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![Huang Shijie](/assets/img/avatar_default.png)
Follow the kernel conventions, rename addr_in_gen_pool to gen_pool_has_addr. [sjhuang@iluvatar.ai: fix Documentation/ too] Link: http://lkml.kernel.org/r/20181229015914.5573-1-sjhuang@iluvatar.ai Link: http://lkml.kernel.org/r/20181228083950.20398-1-sjhuang@iluvatar.ai Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
213 lines
4.9 KiB
C
213 lines
4.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2012 ARM Ltd.
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* Copyright (c) 2014 The Linux Foundation
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*/
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#include <linux/dma-direct.h>
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#include <linux/dma-noncoherent.h>
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#include <linux/dma-contiguous.h>
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#include <linux/init.h>
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#include <linux/genalloc.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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struct page **dma_common_find_pages(void *cpu_addr)
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{
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struct vm_struct *area = find_vm_area(cpu_addr);
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if (!area || area->flags != VM_DMA_COHERENT)
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return NULL;
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return area->pages;
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}
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static struct vm_struct *__dma_common_pages_remap(struct page **pages,
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size_t size, pgprot_t prot, const void *caller)
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{
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struct vm_struct *area;
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area = get_vm_area_caller(size, VM_DMA_COHERENT, caller);
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if (!area)
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return NULL;
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if (map_vm_area(area, prot, pages)) {
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vunmap(area->addr);
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return NULL;
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}
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return area;
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}
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/*
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* Remaps an array of PAGE_SIZE pages into another vm_area.
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* Cannot be used in non-sleeping contexts
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*/
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void *dma_common_pages_remap(struct page **pages, size_t size,
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pgprot_t prot, const void *caller)
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{
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struct vm_struct *area;
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area = __dma_common_pages_remap(pages, size, prot, caller);
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if (!area)
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return NULL;
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area->pages = pages;
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return area->addr;
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}
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/*
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* Remaps an allocated contiguous region into another vm_area.
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* Cannot be used in non-sleeping contexts
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*/
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void *dma_common_contiguous_remap(struct page *page, size_t size,
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pgprot_t prot, const void *caller)
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{
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int i;
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struct page **pages;
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struct vm_struct *area;
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pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
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if (!pages)
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return NULL;
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for (i = 0; i < (size >> PAGE_SHIFT); i++)
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pages[i] = nth_page(page, i);
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area = __dma_common_pages_remap(pages, size, prot, caller);
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kfree(pages);
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if (!area)
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return NULL;
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return area->addr;
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}
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/*
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* Unmaps a range previously mapped by dma_common_*_remap
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*/
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void dma_common_free_remap(void *cpu_addr, size_t size)
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{
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struct vm_struct *area = find_vm_area(cpu_addr);
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if (!area || area->flags != VM_DMA_COHERENT) {
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WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
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return;
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}
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unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
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vunmap(cpu_addr);
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}
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#ifdef CONFIG_DMA_DIRECT_REMAP
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static struct gen_pool *atomic_pool __ro_after_init;
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#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
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static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
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static int __init early_coherent_pool(char *p)
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{
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atomic_pool_size = memparse(p, &p);
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return 0;
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}
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early_param("coherent_pool", early_coherent_pool);
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static gfp_t dma_atomic_pool_gfp(void)
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{
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if (IS_ENABLED(CONFIG_ZONE_DMA))
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return GFP_DMA;
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if (IS_ENABLED(CONFIG_ZONE_DMA32))
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return GFP_DMA32;
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return GFP_KERNEL;
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}
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static int __init dma_atomic_pool_init(void)
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{
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unsigned int pool_size_order = get_order(atomic_pool_size);
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unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
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struct page *page;
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void *addr;
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int ret;
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if (dev_get_cma_area(NULL))
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page = dma_alloc_from_contiguous(NULL, nr_pages,
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pool_size_order, false);
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else
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page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order);
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if (!page)
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goto out;
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arch_dma_prep_coherent(page, atomic_pool_size);
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atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
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if (!atomic_pool)
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goto free_page;
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addr = dma_common_contiguous_remap(page, atomic_pool_size,
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pgprot_dmacoherent(PAGE_KERNEL),
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__builtin_return_address(0));
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if (!addr)
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goto destroy_genpool;
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ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
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page_to_phys(page), atomic_pool_size, -1);
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if (ret)
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goto remove_mapping;
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gen_pool_set_algo(atomic_pool, gen_pool_first_fit_order_align, NULL);
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pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
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atomic_pool_size / 1024);
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return 0;
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remove_mapping:
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dma_common_free_remap(addr, atomic_pool_size);
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destroy_genpool:
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gen_pool_destroy(atomic_pool);
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atomic_pool = NULL;
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free_page:
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if (!dma_release_from_contiguous(NULL, page, nr_pages))
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__free_pages(page, pool_size_order);
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out:
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pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
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atomic_pool_size / 1024);
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return -ENOMEM;
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}
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postcore_initcall(dma_atomic_pool_init);
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bool dma_in_atomic_pool(void *start, size_t size)
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{
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if (unlikely(!atomic_pool))
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return false;
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return gen_pool_has_addr(atomic_pool, (unsigned long)start, size);
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}
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void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
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{
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unsigned long val;
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void *ptr = NULL;
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if (!atomic_pool) {
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WARN(1, "coherent pool not initialised!\n");
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return NULL;
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}
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val = gen_pool_alloc(atomic_pool, size);
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if (val) {
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phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
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*ret_page = pfn_to_page(__phys_to_pfn(phys));
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ptr = (void *)val;
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memset(ptr, 0, size);
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}
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return ptr;
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}
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bool dma_free_from_pool(void *start, size_t size)
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{
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if (!dma_in_atomic_pool(start, size))
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return false;
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gen_pool_free(atomic_pool, (unsigned long)start, size);
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return true;
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}
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#endif /* CONFIG_DMA_DIRECT_REMAP */
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