Merge branch 'wip-2.6.34' into old-private-masterarchived-private-master

1 files changed, 255 insertions, 0 deletions

diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
new file mode 100644
index 000000000000..5a59dad62bd2
--- /dev/null
+++ b/arch/microblaze/mm/consistent.c
@@ -0,0 +1,255 @@
+/*
+ * 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);