Hello!
This patchset replaces custom consistent dma regions usage in
dma-mapping framework in favour of generic vmalloc areas created on
demand for each allocation. The main purpose for this patchset is to
remove 2MiB limit of dma coherent/writecombine allocations.
Atomic allocations are served from special pool preallocated on boot,
becasue vmalloc areas cannot be reliably created in atomic context.
Linux v3.5-rc1 introduced a lot of changes to ARM dma-mapping subsystem
(CMA and dmamap_ops based implementation has been finally merged), so
the previous version of these patches is not applicable anymore. This
version provides an update required for applying them on v3.5-rc2 kernel
as well as some changes requested by Minchan Kim in his review.
This patch is based on vanilla v3.5-rc2 release.
Atomic allocations have been tested with s3c-sdhci driver on Samsung
UniversalC210 board with dmabounce code enabled to force
dma_alloc_coherent() use on each dma_map_* call (some of them are made
from interrupts).
Best regards
Marek Szyprowski
Samsung Poland R&D Center
Changelog:
v3:
- rebased onto v3.4-rc2: added support for IOMMU-aware implementation
of dma-mapping calls, unified with CMA coherent dma pool
- implemented changes requested by Minchan Kim: added more checks for
vmarea->flags & VM_DMA, renamed some variables, removed obsole locks,
squashed find_vm_area() exporting patch into the main redesign patch
v2: http://thread.gmane.org/gmane.linux.kernel.mm/78563
- added support for atomic allocations (served from preallocated pool)
- minor cleanup here and there
- rebased onto v3.4-rc7
v1: http://thread.gmane.org/gmane.linux.kernel.mm/76703
- initial version
Patch summary:
Marek Szyprowski (3):
mm: vmalloc: use const void * for caller argument
mm: vmalloc: add VM_DMA flag to indicate areas used by dma-mapping
framework
ARM: dma-mapping: remove custom consistent dma region
Documentation/kernel-parameters.txt | 2 +-
arch/arm/include/asm/dma-mapping.h | 2 +-
arch/arm/mm/dma-mapping.c | 503 ++++++++++++-----------------------
include/linux/vmalloc.h | 10 +-
mm/vmalloc.c | 31 ++-
5 files changed, 206 insertions(+), 342 deletions(-)
--
1.7.1.569.g6f426
'const void *' is a safer type for caller function type. This patch
updates all references to caller function type.
Signed-off-by: Marek Szyprowski <[email protected]>
Reviewed-by: Kyungmin Park <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>
---
include/linux/vmalloc.h | 8 ++++----
mm/vmalloc.c | 18 +++++++++---------
2 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index dcdfc2b..2e28f4d 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -32,7 +32,7 @@ struct vm_struct {
struct page **pages;
unsigned int nr_pages;
phys_addr_t phys_addr;
- void *caller;
+ const void *caller;
};
/*
@@ -62,7 +62,7 @@ extern void *vmalloc_32_user(unsigned long size);
extern void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot);
extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
unsigned long start, unsigned long end, gfp_t gfp_mask,
- pgprot_t prot, int node, void *caller);
+ pgprot_t prot, int node, const void *caller);
extern void vfree(const void *addr);
extern void *vmap(struct page **pages, unsigned int count,
@@ -85,13 +85,13 @@ static inline size_t get_vm_area_size(const struct vm_struct *area)
extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
extern struct vm_struct *get_vm_area_caller(unsigned long size,
- unsigned long flags, void *caller);
+ unsigned long flags, const void *caller);
extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end);
extern struct vm_struct *__get_vm_area_caller(unsigned long size,
unsigned long flags,
unsigned long start, unsigned long end,
- void *caller);
+ const void *caller);
extern struct vm_struct *remove_vm_area(const void *addr);
extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2aad499..11308f0 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1280,7 +1280,7 @@ DEFINE_RWLOCK(vmlist_lock);
struct vm_struct *vmlist;
static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
- unsigned long flags, void *caller)
+ unsigned long flags, const void *caller)
{
vm->flags = flags;
vm->addr = (void *)va->va_start;
@@ -1306,7 +1306,7 @@ static void insert_vmalloc_vmlist(struct vm_struct *vm)
