Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 150 insertions, 0 deletions

diff --git a/kernel/arch/mips/loongson/common/dma-swiotlb.c b/kernel/arch/mips/loongson/common/dma-swiotlb.c
new file mode 100644
index 000000000..2c6b989c1
--- /dev/null
+++ b/kernel/arch/mips/loongson/common/dma-swiotlb.c
@@ -0,0 +1,150 @@
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+#include <linux/swiotlb.h>
+#include <linux/bootmem.h>
+
+#include <asm/bootinfo.h>
+#include <boot_param.h>
+#include <dma-coherence.h>
+
+static void *loongson_dma_alloc_coherent(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs *attrs)
+{
+	void *ret;
+
+	if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
+		return ret;
+
+	/* ignore region specifiers */
+	gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
+
+#ifdef CONFIG_ISA
+	if (dev == NULL)
+		gfp |= __GFP_DMA;
+	else
+#endif
+#ifdef CONFIG_ZONE_DMA
+	if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
+		gfp |= __GFP_DMA;
+	else
+#endif
+#ifdef CONFIG_ZONE_DMA32
+	if (dev->coherent_dma_mask < DMA_BIT_MASK(40))
+		gfp |= __GFP_DMA32;
+	else
+#endif
+	;
+	gfp |= __GFP_NORETRY;
+
+	ret = swiotlb_alloc_coherent(dev, size, dma_handle, gfp);
+	mb();
+	return ret;
+}
+
+static void loongson_dma_free_coherent(struct device *dev, size_t size,
+		void *vaddr, dma_addr_t dma_handle, struct dma_attrs *attrs)
+{
+	int order = get_order(size);
+
+	if (dma_release_from_coherent(dev, order, vaddr))
+		return;
+
+	swiotlb_free_coherent(dev, size, vaddr, dma_handle);
+}
+
+static dma_addr_t loongson_dma_map_page(struct device *dev, struct page *page,
+				unsigned long offset, size_t size,
+				enum dma_data_direction dir,
+				struct dma_attrs *attrs)
+{
+	dma_addr_t daddr = swiotlb_map_page(dev, page, offset, size,
+					dir, attrs);
+	mb();
+	return daddr;
+}
+
+static int loongson_dma_map_sg(struct device *dev, struct scatterlist *sg,
+				int nents, enum dma_data_direction dir,
+				struct dma_attrs *attrs)
+{
+	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, NULL);
+	mb();
+
+	return r;
+}
+
+static void loongson_dma_sync_single_for_device(struct device *dev,
+				dma_addr_t dma_handle, size_t size,
+				enum dma_data_direction dir)
+{
+	swiotlb_sync_single_for_device(dev, dma_handle, size, dir);
+	mb();
+}
+
+static void loongson_dma_sync_sg_for_device(struct device *dev,
+				struct scatterlist *sg, int nents,
+				enum dma_data_direction dir)
+{
+	swiotlb_sync_sg_for_device(dev, sg, nents, dir);
+	mb();
+}
+
+static int loongson_dma_set_mask(struct device *dev, u64 mask)
+{
+	if (mask > DMA_BIT_MASK(loongson_sysconf.dma_mask_bits)) {
+		*dev->dma_mask = DMA_BIT_MASK(loongson_sysconf.dma_mask_bits);
+		return -EIO;
+	}
+
+	*dev->dma_mask = mask;
+
+	return 0;
+}
+
+dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	long nid;
+#ifdef CONFIG_PHYS48_TO_HT40
+	/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
+	 * Loongson-3's 48bit address space and embed it into 40bit */
+	nid = (paddr >> 44) & 0x3;
+	paddr = ((nid << 44) ^ paddr) | (nid << 37);
+#endif
+	return paddr;
+}
+
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
+{
+	long nid;
+#ifdef CONFIG_PHYS48_TO_HT40
+	/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
+	 * Loongson-3's 48bit address space and embed it into 40bit */
+	nid = (daddr >> 37) & 0x3;
+	daddr = ((nid << 37) ^ daddr) | (nid << 44);
+#endif
+	return daddr;
+}
+
+static struct dma_map_ops loongson_dma_map_ops = {
+	.alloc = loongson_dma_alloc_coherent,
+	.free = loongson_dma_free_coherent,
+	.map_page = loongson_dma_map_page,
+	.unmap_page = swiotlb_unmap_page,
+	.map_sg = loongson_dma_map_sg,
+	.unmap_sg = swiotlb_unmap_sg_attrs,
+	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
+	.sync_single_for_device = loongson_dma_sync_single_for_device,
+	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
+	.sync_sg_for_device = loongson_dma_sync_sg_for_device,
+	.mapping_error = swiotlb_dma_mapping_error,
+	.dma_supported = swiotlb_dma_supported,
+	.set_dma_mask = loongson_dma_set_mask
+};
+
+void __init plat_swiotlb_setup(void)
+{
+	swiotlb_init(1);
+	mips_dma_map_ops = &loongson_dma_map_ops;
+}