iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

dmaengine: dw-edma: Convert ll/dt phys address to PCI bus/DMA address

Browse Source 
The dw_edma_region.paddr field should be a memory base address visible by
the DW eDMA controller. If the DMA engine is embedded in the DW PCIe
Host/Endpoint controller, the address should belong to the Local CPU/
Application memory.  If eDMA is remotely accessible across the PCI bus via
PCI memory IOs, the address should be part of the PCI bus memory space.
The latter case hasn't been well covered in the corresponding glue-driver.

Since pci_dev.resource[] contains resources defined in the CPU memory
space, they need to be converted to the PCI bus address space.  Convert the
LL, DT and CSRs PCI memory ranges with pci_bus_address().

In addition, extend the dw_edma_region.paddr field size. The field normally
contains a memory range base address to be set in the DW eDMA Linked-List
pointer register or as a base address of the Linked-List data buffer. In
accordance with [1] the LL range is supposed to be created in the Local
CPU/Application memory, but depending on the DW eDMA utilization the memory
can be created as a part of the PCI bus address space (as in the case of
the DW PCIe Endpoint prototype kit).

In the former case dw_edma_region.paddr should be a dma_addr_t, while in
the latter one it should be a pci_bus_addr_t. Since the corresponding CSRs
are always 64 bits wide, convert dw_edma_region.paddr to be u64, and let
the client make sure it has a valid address visible by the DW eDMA
controller. For instance, the DW eDMA PCIe glue-driver initializes the
field with addresses from the PCI bus memory space.

[1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port,
    v.5.40a, March 2019, p.1103

Link: https://lore.kernel.org/r/20230113171409.30470-4-Sergey.Semin@baikalelectronics.ru
Fixes: 41aaff2a2a ("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>
This commit is contained in:
Serge Semin 2023-01-13 20:13:45 +03:00 committed by Lorenzo Pieralisi
parent 0278067445
commit 002bbaa2f6
2 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/dma/dw-edma/dw-edma-pcie.c
View File

@ -231,7 +231,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
return -ENOMEM;
ll_region->vaddr += ll_block->off;
ll_region->paddr = pdev->resource[ll_block->bar].start;
ll_region->paddr = pci_bus_address(pdev, ll_block->bar);
ll_region->paddr += ll_block->off;
ll_region->sz = ll_block->sz;
@ -240,7 +240,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
return -ENOMEM;
dt_region->vaddr += dt_block->off;
dt_region->paddr = pdev->resource[dt_block->bar].start;
dt_region->paddr = pci_bus_address(pdev, dt_block->bar);
dt_region->paddr += dt_block->off;
dt_region->sz = dt_block->sz;
}
@ -256,7 +256,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
return -ENOMEM;
ll_region->vaddr += ll_block->off;
ll_region->paddr = pdev->resource[ll_block->bar].start;
ll_region->paddr = pci_bus_address(pdev, ll_block->bar);
ll_region->paddr += ll_block->off;
ll_region->sz = ll_block->sz;
@ -265,7 +265,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
return -ENOMEM;
dt_region->vaddr += dt_block->off;
dt_region->paddr = pdev->resource[dt_block->bar].start;
dt_region->paddr = pci_bus_address(pdev, dt_block->bar);
dt_region->paddr += dt_block->off;
dt_region->sz = dt_block->sz;
}

2
include/linux/dma/edma.h
View File

@ -18,7 +18,7 @@
struct dw_edma;
struct dw_edma_region {
phys_addr_t paddr;
u64 paddr;
void __iomem *vaddr;
size_t sz;
};