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 <h...@lst.de>
Signed-off-by: David Rientjes <rient...@google.com>
---
kernel/dma/Kconfig | 6 ++-
kernel/dma/Makefile | 1 +
kernel/dma/pool.c | 123 ++++++++++++++++++++++++++++++++++++++++++++
kernel/dma/remap.c | 114 ----------------------------------------
4 files changed, 129 insertions(+), 115 deletions(-)
create mode 100644 kernel/dma/pool.c
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 4c103a24e380..d006668c0027 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -79,10 +79,14 @@ config DMA_REMAP
select DMA_NONCOHERENT_MMAP
bool
-config DMA_DIRECT_REMAP
+config DMA_COHERENT_POOL
bool
select DMA_REMAP
+config DMA_DIRECT_REMAP
+ bool
+ select DMA_COHERENT_POOL
+
config DMA_CMA
bool "DMA Contiguous Memory Allocator"
depends on HAVE_DMA_CONTIGUOUS && CMA
diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile
index d237cf3dc181..370f63344e9c 100644
--- a/kernel/dma/Makefile
+++ b/kernel/dma/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_DMA_DECLARE_COHERENT) += coherent.o
obj-$(CONFIG_DMA_VIRT_OPS) += virt.o
obj-$(CONFIG_DMA_API_DEBUG) += debug.o
obj-$(CONFIG_SWIOTLB) += swiotlb.o
+obj-$(CONFIG_DMA_COHERENT_POOL) += pool.o
obj-$(CONFIG_DMA_REMAP) += remap.o
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
new file mode 100644
index 000000000000..6612c2d51d3c
--- /dev/null
+++ b/kernel/dma/pool.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Google LLC
+ */
+#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/slab.h>
+#include <linux/vmalloc.h>
+
+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;
+}
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
index d14cbc83986a..081486007342 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -97,117 +97,3 @@ 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 */
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