1 files changed, 246 insertions, 0 deletions
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
new file mode 100644
index 000000000000..a9b443e3fb98
--- /dev/null
+++ b/arch/microblaze/mm/consistent.c
@@ -0,0 +1,246 @@
+/*
+ * 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>
+ *
+ * Based on PowerPC version derived from arch/arm/mm/consistent.c
+ * Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
+ * Copyright (C) 2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+
+#include <asm/pgalloc.h>
+#include <linux/io.h>
+#include <linux/hardirq.h>
+#include <asm/mmu_context.h>
+#include <asm/mmu.h>
+#include <linux/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/cpuinfo.h>
+
+#ifndef CONFIG_MMU
+
+/* I have to use dcache values because I can't relate on ram size */
+#define UNCACHED_SHADOW_MASK (cpuinfo.dcache_high - cpuinfo.dcache_base + 1)
+
+/*
+ * 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
+ */
+void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
+{
+	struct page *page, *end, *free;
+	unsigned long order;
+	void *ret, *virt;
+
+	if (in_interrupt())
+		BUG();
+
+	size = PAGE_ALIGN(size);
+	order = get_order(size);
+
+	page = alloc_pages(gfp, order);
+	if (!page)
+		goto no_page;
+
+	/* We could do with a page_to_phys and page_to_bus here. */
+	virt = page_address(page);
+	ret = ioremap(virt_to_phys(virt), size);
+	if (!ret)
+		goto no_remap;
+
+	/*
+	 * Here's the magic!  Note if the uncached shadow is not implemented,
+	 * it's up to the calling code to also test that condition and make
+	 * other arranegments, such as manually flushing the cache and so on.
+	 */
+#ifdef CONFIG_XILINX_UNCACHED_SHADOW
+	ret = (void *)((unsigned) ret | UNCACHED_SHADOW_MASK);
+#endif
+	/* dma_handle is same as physical (shadowed) address */
+	*dma_handle = (dma_addr_t)ret;
+
+	/*
+	 * free wasted pages.  We skip the first page since we know
+	 * that it will have count = 1 and won't require freeing.
+	 * We also mark the pages in use as reserved so that
+	 * remap_page_range works.
+	 */
+	page = virt_to_page(virt);
+	free = page + (size >> PAGE_SHIFT);
+	end  = page + (1 << order);
+
+	for (; page < end; page++) {
+		init_page_count(page);
+		if (page >= free)
+			__free_page(page);
+		else
+			SetPageReserved(page);
+	}
+
+	return ret;
+no_remap:
+	__free_pages(page, order);
+no_page:
+	return NULL;
+}
+
+#else
+
+void *consistent_alloc(int gfp, size_t size, dma_addr_t *dma_handle)
+{
+	int order, err, i;
+	unsigned long page, va, flags;
+	phys_addr_t pa;
+	struct vm_struct *area;
+	void	 *ret;
+
+	if (in_interrupt())
+		BUG();
+
+	/* Only allocate page size areas. */
+	size = PAGE_ALIGN(size);
+	order = get_order(size);
+
+	page = __get_free_pages(gfp, order);
+	if (!page) {
+		BUG();
+		return NULL;
+	}
+
+	/*
+	 * we need to ensure that there are no cachelines in use,
+	 * or worse dirty in this area.
+	 */
+	flush_dcache_range(virt_to_phys(page), virt_to_phys(page) + size);
+
+	/* Allocate some common virtual space to map the new pages. */
+	area = get_vm_area(size, VM_ALLOC);
+	if (area == NULL) {
+		free_pages(page, order);
+		return NULL;
+	}
+	va = (unsigned long) area->addr;
+	ret = (void *)va;
+
+	/* This gives us the real physical address of the first page. */
+	*dma_handle = pa = virt_to_bus((void *)page);
+
+	/* MS: This is the whole magic - use cache inhibit pages */
+	flags = _PAGE_KERNEL | _PAGE_NO_CACHE;
+
+	/*
+	 * Set refcount=1 on all pages in an order>0
+	 * allocation so that vfree() will actually
+	 * free all pages that were allocated.
+	 */
+	if (order > 0) {
+		struct page *rpage = virt_to_page(page);
+		for (i = 1; i < (1 << order); i++)
+			init_page_count(rpage+i);
+	}
+
+	err = 0;
+	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
+		err = map_page(va+i, pa+i, flags);
+
+	if (err) {
+		vfree((void *)va);
+		return NULL;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_MMU */
+EXPORT_SYMBOL(consistent_alloc);
+
+/*
+ * free page(s) as defined by the above mapping.
+ */
+void consistent_free(void *vaddr)
+{
+	if (in_interrupt())
+		BUG();
+
+	/* Clear SHADOW_MASK bit in address, and free as per usual */
+#ifdef CONFIG_XILINX_UNCACHED_SHADOW
+	vaddr = (void *)((unsigned)vaddr & ~UNCACHED_SHADOW_MASK);
+#endif
+	vfree(vaddr);
+}
+EXPORT_SYMBOL(consistent_free);
+
+/*
+ * make an area consistent.
+ */
+void consistent_sync(void *vaddr, size_t size, int direction)
+{
+	unsigned long start;
+	unsigned long end;
+
+	start = (unsigned long)vaddr;
+
+	/* Convert start address back down to unshadowed memory region */
+#ifdef CONFIG_XILINX_UNCACHED_SHADOW
+	start &= ~UNCACHED_SHADOW_MASK;
+#endif
+	end = start + size;
+
+	switch (direction) {
+	case PCI_DMA_NONE:
+		BUG();
+	case PCI_DMA_FROMDEVICE:	/* invalidate only */
+		flush_dcache_range(start, end);
+		break;
+	case PCI_DMA_TODEVICE:		/* writeback only */
+		flush_dcache_range(start, end);
+		break;
+	case PCI_DMA_BIDIRECTIONAL:	/* writeback and invalidate */
+		flush_dcache_range(start, end);
+		break;
+	}
+}
+EXPORT_SYMBOL(consistent_sync);
+
+/*
+ * consistent_sync_page makes memory consistent. identical
+ * to consistent_sync, but takes a struct page instead of a
+ * virtual address
+ */
+void consistent_sync_page(struct page *page, unsigned long offset,
+	size_t size, int direction)
+{
+	unsigned long start = (unsigned long)page_address(page) + offset;
+	consistent_sync((void *)start, size, direction);
+}
+EXPORT_SYMBOL(consistent_sync_page);