linux/arch/arm/mm/dma-mapping.c
Russell King 45cd5290bf ARM: add dma coherent region reporting via procfs
Add a new seqfile for reporting coherent DMA allocations.  This contains
the address range, size and the function which was used to allocate
each region, allowing these allocations to be viewed in much the same
way as /proc/vmallocinfo.

The DMA coherent region has limited space, so this allows allocation
failures to be viewed, as well as finding out how much space is being
used.

Make sure this file is only readable by root - same as vmallocinfo - to
prevent information leakage.

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-01-23 10:23:57 +00:00

736 lines
18 KiB
C

/*
* linux/arch/arm/mm/dma-mapping.c
*
* Copyright (C) 2000-2004 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* DMA uncached mapping support.
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/gfp.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <asm/memory.h>
#include <asm/highmem.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/sizes.h>
#include <asm/mach/arch.h>
#include "mm.h"
static u64 get_coherent_dma_mask(struct device *dev)
{
u64 mask = (u64)arm_dma_limit;
if (dev) {
mask = dev->coherent_dma_mask;
/*
* Sanity check the DMA mask - it must be non-zero, and
* must be able to be satisfied by a DMA allocation.
*/
if (mask == 0) {
dev_warn(dev, "coherent DMA mask is unset\n");
return 0;
}
if ((~mask) & (u64)arm_dma_limit) {
dev_warn(dev, "coherent DMA mask %#llx is smaller "
"than system GFP_DMA mask %#llx\n",
mask, (u64)arm_dma_limit);
return 0;
}
}
return mask;
}
/*
* Allocate a DMA buffer for 'dev' of size 'size' using the
* specified gfp mask. Note that 'size' must be page aligned.
*/
static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
{
unsigned long order = get_order(size);
struct page *page, *p, *e;
void *ptr;
u64 mask = get_coherent_dma_mask(dev);
#ifdef CONFIG_DMA_API_DEBUG
u64 limit = (mask + 1) & ~mask;
if (limit && size >= limit) {
dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
size, mask);
return NULL;
}
#endif
if (!mask)
return NULL;
if (mask < 0xffffffffULL)
gfp |= GFP_DMA;
page = alloc_pages(gfp, order);
if (!page)
return NULL;
/*
* Now split the huge page and free the excess pages
*/
split_page(page, order);
for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
__free_page(p);
/*
* Ensure that the allocated pages are zeroed, and that any data
* lurking in the kernel direct-mapped region is invalidated.
*/
ptr = page_address(page);
memset(ptr, 0, size);
dmac_flush_range(ptr, ptr + size);
outer_flush_range(__pa(ptr), __pa(ptr) + size);
return page;
}
/*
* Free a DMA buffer. 'size' must be page aligned.
*/
static void __dma_free_buffer(struct page *page, size_t size)
{
struct page *e = page + (size >> PAGE_SHIFT);
while (page < e) {
__free_page(page);
page++;
}
}
#ifdef CONFIG_MMU
#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - consistent_base) >> PAGE_SHIFT)
#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - consistent_base) >> PMD_SHIFT)
/*
* These are the page tables (2MB each) covering uncached, DMA consistent allocations
*/
static pte_t **consistent_pte;
#define DEFAULT_CONSISTENT_DMA_SIZE SZ_2M
unsigned long consistent_base = CONSISTENT_END - DEFAULT_CONSISTENT_DMA_SIZE;
void __init init_consistent_dma_size(unsigned long size)
{
unsigned long base = CONSISTENT_END - ALIGN(size, SZ_2M);
BUG_ON(consistent_pte); /* Check we're called before DMA region init */
BUG_ON(base < VMALLOC_END);
/* Grow region to accommodate specified size */
if (base < consistent_base)
consistent_base = base;
}
#include "vmregion.h"
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_end = CONSISTENT_END,
};
#ifdef CONFIG_HUGETLB_PAGE
#error ARM Coherent DMA allocator does not (yet) support huge TLB
#endif
/*
* Initialise the consistent memory allocation.
*/
static int __init consistent_init(void)
{
int ret = 0;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
int i = 0;
unsigned long base = consistent_base;
unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT;
consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL);
if (!consistent_pte) {
pr_err("%s: no memory\n", __func__);
return -ENOMEM;
}
pr_debug("DMA memory: 0x%08lx - 0x%08lx:\n", base, CONSISTENT_END);
