1 files changed, 52 insertions, 0 deletions
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
new file mode 100644
index 000000000..81dffe43b
--- /dev/null
+++ b/arch/microblaze/mm/consistent.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Microblaze support for cache consistent memory.
+ * Copyright (C) 2010 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2010 PetaLogix
+ * Copyright (C) 2005 John Williams <jwilliams@itee.uq.edu.au>
+ */
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/dma-map-ops.h>
+#include <asm/cpuinfo.h>
+#include <asm/cacheflush.h>
+
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+	phys_addr_t paddr = page_to_phys(page);
+
+	flush_dcache_range(paddr, paddr + size);
+}
+
+#ifndef CONFIG_MMU
+/*
+ * Consistent memory allocators. Used for DMA devices that want to share
+ * uncached memory with the processor core.  My crufty no-MMU approach is
+ * simple.  In the HW platform we can optionally mirror the DDR up above the
+ * processor cacheable region.  So, memory accessed in this mirror region will
+ * not be cached.  It's alloced from the same pool as normal memory, but the
+ * handle we return is shifted up into the uncached region.  This will no doubt
+ * cause big problems if memory allocated here is not also freed properly. -- JW
+ *
+ * I have to use dcache values because I can't relate on ram size:
+ */
+#ifdef CONFIG_XILINX_UNCACHED_SHADOW
+#define UNCACHED_SHADOW_MASK (cpuinfo.dcache_high - cpuinfo.dcache_base + 1)
+#else
+#define UNCACHED_SHADOW_MASK 0
+#endif /* CONFIG_XILINX_UNCACHED_SHADOW */
+
+void *arch_dma_set_uncached(void *ptr, size_t size)
+{
+	unsigned long addr = (unsigned long)ptr;
+
+	addr |= UNCACHED_SHADOW_MASK;
+	if (addr > cpuinfo.dcache_base && addr < cpuinfo.dcache_high)
+		pr_warn("ERROR: Your cache coherent area is CACHED!!!\n");
+	return (void *)addr;
+}
+#endif /* CONFIG_MMU */