From 19e20740736cc42f3c7997a6c8db66bb5f61a9e6 Mon Sep 17 00:00:00 2001 From: Philippe Bergheaud Date: Mon, 14 May 2018 10:27:35 +0200 Subject: [PATCH] cxl: Set the PBCQ Tunnel BAR register when enabling capi mode Skiboot used to set the default Tunnel BAR register value when capi mode was enabled. This approach was ok for the cxl driver, but prevented other drivers from choosing different values. Skiboot versions > 5.11 will not set the default value any longer. This patch modifies the cxl driver to set/reset the Tunnel BAR register when entering/exiting the cxl mode, with pnv_pci_set_tunnel_bar(). That should work with old skiboot (since we are re-writing the value already set) and new skiboot. mpe: The tunnel support was only merged into Linux recently, in commit ac3c1ca3e85e ("powerpc/powernv: Enable tunneled operations") (v4.17-rc1), so with new skiboot kernels between that commit and this will not work correctly. Fixes: ac3c1ca3e85e ("powerpc/powernv: Enable tunneled operations") Signed-off-by: Philippe Bergheaud Reviewed-by: Christophe Lombard Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman --- drivers/misc/cxl/pci.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 83f1d08058fc2..4eb893284af28 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -1742,6 +1742,10 @@ static int cxl_configure_adapter(struct cxl *adapter, struct pci_dev *dev) /* Required for devices using CAPP DMA mode, harmless for others */ pci_set_master(dev); + if (cxl_is_power9()) + if (pnv_pci_set_tunnel_bar(dev, 0x00020000E0000000ull, 1)) + dev_info(&dev->dev, "Tunneled operations unsupported\n"); + if ((rc = pnv_phb_to_cxl_mode(dev, adapter->native->sl_ops->capi_mode))) goto err; @@ -1768,6 +1772,9 @@ static void cxl_deconfigure_adapter(struct cxl *adapter) { struct pci_dev *pdev = to_pci_dev(adapter->dev.parent); + if (cxl_is_power9()) + pnv_pci_set_tunnel_bar(pdev, 0x00020000E0000000ull, 0); + cxl_native_release_psl_err_irq(adapter); cxl_unmap_adapter_regs(adapter); -- 2.39.5