v4.19.13 snapshot.
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
new file mode 100644
index 0000000..b2a87905
--- /dev/null
+++ b/kernel/dma/contiguous.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Contiguous Memory Allocator for DMA mapping framework
+ * Copyright (c) 2010-2011 by Samsung Electronics.
+ * Written by:
+ * Marek Szyprowski <m.szyprowski@samsung.com>
+ * Michal Nazarewicz <mina86@mina86.com>
+ */
+
+#define pr_fmt(fmt) "cma: " fmt
+
+#ifdef CONFIG_CMA_DEBUG
+#ifndef DEBUG
+# define DEBUG
+#endif
+#endif
+
+#include <asm/page.h>
+#include <asm/dma-contiguous.h>
+
+#include <linux/memblock.h>
+#include <linux/err.h>
+#include <linux/sizes.h>
+#include <linux/dma-contiguous.h>
+#include <linux/cma.h>
+
+#ifdef CONFIG_CMA_SIZE_MBYTES
+#define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES
+#else
+#define CMA_SIZE_MBYTES 0
+#endif
+
+struct cma *dma_contiguous_default_area;
+
+/*
+ * Default global CMA area size can be defined in kernel's .config.
+ * This is useful mainly for distro maintainers to create a kernel
+ * that works correctly for most supported systems.
+ * The size can be set in bytes or as a percentage of the total memory
+ * in the system.
+ *
+ * Users, who want to set the size of global CMA area for their system
+ * should use cma= kernel parameter.
+ */
+static const phys_addr_t size_bytes = (phys_addr_t)CMA_SIZE_MBYTES * SZ_1M;
+static phys_addr_t size_cmdline = -1;
+static phys_addr_t base_cmdline;
+static phys_addr_t limit_cmdline;
+
+static int __init early_cma(char *p)
+{
+ if (!p) {
+ pr_err("Config string not provided\n");
+ return -EINVAL;
+ }
+
+ size_cmdline = memparse(p, &p);
+ if (*p != '@')
+ return 0;
+ base_cmdline = memparse(p + 1, &p);
+ if (*p != '-') {
+ limit_cmdline = base_cmdline + size_cmdline;
+ return 0;
+ }
+ limit_cmdline = memparse(p + 1, &p);
+
+ return 0;
+}
+early_param("cma", early_cma);
+
+#ifdef CONFIG_CMA_SIZE_PERCENTAGE
+
+static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
+{
+ struct memblock_region *reg;
+ unsigned long total_pages = 0;
+
+ /*
+ * We cannot use memblock_phys_mem_size() here, because
+ * memblock_analyze() has not been called yet.
+ */
+ for_each_memblock(memory, reg)
+ total_pages += memblock_region_memory_end_pfn(reg) -
+ memblock_region_memory_base_pfn(reg);
+
+ return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;
+}
+
+#else
+
+static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)
+{
+ return 0;
+}
+
+#endif
+
+/**
+ * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling
+ * @limit: End address of the reserved memory (optional, 0 for any).
+ *
+ * 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.
+ */
+void __init dma_contiguous_reserve(phys_addr_t limit)
+{
+ phys_addr_t selected_size = 0;
+ phys_addr_t selected_base = 0;
+ phys_addr_t selected_limit = limit;
+ bool fixed = false;
+
+ pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);
+
+ if (size_cmdline != -1) {
+ selected_size = size_cmdline;
+ selected_base = base_cmdline;
+ selected_limit = min_not_zero(limit_cmdline, limit);
+ if (base_cmdline + size_cmdline == limit_cmdline)
+ fixed = true;
+ } else {
+#ifdef CONFIG_CMA_SIZE_SEL_MBYTES
+ selected_size = size_bytes;
+#elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE)
+ selected_size = cma_early_percent_memory();
+#elif defined(CONFIG_CMA_SIZE_SEL_MIN)
+ selected_size = min(size_bytes, cma_early_percent_memory());
+#elif defined(CONFIG_CMA_SIZE_SEL_MAX)
+ selected_size = max(size_bytes, cma_early_percent_memory());
+#endif
+ }
+
+ if (selected_size && !dma_contiguous_default_area) {
+ pr_debug("%s: reserving %ld MiB for global area\n", __func__,
+ (unsigned long)selected_size / SZ_1M);
+
+ dma_contiguous_reserve_area(selected_size, selected_base,
+ selected_limit,
+ &dma_contiguous_default_area,
+ fixed);
+ }
+}
+
+/**
+ * dma_contiguous_reserve_area() - reserve custom contiguous area
+ * @size: Size of the reserved area (in bytes),
+ * @base: Base address of the reserved area optional, use 0 for any
+ * @limit: End address of the reserved memory (optional, 0 for any).
