ARM: dma-mapping: split out vmregion code from dma coherent mapping code

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>

1 files changed, 13 insertions, 119 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index b9590a7085ca..c54f1acf92c8 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -68,106 +68,16 @@ static u64 get_coherent_dma_mask(struct device *dev)
  * These are the page tables (2MB each) covering uncached, DMA consistent allocations
  */
 static pte_t *consistent_pte[NUM_CONSISTENT_PTES];
-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 arm_vm_region {
-        struct list_head        vm_list;
-        unsigned long           vm_start;
-        unsigned long           vm_end;
-        struct page             *vm_pages;
-        int                     vm_active;
-};
+#include "vmregion.h"
 
-static struct arm_vm_region consistent_head = {
+static struct arm_vmregion_head consistent_head = {
+        .vm_lock        = __SPIN_LOCK_UNLOCKED(&consistent_head.vm_lock),
         .vm_list        = LIST_HEAD_INIT(consistent_head.vm_list),
         .vm_start       = CONSISTENT_BASE,
         .vm_end         = CONSISTENT_END,
 };
 
-static struct arm_vm_region *
-arm_vm_region_alloc(struct arm_vm_region *head, size_t size, gfp_t gfp)
-{
-        unsigned long addr = head->vm_start, end = head->vm_end - size;
-        unsigned long flags;
-        struct arm_vm_region *c, *new;
-
-        new = kmalloc(sizeof(struct arm_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;
-        new->vm_active = 1;
-
-        spin_unlock_irqrestore(&consistent_lock, flags);
-        return new;
-
- nospc:
-        spin_unlock_irqrestore(&consistent_lock, flags);
-        kfree(new);
- out:
-        return NULL;
-}
-
-static struct arm_vm_region *arm_vm_region_find(struct arm_vm_region *head, unsigned long addr)
-{
-        struct arm_vm_region *c;
-        
-        list_for_each_entry(c, &head->vm_list, vm_list) {
-                if (c->vm_active && c->vm_start == addr)
-                        goto out;
-        }
-        c = NULL;
- out:
-        return c;
-}
-
 #ifdef CONFIG_HUGETLB_PAGE
 #error ARM Coherent DMA allocator does not (yet) support huge TLB
 #endif
@@ -177,7 +87,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
             pgprot_t prot)
 {
         struct page *page;
-        struct arm_vm_region *c;
+        struct arm_vmregion *c;
         unsigned long order;
         u64 mask = get_coherent_dma_mask(dev);
         u64 limit;
@@ -191,13 +101,9 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
         if (!mask)
                 goto no_page;
 
-        /*
-         * Sanity check the allocation size.
-         */
         size = PAGE_ALIGN(size);
         limit = (mask + 1) & ~mask;
-        if ((limit && size >= limit) ||
-            size >= (CONSISTENT_END - CONSISTENT_BASE)) {
+        if (limit && size >= limit) {
                 printk(KERN_WARNING "coherent allocation too big "
                        "(requested %#x mask %#llx)\n", size, mask);
                 goto no_page;
@@ -226,7 +132,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
         /*
          * Allocate a virtual address in the consistent mapping region.
          */
-        c = arm_vm_region_alloc(&consistent_head, size,
+        c = arm_vmregion_alloc(&consistent_head, size,
                             gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
         if (c) {
                 pte_t *pte;
@@ -349,15 +255,12 @@ static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
 {
         int ret = -ENXIO;
 #ifdef CONFIG_MMU
-        unsigned long flags, user_size, kern_size;
-        struct arm_vm_region *c;
+        unsigned long user_size, kern_size;
+        struct arm_vmregion *c;
 
         user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 
-        spin_lock_irqsave(&consistent_lock, flags);
-        c = arm_vm_region_find(&consistent_head, (unsigned long)cpu_addr);
-        spin_unlock_irqrestore(&consistent_lock, flags);
-
+        c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
         if (c) {
                 unsigned long off = vma->vm_pgoff;
 
@@ -399,8 +302,8 @@ EXPORT_SYMBOL(dma_mmap_writecombine);
 #ifdef CONFIG_MMU
 void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
 {
-        struct arm_vm_region *c;
-        unsigned long flags, addr;
+        struct arm_vmregion *c;
+        unsigned long addr;
         pte_t *ptep;
         int idx;
         u32 off;
@@ -417,14 +320,10 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
 
         size = PAGE_ALIGN(size);
 
-        spin_lock_irqsave(&consistent_lock, flags);
-        c = arm_vm_region_find(&consistent_head, (unsigned long)cpu_addr);
+        c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr);
         if (!c)
                 goto no_area;
 
-        c->vm_active = 0;
-        spin_unlock_irqrestore(&consistent_lock, flags);
-
         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);
@@ -470,15 +369,10 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
 
         flush_tlb_kernel_range(c->vm_start, c->vm_end);
 
-        spin_lock_irqsave(&consistent_lock, flags);
-        list_del(&c->vm_list);
-        spin_unlock_irqrestore(&consistent_lock, flags);
-
-        kfree(c);
+        arm_vmregion_free(&consistent_head, c);
         return;
 
  no_area:
-        spin_unlock_irqrestore(&consistent_lock, flags);
         printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
                __func__, cpu_addr);
         dump_stack();