}
static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
- unsigned long flags, void *caller)
+ unsigned long flags, const void *caller)
{
setup_vmalloc_vm(vm, va, flags, caller);
insert_vmalloc_vmlist(vm);
@@ -1314,7 +1314,7 @@ static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
static struct vm_struct *__get_vm_area_node(unsigned long size,
unsigned long align, unsigned long flags, unsigned long start,
- unsigned long end, int node, gfp_t gfp_mask, void *caller)
+ unsigned long end, int node, gfp_t gfp_mask, const void *caller)
{
struct vmap_area *va;
struct vm_struct *area;
@@ -1375,7 +1375,7 @@ EXPORT_SYMBOL_GPL(__get_vm_area);
struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end,
- void *caller)
+ const void *caller)
{
return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
caller);
@@ -1397,7 +1397,7 @@ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
}
struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
- void *caller)
+ const void *caller)
{
return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
-1, GFP_KERNEL, caller);
@@ -1568,9 +1568,9 @@ EXPORT_SYMBOL(vmap);
static void *__vmalloc_node(unsigned long size, unsigned long align,
gfp_t gfp_mask, pgprot_t prot,
- int node, void *caller);
+ int node, const void *caller);
static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
- pgprot_t prot, int node, void *caller)
+ pgprot_t prot, int node, const void *caller)
{
const int order = 0;
struct page **pages;
@@ -1643,7 +1643,7 @@ fail:
*/
void *__vmalloc_node_range(unsigned long size, unsigned long align,
unsigned long start, unsigned long end, gfp_t gfp_mask,
- pgprot_t prot, int node, void *caller)
+ pgprot_t prot, int node, const void *caller)
{
struct vm_struct *area;
void *addr;
@@ -1699,7 +1699,7 @@ fail:
*/
static void *__vmalloc_node(unsigned long size, unsigned long align,
gfp_t gfp_mask, pgprot_t prot,
- int node, void *caller)
+ int node, const void *caller)
{
return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
gfp_mask, prot, node, caller);
--
1.7.1.569.g6f426
Add new type of vm_area intented to be used for mappings created by
dma-mapping framework.
Signed-off-by: Marek Szyprowski <[email protected]>
Reviewed-by: Kyungmin Park <[email protected]>
---
include/linux/vmalloc.h | 1 +
mm/vmalloc.c | 3 +++
2 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 2e28f4d..e725b7b 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -14,6 +14,7 @@ struct vm_area_struct; /* vma defining user mapping in mm_types.h */
#define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */
#define VM_VPAGES 0x00000010 /* buffer for pages was vmalloc'ed */
#define VM_UNLIST 0x00000020 /* vm_struct is not listed in vmlist */
+#define VM_DMA 0x00000040 /* used by dma-mapping framework */
/* bits [20..32] reserved for arch specific ioremap internals */
/*
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 11308f0..e04d59b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2575,6 +2575,9 @@ static int s_show(struct seq_file *m, void *p)
if (v->flags & VM_IOREMAP)
seq_printf(m, " ioremap");
+ if (v->flags & VM_DMA)
+ seq_printf(m, " dma");
+
if (v->flags & VM_ALLOC)
seq_printf(m, " vmalloc");
--
1.7.1.569.g6f426
This patch changes dma-mapping subsystem to use generic vmalloc areas
for all consistent dma allocations. This increases the total size limit
of the consistent allocations and removes platform hacks and a lot of
duplicated code.
Atomic allocations are served from special pool preallocated on boot,
becasue vmalloc areas cannot be reliably created in atomic context.
Signed-off-by: Marek Szyprowski <[email protected]>
Reviewed-by: Kyungmin Park <[email protected]>
---
Documentation/kernel-parameters.txt | 2 +-
arch/arm/include/asm/dma-mapping.h | 2 +-
arch/arm/mm/dma-mapping.c | 503 ++++++++++++-----------------------
include/linux/vmalloc.h | 1 +
mm/vmalloc.c | 10 +-
5 files changed, 189 insertions(+), 329 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a92c5eb..da07f6c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -526,7 +526,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
coherent_pool=nn[KMG] [ARM,KNL]
Sets the size of memory pool for coherent, atomic dma
- allocations if Contiguous Memory Allocator (CMA) is used.
