[POWERPC] 8xx: generic 8xx code arch/powerpc port
authorVitaly Bordug <vbordug@ru.mvista.com>
Wed, 24 Jan 2007 19:41:06 +0000 (22:41 +0300)
committerPaul Mackerras <paulus@samba.org>
Wed, 7 Feb 2007 03:01:02 +0000 (14:01 +1100)
Including support for non-coherent cache, some mm-related things +
relevant field in Kconfig and Makefiles. Also included rheap.o compilation
if 8xx is defined.

Non-coherent mapping were refined and renamed according to Cristoph
Hellwig. Orphaned functions were cleaned up.

[Also removed arch/ppc/kernel/dma-mapping.c, because otherwise
compiling with ARCH=ppc for a non DMA-cache-coherent platform ends up
with two copies of __dma_alloc_coherent etc.
 -- paulus.]

Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/Kconfig
arch/powerpc/lib/Makefile
arch/powerpc/lib/dma-noncoherent.c [new file with mode: 0644]
arch/ppc/kernel/Makefile
arch/ppc/kernel/dma-mapping.c [deleted file]

index 54d77a5b59f682f9736645b8966473cd63e62f4c..ce431b4446f0a294656091651f0d2aec47cc21f8 100644 (file)
@@ -173,6 +173,11 @@ config PPC_86xx
        help
          The Freescale E600 SoCs have 74xx cores.
 
+config PPC_8xx
+       bool "Freescale 8xx"
+       select FSL_SOC
+       select 8xx
+
 config 40x
        bool "AMCC 40x"
        select PPC_DCR_NATIVE
@@ -181,8 +186,6 @@ config 44x
        bool "AMCC 44x"
        select PPC_DCR_NATIVE
 
-config 8xx
-       bool "Freescale 8xx"
 
 config E200
        bool "Freescale e200"
@@ -210,6 +213,10 @@ config POWER4
 config 6xx
        bool
 
+# this is temp to handle compat with arch=ppc
+config 8xx
+       bool
+
 # this is temp to handle compat with arch=ppc
 config 83xx
        bool
index a0360ae10d0ccd5db00a1a0ff77b6bde74bd1629..e2d414160c8394061aad1e7f4a434f3edc14911e 100644 (file)
@@ -16,6 +16,7 @@ obj-$(CONFIG_PPC64)   += checksum_64.o copypage_64.o copyuser_64.o \
                           strcase.o
 obj-$(CONFIG_QUICC_ENGINE) += rheap.o
 obj-$(CONFIG_XMON)     += sstep.o
+obj-$(CONFIG_NOT_COHERENT_CACHE)       += dma-noncoherent.o
 
 ifeq ($(CONFIG_PPC64),y)
 obj-$(CONFIG_SMP)      += locks.o
@@ -24,5 +25,6 @@ endif
 
 # Temporary hack until we have migrated to asm-powerpc
 ifeq ($(CONFIG_PPC_MERGE),y)
+obj-$(CONFIG_8xx)      += rheap.o
 obj-$(CONFIG_CPM2)     += rheap.o
 endif
diff --git a/arch/powerpc/lib/dma-noncoherent.c b/arch/powerpc/lib/dma-noncoherent.c
new file mode 100644 (file)
index 0000000..48f3d13
--- /dev/null
@@ -0,0 +1,418 @@
+/*
+ *  PowerPC version derived from arch/arm/mm/consistent.c
+ *    Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
+ *
+ *  Copyright (C) 2000 Russell King
+ *
+ * Consistent memory allocators.  Used for DMA devices that want to
+ * share uncached memory with the processor core.  The function return
+ * is the virtual address and 'dma_handle' is the physical address.
+ * Mostly stolen from the ARM port, with some changes for PowerPC.
