From 56b4cd4b7da9ee95778eb5c8abea49f641ebfd91 Mon Sep 17 00:00:00 2001
From: Slawomir Pawlowski <slawomir.pawlowski@intel.com>
Date: Tue, 17 Sep 2019 09:20:48 +0000
Subject: [PATCH] PCI: Add DMA alias quirk for Intel VCA NTB
Git-commit: 56b4cd4b7da9ee95778eb5c8abea49f641ebfd91
Patch-mainline: v5.5-rc1
References: bsc#1051510

Intel Visual Compute Accelerator (VCA) is a family of PCIe add-in devices
exposing computational units via Non Transparent Bridges (NTB, PEX 87xx).

Similarly to MIC x200, we need to add DMA aliases to allow buffer access
when IOMMU is enabled.

Add aliases to allow computational unit access to host memory.  These
aliases mark the whole VCA device as one IOMMU group.

All possible slot numbers (0x20) are used, since we are unable to tell what
slot is used on other side.  This quirk is intended for both host and
computational unit sides.  The VCA devices have up to five functions: four
for DMA channels and one additional.

Link: https://lore.kernel.org/r/5683A335CC8BE1438C3C30C49DCC38DF637CED8E@IRSMSX102.ger.corp.intel.com
Signed-off-by: Slawomir Pawlowski <slawomir.pawlowski@intel.com>
Signed-off-by: Przemek Kitszel <przemyslawx.kitszel@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/pci/quirks.c |   34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4136,6 +4136,40 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_I
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2264, quirk_mic_x200_dma_alias);
 
 /*
+ * Intel Visual Compute Accelerator (VCA) is a family of PCIe add-in devices
+ * exposing computational units via Non Transparent Bridges (NTB, PEX 87xx).
+ *
+ * Similarly to MIC x200, we need to add DMA aliases to allow buffer access
+ * when IOMMU is enabled.  These aliases allow computational unit access to
+ * host memory.  These aliases mark the whole VCA device as one IOMMU
+ * group.
+ *
+ * All possible slot numbers (0x20) are used, since we are unable to tell
+ * what slot is used on other side.  This quirk is intended for both host
+ * and computational unit sides.  The VCA devices have up to five functions
+ * (four for DMA channels and one additional).
+ */
+static void quirk_pex_vca_alias(struct pci_dev *pdev)
+{
+	const unsigned int num_pci_slots = 0x20;
+	unsigned int slot;
+
+	for (slot = 0; slot < num_pci_slots; slot++) {
+		pci_add_dma_alias(pdev, PCI_DEVFN(slot, 0x0));
+		pci_add_dma_alias(pdev, PCI_DEVFN(slot, 0x1));
+		pci_add_dma_alias(pdev, PCI_DEVFN(slot, 0x2));
+		pci_add_dma_alias(pdev, PCI_DEVFN(slot, 0x3));
+		pci_add_dma_alias(pdev, PCI_DEVFN(slot, 0x4));
+	}
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2954, quirk_pex_vca_alias);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2955, quirk_pex_vca_alias);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2956, quirk_pex_vca_alias);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2958, quirk_pex_vca_alias);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2959, quirk_pex_vca_alias);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x295A, quirk_pex_vca_alias);
+
+/*
  * The IOMMU and interrupt controller on Broadcom Vulcan/Cavium ThunderX2 are
  * associated not at the root bus, but at a bridge below. This quirk avoids
  * generating invalid DMA aliases.