[PATCH 2/2] NTB: PCI Quirk to Enable Switchtec NT Functionality with IOMMU On

From: dmeyer
Date: Thu May 17 2018 - 07:04:08 EST


From: Doug Meyer <dmeyer@xxxxxxxxxx>

Here we add the PCI quirk for the Microsemi Switchtec parts to allow
non-transparent bridging to work when the IOMMU is turned on.

When a requestor on one NT endpoint accesses memory on another NT
endpoint, it does this via a devfn proxy ID. Proxy IDs are uniquely
assigned on a per-requestor basis within the NT hardware, and are not
visible via PCI enumeration. As a result, a memory access from a peer
NT endpoint will have an unrecognized requestor ID devfn which the
IOMMU will reject.

The quirk introduced here interrogates each configured remote NT
endpoint at runtime to obtain the proxy IDs that have been assigned,
and aliases every proxy ID to the local (enumerated) NT endpoint's
device. The IOMMU then accepts the remote proxy IDs as if they were
requests coming directly from the enumerated endpoint, giving remote
requestors access to memory resources which a given host has made
available. Operation with the IOMMU off is unchanged by this quirk.

Signed-off-by: Doug Meyer <dmeyer@xxxxxxxxxx>
---
drivers/pci/quirks.c | 196 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 196 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 2990ad1..c7e27b3 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -27,6 +27,7 @@
#include <linux/mm.h>
#include <linux/platform_data/x86/apple.h>
#include <linux/pm_runtime.h>
+#include <linux/switchtec.h>
#include <asm/dma.h> /* isa_dma_bridge_buggy */
#include "pci.h"

@@ -4741,3 +4742,198 @@ static void quirk_gpu_hda(struct pci_dev *hda)
PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda);
DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda);
+
+/*
+ * Microsemi Switchtec NTB uses devfn proxy IDs to move TLPs between
+ * NT endpoints via the internal switch fabric. These IDs replace the
+ * originating requestor ID TLPs which access host memory on peer NTB
+ * ports. Therefore, all proxy IDs must be aliased to the NTB device
+ * to permit access when the IOMMU is turned on.
+ */
+static void quirk_switchtec_ntb_dma_alias(struct pci_dev *pdev)
+{
+ void __iomem *mmio = NULL;
+ struct ntb_info_regs __iomem *mmio_ntb = NULL;
+ struct ntb_ctrl_regs __iomem *mmio_ctrl = NULL;
+ struct sys_info_regs __iomem *mmio_sys_info = NULL;
+
+ u64 partition_map;
+ u8 partition;
+ int pp;
+
+ if (pci_enable_device(pdev)) {
+ dev_err(&pdev->dev, "Cannot enable Switchtec device\n");
+ return;
+ }
+
+ mmio = pci_iomap(pdev, 0, 0);
+ if (mmio == NULL) {
+ dev_err(&pdev->dev, "Cannot iomap Switchtec device\n");
+ return;
+ }
+
+ dev_info(&pdev->dev, "Setting Switchtec proxy ID aliases\n");
+
+ mmio_ntb = mmio + SWITCHTEC_GAS_NTB_OFFSET;
+ mmio_ctrl = (void * __iomem) mmio_ntb + SWITCHTEC_NTB_REG_CTRL_OFFSET;
+ mmio_sys_info = mmio + SWITCHTEC_GAS_SYS_INFO_OFFSET;
+
+ partition = ioread8(&mmio_ntb->partition_id);
+
+ partition_map = (u64) ioread32((void * __iomem) &mmio_ntb->ep_map);
+ partition_map |=
+ ((u64) ioread32((void * __iomem) &mmio_ntb->ep_map + 4)) << 32;
+ partition_map &= ~(1ULL << partition);
+
+ for (pp = 0; pp < (sizeof(partition_map) * 8); pp++) {
+ struct ntb_ctrl_regs __iomem *mmio_peer_ctrl;
+ u32 table_sz = 0;
+ int te;
+
+ if (!(partition_map & (1ULL << pp)))
+ continue;
+
+ dev_dbg(&pdev->dev, "Processing partition %d\n", pp);
+
+ mmio_peer_ctrl = &mmio_ctrl[pp];
+
+ table_sz = ioread16(&mmio_peer_ctrl->req_id_table_size);
+ if (!table_sz) {
+ dev_warn(&pdev->dev, "Partition %d table_sz 0\n", pp);
+ continue;
+ }
+
+ if (table_sz > 512) {
+ dev_warn(&pdev->dev,
+ "Invalid Switchtec partition %d table_sz %d\n",
+ pp, table_sz);
+ continue;
+ }
+
+ for (te = 0; te < table_sz; te++) {
+ u32 rid_entry;
+ u8 devfn;
+
+ rid_entry = ioread32(&mmio_peer_ctrl->req_id_table[te]);
+ devfn = (rid_entry >> 1) & 0xFF;
+ dev_dbg(&pdev->dev,
+ "Aliasing Partition %d Proxy ID %02d.%d\n",
+ pp, PCI_SLOT(devfn), PCI_FUNC(devfn));
+ pci_add_dma_alias(pdev, devfn);
+ }
+ }
+
+ pci_iounmap(pdev, mmio);
+}
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFX24XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFX32XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFX48XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFX64XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFX80XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFX96XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PSX48XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PSX64XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PSX80XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PSX96XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PAX24XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PAX32XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PAX48XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PAX64XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PAX80XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PAX96XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXL24XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXL32XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXL48XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXL64XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXL80XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXL96XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXI24XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXI32XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXI48XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXI64XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXI80XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_MICROSEMI,
+ PCI_DEVICE_ID_MICROSEMI_PFXI96XG3,
+ PCI_CLASS_BRIDGE_OTHER, 8,
+ quirk_switchtec_ntb_dma_alias);
--
1.8.3.1