+ allocations.
code_bytes [X86] How many bytes of object code to print
in an oops report.
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index bbef15d..80777d87 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -226,7 +226,7 @@ static inline int dma_mmap_writecombine(struct device *dev, struct vm_area_struc
* DMA region above it's default value of 2MB. It must be called before the
* memory allocator is initialised, i.e. before any core_initcall.
*/
-extern void __init init_consistent_dma_size(unsigned long size);
+static inline void init_consistent_dma_size(unsigned long size) { }
/*
* For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 106c4c0..b3ffcf9 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -22,6 +22,7 @@
#include <linux/memblock.h>
#include <linux/slab.h>
#include <linux/iommu.h>
+#include <linux/io.h>
#include <linux/vmalloc.h>
#include <asm/memory.h>
@@ -217,115 +218,66 @@ static void __dma_free_buffer(struct page *page, size_t size)
}
#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;
-
- if (IS_ENABLED(CONFIG_CMA) && !IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
- return 0;
-
- 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) {
- pr_err("%s: no pud tables\n", __func__);
- ret = -ENOMEM;
- break;
- }
-
- pmd = pmd_alloc(&init_mm, pud, base);
- if (!pmd) {
- pr_err("%s: no pmd tables\n", __func__);
- ret = -ENOMEM;
- break;
- }
- WARN_ON(!pmd_none(*pmd));
-
- pte = pte_alloc_kernel(pmd, base);
- if (!pte) {
- pr_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 *__alloc_from_contiguous(struct device *dev, size_t size,
pgprot_t prot, struct page **ret_page);
-static struct arm_vmregion_head coherent_head = {
- .vm_lock = __SPIN_LOCK_UNLOCKED(&coherent_head.vm_lock),
- .vm_list = LIST_HEAD_INIT(coherent_head.vm_list),
+static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
+ pgprot_t prot, struct page **ret_page,
+ const void *caller);
+
+static void *
+__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
+ const void *caller)
+{
+ struct vm_struct *area;
+ unsigned long addr;
+
+ area = get_vm_area_caller(size, VM_DMA | VM_USERMAP, caller);
+ if (!area)
+ return NULL;
+ addr = (unsigned long)area->addr;
+ area->phys_addr = __pfn_to_phys(page_to_pfn(page));
+
+ if (ioremap_page_range(addr, addr + size, area->phys_addr, prot)) {
+ vunmap((void *)addr);
+ return NULL;
+ }
+ return (void *)addr;
+}
+
+static void __dma_free_remap(void *cpu_addr, size_t size)
+{
+ struct vm_struct *area = find_vm_area(cpu_addr);
+ if (!area || !(area->flags & VM_DMA)) {
+ pr_err("%s: trying to free invalid coherent area: %p\n",
+ __func__, cpu_addr);
+ dump_stack();
+ return;
+ }
+ unmap_kernel_range((unsigned long)cpu_addr, size);
+ vunmap(cpu_addr);
+}
+
+struct dma_pool {
+ size_t size;
+ spinlock_t lock;
+ unsigned long *bitmap;
+ unsigned long nr_pages;
+ void *vaddr;
+ struct page *page;
};
-size_t coherent_pool_size = DEFAULT_CONSISTENT_DMA_SIZE / 8;
+static struct dma_pool atomic_pool = {
+ .size = SZ_256K,
+};
static int __init early_coherent_pool(char *p)
{
- coherent_pool_size = memparse(p, &p);
+ atomic_pool.size = memparse(p, &p);
return 0;
}
early_param("coherent_pool", early_coherent_pool);
@@ -333,32 +285,45 @@ early_param("coherent_pool", early_coherent_pool);
/*
* Initialise the coherent pool for atomic allocations.
