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![Vitaly Andrianov](/assets/img/avatar_default.png)
This commit changes the CMA early initialization code to use phys_addr_t for representing physical addresses instead of unsigned long. Without this change, among other things, dma_declare_contiguous() simply discards any memory regions whose address is not representable as unsigned long. This is a problem on 32-bit PAE machines where unsigned long is 32-bit but physical address space is larger. Signed-off-by: Vitaly Andrianov <vitalya@ti.com> Signed-off-by: Cyril Chemparathy <cyril@ti.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
390 lines
9.9 KiB
C
390 lines
9.9 KiB
C
/*
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* Contiguous Memory Allocator for DMA mapping framework
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* Copyright (c) 2010-2011 by Samsung Electronics.
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* Written by:
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* Marek Szyprowski <m.szyprowski@samsung.com>
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* Michal Nazarewicz <mina86@mina86.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License or (at your optional) any later version of the license.
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*/
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#define pr_fmt(fmt) "cma: " fmt
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#ifdef CONFIG_CMA_DEBUG
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#ifndef DEBUG
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# define DEBUG
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#endif
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#endif
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#include <asm/page.h>
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#include <asm/dma-contiguous.h>
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#include <linux/memblock.h>
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#include <linux/err.h>
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#include <linux/mm.h>
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#include <linux/mutex.h>
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#include <linux/page-isolation.h>
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#include <linux/sizes.h>
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#include <linux/slab.h>
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#include <linux/swap.h>
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#include <linux/mm_types.h>
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#include <linux/dma-contiguous.h>
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struct cma {
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unsigned long base_pfn;
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unsigned long count;
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unsigned long *bitmap;
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};
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struct cma *dma_contiguous_default_area;
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#ifdef CONFIG_CMA_SIZE_MBYTES
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#define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES
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#else
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#define CMA_SIZE_MBYTES 0
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#endif
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/*
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* Default global CMA area size can be defined in kernel's .config.
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* This is usefull mainly for distro maintainers to create a kernel
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* that works correctly for most supported systems.
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* The size can be set in bytes or as a percentage of the total memory
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* in the system.
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*
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* Users, who want to set the size of global CMA area for their system
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* should use cma= kernel parameter.
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*/
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static const phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M;
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static phys_addr_t size_cmdline = -1;
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static int __init early_cma(char *p)
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{
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pr_debug("%s(%s)\n", __func__, p);
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size_cmdline = memparse(p, &p);
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return 0;
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}
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early_param("cma", early_cma);
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#ifdef CONFIG_CMA_SIZE_PERCENTAGE
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static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
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{
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struct memblock_region *reg;
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unsigned long total_pages = 0;
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/*
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* We cannot use memblock_phys_mem_size() here, because
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* memblock_analyze() has not been called yet.
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*/
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for_each_memblock(memory, reg)
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total_pages += memblock_region_memory_end_pfn(reg) -
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memblock_region_memory_base_pfn(reg);
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return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;
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}
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#else
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static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)
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{
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return 0;
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}
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#endif
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/**
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* dma_contiguous_reserve() - reserve area for contiguous memory handling
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* @limit: End address of the reserved memory (optional, 0 for any).
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*
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* This function reserves memory from early allocator. It should be
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* called by arch specific code once the early allocator (memblock or bootmem)
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* has been activated and all other subsystems have already allocated/reserved
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* memory.
