Re: [PATCH v2 2/3] drivers: dma-coherent: add initialization from device tree
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2014-09-24 22:26:10
Also in:
linux-arm-kernel
On Thu, 11 Sep 2014 13:22:40 +0200 Marek Szyprowski [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Initialization procedure of dma coherent pool has been split into two parts, so memory pool can now be initialized without assigning to particular struct device. Then initialized region can be assigned to more than one struct device. To protect from concurent allocations from different devices, a spinlock has been added to dma_coherent_mem structure. The last part of this patch adds support for handling 'shared-dma-pool' reserved-memory device tree nodes.--- a/drivers/base/dma-coherent.c +++ b/drivers/base/dma-coherent.c@@ -14,11 +14,14 @@ struct dma_coherent_mem { int size; int flags; unsigned long *bitmap; + spinlock_t spinlock;
A bit of documentation would be nice: explain what the lock protects, that it is irq-safe, etc.
};
-int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
- dma_addr_t device_addr, size_t size, int flags)
+static int dma_init_coherent_memory(phys_addr_t phys_addr, dma_addr_t device_addr,
+ size_t size, int flags,
+ struct dma_coherent_mem **mem)
{
+ struct dma_coherent_mem *dma_mem = NULL;The only reason to initialise this is so we can kfree() it without checking. In which case we don't need label free1_out?
--- a/drivers/base/dma-coherent.c~drivers-dma-coherent-add-initialization-from-device-tree-fix
+++ a/drivers/base/dma-coherent.c@@ -40,7 +40,7 @@ static int dma_init_coherent_memory(phys goto out; dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); if (!dma_mem->bitmap) - goto free1_out; + goto out; dma_mem->virt_base = mem_base; dma_mem->device_base = device_addr;
@@ -56,9 +56,8 @@ static int dma_init_coherent_memory(phys return DMA_MEMORY_IO; - free1_out: +out: kfree(dma_mem); - out: if (mem_base) iounmap(mem_base); return 0;
_