cma = &cma_areas[cma_area_count]; cma_area_count++; if (name) snprintf(cma->name, CMA_MAX_NAME, "%s", name); else snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", cma_area_count); cma->available_count = cma->count = size >> PAGE_SHIFT; cma->order_per_bit = order_per_bit; *res_cma = cma; totalcma_pages += cma->count; return 0; } static void __init cma_drop_area(struct cma *cma) { totalcma_pages -= cma->count; cma_area_count--; } /** * 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) { struct cma *cma; int ret; /* Sanity checks */ if (!size || !memblock_is_region_reserved(base, size)) return -EINVAL; /* * CMA uses CMA_MIN_ALIGNMENT_BYTES as alignment requirement which * needs pageblock_order to be initialized. Let's enforce it. */ if (!pageblock_order) { pr_err("pageblock_order not yet initialized. Called during early boot?\n"); return -EINVAL; } /* ensure minimal alignment required by mm core */ if (!IS_ALIGNED(base | size, CMA_MIN_ALIGNMENT_BYTES)) return -EINVAL; ret = cma_new_area(name, size, order_per_bit, &cma); if (ret != 0) return ret; cma->ranges[0].base_pfn = PFN_DOWN(base); cma->ranges[0].early_pfn = PFN_DOWN(base); cma->ranges[0].count = cma->count; cma->nranges = 1; cma->nid = NUMA_NO_NODE; *res_cma = cma; return 0; } /* * Structure used while walking physical memory ranges and finding out * which one(s) to use for a CMA area. */ struct cma_init_memrange { phys_addr_t base; phys_addr_t size; struct list_head list; }; /* * Work array used during CMA initialization. */ static struct cma_init_memrange memranges[CMA_MAX_RANGES] __initdata; static bool __init revsizecmp(struct cma_init_memrange *mlp, struct cma_init_memrange *mrp) { return mlp->size > mrp->size; } static bool __init basecmp(struct cma_init_memrange *mlp, struct cma_init_memrange *mrp) { return mlp->base < mrp->base; } /* * Helper function to create sorted lists. */ static void __init list_insert_sorted( struct list_head *ranges, struct cma_init_memrange *mrp, bool (*cmp)(struct cma_init_memrange *lh, struct cma_init_memrange *rh)) { struct list_head *mp; struct cma_init_memrange *mlp; if (list_empty(ranges)) list_add(&mrp->list, ranges); else { list_for_each(mp, ranges) { mlp = list_entry(mp, struct cma_init_memrange, list); if (cmp(mlp, mrp)) break; } __list_add(&mrp->list, mlp->list.prev, &mlp->list); } } /* * Create CMA areas with a total size of @total_size. A normal allocation * for one area is tried first. If that fails, the biggest memblock * ranges above 4G are selected, and allocated bottom up. * * The complexity here is not great, but this function will only be * called during boot, and the lists operated on have fewer than * CMA_MAX_RANGES elements (default value: 8). */ int __init cma_declare_contiguous_multi(phys_addr_t total_size, phys_addr_t align, unsigned int order_per_bit, const char *name, struct cma **res_cma, int nid) { phys_addr_t start = 0, end; phys_addr_t size, sizesum, sizeleft; struct cma_init_memrange *mrp, *mlp, *failed; struct cma_memrange *cmrp; LIST_HEAD(ranges); LIST_HEAD(final_ranges); struct list_head *mp, *next; int ret, nr = 1; u64 i; struct cma *cma; /* * First, try it the normal way, producing just one range. */ ret = __cma_declare_contiguous_nid(&start, total_size, 0, align, order_per_bit, false, name, res_cma, nid); if (ret != -ENOMEM) goto out; /* * Couldn't find one range that fits our needs, so try multiple * ranges. * * No need to do the alignment checks here, the call to * cma_declare_contiguous_nid above would have caught * any issues. With the checks, we know that: * * - @align is a power of 2 * - @align is >= pageblock alignment * - @size is aligned to @align and to @order_per_bit * * So, as long as we create ranges that have a base * aligned to @align, and a size that is aligned to * both @align and @order_to_bit, things will work out. */ nr = 0; sizesum = 0; failed = NULL; ret = cma_new_area(name, total_size, order_per_bit, &cma); if (ret != 0) goto out; align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES); /* * Create a list of ranges above 4G, largest range first. */ for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) { if (upper_32_bits(start) == 0) continue; start = ALIGN(start, align); if (start >= end) continue; end = ALIGN_DOWN(end, align); if (end <= start) continue; size = end - start; size = ALIGN_DOWN(size, (PAGE_SIZE << order_per_bit)); if (!size) continue; sizesum += size; pr_debug("consider %016llx - %016llx\n", (u64)start, (u64)end); /* * If we don't yet have used the maximum number of * areas, grab a new one. * * If we can't use anymore, see if this range is not * smaller than the smallest one already recorded. If * not, re-use the smallest element. */ if (nr < CMA_MAX_RANGES) mrp = &memranges[nr++]; else { mrp = list_last_entry(&ranges, struct cma_init_memrange, list); if (size < mrp->size) continue; list_del(&mrp->list); sizesum -= mrp->size; pr_debug("deleted %016llx - %016llx from the list\n", (u64)mrp->base, (u64)mrp->base + size); } mrp->base = start; mrp->size = size; /* * Now do a sorted insert. */ list_insert_sorted(&ranges, mrp, revsizecmp); pr_debug("added %016llx - %016llx to the list\n", (u64)mrp->base, (u64)mrp->base + size); pr_debug("total size now %llu\n", (u64)sizesum); } /* * There is not enough room in the CMA_MAX_RANGES largest * ranges, so bail out. */ if (sizesum < total_size) { cma_drop_area(cma); ret = -ENOMEM; goto out; } /* * Found ranges that provide enough combined space. * Now, sorted them by address, smallest first, because we * want to mimic a bottom-up memblock allocation. */ sizesum = 0; list_for_each_safe(mp, next, &ranges) { mlp = list_entry(mp, struct cma_init_memrange, list); list_del(mp); list_insert_sorted(&final_ranges, mlp, basecmp); sizesum += mlp->size; if (sizesum >= total_size) break; } /* * Walk the final list, and add a CMA range for * each range, possibly not using the last one fully. */ nr = 0; sizeleft = total_size; list_for_each(mp, &final_ranges) { mlp = list_entry(mp, struct cma_init_memrange, list); size = min(sizeleft, mlp->size); if (memblock_reserve(mlp->base, size)) { /* * Unexpected error. Could go on to * the next one, but just abort to * be safe. */ failed = mlp; break; } pr_debug("created region %d: %016llx - %016llx\n", nr, (u64)mlp->base, (u64)mlp->base + size); cmrp = &cma->ranges[nr++]; cmrp->base_pfn = PHYS_PFN(mlp->base); cmrp->early_pfn = cmrp->base_pfn; cmrp->count = size >> PAGE_SHIFT; sizeleft -= size; if (sizeleft == 0) break; } if (failed) { list_for_each(mp, &final_ranges) { mlp = list_entry(mp, struct cma_init_memrange, list); if (mlp == failed) break; memblock_phys_free(mlp->base, mlp->size); } cma_drop_area(cma); ret = -ENOMEM; goto out; } cma->nranges = nr; cma->nid = nid; *res_cma = cma; out: if (ret != 0) pr_err("Failed to reserve %lu MiB\n", (unsigned long)total_size / SZ_1M); else pr_info("Reserved %lu MiB in %d range%s\n", (unsigned long)total_size / SZ_1M, nr, nr > 1 ? "s" : ""); return ret; } /** * 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) { int ret; ret = __cma_declare_contiguous_nid(&base, size, limit, alignment, order_per_bit, fixed, name, res_cma, nid); if (ret != 0) pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M); else pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M, &base); return ret; } static int __init __cma_declare_contiguous_nid(phys_addr_t *basep, 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) { phys_addr_t memblock_end = memblock_end_of_DRAM(); phys_addr_t highmem_start, base = *basep; int ret; /* * 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; if (!IS_ENABLED(CONFIG_NUMA)) nid = NUMA_NO_NODE; /* Sanitise input arguments. */ alignment = max_t(phys_addr_t, alignment, CMA_MIN_ALIGNMENT_BYTES); if (fixed && base & (alignment - 1)) { pr_err("Region at %pa must be aligned to %pa bytes\n", &base, &alignment); return -EINVAL; } 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) { pr_err("Region at %pa defined on low/high memory boundary (%pa)\n", &base, &highmem_start); return -EINVAL; } /* * 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; if (base + size > limit) { pr_err("Size (%pa) of region at %pa exceeds limit (%pa)\n", &size, &base, &limit); return -EINVAL; } /* Reserve memory */ if (fixed) { if (memblock_is_region_reserved(base, size) || memblock_reserve(base, size) < 0) { return -EBUSY; } } else { phys_addr_t addr = 0; /* * If there is enough memory, try a bottom-up allocation