2005-09-25 19:16:25

by Pierre Ossman

Subject: [PATCH] [MMC] wbsd: use dma_alloc insted of kmalloc

x86_64 doesn't seem to like being passed pointers allocated using
kmalloc to the DMA mapping API. Change allocation to use
dma_alloc_coherent() instead.

Signed-off-by: Pierre Ossman <[email protected]>
---

drivers/mmc/wbsd.c | 26 +++++++++++---------------
1 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/mmc/wbsd.c b/drivers/mmc/wbsd.c
--- a/drivers/mmc/wbsd.c
+++ b/drivers/mmc/wbsd.c
@@ -1543,18 +1543,17 @@ static void __devinit wbsd_request_dma(s
* We need to allocate a special buffer in
* order for ISA to be able to DMA to it.
*/
- host->dma_buffer = kmalloc(WBSD_DMA_SIZE,
+
+ mmc_dev(host->mmc)->coherent_dma_mask = 0xffffff;
+ mmc_dev(host->mmc)->dma_mask = &mmc_dev(host->mmc)->coherent_dma_mask;
+
+ host->dma_buffer = dma_alloc_coherent(mmc_dev(host->mmc),
+ WBSD_DMA_SIZE, &host->dma_addr,
GFP_NOIO | GFP_DMA | __GFP_REPEAT | __GFP_NOWARN);
if (!host->dma_buffer)
goto free;

/*
- * Translate the address to a physical address.
- */
- host->dma_addr = dma_map_single(host->mmc->dev, host->dma_buffer,
- WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
-
- /*
* ISA DMA must be aligned on a 64k basis.
*/
if ((host->dma_addr & 0xffff) != 0)
@@ -1575,12 +1574,11 @@ kfree:
*/
BUG_ON(1);

- dma_unmap_single(host->mmc->dev, host->dma_addr, WBSD_DMA_SIZE,
- DMA_BIDIRECTIONAL);
- host->dma_addr = (dma_addr_t)NULL;
+ dma_free_coherent(mmc_dev(host->mmc), WBSD_DMA_SIZE,
+ host->dma_buffer, host->dma_addr);

- kfree(host->dma_buffer);
host->dma_buffer = NULL;
+ host->dma_addr = (dma_addr_t)NULL;

free:
free_dma(dma);
@@ -1592,11 +1590,9 @@ err:

static void __devexit wbsd_release_dma(struct wbsd_host* host)
{
- if (host->dma_addr)
- dma_unmap_single(host->mmc->dev, host->dma_addr, WBSD_DMA_SIZE,
- DMA_BIDIRECTIONAL);
if (host->dma_buffer)
- kfree(host->dma_buffer);
+ dma_free_coherent(mmc_dev(host->mmc), WBSD_DMA_SIZE,
+ host->dma_buffer, host->dma_addr);
if (host->dma >= 0)
free_dma(host->dma);

2005-09-25 19:30:00

by Christoph Hellwig

Subject: Re: [PATCH] [MMC] wbsd: use dma_alloc insted of kmalloc

On Sun, Sep 25, 2005 at 09:16:23PM +0200, Pierre Ossman wrote:
> x86_64 doesn't seem to like being passed pointers allocated using
> kmalloc to the DMA mapping API.

How so? There's not much else that could be passed to dma_map_single.

Please try to fix x86_64 instead.

2005-09-25 19:37:26

by Pierre Ossman

Subject: Re: [PATCH] [MMC] wbsd: use dma_alloc insted of kmalloc

Christoph Hellwig wrote:
> On Sun, Sep 25, 2005 at 09:16:23PM +0200, Pierre Ossman wrote:
>
>>x86_64 doesn't seem to like being passed pointers allocated using
>>kmalloc to the DMA mapping API.
>
>
> How so? There's not much else that could be passed to dma_map_single.

It kept oopsing on dma_map_single(). I'm guessing it expects som
structures to be present for its IOMMU.

http://list.drzeus.cx/pipermail/wbsd-devel/2005-September/000335.html

>
> Please try to fix x86_64 instead.

I'm not familiar with the x86_64 IOMMU, I don't even have access to the
hardware. So I figured I'd side-step the problem since there was an API
avaiable that works more reliably.

Andi might be more up to the task?

Rgds
Pierre