Merge remote-tracking branch 'xen-tip/linux-next'

Author: sfrothwell

arch/arm/include/asm/xen/page-coherent.h

@@ -5,6 +5,11 @@
 #include <linux/dma-attrs.h>
 #include <linux/dma-mapping.h>
 
+static inline bool xen_is_dma_coherent(struct device *dev)
+{
+    return (__generic_dma_ops(dev) == &arm_coherent_dma_ops);
+}
+ 
 static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
 		dma_addr_t *dma_handle, gfp_t flags,
 		struct dma_attrs *attrs)

arch/arm/include/asm/xen/page.h

@@ -107,4 +107,8 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 #define xen_remap(cookie, size) ioremap_cache((cookie), (size))
 #define xen_unmap(cookie) iounmap((cookie))
 
+bool xen_arch_need_swiotlb(struct device *dev,
+			   unsigned long pfn,
+			   unsigned long mfn);
+
 #endif /* _ASM_ARM_XEN_PAGE_H */

arch/arm/xen/Makefile

@@ -1 +1 @@
-obj-y		:= enlighten.o hypercall.o grant-table.o p2m.o mm.o mm32.o
+obj-y		:= enlighten.o hypercall.o grant-table.o p2m.o mm.o

arch/arm/xen/enlighten.c

@@ -261,11 +261,6 @@ static int __init xen_guest_init(void)
 
 	xen_setup_features();
 
-	if (!xen_feature(XENFEAT_grant_map_identity)) {
-		pr_warn("Please upgrade your Xen.\n"
-				"If your platform has any non-coherent DMA devices, they won't work properly.\n");
-	}
-
 	if (xen_feature(XENFEAT_dom0))
 		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 	else

arch/arm/xen/mm.c

@@ -1,5 +1,8 @@
+#include <linux/cpu.h>
+#include <linux/dma-mapping.h>
 #include <linux/bootmem.h>
 #include <linux/gfp.h>
+#include <linux/highmem.h>
 #include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -8,14 +11,163 @@
 #include <linux/swiotlb.h>
 
 #include <xen/xen.h>
+#include <xen/interface/grant_table.h>
 #include <xen/interface/memory.h>
 #include <xen/swiotlb-xen.h>
 
 #include <asm/cacheflush.h>
 #include <asm/xen/page.h>
+#include <asm/xen/page-coherent.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/interface.h>
 
+
+#ifdef CONFIG_ARM64
+static inline void dmac_map_area(const void *start, size_t size, int dir)
+{
+	return __dma_map_area(start, size, dir);
+}
+
+static inline void dmac_unmap_area(const void *start, size_t size, int dir)
+{
+	return __dma_unmap_area(start, size, dir);
+}
+
+static inline bool cache_is_vipt_nonaliasing(void)
+{
+	return true;
+}
+
+static inline void *kmap_high_get(struct page *page)
+{
+	return NULL;
+}
+
+static inline void kunmap_high(struct page *page) {}
+#endif
+
+static bool hypercall_cflush = false;
+
+
+/* functions called by SWIOTLB */
+
+static void dma_cache_maint(dma_addr_t handle, unsigned long offset,
+	size_t size, enum dma_data_direction dir,
+	void (*op)(const void *, size_t, int))
+{
+	unsigned long pfn;
+	size_t left = size;
+
+	pfn = (handle >> PAGE_SHIFT) + offset / PAGE_SIZE;
+	offset %= PAGE_SIZE;
+
+	do {
+		size_t len = left;
+		void *vaddr;
+
+		/* buffers in highmem or foreign pages cannot cross page
+		 * boundaries */
+		if (len + offset > PAGE_SIZE)
+			len = PAGE_SIZE - offset;
+	
+		if (!pfn_valid(pfn))
+		{
+			struct gnttab_cache_flush cflush;
+
+			cflush.op = 0;
+			cflush.a.dev_bus_addr = pfn << PAGE_SHIFT;
+			cflush.offset = offset;
+			cflush.length = len;
+
+			if (op == dmac_unmap_area && dir != DMA_TO_DEVICE)
+				cflush.op = GNTTAB_CACHE_INVAL;
+			if (op == dmac_map_area) {
+				if (dir == DMA_FROM_DEVICE)
+					cflush.op = GNTTAB_CACHE_INVAL;
+				else
+					cflush.op = GNTTAB_CACHE_CLEAN;
+			}
+			if (cflush.op)
+				HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1);
+		} else {
+			struct page *page = pfn_to_page(pfn);
+
+			if (PageHighMem(page)) {
+				if (cache_is_vipt_nonaliasing()) {
+					vaddr = kmap_atomic(page);
+					op(vaddr + offset, len, dir);
+					kunmap_atomic(vaddr);
+				} else {
+					vaddr = kmap_high_get(page);
+					if (vaddr) {
+						op(vaddr + offset, len, dir);
+						kunmap_high(page);
+					}
+				}
+			} else {
+				vaddr = page_address(page) + offset;
+				op(vaddr, len, dir);
+			}
+		}
+
+		offset = 0;
+		pfn++;
+		left -= len;
+	} while (left);
+}
+
+static void __xen_dma_page_dev_to_cpu(struct device *hwdev, dma_addr_t handle,
+		size_t size, enum dma_data_direction dir)
+{
+	/* Cannot use __dma_page_dev_to_cpu because we don't have a
+	 * struct page for handle */
+
+	dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, dmac_unmap_area);
+}
+
+static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle,
+		size_t size, enum dma_data_direction dir)
+{
+
+	dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, dmac_map_area);
+}
+
+void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+		size_t size, enum dma_data_direction dir,
+		struct dma_attrs *attrs)
+
+{
+	if (xen_is_dma_coherent(hwdev))
+		return;
+	if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+		return;
+
+	__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
+}
+
+void xen_dma_sync_single_for_cpu(struct device *hwdev,
+		dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+	if (xen_is_dma_coherent(hwdev))
+		return;
+	__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
+}
+
+void xen_dma_sync_single_for_device(struct device *hwdev,
+		dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+	if (xen_is_dma_coherent(hwdev))
+		return;
+	__xen_dma_page_cpu_to_dev(hwdev, handle, size, dir);
+}
+
+bool xen_arch_need_swiotlb(struct device *dev,
+			   unsigned long pfn,
+			   unsigned long mfn)
+{
+	return (!hypercall_cflush && (pfn != mfn) && !xen_is_dma_coherent(dev));
+}
+
 int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
 				 unsigned int address_bits,
 				 dma_addr_t *dma_handle)
@@ -56,10 +208,18 @@ static struct dma_map_ops xen_swiotlb_dma_ops = {
 
 int __init xen_mm_init(void)
 {
+	struct gnttab_cache_flush cflush;
 	if (!xen_initial_domain())
 		return 0;
 	xen_swiotlb_init(1, false);
 	xen_dma_ops = &xen_swiotlb_dma_ops;
+
+	cflush.op = 0;
+	cflush.a.dev_bus_addr = 0;
+	cflush.offset = 0;
+	cflush.length = 0;
+	if (HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1) != -ENOSYS)
+		hypercall_cflush = true;
 	return 0;
 }
 arch_initcall(xen_mm_init);