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| author | Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com> | 2021-02-22 09:47:31 +0100 |
|---|---|---|
| committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2021-04-07 17:59:23 +0200 |
| commit | 213e12205232886902507ba4e2af12d79b7cbbab (patch) | |
| tree | 67f402570d02561249cac63df8c3e3705f8153c0 /drivers/pci | |
| parent | Linux 5.12-rc2 (diff) | |
| download | linux-213e12205232886902507ba4e2af12d79b7cbbab.tar.xz linux-213e12205232886902507ba4e2af12d79b7cbbab.zip | |
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 <bharat.kumar.gogada@xilinx.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/controller/pcie-xilinx-nwl.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c b/drivers/pci/controller/pcie-xilinx-nwl.c index 07e36661bbc2..8689311c5ef6 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; |