dmaengine: dw-edma: Add PCI bus address getter to the remote EP glue driver

The Synopsys PCIe Endpoint IP prototype kit can be attached via any PCI
host controller, including one where the PCI bus address space is different
from the CPU address space.  Therefore, we need to make sure the source and
destination addresses of the DMA slave devices are converted to the PCI bus
address space; otherwise DMA transactions may cause memory corruption.

Add a new dw_edma_pcie_address() interface to perform this translation by
using pcibios_resource_to_bus().

Link: https://lore.kernel.org/r/20230113171409.30470-9-Sergey.Semin@baikalelectronics.ru
Fixes: 41aaff2a2ac0 ("dmaengine: Add Synopsys eDMA IP PCIe glue-logic")
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
index 04c95cba1244bd7a66d8efebe68f56bf49fe8cbb..f530bacfd716cdfeb8b86be9281001a0fc28ed2c 100644 (file)
--- 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,