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*/
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void __init dma_contiguous_reserve(phys_addr_t limit)
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{
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phys_addr_t selected_size = 0;
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pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);
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if (size_cmdline != -1) {
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selected_size = size_cmdline;
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} else {
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#ifdef CONFIG_CMA_SIZE_SEL_MBYTES
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selected_size = size_bytes;
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#elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE)
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selected_size = cma_early_percent_memory();
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#elif defined(CONFIG_CMA_SIZE_SEL_MIN)
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selected_size = min(size_bytes, cma_early_percent_memory());
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#elif defined(CONFIG_CMA_SIZE_SEL_MAX)
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selected_size = max(size_bytes, cma_early_percent_memory());
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#endif
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}
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if (selected_size) {
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pr_debug("%s: reserving %ld MiB for global area\n", __func__,
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(unsigned long)selected_size / SZ_1M);
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dma_declare_contiguous(NULL, selected_size, 0, limit);
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}
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};
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static DEFINE_MUTEX(cma_mutex);
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static __init int cma_activate_area(unsigned long base_pfn, unsigned long count)
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{
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unsigned long pfn = base_pfn;
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unsigned i = count >> pageblock_order;
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struct zone *zone;
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WARN_ON_ONCE(!pfn_valid(pfn));
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zone = page_zone(pfn_to_page(pfn));
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do {
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unsigned j;
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base_pfn = pfn;
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for (j = pageblock_nr_pages; j; --j, pfn++) {
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WARN_ON_ONCE(!pfn_valid(pfn));
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if (page_zone(pfn_to_page(pfn)) != zone)
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return -EINVAL;
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}
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init_cma_reserved_pageblock(pfn_to_page(base_pfn));
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} while (--i);
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return 0;
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}
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static __init struct cma *cma_create_area(unsigned long base_pfn,
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unsigned long count)
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{
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int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
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struct cma *cma;
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int ret = -ENOMEM;
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pr_debug("%s(base %08lx, count %lx)\n", __func__, base_pfn, count);
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cma = kmalloc(sizeof *cma, GFP_KERNEL);
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if (!cma)
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return ERR_PTR(-ENOMEM);
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cma->base_pfn = base_pfn;
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cma->count = count;
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cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
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if (!cma->bitmap)
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goto no_mem;
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ret = cma_activate_area(base_pfn, count);
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if (ret)
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goto error;
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pr_debug("%s: returned %p\n", __func__, (void *)cma);
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return cma;
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error:
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kfree(cma->bitmap);
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no_mem:
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kfree(cma);
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return ERR_PTR(ret);
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}
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static struct cma_reserved {
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phys_addr_t start;
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unsigned long size;
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struct device *dev;
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} cma_reserved[MAX_CMA_AREAS] __initdata;
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static unsigned cma_reserved_count __initdata;
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static int __init cma_init_reserved_areas(void)
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{
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struct cma_reserved *r = cma_reserved;
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unsigned i = cma_reserved_count;
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pr_debug("%s()\n", __func__);
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for (; i; --i, ++r) {
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struct cma *cma;
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cma = cma_create_area(PFN_DOWN(r->start),
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r->size >> PAGE_SHIFT);
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if (!IS_ERR(cma))
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dev_set_cma_area(r->dev, cma);
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}
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return 0;
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}
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core_initcall(cma_init_reserved_areas);
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/**
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* dma_declare_contiguous() - reserve area for contiguous memory handling
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* for particular device
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* @dev: Pointer to device structure.
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* @size: Size of the reserved memory.
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* @base: Start address of the reserved memory (optional, 0 for any).
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* @limit: End address of the reserved memory (optional, 0 for any).
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*
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* This function reserves memory for specified device. It should be
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* called by board specific code when early allocator (memblock or bootmem)
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* is still activate.
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*/
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int __init dma_declare_contiguous(struct device *dev, phys_addr_t size,
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phys_addr_t base, phys_addr_t limit)
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{
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struct cma_reserved *r = &cma_reserved[cma_reserved_count];
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phys_addr_t alignment;
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pr_debug("%s(size %lx, base %08lx, limit %08lx)\n", __func__,
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(unsigned long)size, (unsigned long)base,
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(unsigned long)limit);
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/* Sanity checks */
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if (cma_reserved_count == ARRAY_SIZE(cma_reserved)) {
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pr_err("Not enough slots for CMA reserved regions!\n");
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return -ENOSPC;
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}
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if (!size)
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return -EINVAL;
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/* Sanitise input arguments */
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alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
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base = ALIGN(base, alignment);
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size = ALIGN(size, alignment);
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limit &= ~(alignment - 1);
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/* Reserve memory */
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if (base) {
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if (memblock_is_region_reserved(base, size) ||
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memblock_reserve(base, size) < 0) {
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base = -EBUSY;
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goto err;
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}
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} else {
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/*
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* Use __memblock_alloc_base() since
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* memblock_alloc_base() panic()s.
