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 <[email protected]> > Signed-off-by: Abhishek Shah <[email protected]> > Signed-off-by: Ray Jui <[email protected]> > --- > 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 >