consistent_head.vm_start = base;
do {
pgd = pgd_offset(&init_mm, base);
pud = pud_alloc(&init_mm, pgd, base);
if (!pud) {
printk(KERN_ERR "%s: no pud tables\n", __func__);
ret = -ENOMEM;
break;
}
pmd = pmd_alloc(&init_mm, pud, base);
if (!pmd) {
printk(KERN_ERR "%s: no pmd tables\n", __func__);
ret = -ENOMEM;
break;
}
WARN_ON(!pmd_none(*pmd));
pte = pte_alloc_kernel(pmd, base);
if (!pte) {
printk(KERN_ERR "%s: no pte tables\n", __func__);
ret = -ENOMEM;
break;
}
consistent_pte[i++] = pte;
base += PMD_SIZE;
} while (base < CONSISTENT_END);
return ret;
}
core_initcall(consistent_init);
static void *
__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
const void *caller)
{
struct arm_vmregion *c;
size_t align;
int bit;
if (!consistent_pte) {
printk(KERN_ERR "%s: not initialised\n", __func__);
dump_stack();
return NULL;
}
/*
* Align the virtual region allocation - maximum alignment is
* a section size, minimum is a page size. This helps reduce
* fragmentation of the DMA space, and also prevents allocations
* smaller than a section from crossing a section boundary.
*/
bit = fls(size - 1);
if (bit > SECTION_SHIFT)
bit = SECTION_SHIFT;
align = 1 << bit;
/*
* Allocate a virtual address in the consistent mapping region.
*/
c = arm_vmregion_alloc(&consistent_head, align, size,
gfp & ~(__GFP_DMA | __GFP_HIGHMEM), caller);
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);
dsb();
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, c) 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, const void *caller)
{
struct page *page;
void *addr;
/*
* Following is a work-around (a.k.a. hack) to prevent pages
* with __GFP_COMP being passed to split_page() which cannot
* handle them. The real problem is that this flag probably
* should be 0 on ARM as it is not supported on this
* platform; see CONFIG_HUGETLBFS.
*/
gfp &= ~(__GFP_COMP);
*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, caller);
else
addr = page_address(page);
if (addr)
*handle = pfn_to_dma(dev, page_to_pfn(page));
else
__dma_free_buffer(page, size);
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),
__builtin_return_address(0));
}
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),
__builtin_return_address(0));
}
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(pfn_to_page(dma_to_pfn(dev, handle)), size);
}
EXPORT_SYMBOL(dma_free_coherent);
/*
* Make an area consistent for devices.
* Note: Drivers should NOT use this function directly, as it will break
* platforms with CONFIG_DMABOUNCE.
* Use the driver DMA support - see dma-mapping.h (dma_sync_*)
*/
void ___dma_single_cpu_to_dev(const void *kaddr, size_t size,
enum dma_data_direction dir)
{
unsigned long paddr;
BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1));
dmac_map_area(kaddr, size, dir);
paddr = __pa(kaddr);
if (dir == DMA_FROM_DEVICE) {
outer_inv_range(paddr, paddr + size);
} else {
outer_clean_range(paddr, paddr + size);
}
/* FIXME: non-speculating: flush on bidirectional mappings? */
}
EXPORT_SYMBOL(___dma_single_cpu_to_dev);
void ___dma_single_dev_to_cpu(const void *kaddr, size_t size,
enum dma_data_direction dir)
{
BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1));
/* FIXME: non-speculating: not required */
/* don't bother invalidating if DMA to device */
if (dir != DMA_TO_DEVICE) {
unsigned long paddr = __pa(kaddr);
outer_inv_range(paddr, paddr + size);
}
dmac_unmap_area(kaddr, size, dir);
}
EXPORT_SYMBOL(___dma_single_dev_to_cpu);
static void dma_cache_maint_page(struct page *page, unsigned long offset,
size_t size, enum dma_data_direction dir,
void (*op)(const void *, size_t, int))
{
/*
* A single sg entry may refer to multiple physically contiguous
* pages. But we still need to process highmem pages individually.
* If highmem is not configured then the bulk of this loop gets
* optimized out.
*/
size_t left = size;
do {
size_t len = left;
void *vaddr;
if (PageHighMem(page)) {
if (len + offset > PAGE_SIZE) {
if (offset >= PAGE_SIZE) {
page += offset / PAGE_SIZE;
offset %= PAGE_SIZE;
}
len = PAGE_SIZE - offset;
}
vaddr = kmap_high_get(page);
if (vaddr) {
vaddr += offset;
op(vaddr, len, dir);
kunmap_high(page);
} else if (cache_is_vipt()) {
/* unmapped pages might still be cached */
vaddr = kmap_atomic(page);
