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-rw-r--r--arch/microblaze/mm/consistent.c255
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diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
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+/*
+ * 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 <linux/gfp.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>
+#include <asm/tlbflush.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)
+#endif
+
+/*
+ * 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)
+{
+ unsigned long order, vaddr;
+ void *ret;
+ unsigned int i, err = 0;
+ struct page *page, *end;
+
+#ifdef CONFIG_MMU
+ phys_addr_t pa;
+ struct vm_struct *area;
+ unsigned long va;
+#endif
+
+ if (in_interrupt())
+ BUG();
+
+ /* Only allocate page size areas. */
+ size = PAGE_ALIGN(size);
+ order = get_order(size);
+
+ vaddr = __get_free_pages(gfp, order);
+ if (!vaddr)
+ 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((void *)vaddr),
+ virt_to_phys((void *)vaddr) + size);
+
+#ifndef CONFIG_MMU
+ ret = (void *)vaddr;
+ /*
+ * 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
+ if ((unsigned int)ret > cpuinfo.dcache_base &&
+ (unsigned int)ret < cpuinfo.dcache_high)
+ printk(KERN_WARNING
+ "ERROR: Your cache coherent area is CACHED!!!\n");
+
+ /* dma_handle is same as physical (shadowed) address */
+ *dma_handle = (dma_addr_t)ret;
+#else
+ /* Allocate some common virtual space to map the new pages. */
+ area = get_vm_area(size, VM_ALLOC);
+ if (!area) {
+ free_pages(vaddr, 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 *)vaddr);
+#endif
+
+ /*
+ * 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(vaddr);
+ end = page + (1 << order);
+
+ split_page(page, order);
+
+ for (i = 0; i < size && err == 0; i += PAGE_SIZE) {
+#ifdef CONFIG_MMU
+ /* MS: This is the whole magic - use cache inhibit pages */
+ err = map_page(va + i, pa + i, _PAGE_KERNEL | _PAGE_NO_CACHE);
+#endif
+
+ SetPageReserved(page);
+ page++;
+ }
+
+ /* Free the otherwise unused pages. */
+ while (page < end) {
+ __free_page(page);
+ page++;
+ }
+
+ if (err) {
+ free_pages(vaddr, order);
+ return NULL;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(consistent_alloc);
+
+/*
+ * free page(s) as defined by the above mapping.
+ */
+void consistent_free(size_t size, void *vaddr)
+{
+ struct page *page;
+
+ if (in_interrupt())
+ BUG();
+
+ size = PAGE_ALIGN(size);
+
+#ifndef CONFIG_MMU
+ /* Clear SHADOW_MASK bit in address, and free as per usual */
+# ifdef CONFIG_XILINX_UNCACHED_SHADOW
+ vaddr = (void *)((unsigned)vaddr & ~UNCACHED_SHADOW_MASK);
+# endif
+ page = virt_to_page(vaddr);
+
+ do {
+ ClearPageReserved(page);
+ __free_page(page);
+ page++;
+ } while (size -= PAGE_SIZE);
+#else
+ do {
+ pte_t *ptep;
+ unsigned long pfn;
+
+ ptep = pte_offset_kernel(pmd_offset(pgd_offset_k(
+ (unsigned int)vaddr),
+ (unsigned int)vaddr),
+ (unsigned int)vaddr);
+ if (!pte_none(*ptep) && pte_present(*ptep)) {
+ pfn = pte_pfn(*ptep);
+ pte_clear(&init_mm, (unsigned int)vaddr, ptep);
+ if (pfn_valid(pfn)) {
+ page = pfn_to_page(pfn);
+
+ ClearPageReserved(page);
+ __free_page(page);
+ }
+ }
+ vaddr += PAGE_SIZE;
+ } while (size -= PAGE_SIZE);
+
+ /* flush tlb */
+ flush_tlb_all();
+#endif
+}
+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 */
+ invalidate_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);