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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>
This commit is contained in:
Russell King 2009-11-19 15:07:04 +00:00
parent ac50e95078
commit 13ccf3ad99
4 changed files with 174 additions and 120 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm/mm/Makefile
View 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

132
arch/arm/mm/dma-mapping.c
View 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();

131
arch/arm/mm/vmregion.c Normal file
View File

@ -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);
}

29
arch/arm/mm/vmregion.h Normal file
View File

@ -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