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Subject[PATCH 2/7] ARM/nommu: use the generic dma-direct code for non-coherent devices
Date
Select the right options to just use the generic dma-direct code
instead of reimplementing it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dillon Min <dillon.minfei@gmail.com>
---
arch/arm/Kconfig | 5 +-
arch/arm/mm/dma-mapping-nommu.c | 173 ++------------------------------
2 files changed, 9 insertions(+), 169 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3ea1c417339f..fcb192bfd35a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -18,8 +18,8 @@ config ARM
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
select ARCH_HAS_STRICT_MODULE_RWX if MMU
- select ARCH_HAS_SYNC_DMA_FOR_DEVICE if SWIOTLB
- select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB
+ select ARCH_HAS_SYNC_DMA_FOR_DEVICE if SWIOTLB || !MMU
+ select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB || !MMU
select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAVE_CUSTOM_GPIO_H
@@ -44,6 +44,7 @@ config ARM
select CPU_PM if SUSPEND || CPU_IDLE
select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
select DMA_DECLARE_COHERENT
+ select DMA_GLOBAL_POOL if !MMU
select DMA_OPS
select DMA_REMAP if MMU
select EDAC_SUPPORT
diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c
index 6bfd2b884505..cfd9c933d2f0 100644
--- a/arch/arm/mm/dma-mapping-nommu.c
+++ b/arch/arm/mm/dma-mapping-nommu.c
@@ -5,12 +5,7 @@
* Copyright (C) 2000-2004 Russell King
*/

-#include <linux/export.h>
-#include <linux/mm.h>
-#include <linux/dma-direct.h>
#include <linux/dma-map-ops.h>
-#include <linux/scatterlist.h>
-
#include <asm/cachetype.h>
#include <asm/cacheflush.h>
#include <asm/outercache.h>
@@ -18,65 +13,8 @@

#include "dma.h"

-/*
- * The generic direct mapping code is used if
- * - MMU/MPU is off
- * - cpu is v7m w/o cache support
- * - device is coherent
- * otherwise arm_nommu_dma_ops is used.
- *
- * arm_nommu_dma_ops rely on consistent DMA memory (please, refer to
- * [1] on how to declare such memory).
- *
- * [1] Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
- */
-
-static void *arm_nommu_dma_alloc(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t gfp,
- unsigned long attrs)
-
-{
- void *ret = dma_alloc_from_global_coherent(dev, size, dma_handle);
-
- /*
- * dma_alloc_from_global_coherent() may fail because:
- *
- * - no consistent DMA region has been defined, so we can't
- * continue.
- * - there is no space left in consistent DMA region, so we
- * only can fallback to generic allocator if we are
- * advertised that consistency is not required.
- */
-
- WARN_ON_ONCE(ret == NULL);
- return ret;
-}
-
-static void arm_nommu_dma_free(struct device *dev, size_t size,
- void *cpu_addr, dma_addr_t dma_addr,
- unsigned long attrs)
-{
- int ret = dma_release_from_global_coherent(get_order(size), cpu_addr);
-
- WARN_ON_ONCE(ret == 0);
-}
-
-static int arm_nommu_dma_mmap(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size,
- unsigned long attrs)
-{
- int ret;
-
- if (dma_mmap_from_global_coherent(vma, cpu_addr, size, &ret))
- return ret;
- if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
- return ret;
- return -ENXIO;
-}
-
-
-static void __dma_page_cpu_to_dev(phys_addr_t paddr, size_t size,
- enum dma_data_direction dir)
+void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
{
dmac_map_area(__va(paddr), size, dir);

@@ -86,8 +24,8 @@ static void __dma_page_cpu_to_dev(phys_addr_t paddr, size_t size,
outer_clean_range(paddr, paddr + size);
}

-static void __dma_page_dev_to_cpu(phys_addr_t paddr, size_t size,
- enum dma_data_direction dir)
+void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
{
if (dir != DMA_TO_DEVICE) {
outer_inv_range(paddr, paddr + size);
@@ -95,102 +33,6 @@ static void __dma_page_dev_to_cpu(phys_addr_t paddr, size_t size,
}
}

