[PATCH 4/6] dma-mapping: make dma_atomic_pool_init self-contained

From: Christoph Hellwig
Date: Mon Aug 26 2019 - 09:26:23 EST


The memory allocated for the atomic pool needs to have the same
mapping attributes that we use for remapping, so use
pgprot_dmacoherent instead of open coding it. Also deduct a
suitable zone to allocate the memory from based on the presence
of the DMA zones.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/arc/mm/dma.c | 6 ------
arch/arm64/mm/dma-mapping.c | 6 ------
arch/csky/mm/dma-mapping.c | 6 ------
arch/nds32/kernel/dma.c | 6 ------
include/linux/dma-mapping.h | 1 -
kernel/dma/remap.c | 17 ++++++++++++++---
6 files changed, 14 insertions(+), 28 deletions(-)

diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 62c210e7ee4c..ff4a5752f8cc 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -104,9 +104,3 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
dev_info(dev, "use %sncoherent DMA ops\n",
dev->dma_coherent ? "" : "non");
}
-
-static int __init atomic_pool_init(void)
-{
- return dma_atomic_pool_init(GFP_KERNEL, pgprot_noncached(PAGE_KERNEL));
-}
-postcore_initcall(atomic_pool_init);
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 676efcda51e6..a1d05f669f67 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -28,12 +28,6 @@ void arch_dma_prep_coherent(struct page *page, size_t size)
__dma_flush_area(page_address(page), size);
}

-static int __init arm64_dma_init(void)
-{
- return dma_atomic_pool_init(GFP_DMA32, __pgprot(PROT_NORMAL_NC));
-}
-arch_initcall(arm64_dma_init);
-
#ifdef CONFIG_IOMMU_DMA
void arch_teardown_dma_ops(struct device *dev)
{
diff --git a/arch/csky/mm/dma-mapping.c b/arch/csky/mm/dma-mapping.c
index 80783bb71c5c..602a60d47a94 100644
--- a/arch/csky/mm/dma-mapping.c
+++ b/arch/csky/mm/dma-mapping.c
@@ -14,12 +14,6 @@
#include <linux/version.h>
#include <asm/cache.h>

-static int __init atomic_pool_init(void)
-{
- return dma_atomic_pool_init(GFP_KERNEL, pgprot_noncached(PAGE_KERNEL));
-}
-postcore_initcall(atomic_pool_init);
-
void arch_dma_prep_coherent(struct page *page, size_t size)
{
if (PageHighMem(page)) {
diff --git a/arch/nds32/kernel/dma.c b/arch/nds32/kernel/dma.c
index 490e3720d694..4206d4b6c8ce 100644
--- a/arch/nds32/kernel/dma.c
+++ b/arch/nds32/kernel/dma.c
@@ -80,9 +80,3 @@ void arch_dma_prep_coherent(struct page *page, size_t size)
{
cache_op(page_to_phys(page), size, cpu_dma_wbinval_range);
}
-
-static int __init atomic_pool_init(void)
-{
- return dma_atomic_pool_init(GFP_KERNEL, pgprot_noncached(PAGE_KERNEL));
-}
-postcore_initcall(atomic_pool_init);
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f7d1eea32c78..48ebe8295987 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -624,7 +624,6 @@ void *dma_common_pages_remap(struct page **pages, size_t size,
const void *caller);
void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags);

-int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot);
bool dma_in_atomic_pool(void *start, size_t size);
void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags);
bool dma_free_from_pool(void *start, size_t size);
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
index ffe78f0b2fe4..838123f79639 100644
--- a/kernel/dma/remap.c
+++ b/kernel/dma/remap.c
@@ -105,7 +105,16 @@ static int __init early_coherent_pool(char *p)
}
early_param("coherent_pool", early_coherent_pool);

-int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
+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;
@@ -117,7 +126,7 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
page = dma_alloc_from_contiguous(NULL, nr_pages,
pool_size_order, false);
else
- page = alloc_pages(gfp, pool_size_order);
+ page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order);
if (!page)
goto out;

@@ -128,7 +137,8 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
goto free_page;

addr = dma_common_contiguous_remap(page, atomic_pool_size, VM_USERMAP,
- prot, __builtin_return_address(0));
+ pgprot_dmacoherent(PAGE_KERNEL),
+ __builtin_return_address(0));
if (!addr)
goto destroy_genpool;

@@ -155,6 +165,7 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
atomic_pool_size / 1024);
return -ENOMEM;
}
+postcore_initcall(dma_atomic_pool_init);

bool dma_in_atomic_pool(void *start, size_t size)
{
--
2.20.1