This is a note to let you know that I've just added the patch titled
net: davinci_cpdma: use dma_addr_t for DMA address
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-davinci_cpdma-use-dma_addr_t-for-dma-address.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 84092996673211f16ef3b942a191d7952e9dfea9 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Fri, 29 Jan 2016 12:39:10 +0100
Subject: net: davinci_cpdma: use dma_addr_t for DMA address
From: Arnd Bergmann <arnd@xxxxxxxx>
commit 84092996673211f16ef3b942a191d7952e9dfea9 upstream.
The davinci_cpdma mixes up physical addresses as seen from the CPU
and DMA addresses as seen from a DMA master, since it can operate
on both normal memory or an on-chip buffer. If dma_addr_t is
different from phys_addr_t, this means we get a compile-time warning
about the type mismatch:
ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create':
ethernet/ti/davinci_cpdma.c:182:48: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]
pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
In file included from ethernet/ti/davinci_cpdma.c:21:0:
dma-mapping.h:398:21: note: expected 'dma_addr_t * {aka long long unsigned int *}' but argument is of type 'phys_addr_t * {aka unsigned int *}'
static inline void *dma_alloc_coherent(struct device *dev, size_t size,
This slightly restructures the code so the address we use for
mapping RAM into a DMA address is always a dma_addr_t, avoiding
the warning. The code is correct even if both types are 32-bit
because the DMA master in this device only supports 32-bit addressing
anyway, independent of the types that are used.
We still assign this value to pool->phys, and that is wrong if
the driver is ever used with an IOMMU, but that value appears to
be never used, so there is no problem really. I've added a couple
of comments about where we do things that are slightly violating
the API.
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Daniel Wagner <dwagner@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/ti/davinci_cpdma.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -82,7 +82,7 @@ struct cpdma_desc {
struct cpdma_desc_pool {
phys_addr_t phys;
- u32 hw_addr;
+ dma_addr_t hw_addr;
void __iomem *iomap; /* ioremap map */
void *cpumap; /* dma_alloc map */
int desc_size, mem_size;
@@ -152,7 +152,7 @@ struct cpdma_chan {
* abstract out these details
*/
static struct cpdma_desc_pool *
-cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
+cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr,
int size, int align)
{
int bitmap_size;
@@ -176,13 +176,13 @@ cpdma_desc_pool_create(struct device *de
if (phys) {
pool->phys = phys;
- pool->iomap = ioremap(phys, size);
+ pool->iomap = ioremap(phys, size); /* should be memremap? */
pool->hw_addr = hw_addr;
} else {
- pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
+ pool->cpumap = dma_alloc_coherent(dev, size, &pool->hw_addr,
GFP_KERNEL);
- pool->iomap = pool->cpumap;
- pool->hw_addr = pool->phys;
+ pool->iomap = (void __iomem __force *)pool->cpumap;
+ pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */
}
if (pool->iomap)
Patches currently in stable-queue which might be from arnd@xxxxxxxx are
queue-4.4/net-davinci_cpdma-use-dma_addr_t-for-dma-address.patch
