Re: [PATCH] bus: fsl-mc: Use common ranges functions

[Laurentiu Tudor]

On 6/9/2023 9:32 PM, Rob Herring wrote:
> Since commit 3d5089c4263d ("of/address: Add support for 3 address cell
> bus"), the DT address functions can handle translating buses with 3
> address cells. Replace the custom code with the for_each_of_range()
> iterator.
>
> The original code had fallbacks to get "#address-cells"/"#size-cells"
> from the bus parent node if they are missing. This is non-standard
> behavior, and AFAICT the upstream .dts files never relied on that.
>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>

Thanks, Rob!

Reviewed-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
Tested-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>

---
Best Regards, Laurentiu

> ---
>   drivers/bus/fsl-mc/fsl-mc-bus.c | 90 +++++----------------------------
>   1 file changed, 13 insertions(+), 77 deletions(-)
>
> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
> index 653e2d4c116f..5062d73b13e2 100644
> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> @@ -999,75 +999,18 @@ struct fsl_mc_device *fsl_mc_get_endpoint(struct fsl_mc_device *mc_dev,
>   }
>   EXPORT_SYMBOL_GPL(fsl_mc_get_endpoint);
>   
> -static int parse_mc_ranges(struct device *dev,
> -			   int *paddr_cells,
> -			   int *mc_addr_cells,
> -			   int *mc_size_cells,
> -			   const __be32 **ranges_start)
> -{
> -	const __be32 *prop;
> -	int range_tuple_cell_count;
> -	int ranges_len;
> -	int tuple_len;
> -	struct device_node *mc_node = dev->of_node;
> -
> -	*ranges_start = of_get_property(mc_node, "ranges", &ranges_len);
> -	if (!(*ranges_start) || !ranges_len) {
> -		dev_warn(dev,
> -			 "missing or empty ranges property for device tree node '%pOFn'\n",
> -			 mc_node);
> -		return 0;
> -	}
> -
> -	*paddr_cells = of_n_addr_cells(mc_node);
> -
> -	prop = of_get_property(mc_node, "#address-cells", NULL);
> -	if (prop)
> -		*mc_addr_cells = be32_to_cpup(prop);
> -	else
> -		*mc_addr_cells = *paddr_cells;
> -
> -	prop = of_get_property(mc_node, "#size-cells", NULL);
> -	if (prop)
> -		*mc_size_cells = be32_to_cpup(prop);
> -	else
> -		*mc_size_cells = of_n_size_cells(mc_node);
> -
> -	range_tuple_cell_count = *paddr_cells + *mc_addr_cells +
> -				 *mc_size_cells;
> -
> -	tuple_len = range_tuple_cell_count * sizeof(__be32);
> -	if (ranges_len % tuple_len != 0) {
> -		dev_err(dev, "malformed ranges property '%pOFn'\n", mc_node);
> -		return -EINVAL;
> -	}
> -
> -	return ranges_len / tuple_len;
> -}
> -
>   static int get_mc_addr_translation_ranges(struct device *dev,
>   					  struct fsl_mc_addr_translation_range
>   						**ranges,
>   					  u8 *num_ranges)
>   {
> -	int ret;
> -	int paddr_cells;
> -	int mc_addr_cells;
> -	int mc_size_cells;
> -	int i;
> -	const __be32 *ranges_start;
> -	const __be32 *cell;
> -
> -	ret = parse_mc_ranges(dev,
> -			      &paddr_cells,
> -			      &mc_addr_cells,
> -			      &mc_size_cells,
> -			      &ranges_start);
> -	if (ret < 0)
> -		return ret;
> +	struct fsl_mc_addr_translation_range *r;
> +	struct of_range_parser parser;
> +	struct of_range range;
>   
> -	*num_ranges = ret;
> -	if (!ret) {
> +	of_range_parser_init(&parser, dev->of_node);
> +	*num_ranges = of_range_count(&parser);
> +	if (!*num_ranges) {
>   		/*
>   		 * Missing or empty ranges property ("ranges;") for the
>   		 * 'fsl,qoriq-mc' node. In this case, identity mapping
> @@ -1083,20 +1026,13 @@ static int get_mc_addr_translation_ranges(struct device *dev,
>   	if (!(*ranges))
>   		return -ENOMEM;
>   
> -	cell = ranges_start;
> -	for (i = 0; i < *num_ranges; ++i) {
> -		struct fsl_mc_addr_translation_range *range = &(*ranges)[i];
> -
> -		range->mc_region_type = of_read_number(cell, 1);
> -		range->start_mc_offset = of_read_number(cell + 1,
> -							mc_addr_cells - 1);
> -		cell += mc_addr_cells;
> -		range->start_phys_addr = of_read_number(cell, paddr_cells);
> -		cell += paddr_cells;
> -		range->end_mc_offset = range->start_mc_offset +
> -				     of_read_number(cell, mc_size_cells);
> -
> -		cell += mc_size_cells;
> +	r = *ranges;
> +	for_each_of_range(&parser, &range) {
> +		r->mc_region_type = range.flags;
> +		r->start_mc_offset = range.bus_addr;
> +		r->end_mc_offset = range.bus_addr + range.size;
> +		r->start_phys_addr = range.cpu_addr;
> +		r++;
>   	}
>   
>   	return 0;