op(vaddr + offset, len, dir);
kunmap_atomic(vaddr);
}
} else {
vaddr = page_address(page) + offset;
op(vaddr, len, dir);
}
offset = 0;
page++;
left -= len;
} while (left);
}
void ___dma_page_cpu_to_dev(struct page *page, unsigned long off,
size_t size, enum dma_data_direction dir)
{
unsigned long paddr;
dma_cache_maint_page(page, off, size, dir, dmac_map_area);
paddr = page_to_phys(page) + off;
if (dir == DMA_FROM_DEVICE) {
outer_inv_range(paddr, paddr + size);
} else {
outer_clean_range(paddr, paddr + size);
}
/* FIXME: non-speculating: flush on bidirectional mappings? */
}
EXPORT_SYMBOL(___dma_page_cpu_to_dev);
void ___dma_page_dev_to_cpu(struct page *page, unsigned long off,
size_t size, enum dma_data_direction dir)
{
unsigned long paddr = page_to_phys(page) + off;
/* FIXME: non-speculating: not required */
/* don't bother invalidating if DMA to device */
if (dir != DMA_TO_DEVICE)
outer_inv_range(paddr, paddr + size);
dma_cache_maint_page(page, off, size, dir, dmac_unmap_area);
/*
* Mark the D-cache clean for this page to avoid extra flushing.
*/
if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE)
set_bit(PG_dcache_clean, &page->flags);
}
EXPORT_SYMBOL(___dma_page_dev_to_cpu);
/**
* dma_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
* @dir: DMA transfer direction
*
* Map a set of buffers described by scatterlist in streaming mode for DMA.
* This is the scatter-gather version of the dma_map_single interface.
* Here the scatter gather list elements are each tagged with the
* appropriate dma address and length. They are obtained via
* sg_dma_{address,length}.
*
* Device ownership issues as mentioned for dma_map_single are the same
* here.
*/
int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i, j;
BUG_ON(!valid_dma_direction(dir));
for_each_sg(sg, s, nents, i) {
s->dma_address = __dma_map_page(dev, sg_page(s), s->offset,
s->length, dir);
if (dma_mapping_error(dev, s->dma_address))
goto bad_mapping;
}
debug_dma_map_sg(dev, sg, nents, nents, dir);
return nents;
bad_mapping:
for_each_sg(sg, s, i, j)
__dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
return 0;
}
EXPORT_SYMBOL(dma_map_sg);
/**
* dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to unmap (same as was passed to dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*
* Unmap a set of streaming mode DMA translations. Again, CPU access
* rules concerning calls here are the same as for dma_unmap_single().
*/
void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i;
debug_dma_unmap_sg(dev, sg, nents, dir);
for_each_sg(sg, s, nents, i)
__dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
}
EXPORT_SYMBOL(dma_unmap_sg);
/**
* dma_sync_sg_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*/
void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nents, i) {
if (!dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0,
sg_dma_len(s), dir))
continue;
__dma_page_dev_to_cpu(sg_page(s), s->offset,
s->length, dir);
}
debug_dma_sync_sg_for_cpu(dev, sg, nents, dir);
}
EXPORT_SYMBOL(dma_sync_sg_for_cpu);
/**
* dma_sync_sg_for_device
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*/
void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nents, i) {
if (!dmabounce_sync_for_device(dev, sg_dma_address(s), 0,
sg_dma_len(s), dir))
continue;
__dma_page_cpu_to_dev(sg_page(s), s->offset,
s->length, dir);
}
debug_dma_sync_sg_for_device(dev, sg, nents, dir);
}
EXPORT_SYMBOL(dma_sync_sg_for_device);
/*
* Return whether the given device DMA address mask can be supported
* properly. For example, if your device can only drive the low 24-bits
* during bus mastering, then you would pass 0x00ffffff as the mask
* to this function.
*/
int dma_supported(struct device *dev, u64 mask)
{
if (mask < (u64)arm_dma_limit)
return 0;
return 1;
}
EXPORT_SYMBOL(dma_supported);
int dma_set_mask(struct device *dev, u64 dma_mask)
{
if (!dev->dma_mask || !dma_supported(dev, dma_mask))
return -EIO;
#ifndef CONFIG_DMABOUNCE
*dev->dma_mask = dma_mask;
#endif
return 0;
}
EXPORT_SYMBOL(dma_set_mask);
#define PREALLOC_DMA_DEBUG_ENTRIES 4096
static int __init dma_debug_do_init(void)
{
#ifdef CONFIG_MMU
arm_vmregion_create_proc("dma-mappings", &consistent_head);
#endif
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(dma_debug_do_init);