*/
-static int __init coherent_init(void)
+static int __init atomic_pool_init(void)
{
+ struct dma_pool *pool = &atomic_pool;
pgprot_t prot = pgprot_dmacoherent(pgprot_kernel);
- size_t size = coherent_pool_size;
+ unsigned long nr_pages = pool->size >> PAGE_SHIFT;
+ unsigned long *bitmap;
struct page *page;
void *ptr;
+ int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long);
- if (!IS_ENABLED(CONFIG_CMA))
- return 0;
+ bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+ if (!bitmap)
+ goto no_bitmap;
- ptr = __alloc_from_contiguous(NULL, size, prot, &page);
+ if (IS_ENABLED(CONFIG_CMA))
+ ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page);
+ else
+ ptr = __alloc_remap_buffer(NULL, pool->size, GFP_KERNEL, prot,
+ &page, NULL);
if (ptr) {
- coherent_head.vm_start = (unsigned long) ptr;
- coherent_head.vm_end = (unsigned long) ptr + size;
- printk(KERN_INFO "DMA: preallocated %u KiB pool for atomic coherent allocations\n",
- (unsigned)size / 1024);
+ spin_lock_init(&pool->lock);
+ pool->vaddr = ptr;
+ pool->page = page;
+ pool->bitmap = bitmap;
+ pool->nr_pages = nr_pages;
+ pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n",
+ (unsigned)pool->size / 1024);
return 0;
}
- printk(KERN_ERR "DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
- (unsigned)size / 1024);
+ kfree(bitmap);
+no_bitmap:
+ pr_err("DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
+ (unsigned)pool->size / 1024);
return -ENOMEM;
}
/*
* CMA is activated by core_initcall, so we must be called after it.
*/
-postcore_initcall(coherent_init);
+postcore_initcall(atomic_pool_init);
struct dma_contig_early_reserve {
phys_addr_t base;
@@ -406,112 +371,6 @@ void __init dma_contiguous_remap(void)
}
}
-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) {
- pr_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->priv = 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) {
- pr_err("%s: trying to free invalid coherent area: %p\n",
- __func__, cpu_addr);
- dump_stack();
- return;
- }
-
- if ((c->vm_end - c->vm_start) != size) {
- pr_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))
- pr_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);
-}
-
static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
void *data)
{
@@ -552,15 +411,17 @@ static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
return ptr;
}
-static void *__alloc_from_pool(struct device *dev, size_t size,
- struct page **ret_page, const void *caller)
+static void *__alloc_from_pool(size_t size, struct page **ret_page)
{
- struct arm_vmregion *c;
+ struct dma_pool *pool = &atomic_pool;
+ unsigned int count = size >> PAGE_SHIFT;
+ unsigned int pageno;
+ unsigned long flags;
+ void *ptr = NULL;
size_t align;
- if (!coherent_head.vm_start) {
- printk(KERN_ERR "%s: coherent pool not initialised!\n",
- __func__);
+ if (!pool->vaddr) {
+ pr_err("%s: coherent pool not initialised!\n", __func__);
dump_stack();
return NULL;
}
@@ -571,35 +432,42 @@ static void *__alloc_from_pool(struct device *dev, size_t size,
* size. This helps reduce fragmentation of the DMA space.
