cma: Allow option to use strict memblock_reserved memory
Despite all the performance optimizations, some clients are
still unable to use CMA because of the allocation latency.
Rather than make those clients use a separate set of APIs,
extend the CMA code to allow clients to keep the memory out of
the buddy allocator. Since the pages never actually go to the
buddy allocator, allocation and freeing is only based on the bitmap
allocator to find the appropriate region.
Change-Id: Ia31bb1212fd7b19280361128453c8d25369ce592
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 2adcbbc..4745406 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -47,6 +47,7 @@
unsigned long base_pfn;
unsigned long count;
unsigned long *bitmap;
+ bool in_system;
struct mutex lock;
};
@@ -60,6 +61,7 @@
unsigned long size;
struct cma *cma;
const char *name;
+ bool to_system;
} cma_areas[MAX_CMA_AREAS];
static unsigned cma_area_count;
@@ -170,7 +172,7 @@
}
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;
@@ -184,14 +186,17 @@
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;
+ }
mutex_init(&cma->lock);
pr_debug("%s: returned %p\n", __func__, (void *)cma);
@@ -214,6 +219,7 @@
unsigned long len;
__be32 *prop;
char *name;
+ bool in_system;
phys_addr_t limit = MEMBLOCK_ALLOC_ANYWHERE;
if (!of_get_flat_dt_prop(node, "linux,contiguous-region", NULL))
@@ -227,6 +233,8 @@
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;
prop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
if (prop)
@@ -234,7 +242,8 @@
pr_info("Found %s, memory base %lx, size %ld MiB, limit %pa\n", uname,
(unsigned long)base, (unsigned long)size / SZ_1M, &limit);
- dma_contiguous_reserve_area(size, &base, limit, name);
+ dma_contiguous_reserve_area(size, &base, limit, name,
+ in_system);
return 0;
}
@@ -275,8 +284,8 @@
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
@@ -299,7 +308,8 @@
* 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;
@@ -352,6 +362,7 @@
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;
@@ -434,8 +445,9 @@
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;
}
@@ -485,7 +497,7 @@
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)
@@ -521,7 +533,8 @@
pfn = cma->base_pfn + pageno;
mutex_lock(&cma_mutex);
- ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
+ if (cma->in_system)
+ ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
mutex_unlock(&cma_mutex);
if (ret == 0) {
page = pfn_to_page(pfn);
@@ -573,7 +586,8 @@
VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
- free_contig_range(pfn, count);
+ if (cma->in_system)
+ free_contig_range(pfn, count);
clear_cma_bitmap(cma, pfn, count);
return true;