+ *                                             -- Dan
+ *
+ * Reorganized to get rid of the arch-specific consistent_* functions
+ * and provide non-coherent implementations for the DMA API. -Matt
+ *
+ * Added in_interrupt() safe dma_alloc_coherent()/dma_free_coherent()
+ * implementation. This is pulled straight from ARM and barely
+ * modified. -Matt
+ *
+ * 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/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/highmem.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/tlbflush.h>
+
+/*
+ * This address range defaults to a value that is safe for all
+ * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It
+ * can be further configured for specific applications under
+ * the "Advanced Setup" menu. -Matt
+ */
+#define CONSISTENT_BASE        (CONFIG_CONSISTENT_START)
+#define CONSISTENT_END (CONFIG_CONSISTENT_START + CONFIG_CONSISTENT_SIZE)
+#define CONSISTENT_OFFSET(x)   (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
+
+/*
+ * This is the page table (2MB) covering uncached, DMA consistent allocations
+ */
+static pte_t *consistent_pte;
+static DEFINE_SPINLOCK(consistent_lock);
+
+/*
+ * VM region handling support.
+ *
+ * This should become something generic, handling VM region allocations for
+ * vmalloc and similar (ioremap, module space, etc).
+ *
+ * I envisage vmalloc()'s supporting vm_struct becoming:
+ *
+ *  struct vm_struct {
+ *    struct vm_region region;
+ *    unsigned long    flags;
+ *    struct page      **pages;
+ *    unsigned int     nr_pages;
+ *    unsigned long    phys_addr;
+ *  };
+ *
+ * get_vm_area() would then call vm_region_alloc with an appropriate
+ * struct vm_region head (eg):
+ *
+ *  struct vm_region vmalloc_head = {
+ *     .vm_list        = LIST_HEAD_INIT(vmalloc_head.vm_list),
+ *     .vm_start       = VMALLOC_START,
+ *     .vm_end         = VMALLOC_END,
+ *  };
+ *
+ * However, vmalloc_head.vm_start is variable (typically, it is dependent on
+ * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
+ * would have to initialise this each time prior to calling vm_region_alloc().
+ */
+struct vm_region {
+       struct list_head        vm_list;
+       unsigned long           vm_start;
+       unsigned long           vm_end;
+};
+
+static struct vm_region consistent_head = {
+       .vm_list        = LIST_HEAD_INIT(consistent_head.vm_list),
+       .vm_start       = CONSISTENT_BASE,
+       .vm_end         = CONSISTENT_END,
+};
+
+static struct vm_region *
+vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
+{
+       unsigned long addr = head->vm_start, end = head->vm_end - size;
+       unsigned long flags;
+       struct vm_region *c, *new;
+
+       new = kmalloc(sizeof(struct vm_region), gfp);
+       if (!new)
+               goto out;
+
+       spin_lock_irqsave(&consistent_lock, flags);
+
+       list_for_each_entry(c, &head->vm_list, vm_list) {
+               if ((addr + size) < addr)
+                       goto nospc;
+               if ((addr + size) <= c->vm_start)
+                       goto found;
+               addr = c->vm_end;
+               if (addr > end)
+                       goto nospc;
+       }
+
+ found:
+       /*
+        * Insert this entry _before_ the one we found.
+        */
+       list_add_tail(&new->vm_list, &c->vm_list);
+       new->vm_start = addr;
+       new->vm_end = addr + size;
+
+       spin_unlock_irqrestore(&consistent_lock, flags);
+       return new;
+
+ nospc:
+       spin_unlock_irqrestore(&consistent_lock, flags);
+       kfree(new);
+ out:
+       return NULL;
+}
+
+static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr)
+{
+       struct vm_region *c;
+
+       list_for_each_entry(c, &head->vm_list, vm_list) {
+               if (c->vm_start == addr)
+                       goto out;
+       }
+       c = NULL;
+ out:
+       return c;
+}
+
+/*
+ * Allocate DMA-coherent memory space and return both the kernel remapped
+ * virtual and bus address for that space.
+ */
+void *
+__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
+{
+       struct page *page;
+       struct vm_region *c;
+       unsigned long order;
+       u64 mask = 0x00ffffff, limit; /* ISA default */
+
+       if (!consistent_pte) {
+               printk(KERN_ERR "%s: not initialised\n", __func__);
+               dump_stack();
+               return NULL;
+       }
+
+       size = PAGE_ALIGN(size);
+       limit = (mask + 1) & ~mask;
+       if ((limit && size >= limit) || size >= (CONSISTENT_END - CONSISTENT_BASE)) {
+               printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n",
+                      size, mask);
+               return NULL;
+       }
+
+       order = get_order(size);
+
+       if (mask != 0xffffffff)
+               gfp |= GFP_DMA;
+
+       page = alloc_pages(gfp, order);
+       if (!page)
+               goto no_page;
+
+       /*
+        * Invalidate any data that might be lurking in the
+        * kernel direct-mapped region for device DMA.
