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Merge branch 'pending-dma-coherent' into devel

This commit is contained in:
Russell King 2009-12-04 15:00:00 +00:00
parent 5cb2faa6ed 26a26d3296
commit c6baa1963c
6 changed files with 444 additions and 404 deletions
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14
arch/arm/include/asm/pgtable.h
View File

@ -304,13 +304,23 @@ PTE_BIT_FUNC(mkyoung, |= L_PTE_YOUNG);
static inline pte_t pte_mkspecial(pte_t pte) { return pte; } static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
#define __pgprot_modify(prot,mask,bits) \
__pgprot((pgprot_val(prot) & ~(mask)) | (bits))
/* /*
* Mark the prot value as uncacheable and unbufferable. * Mark the prot value as uncacheable and unbufferable.
*/ */
#define pgprot_noncached(prot) \ #define pgprot_noncached(prot) \
__pgprot((pgprot_val(prot) & ~L_PTE_MT_MASK) | L_PTE_MT_UNCACHED) __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
#define pgprot_writecombine(prot) \ #define pgprot_writecombine(prot) \
__pgprot((pgprot_val(prot) & ~L_PTE_MT_MASK) | L_PTE_MT_BUFFERABLE) __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
#if __LINUX_ARM_ARCH__ >= 7
#define pgprot_dmacoherent(prot) \
__pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_BUFFERABLE)
#else
#define pgprot_dmacoherent(prot) \
__pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_UNCACHED)
#endif
#define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_none(pmd) (!pmd_val(pmd))
#define pmd_present(pmd) (pmd_val(pmd)) #define pmd_present(pmd) (pmd_val(pmd))

19
arch/arm/include/asm/system.h
View File

@ -138,21 +138,26 @@ extern unsigned int user_debug;
#define dmb() __asm__ __volatile__ ("" : : : "memory") #define dmb() __asm__ __volatile__ ("" : : : "memory")
#endif #endif
#ifndef CONFIG_SMP #if __LINUX_ARM_ARCH__ >= 7 || defined(CONFIG_SMP)
#define mb() dmb()
#define rmb() dmb()
#define wmb() dmb()
#else
#define mb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) #define mb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
#define rmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) #define rmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
#define wmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) #define wmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
#endif
#ifndef CONFIG_SMP
#define smp_mb() barrier() #define smp_mb() barrier()
#define smp_rmb() barrier() #define smp_rmb() barrier()
#define smp_wmb() barrier() #define smp_wmb() barrier()
#else #else
#define mb() dmb() #define smp_mb() mb()
#define rmb() dmb() #define smp_rmb() rmb()
#define wmb() dmb() #define smp_wmb() wmb()
#define smp_mb() dmb()
#define smp_rmb() dmb()
#define smp_wmb() dmb()
#endif #endif
#define read_barrier_depends() do { } while(0) #define read_barrier_depends() do { } while(0)
#define smp_read_barrier_depends() do { } while(0) #define smp_read_barrier_depends() do { } while(0)

2
arch/arm/mm/Makefile
View File

@ -6,7 +6,7 @@ obj-y := dma-mapping.o extable.o fault.o init.o \
iomap.o iomap.o
obj-$(CONFIG_MMU) += fault-armv.o flush.o ioremap.o mmap.o \ obj-$(CONFIG_MMU) += fault-armv.o flush.o ioremap.o mmap.o \
pgd.o mmu.o pgd.o mmu.o vmregion.o
ifneq ($(CONFIG_MMU),y) ifneq ($(CONFIG_MMU),y)
obj-y += nommu.o obj-y += nommu.o