first. * It will place the new cma area close to the start of the node * and guarantee that the compaction is moving pages out of the * cma area and not into it. * Avoid using first 4GB to not interfere with constrained zones * like DMA/DMA32. */ #ifdef CONFIG_PHYS_ADDR_T_64BIT if (!memblock_bottom_up() && memblock_end >= SZ_4G + size) { memblock_set_bottom_up(true); addr = memblock_alloc_range_nid(size, alignment, SZ_4G, limit, nid, true); memblock_set_bottom_up(false); } #endif /* * 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 (!addr && base < highmem_start && limit > highmem_start) { addr = memblock_alloc_range_nid(size, alignment, highmem_start, limit, nid, true); limit = highmem_start; } if (!addr) { addr = memblock_alloc_range_nid(size, alignment, base, limit, nid, true); if (!addr) return -ENOMEM; } /* * 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, name, res_cma); if (ret) { memblock_phys_free(base, size); return ret; } (*res_cma)->nid = nid; *basep = base; return 0; } static void cma_debug_show_areas(struct cma *cma) { unsigned long next_zero_bit, next_set_bit, nr_zero; unsigned long start; unsigned long nr_part; unsigned long nbits; int r; struct cma_memrange *cmr; spin_lock_irq(&cma->lock); pr_info("number of available pages: "); for (r = 0; r < cma->nranges; r++) { cmr = &cma->ranges[r]; start = 0; nbits = cma_bitmap_maxno(cma, cmr); pr_info("range %d: ", r); for (;;) { next_zero_bit = find_next_zero_bit(cmr->bitmap, nbits, start); if (next_zero_bit >= nbits) break; next_set_bit = find_next_bit(cmr->bitmap, nbits, next_zero_bit); nr_zero = next_set_bit - next_zero_bit; nr_part = nr_zero << cma->order_per_bit; pr_cont("%s%lu@%lu", start ? "+" : "", nr_part, next_zero_bit); start = next_zero_bit + nr_zero; } pr_info("\n"); } pr_cont("=> %lu free of %lu total pages\n", cma->available_count, cma->count); spin_unlock_irq(&cma->lock); } static int cma_range_alloc(struct cma *cma, struct cma_memrange *cmr, unsigned long count, unsigned int align, struct page **pagep, gfp_t gfp) { unsigned long mask, offset; unsigned long pfn = -1; unsigned long start = 0; unsigned long bitmap_maxno, bitmap_no, bitmap_count; int ret = -EBUSY; struct page *page = NULL; mask = cma_bitmap_aligned_mask(cma, align); offset = cma_bitmap_aligned_offset(cma, cmr, align); bitmap_maxno = cma_bitmap_maxno(cma, cmr); bitmap_count = cma_bitmap_pages_to_bits(cma, count); if (bitmap_count > bitmap_maxno) goto out; for (;;) { spin_lock_irq(&cma->lock); /* * If the request is larger than the available number * of pages, stop right away. */ if (count > cma->available_count) { spin_unlock_irq(&cma->lock); break; } bitmap_no = bitmap_find_next_zero_area_off(cmr->bitmap, bitmap_maxno, start, bitmap_count, mask, offset); if (bitmap_no >= bitmap_maxno) { spin_unlock_irq(&cma->lock); break; } bitmap_set(cmr->bitmap, bitmap_no, bitmap_count); cma->available_count -= 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. */ spin_unlock_irq(&cma->lock); pfn = cmr->base_pfn + (bitmap_no << cma->order_per_bit); mutex_lock(&cma->alloc_mutex); ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, gfp); mutex_unlock(&cma->alloc_mutex); if (ret == 0) { page = pfn_to_page(pfn); break; } cma_clear_bitmap(cma, cmr, pfn, count); if (ret != -EBUSY) break; pr_debug("%s(): memory range at pfn 0x%lx %p is busy, retrying\n", __func__, pfn, 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; } out: *pagep = page; return ret; } static struct page *__cma_alloc(struct cma *cma, unsigned long count, unsigned int align, gfp_t gfp) { struct page *page = NULL; int ret = -ENOMEM, r; unsigned long i; const char *name = cma ? cma->name : NULL; trace_cma_alloc_start(name, count, align); if (!cma || !cma->count) return page; pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__, (void *)cma, cma->name, count, align); if (!count) return page; for (r = 0; r < cma->nranges; r++) { page = NULL; ret = cma_range_alloc(cma, &cma->ranges[r], count, align, &page, gfp); if (ret != -EBUSY || page) break; } /* * 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(nth_page(page, i)); } if (ret && !