-static dma_addr_t arm_nommu_dma_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size,
- enum dma_data_direction dir,
- unsigned long attrs)
-{
- dma_addr_t handle = page_to_phys(page) + offset;
-
- __dma_page_cpu_to_dev(handle, size, dir);
-
- return handle;
-}
-
-static void arm_nommu_dma_unmap_page(struct device *dev, dma_addr_t handle,
- size_t size, enum dma_data_direction dir,
- unsigned long attrs)
-{
- __dma_page_dev_to_cpu(handle, size, dir);
-}
-
-
-static int arm_nommu_dma_map_sg(struct device *dev, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir,
- unsigned long attrs)
-{
- int i;
- struct scatterlist *sg;
-
- for_each_sg(sgl, sg, nents, i) {
- sg_dma_address(sg) = sg_phys(sg);
- sg_dma_len(sg) = sg->length;
- __dma_page_cpu_to_dev(sg_dma_address(sg), sg_dma_len(sg), dir);
- }
-
- return nents;
-}
-
-static void arm_nommu_dma_unmap_sg(struct device *dev, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir,
- unsigned long attrs)
-{
- struct scatterlist *sg;
- int i;
-
- for_each_sg(sgl, sg, nents, i)
- __dma_page_dev_to_cpu(sg_dma_address(sg), sg_dma_len(sg), dir);
-}
-
-static void arm_nommu_dma_sync_single_for_device(struct device *dev,
- dma_addr_t handle, size_t size, enum dma_data_direction dir)
-{
- __dma_page_cpu_to_dev(handle, size, dir);
-}
-
-static void arm_nommu_dma_sync_single_for_cpu(struct device *dev,
- dma_addr_t handle, size_t size, enum dma_data_direction dir)
-{
- __dma_page_cpu_to_dev(handle, size, dir);
-}
-
-static void arm_nommu_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir)
-{
- struct scatterlist *sg;
- int i;
-
- for_each_sg(sgl, sg, nents, i)
- __dma_page_cpu_to_dev(sg_dma_address(sg), sg_dma_len(sg), dir);
-}
-
-static void arm_nommu_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir)
-{
- struct scatterlist *sg;
- int i;
-
- for_each_sg(sgl, sg, nents, i)
- __dma_page_dev_to_cpu(sg_dma_address(sg), sg_dma_len(sg), dir);
-}
-
-const struct dma_map_ops arm_nommu_dma_ops = {
- .alloc = arm_nommu_dma_alloc,
- .free = arm_nommu_dma_free,
- .alloc_pages = dma_direct_alloc_pages,
- .free_pages = dma_direct_free_pages,
- .mmap = arm_nommu_dma_mmap,
- .map_page = arm_nommu_dma_map_page,
- .unmap_page = arm_nommu_dma_unmap_page,
- .map_sg = arm_nommu_dma_map_sg,
- .unmap_sg = arm_nommu_dma_unmap_sg,
- .sync_single_for_device = arm_nommu_dma_sync_single_for_device,
- .sync_single_for_cpu = arm_nommu_dma_sync_single_for_cpu,
- .sync_sg_for_device = arm_nommu_dma_sync_sg_for_device,
- .sync_sg_for_cpu = arm_nommu_dma_sync_sg_for_cpu,
-};
-EXPORT_SYMBOL(arm_nommu_dma_ops);
-
void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
const struct iommu_ops *iommu, bool coherent)
{
@@ -201,14 +43,11 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
* enough to check if MPU is in use or not since in absense of
* MPU system memory map is used.
*/
- dev->archdata.dma_coherent = (cacheid) ? coherent : true;
+ dev->dma_coherent = cacheid ? coherent : true;
} else {
/*
* Assume coherent DMA in case MMU/MPU has not been set up.
*/
- dev->archdata.dma_coherent = (get_cr() & CR_M) ? coherent : true;
+ dev->dma_coherent = (get_cr() & CR_M) ? coherent : true;
}
-
- if (!dev->archdata.dma_coherent)
- set_dma_ops(dev, &arm_nommu_dma_ops);
}
--
2.30.2
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