The patch titled
Subject: DMA, CMA: support arbitrary bitmap granularity
has been removed from the -mm tree. Its filename was
dma-cma-support-arbitrary-bitmap-granularity.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Subject: DMA, CMA: support arbitrary bitmap granularity
PPC KVM's CMA area management requires arbitrary bitmap granularity, since
they want to reserve very large memory and manage this region with bitmap
that one bit for several pages to reduce management overheads. So support
arbitrary bitmap granularity for following generalization.
[akpm@xxxxxxxxxxxxxxxxxxxx: s/1/1UL/]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
Acked-by: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Alexander Graf <agraf@xxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Acked-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/base/dma-contiguous.c | 77 ++++++++++++++++++++++----------
1 file changed, 53 insertions(+), 24 deletions(-)
diff -puN drivers/base/dma-contiguous.c~dma-cma-support-arbitrary-bitmap-granularity drivers/base/dma-contiguous.c
--- a/drivers/base/dma-contiguous.c~dma-cma-support-arbitrary-bitmap-granularity
+++ a/drivers/base/dma-contiguous.c
@@ -38,6 +38,7 @@ struct cma {
unsigned long base_pfn;
unsigned long count;
unsigned long *bitmap;
+ unsigned int order_per_bit; /* Order of pages represented by one bit */
struct mutex lock;
};
@@ -157,9 +158,37 @@ void __init dma_contiguous_reserve(phys_
static DEFINE_MUTEX(cma_mutex);
+static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
+{
+ return (1UL << (align_order >> cma->order_per_bit)) - 1;
+}
+
+static unsigned long cma_bitmap_maxno(struct cma *cma)
+{
+ return cma->count >> cma->order_per_bit;
+}
+
+static unsigned long cma_bitmap_pages_to_bits(struct cma *cma,
+ unsigned long pages)
+{
+ return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
+}
+
+static void cma_clear_bitmap(struct cma *cma, unsigned long pfn, int count)
+{
+ unsigned long bitmap_no, bitmap_count;
+
+ bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
+ bitmap_count = cma_bitmap_pages_to_bits(cma, count);
+
+ mutex_lock(&cma->lock);
+ bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
+ mutex_unlock(&cma->lock);
+}
+
static int __init cma_activate_area(struct cma *cma)
{
- int bitmap_size = BITS_TO_LONGS(cma->count) * sizeof(long);
+ int bitmap_size = BITS_TO_LONGS(cma_bitmap_maxno(cma)) * sizeof(long);
unsigned long base_pfn = cma->base_pfn, pfn = base_pfn;
unsigned i = cma->count >> pageblock_order;
struct zone *zone;
@@ -215,9 +244,9 @@ static int __init cma_init_reserved_area
core_initcall(cma_init_reserved_areas);
static int __init __dma_contiguous_reserve_area(phys_addr_t size,
- phys_addr_t base, phys_addr_t limit,
- phys_addr_t alignment,
- struct cma **res_cma, bool fixed)
+ phys_addr_t base, phys_addr_t limit,
+ phys_addr_t alignment, unsigned int order_per_bit,
+ struct cma **res_cma, bool fixed)
{
struct cma *cma = &cma_areas[cma_area_count];
int ret = 0;
@@ -249,6 +278,10 @@ static int __init __dma_contiguous_reser
size = ALIGN(size, alignment);
limit &= ~(alignment - 1);
+ /* size should be aligned with order_per_bit */
+ if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
+ return -EINVAL;
+
/* Reserve memory */
if (base && fixed) {
if (memblock_is_region_reserved(base, size) ||
@@ -273,6 +306,7 @@ static int __init __dma_contiguous_reser
*/
cma->base_pfn = PFN_DOWN(base);
cma->count = size >> PAGE_SHIFT;
+ cma->order_per_bit = order_per_bit;
*res_cma = cma;
cma_area_count++;
@@ -308,7 +342,7 @@ int __init dma_contiguous_reserve_area(p
{
int ret;
- ret = __dma_contiguous_reserve_area(size, base, limit, 0,
+ ret = __dma_contiguous_reserve_area(size, base, limit, 0, 0,
res_cma, fixed);
if (ret)
return ret;
@@ -320,17 +354,11 @@ int __init dma_contiguous_reserve_area(p
return 0;
}
-static void clear_cma_bitmap(struct cma *cma, unsigned long pfn, int count)
-{
- mutex_lock(&cma->lock);
- bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count);
- mutex_unlock(&cma->lock);
-}
-
static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count,
unsigned int align)
{
- unsigned long mask, pfn, pageno, start = 0;
+ unsigned long mask, pfn, start = 0;
+ unsigned long bitmap_maxno, bitmap_no, bitmap_count;
struct page *page = NULL;
int ret;
@@ -343,18 +371,19 @@ static struct page *__dma_alloc_from_con
if (!count)
return NULL;
- mask = (1 << align) - 1;
-
+ mask = cma_bitmap_aligned_mask(cma, align);
+ bitmap_maxno = cma_bitmap_maxno(cma);
+ bitmap_count = cma_bitmap_pages_to_bits(cma, count);
for (;;) {
mutex_lock(&cma->lock);
- pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
- start, count, mask);
- if (pageno >= cma->count) {
+ bitmap_no = bitmap_find_next_zero_area(cma->bitmap,
+ bitmap_maxno, start, bitmap_count, mask);
+ if (bitmap_no >= bitmap_maxno) {
mutex_unlock(&cma->lock);
break;
}
- bitmap_set(cma->bitmap, pageno, count);
+ bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
/*
* It's safe to drop the lock here. We've marked this region for
* our exclusive use. If the migration fails we will take the
@@ -362,7 +391,7 @@ static struct page *__dma_alloc_from_con
*/
mutex_unlock(&cma->lock);
- pfn = cma->base_pfn + pageno;
+ pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
mutex_lock(&cma_mutex);
ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
mutex_unlock(&cma_mutex);
@@ -370,14 +399,14 @@ static struct page *__dma_alloc_from_con
page = pfn_to_page(pfn);
break;
} else if (ret != -EBUSY) {
- clear_cma_bitmap(cma, pfn, count);
+ cma_clear_bitmap(cma, pfn, count);
break;
}
- clear_cma_bitmap(cma, pfn, count);
+ cma_clear_bitmap(cma, pfn, count);
pr_debug("%s(): memory range at %p is busy, retrying\n",
__func__, pfn_to_page(pfn));
/* try again with a bit different memory target */
- start = pageno + mask + 1;
+ start = bitmap_no + mask + 1;
}
pr_debug("%s(): returned %p\n", __func__, page);
@@ -424,7 +453,7 @@ static bool __dma_release_from_contiguou
VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
free_contig_range(pfn, count);
- clear_cma_bitmap(cma, pfn, count);
+ cma_clear_bitmap(cma, pfn, count);
return true;
}
_
Patches currently in -mm which might be from iamjoonsoo.kim@xxxxxxx are
origin.patch
mm-compactionc-isolate_freepages_block-small-tuneup.patch
page-owners-correct-page-order-when-to-free-page.patch
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