ARM/nommu: use the generic dma-direct code for non-coherent devices

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>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2fb7012..4faa11d 100644 (file)
--- 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 6bfd2b8..cfd9c93 100644 (file)
--- 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);
 }