From: Bharat Kumar Gogada Date: Mon, 22 Feb 2021 08:47:31 +0000 (+0530) Subject: PCI: xilinx-nwl: Enable coherent PCIe DMA traffic using CCI X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=213e12205232886902507ba4e2af12d79b7cbbab;p=linux.git PCI: xilinx-nwl: Enable coherent PCIe DMA traffic using CCI Add support for routing PCIe DMA traffic coherently when Cache Coherent Interconnect (CCI) is enabled in the system. The "dma-coherent" property is used to determine if CCI is enabled or not. Refer to https://developer.arm.com/documentation/ddi0470/k/preface for the CCI specification. Link: https://lore.kernel.org/r/20210222084732.21521-1-bharat.kumar.gogada@xilinx.com Signed-off-by: Bharat Kumar Gogada Signed-off-by: Lorenzo Pieralisi --- diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c b/drivers/pci/controller/pcie-xilinx-nwl.c index 07e36661bbc29..8689311c5ef66 100644 --- a/drivers/pci/controller/pcie-xilinx-nwl.c +++ b/drivers/pci/controller/pcie-xilinx-nwl.c @@ -26,6 +26,7 @@ /* Bridge core config registers */ #define BRCFG_PCIE_RX0 0x00000000 +#define BRCFG_PCIE_RX1 0x00000004 #define BRCFG_INTERRUPT 0x00000010 #define BRCFG_PCIE_RX_MSG_FILTER 0x00000020 @@ -128,6 +129,7 @@ #define NWL_ECAM_VALUE_DEFAULT 12 #define CFG_DMA_REG_BAR GENMASK(2, 0) +#define CFG_PCIE_CACHE GENMASK(7, 0) #define INT_PCI_MSI_NR (2 * 32) @@ -675,6 +677,11 @@ static int nwl_pcie_bridge_init(struct nwl_pcie *pcie) nwl_bridge_writel(pcie, CFG_ENABLE_MSG_FILTER_MASK, BRCFG_PCIE_RX_MSG_FILTER); + /* This routes the PCIe DMA traffic to go through CCI path */ + if (of_dma_is_coherent(dev->of_node)) + nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_PCIE_RX1) | + CFG_PCIE_CACHE, BRCFG_PCIE_RX1); + err = nwl_wait_for_link(pcie); if (err) return err;