On 8/9/19 10:56 PM, Simon Horman wrote:
> On Fri, Aug 09, 2019 at 07:34:48PM +0200, marek.vasut@xxxxxxxxx wrote:
>> From: Oza Pawandeep <oza.oza@xxxxxxxxxxxx>
>>
>> The patch exports interface to PCIe RC drivers so that,
>> Drivers can get their inbound memory configuration.
>>
>> It provides basis for IOVA reservations for inbound memory
>> holes, if RC is not capable of addressing all the host memory,
>> Specifically when IOMMU is enabled and on ARMv8 where 64bit IOVA
>> could be allocated.
>>
>> It handles multiple inbound windows, and returns resources,
>> and is left to the caller, how it wants to use them.
>>
>> Signed-off-by: Oza Pawandeep <oza.oza@xxxxxxxxxxxx>
>> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxx>
>> Cc: Arnd Bergmann <arnd@xxxxxxxx>
>> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
>> Cc: Robin Murphy <robin.murphy@xxxxxxx>
>> Cc: Simon Horman <horms+renesas@xxxxxxxxxxxx>
>> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
>> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
>> To: linux-pci@xxxxxxxxxxxxxxx
>> ---
>> drivers/pci/of.c | 96 ++++++++++++++++++++++++++++++++++++++++++
>> include/linux/of_pci.h | 7 +++
>> 2 files changed, 103 insertions(+)
>>
>> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
>> index bc7b27a28795..4018f1a26f6f 100644
>> --- a/drivers/pci/of.c
>> +++ b/drivers/pci/of.c
>> @@ -347,6 +347,102 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
>> return err;
>> }
>> EXPORT_SYMBOL_GPL(devm_of_pci_get_host_bridge_resources);
>> +
>> +/**
>> + * of_pci_get_dma_ranges - Parse PCI host bridge inbound resources from DT
>> + * @np: device node of the host bridge having the dma-ranges property
>> + * @resources: list where the range of resources will be added after DT parsing
>> + *
>> + * It is the caller's job to free the @resources list.
>> + *
>> + * This function will parse the "dma-ranges" property of a
>> + * PCI host bridge device node and setup the resource mapping based
>> + * on its content.
>> + *
>> + * It returns zero if the range parsing has been successful or a standard error
>> + * value if it failed.
>> + */
>> +
>> +int of_pci_get_dma_ranges(struct device_node *dn, struct list_head *resources)
>> +{
>> + struct device_node *node = of_node_get(dn);
>> + int rlen;
>> + int pna = of_n_addr_cells(node);
>> + const int na = 3, ns = 2;
>> + int np = pna + na + ns;
>> + int ret = 0;
>> + struct resource *res;
>> + const u32 *dma_ranges;
>
> It seems that const __be32 * would be a more appropriate type
> for dma_ranges as that seems to be the expected type in
> all uses below.
Noted, but I'm more interested in some conceptual input about this --
whether this is the right approach or not.
Seems like we now have iMX8, R-Car3 and some Broadcom SoCs affected by
this issue, with no solution in sight for years, so I think something
has to be done here.
--
Best regards,
Marek Vasut
