PCI: Add Virtual Channel to save/restore support
While we don't really have any infrastructure for making use of VC
support, the system BIOS can configure the topology to non-default
VC values prior to boot. This may be due to silicon bugs, desire to
reserve traffic classes, or perhaps just BIOS bugs. When we reset
devices, the VC configuration may return to default values, which can
be incompatible with devices upstream. For instance, Nvidia GRID
cards provide a PCIe switch and some number of GPUs, all supporting
VC. The power-on default for VC is to support TC0-7 across VC0,
however some platforms will only enable TC0/VC0 mapping across the
topology. When we do a secondary bus reset on the downstream switch
port, the GPU is reset to a TC0-7/VC0 mapping while the opposite end
of the link only enables TC0/VC0. If the GPU attempts to use TC1-7,
it fails.
This patch attempts to provide complete support for VC save/restore,
even beyond the minimally required use case above. This includes
save/restore and reload of the arbitration table, save/restore and
reload of the port arbitration tables, and re-enabling of the
channels for VC, VC9, and MFVC capabilities.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 4a98e85..5eefacd 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -678,16 +678,33 @@
/* Virtual Channel */
#define PCI_VC_PORT_REG1 4
-#define PCI_VC_REG1_EVCC 0x7 /* extended VC count */
+#define PCI_VC_REG1_EVCC 0x00000007 /* extended VC count */
+#define PCI_VC_REG1_LPEVCC 0x00000070 /* low prio extended VC count */
+#define PCI_VC_REG1_ARB_SIZE 0x00000c00
#define PCI_VC_PORT_REG2 8
-#define PCI_VC_REG2_32_PHASE 0x2
-#define PCI_VC_REG2_64_PHASE 0x4
-#define PCI_VC_REG2_128_PHASE 0x8
+#define PCI_VC_REG2_32_PHASE 0x00000002
+#define PCI_VC_REG2_64_PHASE 0x00000004
+#define PCI_VC_REG2_128_PHASE 0x00000008
+#define PCI_VC_REG2_ARB_OFF 0xff000000
#define PCI_VC_PORT_CTRL 12
+#define PCI_VC_PORT_CTRL_LOAD_TABLE 0x00000001
#define PCI_VC_PORT_STATUS 14
+#define PCI_VC_PORT_STATUS_TABLE 0x00000001
#define PCI_VC_RES_CAP 16
+#define PCI_VC_RES_CAP_32_PHASE 0x00000002
+#define PCI_VC_RES_CAP_64_PHASE 0x00000004
+#define PCI_VC_RES_CAP_128_PHASE 0x00000008
+#define PCI_VC_RES_CAP_128_PHASE_TB 0x00000010
+#define PCI_VC_RES_CAP_256_PHASE 0x00000020
+#define PCI_VC_RES_CAP_ARB_OFF 0xff000000
#define PCI_VC_RES_CTRL 20
+#define PCI_VC_RES_CTRL_LOAD_TABLE 0x00010000
+#define PCI_VC_RES_CTRL_ARB_SELECT 0x000e0000
+#define PCI_VC_RES_CTRL_ID 0x07000000
+#define PCI_VC_RES_CTRL_ENABLE 0x80000000
#define PCI_VC_RES_STATUS 26
+#define PCI_VC_RES_STATUS_TABLE 0x00000001
+#define PCI_VC_RES_STATUS_NEGO 0x00000002
#define PCI_CAP_VC_BASE_SIZEOF 0x10
#define PCI_CAP_VC_PER_VC_SIZEOF 0x0C