arm64: Enable CMA

arm64 bit targets need the features CMA provides. Add the appropriate
hooks, header files, and Kconfig to allow this to happen.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

4 files changed, 56 insertions, 2 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index cb9421b540c8..101683d336c9 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -27,6 +27,7 @@ config ARM64
         select HAVE_DEBUG_KMEMLEAK
         select HAVE_DMA_API_DEBUG
         select HAVE_DMA_ATTRS
+        select HAVE_DMA_CONTIGUOUS
         select HAVE_EFFICIENT_UNALIGNED_ACCESS
         select HAVE_GENERIC_DMA_COHERENT
         select HAVE_HW_BREAKPOINT if PERF_EVENTS
diff --git a/arch/arm64/include/asm/dma-contiguous.h b/arch/arm64/include/asm/dma-contiguous.h
new file mode 100644
index 000000000000..d6aacb61ff4a
--- /dev/null
+++ b/arch/arm64/include/asm/dma-contiguous.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _ASM_DMA_CONTIGUOUS_H
+#define _ASM_DMA_CONTIGUOUS_H
+
+#ifdef __KERNEL__
+#ifdef CONFIG_DMA_CMA
+
+#include <linux/types.h>
+#include <asm-generic/dma-contiguous.h>
+
+static inline void
+dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) { }
+
+#endif
+#endif
+
+#endif
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 83e643131e10..45b5ab54c9ee 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -21,6 +21,7 @@
 #include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
+#include <linux/dma-contiguous.h>
 #include <linux/vmalloc.h>
 #include <linux/swiotlb.h>
 
@@ -41,7 +42,19 @@ static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size,
         if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
             dev->coherent_dma_mask <= DMA_BIT_MASK(32))
                 flags |= GFP_DMA32;
-        return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
+        if (IS_ENABLED(CONFIG_DMA_CMA)) {
+                struct page *page;
+
+                page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
+                                                        get_order(size));
+                if (!page)
+                        return NULL;
+
+                *dma_handle = phys_to_dma(dev, page_to_phys(page));
+                return page_address(page);
+        } else {
+                return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
+        }
 }
 
 static void arm64_swiotlb_free_coherent(struct device *dev, size_t size,
@@ -53,7 +66,15 @@ static void arm64_swiotlb_free_coherent(struct device *dev, size_t size,
                 return;
         }
 
-        swiotlb_free_coherent(dev, size, vaddr, dma_handle);
+        if (IS_ENABLED(CONFIG_DMA_CMA)) {
+                phys_addr_t paddr = dma_to_phys(dev, dma_handle);
+
+                dma_release_from_contiguous(dev,
+                                        phys_to_page(paddr),
+                                        size >> PAGE_SHIFT);
+        } else {
+                swiotlb_free_coherent(dev, size, vaddr, dma_handle);
+        }
 }
 
 static struct dma_map_ops arm64_swiotlb_dma_ops = {
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 0cb8742de4f2..d0b4c2efda90 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -30,6 +30,7 @@
 #include <linux/memblock.h>
 #include <linux/sort.h>
 #include <linux/of_fdt.h>
+#include <linux/dma-contiguous.h>
 
 #include <asm/sections.h>
 #include <asm/setup.h>
@@ -159,6 +160,8 @@ void __init arm64_memblock_init(void)
                 memblock_reserve(base, size);
         }
 
+        dma_contiguous_reserve(0);
+
         memblock_allow_resize();
         memblock_dump_all();
 }