653
arch/arm/mm/dma-mapping.c
View File

@ -63,435 +63,86 @@ static u64 get_coherent_dma_mask(struct device *dev)
return mask; return mask;
} }
#ifdef CONFIG_MMU
/* /*
* These are the page tables (2MB each) covering uncached, DMA consistent allocations * Allocate a DMA buffer for 'dev' of size 'size' using the
* specified gfp mask. Note that 'size' must be page aligned.
*/ */
static pte_t *consistent_pte[NUM_CONSISTENT_PTES]; static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
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;
};
static struct arm_vm_region consistent_head = {
.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 order = get_order(size);
unsigned long flags; struct page *page, *p, *e;
struct arm_vm_region *c, *new; void *ptr;
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
static void *
__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;
unsigned long order;
u64 mask = get_coherent_dma_mask(dev); u64 mask = get_coherent_dma_mask(dev);
u64 limit;
if (!consistent_pte[0]) { #ifdef CONFIG_DMA_API_DEBUG
printk(KERN_ERR "%s: not initialised\n", __func__); u64 limit = (mask + 1) & ~mask;
dump_stack(); if (limit && size >= limit) {
dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
size, mask);
return NULL; return NULL;
} }
#endif
if (!mask) if (!mask)
goto no_page; return NULL;
/*
* Sanity check the allocation size.
*/
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 %#llx)\n", size, mask);
goto no_page;
}
order = get_order(size);
if (mask < 0xffffffffULL) if (mask < 0xffffffffULL)
gfp |= GFP_DMA; gfp |= GFP_DMA;
page = alloc_pages(gfp, order); page = alloc_pages(gfp, order);
if (!page) if (!page)
goto no_page; return NULL;
/* /*
* Invalidate any data that might be lurking in the * Now split the huge page and free the excess pages
* kernel direct-mapped region for device DMA.
*/ */
{ split_page(page, order);
void *ptr = page_address(page); for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
memset(ptr, 0, size); __free_page(p);
dmac_flush_range(ptr, ptr + size);
outer_flush_range(__pa(ptr), __pa(ptr) + size);
}
/* /*
* Allocate a virtual address in the consistent mapping region. * Ensure that the allocated pages are zeroed, and that any data
* lurking in the kernel direct-mapped region is invalidated.
*/ */
c = arm_vm_region_alloc(&consistent_head, size, ptr = page_address(page);
gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); memset(ptr, 0, size);
if (c) { dmac_flush_range(ptr, ptr + size);
pte_t *pte; outer_flush_range(__pa(ptr), __pa(ptr) + size);
struct page *end = page + (1 << order);
int idx = CONSISTENT_PTE_INDEX(c->vm_start);
u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
pte = consistent_pte[idx] + off; return page;
c->vm_pages = page;
split_page(page, order);
/*
* Set the "dma handle"
*/
*handle = page_to_dma(dev, page);
do {
BUG_ON(!pte_none(*pte));
/*
* x86 does not mark the pages reserved...
*/
SetPageReserved(page);
set_pte_ext(pte, mk_pte(page, prot), 0);
page++;
pte++;
off++;
if (off >= PTRS_PER_PTE) {
off = 0;
pte = consistent_pte[++idx];
}
} 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:
*handle = ~0;
return NULL;
} }
#else /* !CONFIG_MMU */
static void *
__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
pgprot_t prot)
{
void *virt;
u64 mask = get_coherent_dma_mask(dev);
if (!mask)
goto error;
if (mask < 0xffffffffULL)
gfp |= GFP_DMA;
virt = kmalloc(size, gfp);
if (!virt)
goto error;
*handle = virt_to_dma(dev, virt);
return virt;
error:
*handle = ~0;
return NULL;
}
#endif /* CONFIG_MMU */
/* /*
* Allocate DMA-coherent memory space and return both the kernel remapped * Free a DMA buffer. 'size' must be page aligned.
* virtual and bus address for that space.
*/ */
void * static void __dma_free_buffer(struct page *page, size_t size)
dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
{ {
void *memory; struct page *e = page + (size >> PAGE_SHIFT);
if (dma_alloc_from_coherent(dev, size, handle, &memory)) while (page < e) {
return memory; __free_page(page);
page++;
if (arch_is_coherent()) {
void *virt;
virt = kmalloc(size, gfp);
if (!virt)
return NULL;
*handle = virt_to_dma(dev, virt);
