Re: [PATCH 11/11] PCI: rcar: Use inbound resources for setup

[Andrew Murray <andrew.murray@arm.com>]

On Tue, Sep 24, 2019 at 04:46:30PM -0500, Rob Herring wrote:
> Now that the helpers provide the inbound resources in the host bridge
> 'dma_ranges' resource list, convert Renesas R-Car PCIe host bridge to
> use the resource list to setup the inbound addresses.
> 
> Cc: Simon Horman <horms@verge.net.au>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
>  drivers/pci/controller/pcie-rcar.c | 45 +++++++++++-------------------
>  1 file changed, 16 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
> index b8d6e86a5539..453c931aaf77 100644
> --- a/drivers/pci/controller/pcie-rcar.c
> +++ b/drivers/pci/controller/pcie-rcar.c
> @@ -1014,16 +1014,16 @@ static int rcar_pcie_get_resources(struct rcar_pcie *pcie)
>  }
>  
>  static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
> -				    struct of_pci_range *range,
> +				    struct resource_entry *entry,
>  				    int *index)
>  {
> -	u64 restype = range->flags;
> -	u64 cpu_addr = range->cpu_addr;
> -	u64 cpu_end = range->cpu_addr + range->size;
> -	u64 pci_addr = range->pci_addr;
> +	u64 restype = entry->res->flags;
> +	u64 cpu_addr = entry->res->start;
> +	u64 cpu_end = entry->res->end;
> +	u64 pci_addr = entry->res->start - entry->offset;
>  	u32 flags = LAM_64BIT | LAR_ENABLE;
>  	u64 mask;
> -	u64 size;
> +	u64 size = resource_size(entry->res);
>  	int idx = *index;
>  
>  	if (restype & IORESOURCE_PREFETCH)
> @@ -1037,9 +1037,7 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
>  		unsigned long nr_zeros = __ffs64(cpu_addr);
>  		u64 alignment = 1ULL << nr_zeros;
>  
> -		size = min(range->size, alignment);
> -	} else {
> -		size = range->size;
> +		size = min(size, alignment);
>  	}

AFAICT the (if cpu_addr > 0) is here because the result of __ffs64 is undefined
if no bits are set (according to the comment). However by removing the else
statement we no longer guarantee that nr_zeros is defined.

>  	/* Hardware supports max 4GiB inbound region */
>  	size = min(size, 1ULL << 32);
> @@ -1078,30 +1076,19 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
>  	return 0;
>  }
>  
> -static int rcar_pcie_parse_map_dma_ranges(struct rcar_pcie *pcie,
> -					  struct device_node *np)
> +static int rcar_pcie_parse_map_dma_ranges(struct rcar_pcie *pcie)
>  {
> -	struct of_pci_range range;
> -	struct of_pci_range_parser parser;
> -	int index = 0;
> -	int err;
> -
> -	if (of_pci_dma_range_parser_init(&parser, np))
> -		return -EINVAL;
> -
> -	/* Get the dma-ranges from DT */
> -	for_each_of_pci_range(&parser, &range) {
> -		u64 end = range.cpu_addr + range.size - 1;
> -
> -		dev_dbg(pcie->dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
> -			range.flags, range.cpu_addr, end, range.pci_addr);
> +	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
> +	struct resource_entry *entry;
> +	int index = 0, err = 0;
>  
> -		err = rcar_pcie_inbound_ranges(pcie, &range, &index);
> +	resource_list_for_each_entry(entry, &bridge->dma_ranges) {
> +		err = rcar_pcie_inbound_ranges(pcie, entry, &index);
>  		if (err)
> -			return err;
> +			break;
>  	}
>  
> -	return 0;
> +	return err;
>  }
>  
>  static const struct of_device_id rcar_pcie_of_match[] = {
> @@ -1162,7 +1149,7 @@ static int rcar_pcie_probe(struct platform_device *pdev)
>  		goto err_unmap_msi_irqs;
>  	}
>  
> -	err = rcar_pcie_parse_map_dma_ranges(pcie, dev->of_node);
> +	err = rcar_pcie_parse_map_dma_ranges(pcie);
>  	if (err)
>  		goto err_clk_disable;
>  
> -- 
> 2.20.1
>