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Diffstat (limited to 'drivers/base/dma-contiguous.c')
-rw-r--r--drivers/base/dma-contiguous.c76
1 files changed, 58 insertions, 18 deletions
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 165c2c299e57..83969f8c5727 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -37,6 +37,7 @@ struct cma {
unsigned long base_pfn;
unsigned long count;
unsigned long *bitmap;
+ struct mutex lock;
};
struct cma *dma_contiguous_default_area;
@@ -59,11 +60,22 @@ struct cma *dma_contiguous_default_area;
*/
static const phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M;
static phys_addr_t size_cmdline = -1;
+static phys_addr_t base_cmdline;
+static phys_addr_t limit_cmdline;
static int __init early_cma(char *p)
{
pr_debug("%s(%s)\n", __func__, p);
size_cmdline = memparse(p, &p);
+ if (*p != '@')
+ return 0;
+ base_cmdline = memparse(p + 1, &p);
+ if (*p != '-') {
+ limit_cmdline = base_cmdline + size_cmdline;
+ return 0;
+ }
+ limit_cmdline = memparse(p + 1, &p);
+
return 0;
}
early_param("cma", early_cma);
@@ -107,11 +119,18 @@ static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)
void __init dma_contiguous_reserve(phys_addr_t limit)
{
phys_addr_t selected_size = 0;
+ phys_addr_t selected_base = 0;
+ phys_addr_t selected_limit = limit;
+ bool fixed = false;
pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);
if (size_cmdline != -1) {
selected_size = size_cmdline;
+ selected_base = base_cmdline;
+ selected_limit = min_not_zero(limit_cmdline, limit);
+ if (base_cmdline + size_cmdline == limit_cmdline)
+ fixed = true;
} else {
#ifdef CONFIG_CMA_SIZE_SEL_MBYTES
selected_size = size_bytes;
@@ -128,10 +147,12 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
pr_debug("%s: reserving %ld MiB for global area\n", __func__,
(unsigned long)selected_size / SZ_1M);
- dma_contiguous_reserve_area(selected_size, 0, limit,
- &dma_contiguous_default_area);
+ dma_contiguous_reserve_area(selected_size, selected_base,
+ selected_limit,
+ &dma_contiguous_default_area,
+ fixed);
}
-};
+}
static DEFINE_MUTEX(cma_mutex);
@@ -161,6 +182,7 @@ static int __init cma_activate_area(struct cma *cma)
init_cma_reserved_pageblock(pfn_to_page(base_pfn));
} while (--i);
+ mutex_init(&cma->lock);
return 0;
}
@@ -187,15 +209,20 @@ core_initcall(cma_init_reserved_areas);
* @base: Base address of the reserved area optional, use 0 for any
* @limit: End address of the reserved memory (optional, 0 for any).
* @res_cma: Pointer to store the created cma region.
+ * @fixed: hint about where to place the reserved area
*
* This function reserves memory from early allocator. It should be
* called by arch specific code once the early allocator (memblock or bootmem)
* has been activated and all other subsystems have already allocated/reserved
* memory. This function allows to create custom reserved areas for specific
* devices.
+ *
+ * If @fixed is true, reserve contiguous area at exactly @base. If false,
+ * reserve in range from @base to @limit.
*/
int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
- phys_addr_t limit, struct cma **res_cma)
+ phys_addr_t limit, struct cma **res_cma,
+ bool fixed)
{
struct cma *cma = &cma_areas[cma_area_count];
phys_addr_t alignment;
@@ -221,18 +248,15 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
limit &= ~(alignment - 1);
/* Reserve memory */
- if (base) {
+ if (base && fixed) {
if (memblock_is_region_reserved(base, size) ||
memblock_reserve(base, size) < 0) {
ret = -EBUSY;
goto err;
}
} else {
- /*
- * Use __memblock_alloc_base() since
- * memblock_alloc_base() panic()s.
- */
- phys_addr_t addr = __memblock_alloc_base(size, alignment, limit);
+ phys_addr_t addr = memblock_alloc_range(size, alignment, base,
+ limit);
if (!addr) {
ret = -ENOMEM;
goto err;
@@ -261,6 +285,13 @@ err:
return ret;
}
+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);
+}
+
/**
* dma_alloc_from_contiguous() - allocate pages from contiguous area
* @dev: Pointer to device for which the allocation is performed.
@@ -269,7 +300,7 @@ err:
*
* This function allocates memory buffer for specified device. It uses
* device specific contiguous memory area if available or the default
- * global one. Requires architecture specific get_dev_cma_area() helper
+ * global one. Requires architecture specific dev_get_cma_area() helper
* function.
*/
struct page *dma_alloc_from_contiguous(struct device *dev, int count,
@@ -294,30 +325,41 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
mask = (1 << align) - 1;
- mutex_lock(&cma_mutex);
for (;;) {
+ mutex_lock(&cma->lock);
pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
start, count, mask);
- if (pageno >= cma->count)
+ if (pageno >= cma->count) {
+ mutex_unlock(&cma->lock);
break;
+ }
+ bitmap_set(cma->bitmap, pageno, 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
+ * lock again and unmark it.
+ */
+ mutex_unlock(&cma->lock);
pfn = cma->base_pfn + pageno;
+ mutex_lock(&cma_mutex);
ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
+ mutex_unlock(&cma_mutex);
if (ret == 0) {
- bitmap_set(cma->bitmap, pageno, count);
page = pfn_to_page(pfn);
break;
} else if (ret != -EBUSY) {
+ clear_cma_bitmap(cma, pfn, count);
break;
}
+ clear_cma_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;
}
- mutex_unlock(&cma_mutex);
pr_debug("%s(): returned %p\n", __func__, page);
return page;
}
@@ -350,10 +392,8 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
- mutex_lock(&cma_mutex);
- bitmap_clear(cma->bitmap, pfn - cma->base_pfn, count);
free_contig_range(pfn, count);
- mutex_unlock(&cma_mutex);
+ clear_cma_bitmap(cma, pfn, count);
return true;
}