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authorDavid Rientjes <rientjes@google.com>2020-04-15 03:04:52 +0300
committerChristoph Hellwig <hch@lst.de>2020-04-20 13:08:45 +0300
commite860c299ac0d738b44ff91693f11e63080a29698 (patch)
tree83a12cd22838d82b62b71575c7ea6777750137cb /kernel/dma/remap.c
parent05f099a7d0a73114c6eb3e6a359ea97563b47031 (diff)
downloadlinux-e860c299ac0d738b44ff91693f11e63080a29698.tar.xz
dma-remap: separate DMA atomic pools from direct remap code
DMA atomic pools will be needed beyond only CONFIG_DMA_DIRECT_REMAP so separate them out into their own file. This also adds a new Kconfig option that can be subsequently used for options, such as CONFIG_AMD_MEM_ENCRYPT, that will utilize the coherent pools but do not have a dependency on direct remapping. For this patch alone, there is no functional change introduced. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Rientjes <rientjes@google.com> [hch: fixup copyrights and remove unused includes] Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel/dma/remap.c')
-rw-r--r--kernel/dma/remap.c121
1 files changed, 1 insertions, 120 deletions
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
index d14cbc83986a..f7b402849891 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -1,13 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (C) 2012 ARM Ltd.
* Copyright (c) 2014 The Linux Foundation
*/
-#include <linux/dma-direct.h>
-#include <linux/dma-noncoherent.h>
-#include <linux/dma-contiguous.h>
-#include <linux/init.h>
-#include <linux/genalloc.h>
+#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -97,117 +92,3 @@ void dma_common_free_remap(void *cpu_addr, size_t size)
unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
vunmap(cpu_addr);
}
-
-#ifdef CONFIG_DMA_DIRECT_REMAP
-static struct gen_pool *atomic_pool __ro_after_init;
-
-#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
-static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
-
-static int __init early_coherent_pool(char *p)
-{
- atomic_pool_size = memparse(p, &p);
- return 0;
-}
-early_param("coherent_pool", early_coherent_pool);
-
-static gfp_t dma_atomic_pool_gfp(void)
-{
- if (IS_ENABLED(CONFIG_ZONE_DMA))
- return GFP_DMA;
- if (IS_ENABLED(CONFIG_ZONE_DMA32))
- return GFP_DMA32;
- return GFP_KERNEL;
-}
-
-static int __init dma_atomic_pool_init(void)
-{
- unsigned int pool_size_order = get_order(atomic_pool_size);
- unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
- struct page *page;
- void *addr;
- int ret;
-
- if (dev_get_cma_area(NULL))
- page = dma_alloc_from_contiguous(NULL, nr_pages,
- pool_size_order, false);
- else
- page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order);
- if (!page)
- goto out;
-
- arch_dma_prep_coherent(page, atomic_pool_size);
-
- atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
- if (!atomic_pool)
- goto free_page;
-
- addr = dma_common_contiguous_remap(page, atomic_pool_size,
- pgprot_dmacoherent(PAGE_KERNEL),
- __builtin_return_address(0));
- if (!addr)
- goto destroy_genpool;
-
- ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
- page_to_phys(page), atomic_pool_size, -1);
- if (ret)
- goto remove_mapping;
- gen_pool_set_algo(atomic_pool, gen_pool_first_fit_order_align, NULL);
-
- pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
- atomic_pool_size / 1024);
- return 0;
-
-remove_mapping:
- dma_common_free_remap(addr, atomic_pool_size);
-destroy_genpool:
- gen_pool_destroy(atomic_pool);
- atomic_pool = NULL;
-free_page:
- if (!dma_release_from_contiguous(NULL, page, nr_pages))
- __free_pages(page, pool_size_order);
-out:
- pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
- atomic_pool_size / 1024);
- return -ENOMEM;
-}
-postcore_initcall(dma_atomic_pool_init);
-
-bool dma_in_atomic_pool(void *start, size_t size)
-{
- if (unlikely(!atomic_pool))
- return false;
-
- return gen_pool_has_addr(atomic_pool, (unsigned long)start, size);
-}
-
-void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
-{
- unsigned long val;
- void *ptr = NULL;
-
- if (!atomic_pool) {
- WARN(1, "coherent pool not initialised!\n");
- return NULL;
- }
-
- val = gen_pool_alloc(atomic_pool, size);
- if (val) {
- phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
-
- *ret_page = pfn_to_page(__phys_to_pfn(phys));
- ptr = (void *)val;
- memset(ptr, 0, size);
- }
-
- return ptr;
-}
-
-bool dma_free_from_pool(void *start, size_t size)
-{
- if (!dma_in_atomic_pool(start, size))
- return false;
- gen_pool_free(atomic_pool, (unsigned long)start, size);
- return true;
-}
-#endif /* CONFIG_DMA_DIRECT_REMAP */