+        */
+       {
+               unsigned long kaddr = (unsigned long)page_address(page);
+               memset(page_address(page), 0, size);
+               flush_dcache_range(kaddr, kaddr + size);
+       }
+
+       /*
+        * Allocate a virtual address in the consistent mapping region.
+        */
+       c = vm_region_alloc(&consistent_head, size,
+                           gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
+       if (c) {
+               unsigned long vaddr = c->vm_start;
+               pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr);
+               struct page *end = page + (1 << order);
+
+               split_page(page, order);
+
+               /*
+                * Set the "dma handle"
+                */
+               *handle = page_to_bus(page);
+
+               do {
+                       BUG_ON(!pte_none(*pte));
+
+                       SetPageReserved(page);
+                       set_pte_at(&init_mm, vaddr,
+                                  pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL)));
+                       page++;
+                       pte++;
+                       vaddr += PAGE_SIZE;
+               } while (size -= PAGE_SIZE);
+
+               /*
+                * Free the otherwise unused pages.
+                */
+               while (page < end) {
+                       __free_page(page);
+                       page++;
+               }
+
+               return (void *)c->vm_start;
+       }
+
+       if (page)
+               __free_pages(page, order);
+ no_page:
+       return NULL;
+}
+EXPORT_SYMBOL(__dma_alloc_coherent);
+
+/*
+ * free a page as defined by the above mapping.
+ */
+void __dma_free_coherent(size_t size, void *vaddr)
+{
+       struct vm_region *c;
+       unsigned long flags, addr;
+       pte_t *ptep;
+
+       size = PAGE_ALIGN(size);
+
+       spin_lock_irqsave(&consistent_lock, flags);
+
+       c = vm_region_find(&consistent_head, (unsigned long)vaddr);
+       if (!c)
+               goto no_area;
+
+       if ((c->vm_end - c->vm_start) != size) {
+               printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
+                      __func__, c->vm_end - c->vm_start, size);
+               dump_stack();
+               size = c->vm_end - c->vm_start;
+       }
+
+       ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
+       addr = c->vm_start;
+       do {
+               pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
+               unsigned long pfn;
+
+               ptep++;
+               addr += PAGE_SIZE;
+
+               if (!pte_none(pte) && pte_present(pte)) {
+                       pfn = pte_pfn(pte);
+
+                       if (pfn_valid(pfn)) {
+                               struct page *page = pfn_to_page(pfn);
+                               ClearPageReserved(page);
+
+                               __free_page(page);
+                               continue;
+                       }
+               }
+
+               printk(KERN_CRIT "%s: bad page in kernel page table\n",
+                      __func__);
+       } while (size -= PAGE_SIZE);
+
+       flush_tlb_kernel_range(c->vm_start, c->vm_end);
+
+       list_del(&c->vm_list);
+
+       spin_unlock_irqrestore(&consistent_lock, flags);
+
+       kfree(c);
+       return;
+
+ no_area:
+       spin_unlock_irqrestore(&consistent_lock, flags);
+       printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
+              __func__, vaddr);
+       dump_stack();
+}
+EXPORT_SYMBOL(__dma_free_coherent);
+
+/*
+ * Initialise the consistent memory allocation.
+ */
+static int __init dma_alloc_init(void)
+{
+       pgd_t *pgd;
+       pmd_t *pmd;
+       pte_t *pte;
+       int ret = 0;
+
+       do {
+               pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
+               pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
+               if (!pmd) {
+                       printk(KERN_ERR "%s: no pmd tables\n", __func__);
+                       ret = -ENOMEM;
+                       break;
+               }
+               WARN_ON(!pmd_none(*pmd));
+
+               pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
+               if (!pte) {
+                       printk(KERN_ERR "%s: no pte tables\n", __func__);
+                       ret = -ENOMEM;
+                       break;
+               }
+
+               consistent_pte = pte;
+       } while (0);
+
+       return ret;
+}
+
+core_initcall(dma_alloc_init);
+
+/*
+ * make an area consistent.
