Ported pcie-brcmstb bounce buffer implementation to ARM64. (#3144)

Ported pcie-brcmstb bounce buffer implementation to ARM64.
This enables full 4G RAM usage on Raspberry Pi in 64-bit mode.

Signed-off-by: Yaroslav Rosomakho <yaroslavros@gmail.com>

arch/arm64/mm/dma-mapping.c

@@ -160,37 +160,6 @@ void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
  __dma_unmap_area(phys_to_virt(paddr), size, dir);
 }
 
-#ifdef CONFIG_IOMMU_DMA
-static int __swiotlb_get_sgtable_page(struct sg_table *sgt,
- struct page *page, size_t size)
-{
- int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
-
- if (!ret)
- sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
-
- return ret;
-}
-
-static int __swiotlb_mmap_pfn(struct vm_area_struct *vma,
- unsigned long pfn, size_t size)
-{
- int ret = -ENXIO;
- unsigned long nr_vma_pages = vma_pages(vma);
- unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
- unsigned long off = vma->vm_pgoff;
-
- if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
- ret = remap_pfn_range(vma, vma->vm_start,
- pfn + off,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
- }
-
- return ret;
-}
-#endif /* CONFIG_IOMMU_DMA */
-
 static int __init atomic_pool_init(void)
 {
  pgprot_t prot = __pgprot(PROT_NORMAL_NC);
@@ -579,9 +548,9 @@ static dma_addr_t __iommu_map_page(struct device *dev, struct page *page,
  int prot = dma_info_to_prot(dir, coherent, attrs);
  dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
 
- if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
- !iommu_dma_mapping_error(dev, dev_addr))
- __dma_map_area(page_address(page) + offset, size, dir);
+ if (!iommu_dma_mapping_error(dev, dev_addr) &&
+ (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
+ __iommu_sync_single_for_device(dev, dev_addr, size, dir);
 
  return dev_addr;
 }

drivers/pci/controller/Makefile

@@ -32,6 +32,9 @@ obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
 ifdef CONFIG_ARM
 obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb-bounce.o
 endif
+ifdef CONFIG_ARM64
+obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb-bounce64.o
+endif
 
 obj-$(CONFIG_VMD) += vmd.o
 # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW

drivers/pci/controller/pcie-brcmstb-bounce.h

@@ -6,7 +6,7 @@
 #ifndef _PCIE_BRCMSTB_BOUNCE_H
 #define _PCIE_BRCMSTB_BOUNCE_H
 
-#ifdef CONFIG_ARM
+#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
 
 int brcm_pcie_bounce_init(struct device *dev, unsigned long buffer_size,
  dma_addr_t threshold);