Merge pull request #37 from dayeol/dev-cma

Enable CMA in the kernel and the driver

patches/linux-cma.patch

@@ -0,0 +1,76 @@
+diff --git arch/riscv/mm/dma.c arch/riscv/mm/dma.c
+index 0689bb2..9fa9f11 100644
+--- arch/riscv/mm/dma.c
++++ arch/riscv/mm/dma.c
+@@ -20,6 +20,7 @@
+ #include <linux/gfp.h>
+ #include <linux/mm.h>
+ #include <linux/dma-mapping.h>
++#include <linux/dma-contiguous.h>
+ #include <linux/scatterlist.h>
+ #include <linux/swiotlb.h>
+
+@@ -35,14 +36,41 @@ static void *dma_riscv_alloc(struct device *dev, size_t size,
+ 		gfp |= __GFP_DMA32;
+ 	}
+
+-	return swiotlb_alloc_coherent(dev, size, dma_handle, gfp);
++	if (dev_get_cma_area(dev) && gfpflags_allow_blocking(gfp)) {
++		void* addr;
++		struct page *page;
++		page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
++				get_order(size), gfp);
++		if (!page)
++		{
++			pr_err("Unabled to allocated from contiguous memory\n");
++			return NULL;
++		}
++
++		*dma_handle = phys_to_dma(dev, page_to_phys(page));
++		addr = page_address(page);
++		memset(addr, 0, size);
++		return addr;
++	} else {
++		return swiotlb_alloc_coherent(dev, size, dma_handle, gfp);
++	}
+ }
+
+ static void dma_riscv_free(struct device *dev, size_t size,
+                           void *cpu_addr, dma_addr_t dma_addr,
+                           unsigned long attrs)
+ {
+-	return swiotlb_free_coherent(dev, size, cpu_addr, dma_addr);
++	bool freed;
++	phys_addr_t paddr = dma_to_phys(dev, dma_addr);
++
++	freed = dma_release_from_contiguous(dev, 
++			phys_to_page(paddr), 
++			size >> PAGE_SHIFT);
++ 	if(!freed) {
++		swiotlb_free_coherent(dev, size, cpu_addr, dma_addr);
++	}
++	
++	return;
+ }
+
+ static int dma_riscv_supported(struct device *dev, u64 mask)
+diff --git arch/riscv/mm/init.c arch/riscv/mm/init.c
+index c77df81..312c84d 100644
+--- arch/riscv/mm/init.c
++++ arch/riscv/mm/init.c
+@@ -18,6 +18,7 @@
+ #include <linux/memblock.h>
+ #include <linux/swap.h>
+ #include <linux/sizes.h>
++#include <linux/dma-contiguous.h>
+
+ #include <asm/tlbflush.h>
+ #include <asm/sections.h>
+@@ -44,6 +45,7 @@ void __init paging_init(void)
+ 	setup_zero_page();
+ 	local_flush_tlb_all();
+ 	zone_sizes_init();
++  dma_contiguous_reserve(memblock_end_of_DRAM());
+ }
+
+ void __init mem_init(void)

scripts/apply-patch.sh

@@ -1,3 +1,10 @@
 #!/usr/bin/env bash
 cd riscv-qemu
-patch -p0 --forward hw/riscv/boot.c < ../patches/qemu-kernel-reloc.patch || true
+patch --forward hw/riscv/boot.c < ../patches/qemu-kernel-reloc.patch || true
+cd ..
+
+# linux patch
+cd riscv-linux
+patch -p0 --forward <  ../patches/linux-cma.patch || true
+cd ..
+