On Fri, Mar 01, 2019 at 10:22:16AM +0530, Srinath Mannam wrote:
> In the present driver outbound window configuration is done to map above
> 32-bit address I/O regions with corresponding PCI memory range given in
> ranges DT property.
>
> This patch add outbound window configuration to map below 32-bit I/O range
> with corresponding PCI memory, which helps to access I/O region in ARM
> 32-bit and one to one mapping of I/O region to PCI memory.
>
> Ex:
> 1. ranges DT property given for current driver is,
> ranges = <0x83000000 0x0 0x40000000 0x4 0x00000000 0 0x40000000>;
> I/O region address is 0x400000000
> 2. ranges DT property can be given after this patch,
> ranges = <0x83000000 0x0 0x42000000 0x0 0x42000000 0 0x2000000>;
> I/O region address is 0x42000000
I was applying this patch but I don't understand the commit log and
how it matches the code, please explain it to me and I will reword
it.
Thanks,
Lorenzo
> Signed-off-by: Srinath Mannam <srinath.mannam@xxxxxxxxxxxx>
> Signed-off-by: Abhishek Shah <abhishek.shah@xxxxxxxxxxxx>
> Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
> ---
> drivers/pci/controller/pcie-iproc.c | 21 +++++++++++++++++++--
> 1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
> index b882255..080f142 100644
> --- a/drivers/pci/controller/pcie-iproc.c
> +++ b/drivers/pci/controller/pcie-iproc.c
> @@ -955,8 +955,25 @@ static int iproc_pcie_setup_ob(struct iproc_pcie *pcie, u64 axi_addr,
> resource_size_t window_size =
> ob_map->window_sizes[size_idx] * SZ_1M;
>
> - if (size < window_size)
> - continue;
> + /*
> + * Keep iterating until we reach the last window and
> + * with the minimal window size at index zero. In this
> + * case, we take a compromise by mapping it using the
> + * minimum window size that can be supported
> + */
> + if (size < window_size) {
> + if (size_idx > 0 || window_idx > 0)
> + continue;
> +
> + /*
> + * For the corner case of reaching the minimal
> + * window size that can be supported on the
> + * last window
> + */
> + axi_addr = ALIGN_DOWN(axi_addr, window_size);
> + pci_addr = ALIGN_DOWN(pci_addr, window_size);
> + size = window_size;
> + }
>
> if (!IS_ALIGNED(axi_addr, window_size) ||
> !IS_ALIGNED(pci_addr, window_size)) {
> --
> 2.7.4
>