return virt;
} }
return __dma_alloc(dev, size, handle, gfp,
pgprot_noncached(pgprot_kernel));
} }
EXPORT_SYMBOL(dma_alloc_coherent);
/*
* Allocate a writecombining region, in much the same way as
* dma_alloc_coherent above.
*/
void *
dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
{
return __dma_alloc(dev, size, handle, gfp,
pgprot_writecombine(pgprot_kernel));
}
EXPORT_SYMBOL(dma_alloc_writecombine);
static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
int ret = -ENXIO;
#ifdef CONFIG_MMU #ifdef CONFIG_MMU
unsigned long flags, user_size, kern_size;
struct arm_vm_region *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);
if (c) {
unsigned long off = vma->vm_pgoff;
kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT;
if (off < kern_size &&
user_size <= (kern_size - off)) {
ret = remap_pfn_range(vma, vma->vm_start,
page_to_pfn(c->vm_pages) + off,
user_size << PAGE_SHIFT,
vma->vm_page_prot);
}
}
#endif /* CONFIG_MMU */
return ret;
}
int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
}
EXPORT_SYMBOL(dma_mmap_coherent);
int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
}
EXPORT_SYMBOL(dma_mmap_writecombine);
/* /*
* free a page as defined by the above mapping. * These are the page tables (2MB each) covering uncached, DMA consistent allocations
* Must not be called with IRQs disabled.
*/ */
#ifdef CONFIG_MMU static pte_t *consistent_pte[NUM_CONSISTENT_PTES];
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;
pte_t *ptep;
int idx;
u32 off;
WARN_ON(irqs_disabled()); #include "vmregion.h"
if (dma_release_from_coherent(dev, get_order(size), cpu_addr)) static struct arm_vmregion_head consistent_head = {
return; .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,
};
if (arch_is_coherent()) { #ifdef CONFIG_HUGETLB_PAGE
kfree(cpu_addr); #error ARM Coherent DMA allocator does not (yet) support huge TLB
return; #endif
}
size = PAGE_ALIGN(size);
spin_lock_irqsave(&consistent_lock, flags);
c = arm_vm_region_find(&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);
dump_stack();
size = c->vm_end - c->vm_start;
}
idx = CONSISTENT_PTE_INDEX(c->vm_start);
off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
ptep = consistent_pte[idx] + off;
addr = c->vm_start;
do {
pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
unsigned long pfn;
ptep++;
addr += PAGE_SIZE;
off++;
if (off >= PTRS_PER_PTE) {
off = 0;
ptep = consistent_pte[++idx];
}
if (!pte_none(pte) && pte_present(pte)) {
pfn = pte_pfn(pte);
if (pfn_valid(pfn)) {
struct page *page = pfn_to_page(pfn);
/*
* x86 does not mark the pages reserved...
*/
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);
spin_lock_irqsave(&consistent_lock, flags);
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__, cpu_addr);
dump_stack();
}
#else /* !CONFIG_MMU */
void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
{
if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
return;
kfree(cpu_addr);
}
#endif /* CONFIG_MMU */
EXPORT_SYMBOL(dma_free_coherent);
/* /*
* Initialise the consistent memory allocation. * Initialise the consistent memory allocation.
@ -499,7 +150,6 @@ EXPORT_SYMBOL(dma_free_coherent);
static int __init consistent_init(void) static int __init consistent_init(void)
{ {
int ret = 0; int ret = 0;
#ifdef CONFIG_MMU
pgd_t *pgd; pgd_t *pgd;
pmd_t *pmd; pmd_t *pmd;
pte_t *pte; pte_t *pte;
@ -526,13 +176,228 @@ static int __init consistent_init(void)
consistent_pte[i++] = pte; consistent_pte[i++] = pte;
base += (1 << PGDIR_SHIFT); base += (1 << PGDIR_SHIFT);
} while (base < CONSISTENT_END); } while (base < CONSISTENT_END);
#endif /* !CONFIG_MMU */
return ret; return ret;
} }
core_initcall(consistent_init); core_initcall(consistent_init);
static void *
__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot)
{
struct arm_vmregion *c;
if (!consistent_pte[0]) {
printk(KERN_ERR "%s: not initialised\n", __func__);
dump_stack();
return NULL;
}
/*
* Allocate a virtual address in the consistent mapping region.
*/
c = arm_vmregion_alloc(&consistent_head, size,
gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
if (c) {
pte_t *pte;
int idx = CONSISTENT_PTE_INDEX(c->vm_start);