(gfp & __GFP_NOWARN)) { 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); trace_cma_alloc_finish(name, page ? page_to_pfn(page) : 0, page, count, align, ret); if (page) { count_vm_event(CMA_ALLOC_SUCCESS); cma_sysfs_account_success_pages(cma, count); } else { count_vm_event(CMA_ALLOC_FAIL); cma_sysfs_account_fail_pages(cma, count); } return page; } /** * 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) { return __cma_alloc(cma, count, align, GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0)); } struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp) { struct page *page; if (WARN_ON(!order || !(gfp & __GFP_COMP))) return NULL; page = __cma_alloc(cma, 1 << order, order, gfp); return page ? page_folio(page) : NULL; } bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count) { unsigned long pfn, end; int r; struct cma_memrange *cmr; bool ret; if (!cma || !pages || count > cma->count) return false; pfn = page_to_pfn(pages); ret = false; for (r = 0; r < cma->nranges; r++) { cmr = &cma->ranges[r]; end = cmr->base_pfn + cmr->count; if (pfn >= cmr->base_pfn && pfn < end) { ret = pfn + count <= end; break; } } if (!ret) pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count); return ret; } /** * 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) { struct cma_memrange *cmr; unsigned long pfn, end_pfn; int r; pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count); if (!cma_pages_valid(cma, pages, count)) return false; pfn = page_to_pfn(pages); end_pfn = pfn + count; for (r = 0; r < cma->nranges; r++) { cmr = &cma->ranges[r]; if (pfn >= cmr->base_pfn && pfn < (cmr->base_pfn + cmr->count)) { VM_BUG_ON(end_pfn > cmr->base_pfn + cmr->count); break; } } if (r == cma->nranges) return false; free_contig_range(pfn, count); cma_clear_bitmap(cma, cmr, pfn, count); cma_sysfs_account_release_pages(cma, count); trace_cma_release(cma->name, pfn, pages, count); return true; } bool cma_free_folio(struct cma *cma, const struct folio *folio) { if (WARN_ON(!folio_test_large(folio))) return false; return cma_release(cma, &folio->page, folio_nr_pages(folio)); } 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; } bool cma_intersects(struct cma *cma, unsigned long start, unsigned long end) { int r; struct cma_memrange *cmr; unsigned long rstart, rend; for (r = 0; r < cma->nranges; r++) { cmr = &cma->ranges[r]; rstart = PFN_PHYS(cmr->base_pfn); rend = PFN_PHYS(cmr->base_pfn + cmr->count); if (end < rstart) continue; if (start >= rend) continue; return true; } return false; } /* * Very basic function to reserve memory from a CMA area that has not * yet been activated. This is expected to be called early, when the * system is single-threaded, so there is no locking. The alignment * checking is restrictive - only pageblock-aligned areas * (CMA_MIN_ALIGNMENT_BYTES) may be reserved through this function. * This keeps things simple, and is enough for the current use case. * * The CMA bitmaps have not yet been allocated, so just start * reserving from the bottom up, using a PFN to keep track * of what has been reserved. Unreserving is not possible. * * The caller is responsible for initializing the page structures * in the area properly, since this just points to memblock-allocated * memory. The caller should subsequently use init_cma_pageblock to * set the migrate type and CMA stats the pageblocks that were reserved. * * If the CMA area fails to activate later, memory obtained through * this interface is not handed to the page allocator, this is * the responsibility of the caller (e.g. like normal memblock-allocated * memory). */ void __init *cma_reserve_early(struct cma *cma, unsigned long size) { int r; struct cma_memrange *cmr; unsigned long available; void *ret = NULL; if (!cma || !cma->count) return NULL; /* * Can only be called early in init. */ if (test_bit(CMA_ACTIVATED, &cma->flags)) return NULL; if (!IS_ALIGNED(size, CMA_MIN_ALIGNMENT_BYTES)) return NULL; if (!IS_ALIGNED(size, (PAGE_SIZE << cma->order_per_bit))) return NULL; size >>= PAGE_SHIFT; if (size > cma->available_count) return NULL; for (r = 0; r < cma->nranges; r++) { cmr = &cma->ranges[r]; available = cmr->count - (cmr->early_pfn - cmr->base_pfn); if (size <= available) { ret = phys_to_virt(PFN_PHYS(cmr->early_pfn)); cmr->early_pfn += size; cma->available_count -= size; return ret; } } return ret; }