// 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);} /** * dma_alloc_contiguous() - allocate contiguous pages * @dev:   Pointer to device for which the allocation is performed. * @size:  Requested allocation size. * @gfp:   Allocation flags. * * This function allocates contiguous memory buffer for specified device. It * first tries to use device specific contiguous memory area if available or * the default global one, then tries a fallback allocation of normal pages. * * Note that it byapss one-page size of allocations from the global area as * the addresses within one page are always contiguous, so there is no need * to waste CMA pages for that kind; it also helps reduce fragmentations. */struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp){	size_t count = size >> PAGE_SHIFT;	struct page *page = NULL;	struct cma *cma = NULL; 	if (dev && dev->cma_area)		cma = dev->cma_area;	else if (count > 1)		cma = dma_contiguous_default_area; 	/* CMA can be used only in the context which permits sleeping */	if (cma && gfpflags_allow_blocking(gfp)) {		size_t align = get_order(size);		size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT); 		page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN);	} 	return page;} /** * dma_free_contiguous() - release allocated pages * @dev:   Pointer to device for which the pages were allocated. * @page:  Pointer to the allocated pages. * @size:  Size of allocated pages. * * This function releases memory allocated by dma_alloc_contiguous(). As the * cma_release returns false when provided pages do not belong to contiguous * area and true otherwise, this function then does a fallback __free_pages() * upon a false-return. */void dma_free_contiguous(struct device *dev, struct page *page, size_t size){	if (!cma_release(dev_get_cma_area(dev), page,			 PAGE_ALIGN(size) >> PAGE_SHIFT))		__free_pages(page, get_order(size));} /* * 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