ARM: dma-mapping: split out vmregion code from dma coherent mapping code
authorRussell King <rmk+kernel@arm.linux.org.uk>
Thu, 19 Nov 2009 15:07:04 +0000 (15:07 +0000)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Tue, 24 Nov 2009 17:41:34 +0000 (17:41 +0000)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
arch/arm/mm/Makefile
arch/arm/mm/dma-mapping.c
arch/arm/mm/vmregion.c [new file with mode: 0644]
arch/arm/mm/vmregion.h [new file with mode: 0644]

index 055cb2a..42352e7 100644 (file)
@@ -6,7 +6,7 @@ obj-y                           := dma-mapping.o extable.o fault.o init.o \
                                   iomap.o
 
 obj-$(CONFIG_MMU)              += fault-armv.o flush.o ioremap.o mmap.o \
-                                  pgd.o mmu.o
+                                  pgd.o mmu.o vmregion.o
 
 ifneq ($(CONFIG_MMU),y)
 obj-y                          += nommu.o
index b9590a7..c54f1ac 100644 (file)
@@ -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();
diff --git a/arch/arm/mm/vmregion.c b/arch/arm/mm/vmregion.c
new file mode 100644 (file)
index 0000000..19e09bd
--- /dev/null
@@ -0,0 +1,131 @@
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#include "vmregion.h"
+
+/*
+ * 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 vmregion  region;
+ *    unsigned long    flags;
+ *    struct page      **pages;
+ *    unsigned int     nr_pages;
+ *    unsigned long    phys_addr;
+ *  };
+ *
+ * get_vm_area() would then call vmregion_alloc with an appropriate
+ * struct vmregion head (eg):
+ *
+ *  struct vmregion 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 vmregion_alloc().
+ */
+
+struct arm_vmregion *
+arm_vmregion_alloc(struct arm_vmregion_head *head, size_t size, gfp_t gfp)
+{
+       unsigned long addr = head->vm_start, end = head->vm_end - size;
+       unsigned long flags;
+       struct arm_vmregion *c, *new;
+
+       if (head->vm_end - head->vm_start < size) {
+               printk(KERN_WARNING "%s: allocation too big (requested %#x)\n",
+                       __func__, size);
+               goto out;
+       }
+
+       new = kmalloc(sizeof(struct arm_vmregion), gfp);
+       if (!new)
+               goto out;
+
+       spin_lock_irqsave(&head->vm_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(&head->vm_lock, flags);
+       return new;
+
+ nospc:
+       spin_unlock_irqrestore(&head->vm_lock, flags);
+       kfree(new);
+ out:
+       return NULL;
+}
+
+static struct arm_vmregion *__arm_vmregion_find(struct arm_vmregion_head *head, unsigned long addr)
+{
+       struct arm_vmregion *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;
+}
+
+struct arm_vmregion *arm_vmregion_find(struct arm_vmregion_head *head, unsigned long addr)
+{
+       struct arm_vmregion *c;
+       unsigned long flags;
+
+       spin_lock_irqsave(&head->vm_lock, flags);
+       c = __arm_vmregion_find(head, addr);
+       spin_unlock_irqrestore(&head->vm_lock, flags);
+       return c;
+}
+
+struct arm_vmregion *arm_vmregion_find_remove(struct arm_vmregion_head *head, unsigned long addr)
+{
+       struct arm_vmregion *c;
+       unsigned long flags;
+
+       spin_lock_irqsave(&head->vm_lock, flags);
+       c = __arm_vmregion_find(head, addr);
+       if (c)
+               c->vm_active = 0;
+       spin_unlock_irqrestore(&head->vm_lock, flags);
+       return c;
+}
+
+void arm_vmregion_free(struct arm_vmregion_head *head, struct arm_vmregion *c)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&head->vm_lock, flags);
+       list_del(&c->vm_list);
+       spin_unlock_irqrestore(&head->vm_lock, flags);
+
+       kfree(c);
+}
diff --git a/arch/arm/mm/vmregion.h b/arch/arm/mm/vmregion.h
new file mode 100644 (file)
index 0000000..6b2cdbd
--- /dev/null
@@ -0,0 +1,29 @@
+#ifndef VMREGION_H
+#define VMREGION_H
+
+#include <linux/spinlock.h>
+#include <linux/list.h>
+
+struct page;
+
+struct arm_vmregion_head {
+       spinlock_t              vm_lock;
+       struct list_head        vm_list;
+       unsigned long           vm_start;
+       unsigned long           vm_end;
+};
+
+struct arm_vmregion {
+       struct list_head        vm_list;
+       unsigned long           vm_start;
+       unsigned long           vm_end;
+       struct page             *vm_pages;
+       int                     vm_active;
+};
+
+struct arm_vmregion *arm_vmregion_alloc(struct arm_vmregion_head *, size_t, gfp_t);
+struct arm_vmregion *arm_vmregion_find(struct arm_vmregion_head *, unsigned long);
+struct arm_vmregion *arm_vmregion_find_remove(struct arm_vmregion_head *, unsigned long);
+void arm_vmregion_free(struct arm_vmregion_head *, struct arm_vmregion *);
+
+#endif