+ */
+void __dma_sync(void *vaddr, size_t size, int direction)
+{
+       unsigned long start = (unsigned long)vaddr;
+       unsigned long end   = start + size;
+
+       switch (direction) {
+       case DMA_NONE:
+               BUG();
+       case DMA_FROM_DEVICE:   /* invalidate only */
+               invalidate_dcache_range(start, end);
+               break;
+       case DMA_TO_DEVICE:             /* writeback only */
+               clean_dcache_range(start, end);
+               break;
+       case DMA_BIDIRECTIONAL: /* writeback and invalidate */
+               flush_dcache_range(start, end);
+               break;
+       }
+}
+EXPORT_SYMBOL(__dma_sync);
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * __dma_sync_page() implementation for systems using highmem.
+ * In this case, each page of a buffer must be kmapped/kunmapped
+ * in order to have a virtual address for __dma_sync(). This must
+ * not sleep so kmap_atomic()/kunmap_atomic() are used.
+ *
+ * Note: yes, it is possible and correct to have a buffer extend
+ * beyond the first page.
+ */
+static inline void __dma_sync_page_highmem(struct page *page,
+               unsigned long offset, size_t size, int direction)
+{
+       size_t seg_size = min((size_t)(PAGE_SIZE - offset), size);
+       size_t cur_size = seg_size;
+       unsigned long flags, start, seg_offset = offset;
+       int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE;
+       int seg_nr = 0;
+
+       local_irq_save(flags);
+
+       do {
+               start = (unsigned long)kmap_atomic(page + seg_nr,
+                               KM_PPC_SYNC_PAGE) + seg_offset;
+
+               /* Sync this buffer segment */
+               __dma_sync((void *)start, seg_size, direction);
+               kunmap_atomic((void *)start, KM_PPC_SYNC_PAGE);
+               seg_nr++;
+
+               /* Calculate next buffer segment size */
+               seg_size = min((size_t)PAGE_SIZE, size - cur_size);
+
+               /* Add the segment size to our running total */
+               cur_size += seg_size;
+               seg_offset = 0;
+       } while (seg_nr < nr_segs);
+
+       local_irq_restore(flags);
+}
+#endif /* CONFIG_HIGHMEM */
+
+/*
+ * __dma_sync_page makes memory consistent. identical to __dma_sync, but
+ * takes a struct page instead of a virtual address
+ */
+void __dma_sync_page(struct page *page, unsigned long offset,
+       size_t size, int direction)
+{
+#ifdef CONFIG_HIGHMEM
+       __dma_sync_page_highmem(page, offset, size, direction);
+#else
+       unsigned long start = (unsigned long)page_address(page) + offset;
+       __dma_sync((void *)start, size, direction);
+#endif
+}
+EXPORT_SYMBOL(__dma_sync_page);
index 466437f4bcbb40fa7113faf183b213850e5db6e2..6b4f022111e703fe23a062c4492e718f47b209c6 100644 (file)
@@ -12,7 +12,6 @@ obj-y                         := entry.o traps.o time.o misc.o \
                                        setup.o \
                                        ppc_htab.o
 obj-$(CONFIG_MODULES)          += ppc_ksyms.o
-obj-$(CONFIG_NOT_COHERENT_CACHE)       += dma-mapping.o
 obj-$(CONFIG_PCI)              += pci.o
 obj-$(CONFIG_RAPIDIO)          += rio.o
 obj-$(CONFIG_KGDB)             += ppc-stub.o
diff --git a/arch/ppc/kernel/dma-mapping.c b/arch/ppc/kernel/dma-mapping.c
deleted file mode 100644 (file)
index 10fec73..0000000
+++ /dev/null
@@ -1,442 +0,0 @@
-/*
- *  PowerPC version derived from arch/arm/mm/consistent.c
- *    Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
- *
- *  Copyright (C) 2000 Russell King
- *
- * Consistent memory allocators.  Used for DMA devices that want to
- * share uncached memory with the processor core.  The function return
- * is the virtual address and 'dma_handle' is the physical address.
