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-rw-r--r--mm/cma.c593
1 files changed, 593 insertions, 0 deletions
diff --git a/mm/cma.c b/mm/cma.c
new file mode 100644
index 000000000..2b2494fd6
--- /dev/null
+++ b/mm/cma.c
@@ -0,0 +1,593 @@
+// 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 <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>
+ */
+
+#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/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)
+{
+ 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;
+}
+
+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,
+ unsigned int align_order)
+{
+ return (cma->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, unsigned long pfn,
+ unsigned long count)
+{
+ unsigned long bitmap_no, bitmap_count;
+ unsigned long flags;
+
+ bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
+ bitmap_count = cma_bitmap_pages_to_bits(cma, count);
+
+ spin_lock_irqsave(&cma->lock, flags);
+ bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
+ spin_unlock_irqrestore(&cma->lock, flags);
+}
+
+static void __init cma_activate_area(struct cma *cma)
+{
+ unsigned long base_pfn = cma->base_pfn, pfn;
+ struct zone *zone;
+
+ cma->bitmap = bitmap_zalloc(cma_bitmap_maxno(cma), GFP_KERNEL);
+ if (!cma->bitmap)
+ goto out_error;
+
+ /*
+ * 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));
+ zone = page_zone(pfn_to_page(base_pfn));
+ for (pfn = base_pfn + 1; pfn < base_pfn + cma->count; pfn++) {
+ WARN_ON_ONCE(!pfn_valid(pfn));
+ if (page_zone(pfn_to_page(pfn)) != zone)
+ goto not_in_zone;
+ }
+
+ for (pfn = base_pfn; pfn < base_pfn + cma->count;
+ pfn += pageblock_nr_pages)
+ init_cma_reserved_pageblock(pfn_to_page(pfn));
+
+ spin_lock_init(&cma->lock);
+
+#ifdef CONFIG_CMA_DEBUGFS
+ INIT_HLIST_HEAD(&cma->mem_head);
+ spin_lock_init(&cma->mem_head_lock);
+#endif
+
+ return;
+
+not_in_zone:
+ bitmap_free(cma->bitmap);
+out_error:
+ /* Expose all pages to the buddy, they are useless for CMA. */
+ if (!cma->reserve_pages_on_error) {
+ for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++)
+ free_reserved_page(pfn_to_page(pfn));
+ }
+ totalcma_pages -= cma->count;
+ cma->count = 0;
+ pr_err("CMA area %s could not be activated\n", cma->name);
+ return;
+}
+
+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)
+{
+ cma->reserve_pages_on_error = true;
+}
+
+/**
+ * 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;
+
+ /* 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;
+
+ /* alignment should be aligned with order_per_bit */
+ if (!IS_ALIGNED(CMA_MIN_ALIGNMENT_PAGES, 1 << order_per_bit))
+ return -EINVAL;
+
+ /* ensure minimal alignment required by mm core */
+ if (!IS_ALIGNED(base | size, CMA_MIN_ALIGNMENT_BYTES))
+ 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)
+ snprintf(cma->name, CMA_MAX_NAME, name);
+ else
+ snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", 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;
+}
+
+/**
+ * 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)
+{
+ 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;
+
+ 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)) {
+ ret = -EINVAL;
+ pr_err("Region at %pa must be aligned to %pa bytes\n",
+ &base, &alignment);
+ goto err;
+ }
+ 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;
+
+ if (base + size > limit) {
+ ret = -EINVAL;
+ pr_err("Size (%pa) of region at %pa exceeds limit (%pa)\n",
+ &size, &base, &limit);
+ goto err;
+ }
+
+ /* 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;
+
+ /*
+ * 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) {
+ 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, name, res_cma);
+ if (ret)
+ goto free_mem;
+
+ pr_info("Reserved %ld MiB at %pa on node %d\n", (unsigned long)size / SZ_1M,
+ &base, nid);
+ return 0;
+
+free_mem:
+ memblock_phys_free(base, size);
+err:
+ pr_err("Failed to reserve %ld MiB on node %d\n", (unsigned long)size / SZ_1M,
+ nid);
+ return ret;
+}
+
+#ifdef CONFIG_CMA_DEBUG
+static void cma_debug_show_areas(struct cma *cma)
+{
+ unsigned long next_zero_bit, next_set_bit, nr_zero;
+ unsigned long start = 0;
+ unsigned long nr_part, nr_total = 0;
+ unsigned long nbits = cma_bitmap_maxno(cma);
+
+ spin_lock_irq(&cma->lock);
+ pr_info("number of available pages: ");
+ for (;;) {
+ next_zero_bit = find_next_zero_bit(cma->bitmap, nbits, start);
+ if (next_zero_bit >= nbits)
+ break;
+ next_set_bit = find_next_bit(cma->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", nr_total ? "+" : "", nr_part,
+ next_zero_bit);
+ nr_total += nr_part;
+ start = next_zero_bit + nr_zero;
+ }
+ pr_cont("=> %lu free of %lu total pages\n", nr_total, cma->count);
+ spin_unlock_irq(&cma->lock);
+}
+#else
+static inline void cma_debug_show_areas(struct cma *cma) { }
+#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).
+ * @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)
+{
+ unsigned long mask, offset;
+ unsigned long pfn = -1;
+ unsigned long start = 0;
+ unsigned long bitmap_maxno, bitmap_no, bitmap_count;
+ unsigned long i;
+ struct page *page = NULL;
+ int ret = -ENOMEM;
+
+ if (!cma || !cma->count || !cma->bitmap)
+ goto out;
+
+ pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__,
+ (void *)cma, cma->name, count, align);
+
+ if (!count)
+ goto out;
+
+ trace_cma_alloc_start(cma->name, count, align);
+
+ 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)
+ goto out;
+
+ for (;;) {
+ spin_lock_irq(&cma->lock);
+ bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
+ bitmap_maxno, start, bitmap_count, mask,
+ offset);
+ if (bitmap_no >= bitmap_maxno) {
+ spin_unlock_irq(&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.
+ */
+ spin_unlock_irq(&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_KERNEL | (no_warn ? __GFP_NOWARN : 0));
+ 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 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;
+ }
+
+ trace_cma_alloc_finish(cma->name, pfn, page, count, align, ret);
+
+ /*
+ * 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 && !no_warn) {
+ 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);
+out:
+ if (page) {
+ count_vm_event(CMA_ALLOC_SUCCESS);
+ cma_sysfs_account_success_pages(cma, count);
+ } else {
+ count_vm_event(CMA_ALLOC_FAIL);
+ if (cma)
+ cma_sysfs_account_fail_pages(cma, count);
+ }
+
+ return page;
+}
+
+bool cma_pages_valid(struct cma *cma, const struct page *pages,
+ unsigned long count)
+{
+ unsigned long pfn;
+
+ if (!cma || !pages)
+ return false;
+
+ pfn = page_to_pfn(pages);
+
+ if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count) {
+ pr_debug("%s(page %p, count %lu)\n", __func__,
+ (void *)pages, count);
+ return false;
+ }
+
+ return true;
+}
+
+/**
+ * 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)
+{
+ unsigned long pfn;
+
+ if (!cma_pages_valid(cma, pages, count))
+ return false;
+
+ pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count);
+
+ pfn = page_to_pfn(pages);
+
+ VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
+
+ free_contig_range(pfn, count);
+ cma_clear_bitmap(cma, pfn, count);
+ trace_cma_release(cma->name, pfn, pages, count);
+
+ return true;
+}
+
+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;
+}
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