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From: James Sewart <jamessewart@arista.com>
To: linux-pci@vger.kernel.org
Cc: Logan Gunthorpe <logang@deltatee.com>,
	Christoph Hellwig <hch@infradead.org>,
	Dmitry Safonov <0x7f454c46@gmail.com>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	Dmitry Safonov <dima@arista.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Bjorn Helgaas <helgaas@kernel.org>
Subject: [PATCH v6 3/3] PCI: Add DMA alias quirk for PLX PEX NTB
Date: Tue, 3 Dec 2019 15:44:15 +0000	[thread overview]
Message-ID: <DB3DFAF8-D126-4ECB-A4E0-C314F4F46205@arista.com> (raw)
In-Reply-To: <D4C7374E-4DFE-4024-8E76-9F54BF421B62@arista.com>

The PLX PEX NTB forwards DMA transactions using Requester ID's that
don't exist as PCI devices. The devfn for a transaction is used as an
index into a lookup table storing the origin of a transaction on the
other side of the bridge.

This patch aliases all possible devfn's to the NTB device so that any
transaction coming in is governed by the mappings for the NTB.

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: James Sewart <jamessewart@arista.com>
---
 drivers/pci/quirks.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 0f3f5afc73fd..3a67049ca630 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5315,6 +5315,21 @@ SWITCHTEC_QUIRK(0x8574);  /* PFXI 64XG3 */
 SWITCHTEC_QUIRK(0x8575);  /* PFXI 80XG3 */
 SWITCHTEC_QUIRK(0x8576);  /* PFXI 96XG3 */
 
+/*
+ * PLX NTB uses devfn proxy IDs to move TLPs between NT endpoints. These IDs
+ * are used to forward responses to the originator on the other side of the
+ * NTB. Alias all possible IDs to the NTB to permit access when the IOMMU is
+ * turned on.
+ */
+static void quirk_plx_ntb_dma_alias(struct pci_dev *pdev)
+{
+	pci_info(pdev, "Setting PLX NTB proxy ID aliases\n");
+	/* PLX NTB may use all 256 devfns */
+	pci_add_dma_alias(pdev, 0, 256);
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x87b0, quirk_plx_ntb_dma_alias);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x87b1, quirk_plx_ntb_dma_alias);
+
 /*
  * On Lenovo Thinkpad P50 SKUs with a Nvidia Quadro M1000M, the BIOS does
  * not always reset the secondary Nvidia GPU between reboots if the system
-- 
2.24.0


WARNING: multiple messages have this Message-ID (diff)
From: James Sewart via iommu <iommu@lists.linux-foundation.org>
To: linux-pci@vger.kernel.org
Cc: Alex Williamson <alex.williamson@redhat.com>,
	Dmitry Safonov <dima@arista.com>,
	Dmitry Safonov <0x7f454c46@gmail.com>,
	linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	Bjorn Helgaas <helgaas@kernel.org>,
	Logan Gunthorpe <logang@deltatee.com>
Subject: [PATCH v6 3/3] PCI: Add DMA alias quirk for PLX PEX NTB
Date: Tue, 3 Dec 2019 15:44:15 +0000	[thread overview]
Message-ID: <DB3DFAF8-D126-4ECB-A4E0-C314F4F46205@arista.com> (raw)
In-Reply-To: <D4C7374E-4DFE-4024-8E76-9F54BF421B62@arista.com>

The PLX PEX NTB forwards DMA transactions using Requester ID's that
don't exist as PCI devices. The devfn for a transaction is used as an
index into a lookup table storing the origin of a transaction on the
other side of the bridge.

This patch aliases all possible devfn's to the NTB device so that any
transaction coming in is governed by the mappings for the NTB.

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: James Sewart <jamessewart@arista.com>
---
 drivers/pci/quirks.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 0f3f5afc73fd..3a67049ca630 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5315,6 +5315,21 @@ SWITCHTEC_QUIRK(0x8574);  /* PFXI 64XG3 */
 SWITCHTEC_QUIRK(0x8575);  /* PFXI 80XG3 */
 SWITCHTEC_QUIRK(0x8576);  /* PFXI 96XG3 */
 
+/*
+ * PLX NTB uses devfn proxy IDs to move TLPs between NT endpoints. These IDs
+ * are used to forward responses to the originator on the other side of the
+ * NTB. Alias all possible IDs to the NTB to permit access when the IOMMU is
+ * turned on.
+ */
+static void quirk_plx_ntb_dma_alias(struct pci_dev *pdev)
+{
+	pci_info(pdev, "Setting PLX NTB proxy ID aliases\n");
+	/* PLX NTB may use all 256 devfns */
+	pci_add_dma_alias(pdev, 0, 256);
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x87b0, quirk_plx_ntb_dma_alias);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PLX, 0x87b1, quirk_plx_ntb_dma_alias);
+
 /*
  * On Lenovo Thinkpad P50 SKUs with a Nvidia Quadro M1000M, the BIOS does
  * not always reset the secondary Nvidia GPU between reboots if the system
-- 
2.24.0

_______________________________________________
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  reply	other threads:[~2019-12-03 15:44 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-03 15:43 [PATCH v6 1/3] PCI: Fix off by one in dma_alias_mask allocation size James Sewart
2019-12-03 15:43 ` James Sewart via iommu
2019-12-03 15:43 ` [PATCH v6 2/3] PCI: Add parameter nr_devfns to pci_add_dma_alias James Sewart
2019-12-03 15:43   ` James Sewart via iommu
2019-12-03 15:44   ` James Sewart [this message]
2019-12-03 15:44     ` [PATCH v6 3/3] PCI: Add DMA alias quirk for PLX PEX NTB James Sewart via iommu
2019-12-08  0:48   ` [PATCH v6 2/3] PCI: Add parameter nr_devfns to pci_add_dma_alias kbuild test robot
2019-12-08  0:48     ` kbuild test robot
2019-12-08  0:48     ` kbuild test robot
2019-12-10 22:37   ` Bjorn Helgaas
2019-12-10 22:37     ` Bjorn Helgaas
2019-12-11 15:37     ` James Sewart
2019-12-11 15:37       ` James Sewart via iommu
2019-12-11 20:56       ` Bjorn Helgaas
2019-12-11 20:56         ` Bjorn Helgaas
2019-12-17 10:24     ` Joerg Roedel
2019-12-17 10:24       ` Joerg Roedel
2019-12-10 22:31 ` [PATCH v6 1/3] PCI: Fix off by one in dma_alias_mask allocation size Bjorn Helgaas
2019-12-10 22:31   ` Bjorn Helgaas

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