- * Mostly stolen from the ARM port, with some changes for PowerPC.
- *                                             -- Dan
- *
- * Reorganized to get rid of the arch-specific consistent_* functions
- * and provide non-coherent implementations for the DMA API. -Matt
- *
- * Added in_interrupt() safe dma_alloc_coherent()/dma_free_coherent()
- * implementation. This is pulled straight from ARM and barely
- * modified. -Matt
- *
- * 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/dma-mapping.h>
-#include <linux/hardirq.h>
-
-#include <asm/pgalloc.h>
-#include <asm/prom.h>
-#include <asm/io.h>
-#include <asm/mmu_context.h>
-#include <asm/pgtable.h>
-#include <asm/mmu.h>
-#include <asm/uaccess.h>
-#include <asm/smp.h>
-#include <asm/machdep.h>
-
-int map_page(unsigned long va, phys_addr_t pa, int flags);
-
-#include <asm/tlbflush.h>
-
-/*
- * This address range defaults to a value that is safe for all
- * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It
- * can be further configured for specific applications under
- * the "Advanced Setup" menu. -Matt
- */
-#define CONSISTENT_BASE        (CONFIG_CONSISTENT_START)
-#define CONSISTENT_END (CONFIG_CONSISTENT_START + CONFIG_CONSISTENT_SIZE)
-#define CONSISTENT_OFFSET(x)   (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
-
-/*
- * This is the page table (2MB) covering uncached, DMA consistent allocations
- */
-static pte_t *consistent_pte;
-static DEFINE_SPINLOCK(consistent_lock);
-
-/*
- * VM region handling support.
- *
- * This should become something generic, handling VM region allocations for
- * vmalloc and similar (ioremap, module space, etc).
- *
- * I envisage vmalloc()'s supporting vm_struct becoming:
- *
- *  struct vm_struct {
- *    struct vm_region region;
- *    unsigned long    flags;
- *    struct page      **pages;
- *    unsigned int     nr_pages;
- *    unsigned long    phys_addr;
- *  };
- *
- * get_vm_area() would then call vm_region_alloc with an appropriate
- * struct vm_region head (eg):
- *
- *  struct vm_region vmalloc_head = {
- *     .vm_list        = LIST_HEAD_INIT(vmalloc_head.vm_list),
- *     .vm_start       = VMALLOC_START,
- *     .vm_end         = VMALLOC_END,
- *  };
- *
- * However, vmalloc_head.vm_start is variable (typically, it is dependent on
- * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
- * would have to initialise this each time prior to calling vm_region_alloc().
- */
-struct vm_region {
-       struct list_head        vm_list;
-       unsigned long           vm_start;
-       unsigned long           vm_end;
-};
-
-static struct vm_region consistent_head = {
-       .vm_list        = LIST_HEAD_INIT(consistent_head.vm_list),
-       .vm_start       = CONSISTENT_BASE,
-       .vm_end         = CONSISTENT_END,
-};
-
-static struct vm_region *
-vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
-{
-       unsigned long addr = head->vm_start, end = head->vm_end - size;
-       unsigned long flags;
-       struct vm_region *c, *new;
-
-       new = kmalloc(sizeof(struct vm_region), gfp);
-       if (!new)
-               goto out;
-
-       spin_lock_irqsave(&consistent_lock, flags);
-
-       list_for_each_entry(c, &head->vm_list, vm_list) {
-               if ((addr + size) < addr)
-                       goto nospc;
-               if ((addr + size) <= c->vm_start)
-                       goto found;
-               addr = c->vm_end;
-               if (addr > end)
-                       goto nospc;
-       }
-
- found:
-       /*
-        * Insert this entry _before_ the one we found.