u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
pte = consistent_pte[idx] + off;
c->vm_pages = page;
do {
BUG_ON(!pte_none(*pte));
set_pte_ext(pte, mk_pte(page, prot), 0);
page++;
pte++;
off++;
if (off >= PTRS_PER_PTE) {
off = 0;
pte = consistent_pte[++idx];
}
} while (size -= PAGE_SIZE);
return (void *)c->vm_start;
}
return NULL;
}
static void __dma_free_remap(void *cpu_addr, size_t size)
{
struct arm_vmregion *c;
unsigned long addr;
pte_t *ptep;
int idx;
u32 off;
c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr);
if (!c) {
printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
__func__, cpu_addr);
dump_stack();
return;
}
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;
}
idx = CONSISTENT_PTE_INDEX(c->vm_start);
off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
ptep = consistent_pte[idx] + off;
addr = c->vm_start;
do {
pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
ptep++;
addr += PAGE_SIZE;
off++;
if (off >= PTRS_PER_PTE) {
off = 0;
ptep = consistent_pte[++idx];
}
if (pte_none(pte) || !pte_present(pte))
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);
arm_vmregion_free(&consistent_head, c);
}
#else /* !CONFIG_MMU */
#define __dma_alloc_remap(page, size, gfp, prot) page_address(page)
#define __dma_free_remap(addr, size) do { } while (0)
#endif /* CONFIG_MMU */
static void *
__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
pgprot_t prot)
{
struct page *page;
void *addr;
*handle = ~0;
size = PAGE_ALIGN(size);
page = __dma_alloc_buffer(dev, size, gfp);
if (!page)
return NULL;
if (!arch_is_coherent())
addr = __dma_alloc_remap(page, size, gfp, prot);
else
addr = page_address(page);
if (addr)
*handle = page_to_dma(dev, page);
return addr;
}
/*
* Allocate DMA-coherent memory space and return both the kernel remapped
* virtual and bus address for that space.
*/
void *
dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
{
void *memory;
if (dma_alloc_from_coherent(dev, size, handle, &memory))
return memory;
return __dma_alloc(dev, size, handle, gfp,
pgprot_dmacoherent(pgprot_kernel));
}
EXPORT_SYMBOL(dma_alloc_coherent);
/*
* Allocate a writecombining region, in much the same way as
* dma_alloc_coherent above.
*/
void *
dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
{
return __dma_alloc(dev, size, handle, gfp,
pgprot_writecombine(pgprot_kernel));
}
EXPORT_SYMBOL(dma_alloc_writecombine);
static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
int ret = -ENXIO;
#ifdef CONFIG_MMU
unsigned long user_size, kern_size;
struct arm_vmregion *c;
user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
if (c) {
unsigned long off = vma->vm_pgoff;
kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT;
if (off < kern_size &&
user_size <= (kern_size - off)) {
ret = remap_pfn_range(vma, vma->vm_start,
page_to_pfn(c->vm_pages) + off,
user_size << PAGE_SHIFT,
vma->vm_page_prot);
}
}
#endif /* CONFIG_MMU */
return ret;
}
int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot);
return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
}
EXPORT_SYMBOL(dma_mmap_coherent);
int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
}
EXPORT_SYMBOL(dma_mmap_writecombine);
/*
* free a page as defined by the above mapping.
* Must not be called with IRQs disabled.
*/
void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
{
WARN_ON(irqs_disabled());
if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
return;
size = PAGE_ALIGN(size);
if (!arch_is_coherent())
__dma_free_remap(cpu_addr, size);
__dma_free_buffer(dma_to_page(dev, handle), size);
}
EXPORT_SYMBOL(dma_free_coherent);
/* /*
* Make an area consistent for devices. * Make an area consistent for devices.
* Note: Drivers should NOT use this function directly, as it will break * Note: Drivers should NOT use this function directly, as it will break

131
arch/arm/mm/vmregion.c Normal file
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#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);
}

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arch/arm/mm/vmregion.h Normal file
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#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