Re: [PATCH 10/25] dmaengine: dw-edma: Add PCIe bus address getter to the remote EP glue-driver

Manivannan Sadhasivam
2022-03-24T17:41:45Z

On Thu, Mar 24, 2022 at 04:48:21AM +0300, Serge Semin wrote:
> In general the Synopsys PCIe EndPoint IP prototype kit can be attached to
> a PCIe bus with any PCIe Host controller including to the one with
> distinctive from CPU address space. Due to that we need to make sure that
> the source and destination addresses of the DMA-slave devices are properly
> converted to the PCIe bus address space, otherwise the DMA transaction
> will not only work as expected, but may cause the memory corruption with
> subsequent system crash. Let's do that by introducing a new
> dw_edma_pcie_address() method defined in the dw-edma-pcie.c, which will
> perform the denoted translation by using the pcibios_resource_to_bus()
> method.
>
> Fixes: 41aaff2a2ac0 ("dmaengine: Add Synopsys eDMA IP PCIe glue-logic")
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Thanks,
Mani

> ---
>
> Note this patch depends on the patch "dmaengine: dw-edma: Add CPU to PCIe
> bus address translation" from this series.
> ---
> drivers/dma/dw-edma/dw-edma-pcie.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
> index 04c95cba1244..f530bacfd716 100644
> --- a/drivers/dma/dw-edma/dw-edma-pcie.c
> +++ b/drivers/dma/dw-edma/dw-edma-pcie.c
> @@ -95,8 +95,23 @@ static int dw_edma_pcie_irq_vector(struct device *dev, unsigned int nr)
> return pci_irq_vector(to_pci_dev(dev), nr);
> }
>
> +static u64 dw_edma_pcie_address(struct device *dev, phys_addr_t cpu_addr)
> +{
> + struct pci_dev *pdev = to_pci_dev(dev);
> + struct pci_bus_region region;
> + struct resource res = {
> + .flags = IORESOURCE_MEM,
> + .start = cpu_addr,
> + .end = cpu_addr,
> + };
> +
> + pcibios_resource_to_bus(pdev->bus, &region, &res);
> + return region.start;
> +}
> +
> static const struct dw_edma_core_ops dw_edma_pcie_core_ops = {
> .irq_vector = dw_edma_pcie_irq_vector,
> + .pci_address = dw_edma_pcie_address,
> };
>
> static void dw_edma_pcie_get_vsec_dma_data(struct pci_dev *pdev,
> --
> 2.35.1
>