-        */
-       list_add_tail(&new->vm_list, &c->vm_list);
-       new->vm_start = addr;
-       new->vm_end = addr + size;
-
-       spin_unlock_irqrestore(&consistent_lock, flags);
-       return new;
-
- nospc:
-       spin_unlock_irqrestore(&consistent_lock, flags);
-       kfree(new);
- out:
-       return NULL;
-}
-
-static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr)
-{
-       struct vm_region *c;
-
-       list_for_each_entry(c, &head->vm_list, vm_list) {
-               if (c->vm_start == addr)
-                       goto out;
-       }
-       c = NULL;
- out:
-       return c;
-}
-
-/*
- * Allocate DMA-coherent memory space and return both the kernel remapped
- * virtual and bus address for that space.
- */
-void *
-__dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
-{
-       struct page *page;
-       struct vm_region *c;
-       unsigned long order;
-       u64 mask = 0x00ffffff, limit; /* ISA default */
-
-       if (!consistent_pte) {
-               printk(KERN_ERR "%s: not initialised\n", __func__);
-               dump_stack();
-               return NULL;
-       }
-
-       size = PAGE_ALIGN(size);
-       limit = (mask + 1) & ~mask;
-       if ((limit && size >= limit) || size >= (CONSISTENT_END - CONSISTENT_BASE)) {
-               printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n",
-                      size, mask);
-               return NULL;
-       }
-
-       order = get_order(size);
-
-       if (mask != 0xffffffff)
-               gfp |= GFP_DMA;
-
-       page = alloc_pages(gfp, order);
-       if (!page)
-               goto no_page;
-
-       /*
-        * Invalidate any data that might be lurking in the
-        * kernel direct-mapped region for device DMA.
-        */
-       {
-               unsigned long kaddr = (unsigned long)page_address(page);
-               memset(page_address(page), 0, size);
-               flush_dcache_range(kaddr, kaddr + size);
-       }
-
-       /*
-        * Allocate a virtual address in the consistent mapping region.
-        */
-       c = vm_region_alloc(&consistent_head, size,
-                           gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
-       if (c) {
-               unsigned long vaddr = c->vm_start;
-               pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr);
-               struct page *end = page + (1 << order);
-
-               split_page(page, order);
-
-               /*
-                * Set the "dma handle"
-                */
-               *handle = page_to_bus(page);
-
-               do {
-                       BUG_ON(!pte_none(*pte));
-
-                       SetPageReserved(page);
-                       set_pte_at(&init_mm, vaddr,
-                                  pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL)));
-                       page++;
-                       pte++;
-                       vaddr += PAGE_SIZE;
-               } while (size -= PAGE_SIZE);
-
-               /*
-                * Free the otherwise unused pages.
-                */
-               while (page < end) {
-                       __free_page(page);
-                       page++;
-               }
-
-               return (void *)c->vm_start;
-       }
-
-       if (page)
-               __free_pages(page, order);
- no_page:
-       return NULL;
-}
-EXPORT_SYMBOL(__dma_alloc_coherent);
-
-/*
- * free a page as defined by the above mapping.
- */
-void __dma_free_coherent(size_t size, void *vaddr)
-{
-       struct vm_region *c;
-       unsigned long flags, addr;
-       pte_t *ptep;
-
-       size = PAGE_ALIGN(size);
-
-       spin_lock_irqsave(&consistent_lock, flags);
-
-       c = vm_region_find(&consistent_head, (unsigned long)vaddr);
-       if (!c)
-               goto no_area;
-
-       if ((c->vm_end - c->vm_start) != size) {
-               printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
-                      __func__, c->vm_end - c->vm_start, size);
-               dump_stack();
-               size = c->vm_end - c->vm_start;
-       }
-
-       ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
-       addr = c->vm_start;
-       do {
-               pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
-               unsigned long pfn;
-
-               ptep++;
-               addr += PAGE_SIZE;
-
-               if (!pte_none(pte) && pte_present(pte)) {
-                       pfn = pte_pfn(pte);
-
-                       if (pfn_valid(pfn)) {
-                               struct page *page = pfn_to_page(pfn);
-                               ClearPageReserved(page);
-
-                               __free_page(page);
-                               continue;
-                       }
-               }
-
-               printk(KERN_CRIT "%s: bad page in kernel page table\n",
-                      __func__);
-       } while (size -= PAGE_SIZE);
-
-       flush_tlb_kernel_range(c->vm_start, c->vm_end);
-
-       list_del(&c->vm_list);
-
-       spin_unlock_irqrestore(&consistent_lock, flags);
-
-       kfree(c);
-       return;
-
- no_area:
-       spin_unlock_irqrestore(&consistent_lock, flags);
-       printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
-              __func__, vaddr);
-       dump_stack();
-}
-EXPORT_SYMBOL(__dma_free_coherent);
-
-/*
- * Initialise the consistent memory allocation.