+ * @res_cma: Pointer to store the created cma region.
+ * @fixed: hint about where to place the reserved area
+ *
+ * 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 for specific
+ * devices.
+ *
+ * If @fixed is true, reserve contiguous area at exactly @base. If false,
+ * reserve in range from @base to @limit.
+ */
+int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
+ phys_addr_t limit, struct cma **res_cma,
+ bool fixed)
+{
+ int ret;
+
+ ret = cma_declare_contiguous(base, size, limit, 0, 0, fixed,
+ "reserved", res_cma);
+ if (ret)
+ return ret;
+
+ /* Architecture specific contiguous memory fixup. */
+ dma_contiguous_early_fixup(cma_get_base(*res_cma),
+ cma_get_size(*res_cma));
+
+ return 0;
+}
+
+/**
+ * dma_alloc_from_contiguous() - allocate pages from contiguous area
+ * @dev: Pointer to device 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 memory buffer for specified device. It uses
+ * device specific contiguous memory area if available or the default
+ * global one. Requires architecture specific dev_get_cma_area() helper
+ * function.
+ */
+struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
+ unsigned int align, bool no_warn)
+{
+ if (align > CONFIG_CMA_ALIGNMENT)
+ align = CONFIG_CMA_ALIGNMENT;
+
+ return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);
+}
+
+/**
+ * dma_release_from_contiguous() - release allocated pages
+ * @dev: Pointer to device for which the pages were allocated.
+ * @pages: Allocated pages.
+ * @count: Number of allocated pages.
+ *
+ * This function releases memory allocated by dma_alloc_from_contiguous().
+ * It returns false when provided pages do not belong to contiguous area and
+ * true otherwise.
+ */
+bool dma_release_from_contiguous(struct device *dev, struct page *pages,
+ int count)
+{
+ return cma_release(dev_get_cma_area(dev), pages, count);
+}
+
+/*
+ * Support for reserved memory regions defined in device tree
+ */
+#ifdef CONFIG_OF_RESERVED_MEM
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) fmt
+
+static int rmem_cma_device_init(struct reserved_mem *rmem, struct device *dev)
+{
+ dev_set_cma_area(dev, rmem->priv);
+ return 0;
+}
+
+static void rmem_cma_device_release(struct reserved_mem *rmem,
+ struct device *dev)
+{
+ dev_set_cma_area(dev, NULL);
+}
+
+static const struct reserved_mem_ops rmem_cma_ops = {
+ .device_init = rmem_cma_device_init,
+ .device_release = rmem_cma_device_release,
+};
+
+static int __init rmem_cma_setup(struct reserved_mem *rmem)
+{
+ phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
+ phys_addr_t mask = align - 1;
+ unsigned long node = rmem->fdt_node;
+ struct cma *cma;
+ int err;
+
+ if (!of_get_flat_dt_prop(node, "reusable", NULL) ||
+ of_get_flat_dt_prop(node, "no-map", NULL))
+ return -EINVAL;
+
+ if ((rmem->base & mask) || (rmem->size & mask)) {
+ pr_err("Reserved memory: incorrect alignment of CMA region\n");
+ return -EINVAL;
+ }
+
+ err = cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name, &cma);
+ if (err) {
+ pr_err("Reserved memory: unable to setup CMA region\n");
+ return err;
+ }
+ /* Architecture specific contiguous memory fixup. */
+ dma_contiguous_early_fixup(rmem->base, rmem->size);
+
+ if (of_get_flat_dt_prop(node, "linux,cma-default", NULL))
+ dma_contiguous_set_default(cma);
+
+ rmem->ops = &rmem_cma_ops;
+ rmem->priv = cma;
+
+ pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n",
+ &rmem->base, (unsigned long)rmem->size / SZ_1M);
+
+ return 0;
+}
+RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", rmem_cma_setup);
+#endif