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*/
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phys_addr_t addr = __memblock_alloc_base(size, alignment, limit);
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if (!addr) {
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base = -ENOMEM;
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goto err;
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} else {
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base = addr;
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}
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}
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/*
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* Each reserved area must be initialised later, when more kernel
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* subsystems (like slab allocator) are available.
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*/
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r->start = base;
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r->size = size;
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r->dev = dev;
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cma_reserved_count++;
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pr_info("CMA: reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M,
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(unsigned long)base);
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/* Architecture specific contiguous memory fixup. */
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dma_contiguous_early_fixup(base, size);
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return 0;
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err:
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pr_err("CMA: failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
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return base;
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}
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/**
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* dma_alloc_from_contiguous() - allocate pages from contiguous area
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* @dev: Pointer to device for which the allocation is performed.
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* @count: Requested number of pages.
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* @align: Requested alignment of pages (in PAGE_SIZE order).
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*
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* This function allocates memory buffer for specified device. It uses
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* device specific contiguous memory area if available or the default
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* global one. Requires architecture specific get_dev_cma_area() helper
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* function.
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*/
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struct page *dma_alloc_from_contiguous(struct device *dev, int count,
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unsigned int align)
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{
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unsigned long mask, pfn, pageno, start = 0;
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struct cma *cma = dev_get_cma_area(dev);
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struct page *page = NULL;
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int ret;
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if (!cma || !cma->count)
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return NULL;
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if (align > CONFIG_CMA_ALIGNMENT)
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align = CONFIG_CMA_ALIGNMENT;
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pr_debug("%s(cma %p, count %d, align %d)\n", __func__, (void *)cma,
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count, align);
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if (!count)
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return NULL;
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mask = (1 << align) - 1;
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mutex_lock(&cma_mutex);
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for (;;) {
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pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
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start, count, mask);
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if (pageno >= cma->count)
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break;
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pfn = cma->base_pfn + pageno;
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ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
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if (ret == 0) {
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bitmap_set(cma->bitmap, pageno, count);
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page = pfn_to_page(pfn);
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break;
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} else if (ret != -EBUSY) {
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break;
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}
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pr_debug("%s(): memory range at %p is busy, retrying\n",
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__func__, pfn_to_page(pfn));
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/* try again with a bit different memory target */
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start = pageno + mask + 1;
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}
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mutex_unlock(&cma_mutex);
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pr_debug("%s(): returned %p\n", __func__, page);
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return page;
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}
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/**
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* dma_release_from_contiguous() - release allocated pages
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* @dev: Pointer to device for which the pages were allocated.
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* @pages: Allocated pages.
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* @count: Number of allocated pages.
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*
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* This function releases memory allocated by dma_alloc_from_contiguous().
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* It returns false when provided pages do not belong to contiguous area and
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* true otherwise.
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*/
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bool dma_release_from_contiguous(struct device *dev, struct page *pages,
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int count)
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{
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struct cma *cma = dev_get_cma_area(dev);
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unsigned long pfn;
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if (!cma || !pages)
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return false;
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pr_debug("%s(page %p)\n", __func__, (void *)pages);
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pfn = page_to_pfn(pages);
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if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
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return false;
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VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
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mutex_lock(&cma_mutex);
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bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count);
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free_contig_range(pfn, count);
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mutex_unlock(&cma_mutex);
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return true;
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}
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