Re: [PATCH 3/4] iommu: dart: Write to all DART_T8020_STREAM_SELECT

[Hector Martin]

On 28/01/2023 20.11, Sven Peter wrote:
> We're about to add support for a DART variant that use more than 16
> streams and requires writing to two separate stream select registers
> when issuing TLB flushes.
> 
> Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx>
> ---
>  drivers/iommu/apple-dart.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
> index 7d8b2b90cdb6..7579c97a9062 100644
> --- a/drivers/iommu/apple-dart.c
> +++ b/drivers/iommu/apple-dart.c
> @@ -372,12 +372,14 @@ apple_dart_t8020_hw_stream_command(struct apple_dart_stream_map *stream_map,
>  			     u32 command)
>  {
>  	unsigned long flags;
> -	int ret;
> +	int ret, i;
>  	u32 command_reg;
>  
>  	spin_lock_irqsave(&stream_map->dart->lock, flags);
>  
> -	writel(stream_map->sidmap[0], stream_map->dart->regs + DART_T8020_STREAM_SELECT);
> +	for (i = 0; i < BITS_TO_U32(stream_map->dart->num_streams); i++)
> +		writel(stream_map->sidmap[i],
> +		       stream_map->dart->regs + DART_T8020_STREAM_SELECT + 4 * i);
>  	writel(command, stream_map->dart->regs + DART_T8020_STREAM_COMMAND);
>  
>  	ret = readl_poll_timeout_atomic(

Acked-by: Hector Martin <marcan@xxxxxxxxx>

- Hector