On Fri, Apr 12, 2019 at 08:43:35AM +0530, Srinath Mannam wrote:
> IPROC host has the limitation that it can use only those address ranges
> given by dma-ranges property as inbound address. So that the memory
> address holes in dma-ranges should be reserved to allocate as DMA address.
>
> Inbound address of host accessed by PCIe devices will not be translated
> before it comes to IOMMU or directly to PE.
What does that mean "directly to PE" ?
IIUC all you want to say is that there is no entity translating
PCI memory transactions addresses before they it the PCI host
controller inbound regions address decoder.
> But the limitation of this host is, access to few address ranges are
> ignored. So that IOVA ranges for these address ranges have to be
> reserved.
>
> All allowed address ranges are listed in dma-ranges DT parameter. These
> address ranges are converted as resource entries and listed in sorted
> order add added to dma_ranges list of PCI host bridge structure.
>
> Ex:
> dma-ranges = < \
> 0x43000000 0x00 0x80000000 0x00 0x80000000 0x00 0x80000000 \
> 0x43000000 0x08 0x00000000 0x08 0x00000000 0x08 0x00000000 \
> 0x43000000 0x80 0x00000000 0x80 0x00000000 0x40 0x00000000>
>
> In the above example of dma-ranges, memory address from
> 0x0 - 0x80000000,
> 0x100000000 - 0x800000000,
> 0x1000000000 - 0x8000000000 and
> 0x10000000000 - 0xffffffffffffffff.
> are not allowed to use as inbound addresses.
>
> Signed-off-by: Srinath Mannam <srinath.man...@broadcom.com>
> Based-on-patch-by: Oza Pawandeep <oza....@broadcom.com>
> Reviewed-by: Oza Pawandeep <p...@codeaurora.org>
> ---
> drivers/pci/controller/pcie-iproc.c | 44
> ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 43 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/pcie-iproc.c
> b/drivers/pci/controller/pcie-iproc.c
> index c20fd6b..94ba5c0 100644
> --- a/drivers/pci/controller/pcie-iproc.c
> +++ b/drivers/pci/controller/pcie-iproc.c
> @@ -1146,11 +1146,43 @@ static int iproc_pcie_setup_ib(struct iproc_pcie
> *pcie,
> return ret;
> }
>
> +static int
> +iproc_pcie_add_dma_range(struct device *dev, struct list_head *resources,
> + struct of_pci_range *range)
> +{
> + struct resource *res;
> + struct resource_entry *entry, *tmp;
> + struct list_head *head = resources;
> +
> + res = devm_kzalloc(dev, sizeof(struct resource), GFP_KERNEL);
> + if (!res)
> + return -ENOMEM;
> +
> + resource_list_for_each_entry(tmp, resources) {
> + if (tmp->res->start < range->cpu_addr)
> + head = &tmp->node;
> + }
> +
> + res->start = range->cpu_addr;
> + res->end = res->start + range->size - 1;
> +
> + entry = resource_list_create_entry(res, 0);
> + if (!entry)
> + return -ENOMEM;
> +
> + entry->offset = res->start - range->cpu_addr;
> + resource_list_add(entry, head);
> +
> + return 0;
> +}
> +
> static int iproc_pcie_map_dma_ranges(struct iproc_pcie *pcie)
> {
> + struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
> struct of_pci_range range;
> struct of_pci_range_parser parser;
> int ret;
> + LIST_HEAD(resources);
>
> /* Get the dma-ranges from DT */
> ret = of_pci_dma_range_parser_init(&parser, pcie->dev->of_node);
> @@ -1158,13 +1190,23 @@ static int iproc_pcie_map_dma_ranges(struct
> iproc_pcie *pcie)
> return ret;
>
> for_each_of_pci_range(&parser, &range) {
> + ret = iproc_pcie_add_dma_range(pcie->dev,
> + &resources,
> + &range);
> + if (ret)
> + goto out;
> /* Each range entry corresponds to an inbound mapping region */
> ret = iproc_pcie_setup_ib(pcie, &range, IPROC_PCIE_IB_MAP_MEM);
> if (ret)
> - return ret;
> + goto out;
> }
>
> + list_splice_init(&resources, &host->dma_ranges);
> +
> return 0;
> +out:
> + pci_free_resource_list(&resources);
> + return ret;
> }
>
> static int iproce_pcie_get_msi(struct iproc_pcie *pcie,
> --
> 2.7.4
>
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