*/
align = PAGE_SIZE << get_order(size);
- c = arm_vmregion_alloc(&coherent_head, align, size, 0, caller);
- if (c) {
- void *ptr = (void *)c->vm_start;
- struct page *page = virt_to_page(ptr);
- *ret_page = page;
- return ptr;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ pageno = bitmap_find_next_zero_area(pool->bitmap, pool->nr_pages,
+ 0, count, (1 << align) - 1);
+ if (pageno < pool->nr_pages) {
+ bitmap_set(pool->bitmap, pageno, count);
+ ptr = pool->vaddr + PAGE_SIZE * pageno;
+ *ret_page = pool->page + pageno;
}
- return NULL;
+ spin_unlock_irqrestore(&pool->lock, flags);
+
+ return ptr;
}
-static int __free_from_pool(void *cpu_addr, size_t size)
+static int __free_from_pool(void *start, size_t size)
{
- unsigned long start = (unsigned long)cpu_addr;
- unsigned long end = start + size;
- struct arm_vmregion *c;
+ struct dma_pool *pool = &atomic_pool;
+ unsigned long pageno, count;
+ unsigned long flags;
- if (start < coherent_head.vm_start || end > coherent_head.vm_end)
+ if (start < pool->vaddr || start > pool->vaddr + pool->size)
return 0;
- c = arm_vmregion_find_remove(&coherent_head, (unsigned long)start);
-
- 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);
+ if (start + size > pool->vaddr + pool->size) {
+ pr_err("%s: freeing wrong coherent size from pool\n", __func__);
dump_stack();
- size = c->vm_end - c->vm_start;
+ return 0;
}
- arm_vmregion_free(&coherent_head, c);
+ pageno = (start - pool->vaddr) >> PAGE_SHIFT;
+ count = size >> PAGE_SHIFT;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ bitmap_clear(pool->bitmap, pageno, count);
+ spin_unlock_irqrestore(&pool->lock, flags);
+
return 1;
}
@@ -702,10 +570,10 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
if (arch_is_coherent() || nommu())
addr = __alloc_simple_buffer(dev, size, gfp, &page);
+ else if (gfp & GFP_ATOMIC)
+ addr = __alloc_from_pool(size, &page);
else if (!IS_ENABLED(CONFIG_CMA))
addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);
- else if (gfp & GFP_ATOMIC)
- addr = __alloc_from_pool(dev, size, &page, caller);
else
addr = __alloc_from_contiguous(dev, size, prot, &page);
@@ -741,16 +609,22 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
{
int ret = -ENXIO;
#ifdef CONFIG_MMU
+ unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+ unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long pfn = dma_to_pfn(dev, dma_addr);
+ unsigned long off = vma->vm_pgoff;
+
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
- ret = remap_pfn_range(vma, vma->vm_start,
- pfn + vma->vm_pgoff,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
+ if (off < count && user_count <= (count - off)) {
+ ret = remap_pfn_range(vma, vma->vm_start,
+ pfn + off,
+ user_count << PAGE_SHIFT,
+ vma->vm_page_prot);
+ }
#endif /* CONFIG_MMU */
return ret;
@@ -998,9 +872,6 @@ static int arm_dma_set_mask(struct device *dev, u64 dma_mask)
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;
}
@@ -1117,61 +988,31 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t s
* Create a CPU mapping for a specified pages
*/
static void *
-__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot)
+__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
+ const void *caller)
{
- struct arm_vmregion *c;
- size_t align;
- size_t count = size >> PAGE_SHIFT;
- int bit;
+ unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ struct vm_struct *area;
+ unsigned long p;
- if (!consistent_pte[0]) {
- pr_err("%s: not initialised\n", __func__);
- dump_stack();
+ area = get_vm_area_caller(size, VM_DMA | VM_USERMAP, caller);
+ if (!area)
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), NULL);
- if (c) {
- pte_t *pte;
- int idx = CONSISTENT_PTE_INDEX(c->vm_start);
- int i = 0;
- u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
-
- pte = consistent_pte[idx] + off;
- c->priv = pages;
-
- do {
- BUG_ON(!pte_none(*pte));
-
- set_pte_ext(pte, mk_pte(pages[i], prot), 0);
- pte++;
- off++;
- i++;
- if (off >= PTRS_PER_PTE) {
- off = 0;
- pte = consistent_pte[++idx];
- }
- } while (i < count);
- dsb();
