[PATCH 01/10] ARM: dma-mapping: split out vmregion code from dma coherent mapping code
Russell King - ARM Linux
linux at arm.linux.org.uk
Sat Nov 21 14:37:22 EST 2009
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
arch/arm/mm/Makefile | 2 +-
arch/arm/mm/dma-mapping.c | 132 +++++----------------------------------------
arch/arm/mm/vmregion.c | 131 ++++++++++++++++++++++++++++++++++++++++++++
arch/arm/mm/vmregion.h | 29 ++++++++++
4 files changed, 174 insertions(+), 120 deletions(-)
create mode 100644 arch/arm/mm/vmregion.c
create mode 100644 arch/arm/mm/vmregion.h
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 055cb2a..42352e7 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -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
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4193904..536dfb2 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();
diff --git a/arch/arm/mm/vmregion.c b/arch/arm/mm/vmregion.c
new file mode 100644
index 0000000..19e09bd
--- /dev/null
+++ b/arch/arm/mm/vmregion.c
@@ -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
index 0000000..6b2cdbd
--- /dev/null
+++ b/arch/arm/mm/vmregion.h
@@ -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
--
1.6.2.5
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