[PATCH 1/2] Staging: VME: Convert TSI148 to use dma_map_single

[Martyn Welch]

Hi Greg,

Any chance these can be included in the staging tree soon? They form some
fairly fundamental bug fixing for the DMA support on the tsi148.

Martyn

On 22/03/12 13:27, Martyn Welch wrote:
> The DMA functionality fails to work on some Intel based platforms. Some
> recent Intel platforms have an IOMMU. Transferring the DMA descriptors,
> which were mapped using virt_to_phys(), failed. This patch updates the
> driver to use dma_map_single().
> 
> Signed-off-by: Martyn Welch <martyn.welch at ge.com>
> ---
>  drivers/staging/vme/bridges/vme_tsi148.c |   22 +++++++++++++++-------
>  drivers/staging/vme/bridges/vme_tsi148.h |    1 +
>  2 files changed, 16 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/staging/vme/bridges/vme_tsi148.c b/drivers/staging/vme/bridges/vme_tsi148.c
> index f505821..cd3c821 100644
> --- a/drivers/staging/vme/bridges/vme_tsi148.c
> +++ b/drivers/staging/vme/bridges/vme_tsi148.c
> @@ -1614,7 +1614,6 @@ static int tsi148_dma_list_add(struct vme_dma_list *list,
>  	struct vme_dma_pattern *pattern_attr;
>  	struct vme_dma_pci *pci_attr;
>  	struct vme_dma_vme *vme_attr;
> -	dma_addr_t desc_ptr;
>  	int retval = 0;
>  	struct vme_bridge *tsi148_bridge;
>  
> @@ -1739,9 +1738,12 @@ static int tsi148_dma_list_add(struct vme_dma_list *list,
>  		prev = list_entry(entry->list.prev, struct tsi148_dma_entry,
>  			list);
>  		/* We need the bus address for the pointer */
> -		desc_ptr = virt_to_bus(&entry->descriptor);
> -		reg_split(desc_ptr, &prev->descriptor.dnlau,
> -			&prev->descriptor.dnlal);
> +		entry->dma_handle = dma_map_single(tsi148_bridge->parent,
> +			&entry->descriptor,
> +			sizeof(struct tsi148_dma_descriptor), DMA_TO_DEVICE);
> +
> +		reg_split((unsigned long long)entry->dma_handle,
> +			&prev->descriptor.dnlau, &prev->descriptor.dnlal);
>  	}
>  
>  	return 0;
> @@ -1784,7 +1786,6 @@ static int tsi148_dma_list_exec(struct vme_dma_list *list)
>  	struct vme_dma_resource *ctrlr;
>  	int channel, retval = 0;
>  	struct tsi148_dma_entry *entry;
> -	dma_addr_t bus_addr;
>  	u32 bus_addr_high, bus_addr_low;
>  	u32 val, dctlreg = 0;
>  	struct vme_bridge *tsi148_bridge;
> @@ -1817,11 +1818,13 @@ static int tsi148_dma_list_exec(struct vme_dma_list *list)
>  	entry = list_first_entry(&list->entries, struct tsi148_dma_entry,
>  		list);
>  
> -	bus_addr = virt_to_bus(&entry->descriptor);
> +	entry->dma_handle = dma_map_single(tsi148_bridge->parent,
> +		&entry->descriptor,
> +		sizeof(struct tsi148_dma_descriptor), DMA_TO_DEVICE);
>  
>  	mutex_unlock(&ctrlr->mtx);
>  
> -	reg_split(bus_addr, &bus_addr_high, &bus_addr_low);
> +	reg_split(entry->dma_handle, &bus_addr_high, &bus_addr_low);
>  
>  	iowrite32be(bus_addr_high, bridge->base +
>  		TSI148_LCSR_DMA[channel] + TSI148_LCSR_OFFSET_DNLAU);
> @@ -1864,10 +1867,15 @@ static int tsi148_dma_list_empty(struct vme_dma_list *list)
>  	struct list_head *pos, *temp;
>  	struct tsi148_dma_entry *entry;
>  
> +	struct vme_bridge *tsi148_bridge = list->parent->parent;
> +
>  	/* detach and free each entry */
>  	list_for_each_safe(pos, temp, &list->entries) {
>  		list_del(pos);
>  		entry = list_entry(pos, struct tsi148_dma_entry, list);
> +
> +		dma_unmap_single(tsi148_bridge->parent, entry->dma_handle,
> +			sizeof(struct tsi148_dma_descriptor), DMA_TO_DEVICE);
>  		kfree(entry);
>  	}
>  
> diff --git a/drivers/staging/vme/bridges/vme_tsi148.h b/drivers/staging/vme/bridges/vme_tsi148.h
> index a3ac2fe..00b1160 100644
> --- a/drivers/staging/vme/bridges/vme_tsi148.h
> +++ b/drivers/staging/vme/bridges/vme_tsi148.h
> @@ -75,6 +75,7 @@ struct tsi148_dma_entry {
>  	 */
>  	struct tsi148_dma_descriptor descriptor;
>  	struct list_head list;
> +	dma_addr_t dma_handle;
>  };
>  
>  /*


-- 
Martyn Welch (Lead Software Engineer)  | Registered in England and Wales
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