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Diffstat (limited to 'drivers/base/dma-coherent.c')
-rw-r--r--drivers/base/dma-coherent.c74
1 files changed, 65 insertions, 9 deletions
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c
index 640a7e63c453..2ae24c28e70c 100644
--- a/drivers/base/dma-coherent.c
+++ b/drivers/base/dma-coherent.c
@@ -16,8 +16,27 @@ struct dma_coherent_mem {
int flags;
unsigned long *bitmap;
spinlock_t spinlock;
+ bool use_dev_dma_pfn_offset;
};
+static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init;
+
+static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev)
+{
+ if (dev && dev->dma_mem)
+ return dev->dma_mem;
+ return dma_coherent_default_memory;
+}
+
+static inline dma_addr_t dma_get_device_base(struct device *dev,
+ struct dma_coherent_mem * mem)
+{
+ if (mem->use_dev_dma_pfn_offset)
+ return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT;
+ else
+ return mem->device_base;
+}
+
static bool dma_init_coherent_memory(
phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags,
struct dma_coherent_mem **mem)
@@ -83,6 +102,9 @@ static void dma_release_coherent_memory(struct dma_coherent_mem *mem)
static int dma_assign_coherent_memory(struct device *dev,
struct dma_coherent_mem *mem)
{
+ if (!dev)
+ return -ENODEV;
+
if (dev->dma_mem)
return -EBUSY;
@@ -133,7 +155,7 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
return ERR_PTR(-EINVAL);
spin_lock_irqsave(&mem->spinlock, flags);
- pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
+ pos = PFN_DOWN(device_addr - dma_get_device_base(dev, mem));
err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
spin_unlock_irqrestore(&mem->spinlock, flags);
@@ -161,15 +183,12 @@ EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret)
{
- struct dma_coherent_mem *mem;
+ struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
int order = get_order(size);
unsigned long flags;
int pageno;
int dma_memory_map;
- if (!dev)
- return 0;
- mem = dev->dma_mem;
if (!mem)
return 0;
@@ -186,7 +205,7 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size,
/*
* Memory was found in the per-device area.
*/
- *dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
+ *dma_handle = dma_get_device_base(dev, mem) + (pageno << PAGE_SHIFT);
*ret = mem->virt_base + (pageno << PAGE_SHIFT);
dma_memory_map = (mem->flags & DMA_MEMORY_MAP);
spin_unlock_irqrestore(&mem->spinlock, flags);
@@ -223,7 +242,7 @@ EXPORT_SYMBOL(dma_alloc_from_coherent);
*/
int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
{
- struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+ struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
if (mem && vaddr >= mem->virt_base && vaddr <
(mem->virt_base + (mem->size << PAGE_SHIFT))) {
@@ -257,7 +276,7 @@ EXPORT_SYMBOL(dma_release_from_coherent);
int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
void *vaddr, size_t size, int *ret)
{
- struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+ struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
if (mem && vaddr >= mem->virt_base && vaddr + size <=
(mem->virt_base + (mem->size << PAGE_SHIFT))) {
@@ -287,6 +306,8 @@ EXPORT_SYMBOL(dma_mmap_from_coherent);
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>
+static struct reserved_mem *dma_reserved_default_memory __initdata;
+
static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
{
struct dma_coherent_mem *mem = rmem->priv;
@@ -299,6 +320,7 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
&rmem->base, (unsigned long)rmem->size / SZ_1M);
return -ENODEV;
}
+ mem->use_dev_dma_pfn_offset = true;
rmem->priv = mem;
dma_assign_coherent_memory(dev, mem);
return 0;
@@ -307,7 +329,8 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
static void rmem_dma_device_release(struct reserved_mem *rmem,
struct device *dev)
{
- dev->dma_mem = NULL;
+ if (dev)
+ dev->dma_mem = NULL;
}
static const struct reserved_mem_ops rmem_dma_ops = {
@@ -327,6 +350,12 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem)
pr_err("Reserved memory: regions without no-map are not yet supported\n");
return -EINVAL;
}
+
+ if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) {
+ WARN(dma_reserved_default_memory,
+ "Reserved memory: region for default DMA coherent area is redefined\n");
+ dma_reserved_default_memory = rmem;
+ }
#endif
rmem->ops = &rmem_dma_ops;
@@ -334,5 +363,32 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem)
&rmem->base, (unsigned long)rmem->size / SZ_1M);
return 0;
}
+
+static int __init dma_init_reserved_memory(void)
+{
+ const struct reserved_mem_ops *ops;
+ int ret;
+
+ if (!dma_reserved_default_memory)
+ return -ENOMEM;
+
+ ops = dma_reserved_default_memory->ops;
+
+ /*
+ * We rely on rmem_dma_device_init() does not propagate error of
+ * dma_assign_coherent_memory() for "NULL" device.
+ */
+ ret = ops->device_init(dma_reserved_default_memory, NULL);
+
+ if (!ret) {
+ dma_coherent_default_memory = dma_reserved_default_memory->priv;
+ pr_info("DMA: default coherent area is set\n");
+ }
+
+ return ret;
+}
+
+core_initcall(dma_init_reserved_memory);
+
RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
#endif