- */
-static int __init dma_alloc_init(void)
-{
-       pgd_t *pgd;
-       pmd_t *pmd;
-       pte_t *pte;
-       int ret = 0;
-
-       do {
-               pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
-               pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
-               if (!pmd) {
-                       printk(KERN_ERR "%s: no pmd tables\n", __func__);
-                       ret = -ENOMEM;
-                       break;
-               }
-               WARN_ON(!pmd_none(*pmd));
-
-               pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
-               if (!pte) {
-                       printk(KERN_ERR "%s: no pte tables\n", __func__);
-                       ret = -ENOMEM;
-                       break;
-               }
-
-               consistent_pte = pte;
-       } while (0);
-
-       return ret;
-}
-
-core_initcall(dma_alloc_init);
-
-/*
- * make an area consistent.
- */
-void __dma_sync(void *vaddr, size_t size, int direction)
-{
-       unsigned long start = (unsigned long)vaddr;
-       unsigned long end   = start + size;
-
-       switch (direction) {
-       case DMA_NONE:
-               BUG();
-       case DMA_FROM_DEVICE:   /* invalidate only */
-               invalidate_dcache_range(start, end);
-               break;
-       case DMA_TO_DEVICE:             /* writeback only */
-               clean_dcache_range(start, end);
-               break;
-       case DMA_BIDIRECTIONAL: /* writeback and invalidate */
-               flush_dcache_range(start, end);
-               break;
-       }
-}
-EXPORT_SYMBOL(__dma_sync);
-
-#ifdef CONFIG_HIGHMEM
-/*
- * __dma_sync_page() implementation for systems using highmem.
- * In this case, each page of a buffer must be kmapped/kunmapped
- * in order to have a virtual address for __dma_sync(). This must
- * not sleep so kmap_atomic()/kunmap_atomic() are used.
- *
- * Note: yes, it is possible and correct to have a buffer extend
- * beyond the first page.
- */
-static inline void __dma_sync_page_highmem(struct page *page,
-               unsigned long offset, size_t size, int direction)
-{
-       size_t seg_size = min((size_t)(PAGE_SIZE - offset), size);
-       size_t cur_size = seg_size;
-       unsigned long flags, start, seg_offset = offset;
-       int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE;
-       int seg_nr = 0;
-
-       local_irq_save(flags);
-
-       do {
-               start = (unsigned long)kmap_atomic(page + seg_nr,
-                               KM_PPC_SYNC_PAGE) + seg_offset;
-
-               /* Sync this buffer segment */
-               __dma_sync((void *)start, seg_size, direction);
-               kunmap_atomic((void *)start, KM_PPC_SYNC_PAGE);
-               seg_nr++;
-
-               /* Calculate next buffer segment size */
-               seg_size = min((size_t)PAGE_SIZE, size - cur_size);
-
-               /* Add the segment size to our running total */
-               cur_size += seg_size;
-               seg_offset = 0;
-       } while (seg_nr < nr_segs);
-
-       local_irq_restore(flags);
-}
-#endif /* CONFIG_HIGHMEM */
-
-/*
- * __dma_sync_page makes memory consistent. identical to __dma_sync, but
- * takes a struct page instead of a virtual address
- */
-void __dma_sync_page(struct page *page, unsigned long offset,
-       size_t size, int direction)
-{
-#ifdef CONFIG_HIGHMEM
-       __dma_sync_page_highmem(page, offset, size, direction);
-#else
-       unsigned long start = (unsigned long)page_address(page) + offset;
-       __dma_sync((void *)start, size, direction);
-#endif
-}
-EXPORT_SYMBOL(__dma_sync_page);