+ area->pages = pages;
+ area->nr_pages = nr_pages;
+ p = (unsigned long)area->addr;
- return (void *)c->vm_start;
+ for (i = 0; i < nr_pages; i++) {
+ phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i]));
+ if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot))
+ goto err;
+ p += PAGE_SIZE;
}
+ return area->addr;
+err:
+ unmap_kernel_range((unsigned long)area->addr, size);
+ vunmap(area->addr);
return NULL;
}
@@ -1230,6 +1071,16 @@ static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t si
return 0;
}
+static struct page **__iommu_get_pages(void *cpu_addr)
+{
+ struct vm_struct *area;
+
+ area = find_vm_area(cpu_addr);
+ if (area && (area->flags & VM_DMA))
+ return area->pages;
+ return NULL;
+}
+
static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
{
@@ -1248,7 +1099,8 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
if (*handle == DMA_ERROR_CODE)
goto err_buffer;
- addr = __iommu_alloc_remap(pages, size, gfp, prot);
+ addr = __iommu_alloc_remap(pages, size, gfp, prot,
+ __builtin_return_address(0));
if (!addr)
goto err_mapping;
@@ -1265,31 +1117,25 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
struct dma_attrs *attrs)
{
- struct arm_vmregion *c;
+ unsigned long uaddr = vma->vm_start;
+ unsigned long usize = vma->vm_end - vma->vm_start;
+ struct page **pages = __iommu_get_pages(cpu_addr);
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
- c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
- if (c) {
- struct page **pages = c->priv;
+ if (!pages)
+ return -ENXIO;
- unsigned long uaddr = vma->vm_start;
- unsigned long usize = vma->vm_end - vma->vm_start;
- int i = 0;
+ do {
+ int ret = vm_insert_page(vma, uaddr, *pages++);
+ if (ret) {
+ pr_err("Remapping memory failed: %d\n", ret);
+ return ret;
+ }
+ uaddr += PAGE_SIZE;
+ usize -= PAGE_SIZE;
+ } while (usize > 0);
- do {
- int ret;
-
- ret = vm_insert_page(vma, uaddr, pages[i++]);
- if (ret) {
- pr_err("Remapping memory, error: %d\n", ret);
- return ret;
- }
-
- uaddr += PAGE_SIZE;
- usize -= PAGE_SIZE;
- } while (usize > 0);
- }
return 0;
}
@@ -1300,16 +1146,21 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t handle, struct dma_attrs *attrs)
{
- struct arm_vmregion *c;
+ struct page **pages = __iommu_get_pages(cpu_addr);
size = PAGE_ALIGN(size);
- c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
- if (c) {
- struct page **pages = c->priv;
- __dma_free_remap(cpu_addr, size);
- __iommu_remove_mapping(dev, handle, size);
- __iommu_free_buffer(dev, pages, size);
+ if (!pages) {
+ pr_err("%s: trying to free invalid coherent area: %p\n",
+ __func__, cpu_addr);
+ dump_stack();
+ return;
}
+
+ unmap_kernel_range((unsigned long)cpu_addr, size);
+ vunmap(cpu_addr);
+
+ __iommu_remove_mapping(dev, handle, size);
+ __iommu_free_buffer(dev, pages, size);
}
/*
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index e725b7b..8a9555a 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -94,6 +94,7 @@ extern struct vm_struct *__get_vm_area_caller(unsigned long size,
unsigned long start, unsigned long end,
const void *caller);
extern struct vm_struct *remove_vm_area(const void *addr);
+extern struct vm_struct *find_vm_area(const void *addr);
extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
struct page ***pages);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e04d59b..4ab106c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1403,7 +1403,15 @@ struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
-1, GFP_KERNEL, caller);
}
-static struct vm_struct *find_vm_area(const void *addr)
+/**
+ * find_vm_area - find a continuous kernel virtual area
+ * @addr: base address
+ *
+ * Search for the kernel VM area starting at @addr, and return it.
+ * It is up to the caller to do all required locking to keep the returned
+ * pointer valid.
+ */
+struct vm_struct *find_vm_area(const void *addr)
{
struct vmap_area *va;
--
1.7.1.569.g6f426
Hi Marek,
On 06/13/2012 08:01 PM, Marek Szyprowski wrote:
> Add new type of vm_area intented to be used for mappings created by
> dma-mapping framework.
