diff --git a/Documentation/devicetree/bindings/memory.txt b/Documentation/devicetree/bindings/memory.txt
index e98ee0588f3c9ecffe829139ed95bfd042ed545a..21299d1525c4bf06941fa636d09acb7cc1891d7e 100644
--- a/Documentation/devicetree/bindings/memory.txt
+++ b/Documentation/devicetree/bindings/memory.txt
@@ -36,6 +36,7 @@ wit the following convention:
reg = <(baseaddr) (size)>;
(linux,contiguous-region);
(linux,default-contiguous-region);
+ (linux,reserve-region);
label = (unique_name);
};
@@ -48,6 +49,9 @@ linux,contiguous-region: property indicating that the defined memory
linux,default-contiguous-region: property indicating that the region
is the default region for all contiguous memory
allocations, Linux specific (optional)
+linux,reserve-region: property indicating that the contiguous memory will
+ not be given back to the system allocator. The memory be
+ always be available for contiguous use.
label: an internal name used for automatically associating the
cma region with a given device. The label is optional;
if the label is not given the client is responsible for
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index ebfe0043cb8ddc1ec5f017ab95153daab07c88c8..531c166f1b7b93df5d78775cfdce459a0b1b5d2e 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -44,6 +44,7 @@ struct cma {
unsigned long base_pfn;
unsigned long count;
unsigned long *bitmap;
+ bool in_system;
};
static DEFINE_MUTEX(cma_mutex);
@@ -56,6 +57,7 @@ static struct cma_area {
unsigned long size;
struct cma *cma;
const char *name;
+ bool to_system;
} cma_areas[MAX_CMA_AREAS];
static unsigned cma_area_count;
@@ -166,7 +168,7 @@ static __init int cma_activate_area(unsigned long base_pfn, unsigned long count)
}
static __init struct cma *cma_create_area(unsigned long base_pfn,
- unsigned long count)
+ unsigned long count, bool system)
{
int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
struct cma *cma;
@@ -180,14 +182,17 @@ static __init struct cma *cma_create_area(unsigned long base_pfn,
cma->base_pfn = base_pfn;
cma->count = count;
+ cma->in_system = system;
cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
if (!cma->bitmap)
goto no_mem;
- ret = cma_activate_area(base_pfn, count);
- if (ret)
- goto error;
+ if (cma->in_system) {
+ ret = cma_activate_area(base_pfn, count);
+ if (ret)
+ goto error;
+ }
pr_debug("%s: returned %p\n", __func__, (void *)cma);
return cma;
@@ -209,6 +214,7 @@ int __init cma_fdt_scan(unsigned long node, const char *uname,
unsigned long len;
__be32 *prop;
char *name;
+ bool in_system;
if (!of_get_flat_dt_prop(node, "linux,contiguous-region", NULL))
return 0;
@@ -221,10 +227,13 @@ int __init cma_fdt_scan(unsigned long node, const char *uname,
size = be32_to_cpu(prop[1]);
name = of_get_flat_dt_prop(node, "label", NULL);
+ in_system =
+ of_get_flat_dt_prop(node, "linux,reserve-region", NULL) ? 0 : 1;
pr_info("Found %s, memory base %lx, size %ld MiB\n", uname,
(unsigned long)base, (unsigned long)size / SZ_1M);
- dma_contiguous_reserve_area(size, &base, MEMBLOCK_ALLOC_ANYWHERE, name);
+ dma_contiguous_reserve_area(size, &base, MEMBLOCK_ALLOC_ANYWHERE, name,
+ in_system);
return 0;
}
@@ -265,8 +274,8 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
pr_debug("%s: reserving %ld MiB for global area\n", __func__,
(unsigned long)sel_size / SZ_1M);
- if (dma_contiguous_reserve_area(sel_size, &base, limit, NULL)
- == 0)
+ if (dma_contiguous_reserve_area(sel_size, &base, limit, NULL,
+ true) == 0)
dma_contiguous_def_base = base;
}
#ifdef CONFIG_OF
@@ -289,7 +298,8 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
* devices.
*/
int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t *res_base,
- phys_addr_t limit, const char *name)
+ phys_addr_t limit, const char *name,
+ bool to_system)
{
phys_addr_t base = *res_base;
phys_addr_t alignment;
@@ -342,6 +352,7 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t *res_base,
cma_areas[cma_area_count].base = base;
cma_areas[cma_area_count].size = size;
cma_areas[cma_area_count].name = name;
+ cma_areas[cma_area_count].to_system = to_system;
cma_area_count++;
*res_base = base;
@@ -424,8 +435,9 @@ static int __init cma_init_reserved_areas(void)
for (i = 0; i < cma_area_count; i++) {
phys_addr_t base = PFN_DOWN(cma_areas[i].base);
unsigned int count = cma_areas[i].size >> PAGE_SHIFT;
+ bool system = cma_areas[i].to_system;
- cma = cma_create_area(base, count);
+ cma = cma_create_area(base, count, system);
if (!IS_ERR(cma))
cma_areas[i].cma = cma;
}
@@ -461,7 +473,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
unsigned long mask, pfn, pageno, start = 0;
struct cma *cma = dev_get_cma_area(dev);
struct page *page = NULL;
- int ret;
+ int ret = 0;
int tries = 0;
if (!cma || !cma->count)
@@ -487,7 +499,8 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
break;
pfn = cma->base_pfn + pageno;
- ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
+ if (cma->in_system)
+ ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
if (ret == 0) {
bitmap_set(cma->bitmap, pageno, count);
page = pfn_to_page(pfn);
@@ -539,7 +552,8 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
mutex_lock(&cma_mutex);
bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count);
- free_contig_range(pfn, count);
+ if (cma->in_system)
+ free_contig_range(pfn, count);
mutex_unlock(&cma_mutex);
return true;
diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h
index 8a1b3a1b41bddad77ac52325aaf317e96015b67f..e5ebd7e16ac8bfd791016feadee2b46ac3d466d7 100644
--- a/include/linux/dma-contiguous.h
+++ b/include/linux/dma-contiguous.h
@@ -70,7 +70,8 @@ extern struct cma *dma_contiguous_def_area;
void dma_contiguous_reserve(phys_addr_t addr_limit);
int dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t *res_base,
- phys_addr_t limit, const char *name);
+ phys_addr_t limit, const char *name,
+ bool in_system);
int dma_contiguous_add_device(struct device *dev, phys_addr_t base);
@@ -91,7 +92,19 @@ static inline int dma_declare_contiguous(struct device *dev, phys_addr_t size,
phys_addr_t base, phys_addr_t limit)
{
int ret;
- ret = dma_contiguous_reserve_area(size, &base, limit, NULL);
+ ret = dma_contiguous_reserve_area(size, &base, limit, NULL, true);
+ if (ret == 0)
+ ret = dma_contiguous_add_device(dev, base);
+ return ret;
+}
+
+static inline int dma_declare_contiguous_reserved(struct device *dev,
+ phys_addr_t size,
+ phys_addr_t base,
+ phys_addr_t limit)
+{
+ int ret;
+ ret = dma_contiguous_reserve_area(size, &base, limit, NULL, false);
if (ret == 0)
ret = dma_contiguous_add_device(dev, base);
return ret;