>
> Signed-off-by: Marek Szyprowski <[email protected]>
> Reviewed-by: Kyungmin Park <[email protected]>
> ---
> include/linux/vmalloc.h | 1 +
> mm/vmalloc.c | 3 +++
> 2 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> index 2e28f4d..e725b7b 100644
> --- a/include/linux/vmalloc.h
> +++ b/include/linux/vmalloc.h
> @@ -14,6 +14,7 @@ struct vm_area_struct; /* vma defining user mapping in mm_types.h */
> #define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */
> #define VM_VPAGES 0x00000010 /* buffer for pages was vmalloc'ed */
> #define VM_UNLIST 0x00000020 /* vm_struct is not listed in vmlist */
> +#define VM_DMA 0x00000040 /* used by dma-mapping framework */
> /* bits [20..32] reserved for arch specific ioremap internals */
>
> /*
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 11308f0..e04d59b 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -2575,6 +2575,9 @@ static int s_show(struct seq_file *m, void *p)
> if (v->flags & VM_IOREMAP)
> seq_printf(m, " ioremap");
>
> + if (v->flags & VM_DMA)
> + seq_printf(m, " dma");
> +
> if (v->flags & VM_ALLOC)
> seq_printf(m, " vmalloc");
>
I still don't make sure that we should add new type for only ARM arch.
I remember you said "It would be used for other architectures once we add" and
Paul said he has a plan for SH. So at least, you should add such comment in changelog
for persuading grumpy maintainers. :)
Frankly speaking, I could add my Reviewed-by but I think it wouldn't carry much weight
because code is very tiny so you need Acked-by rather than Reviewed-by.
IMHO, This problem is the thing only maintainer should decide.
So I will toss the decision to akpm. Ccing akpm.(Ccing KOSAKI because he had a concern about this).
If anyone have a question to me, I'm Acked-by iff other architecture will use it.
--
Kind regards,
Minchan Kim
Hi,
On Thursday, June 21, 2012 10:36 AM Minchan Kim wrote:
> On 06/13/2012 08:01 PM, Marek Szyprowski wrote:
>
> > Add new type of vm_area intented to be used for mappings created by
> > dma-mapping framework.
> >
> > Signed-off-by: Marek Szyprowski <[email protected]>
> > Reviewed-by: Kyungmin Park <[email protected]>
> > ---
> > include/linux/vmalloc.h | 1 +
> > mm/vmalloc.c | 3 +++
> > 2 files changed, 4 insertions(+), 0 deletions(-)
> >
> > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> > index 2e28f4d..e725b7b 100644
> > --- a/include/linux/vmalloc.h
> > +++ b/include/linux/vmalloc.h
> > @@ -14,6 +14,7 @@ struct vm_area_struct; /* vma defining user mapping in
> mm_types.h */
> > #define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */
> > #define VM_VPAGES 0x00000010 /* buffer for pages was vmalloc'ed */
> > #define VM_UNLIST 0x00000020 /* vm_struct is not listed in vmlist */
> > +#define VM_DMA 0x00000040 /* used by dma-mapping framework */
> > /* bits [20..32] reserved for arch specific ioremap internals */
> >
> > /*
> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> > index 11308f0..e04d59b 100644
> > --- a/mm/vmalloc.c
> > +++ b/mm/vmalloc.c
> > @@ -2575,6 +2575,9 @@ static int s_show(struct seq_file *m, void *p)
> > if (v->flags & VM_IOREMAP)
> > seq_printf(m, " ioremap");
> >
> > + if (v->flags & VM_DMA)
> > + seq_printf(m, " dma");
> > +
> > if (v->flags & VM_ALLOC)
> > seq_printf(m, " vmalloc");
> >
>
>
> I still don't make sure that we should add new type for only ARM arch.
> I remember you said "It would be used for other architectures once we add" and
> Paul said he has a plan for SH. So at least, you should add such comment in changelog
> for persuading grumpy maintainers. :)
>
> Frankly speaking, I could add my Reviewed-by but I think it wouldn't carry much weight
> because code is very tiny so you need Acked-by rather than Reviewed-by.
> IMHO, This problem is the thing only maintainer should decide.
> So I will toss the decision to akpm. Ccing akpm.(Ccing KOSAKI because he had a concern about
> this).
>
> If anyone have a question to me, I'm Acked-by iff other architecture will use it.
Ok, if this flag is so controversial, I can change it to arch specific VM flag and utilize
'bits [20..32] reserved for arch specific ioremap internals'. Later, when other architectures
start using similar flag, one can unify them and add such generic flag.
Best regards
--
Marek Szyprowski
Samsung Poland R&D Center