MSI: Blacklist PCI-E chipsets depending on Hypertransport MSI capability

Introduce msi_ht_cap_enabled() to check the MSI capability in the
Hypertransport configuration space.
It is used in a generic quirk quirk_msi_ht_cap() to check whether
MSI is enabled on hypertransport chipset, and a nVidia specific quirk
quirk_nvidia_ck804_msi_ht_cap() where two 2 HT MSI mappings have to
be checked.
Both quirks set the PCI_BUS_FLAGS_NO_MSI bus flag when MSI is disabled.

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 60 insertions, 0 deletions

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 8385b815ecb1..08cd86a6dd66 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1703,6 +1703,65 @@ static void __devinit quirk_disable_msi(struct pci_dev *dev)
         }
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8131_BRIDGE, quirk_disable_msi);
+
+/* Go through the list of Hypertransport capabilities and
+ * return 1 if a HT MSI capability is found and enabled */
+static int __devinit msi_ht_cap_enabled(struct pci_dev *dev)
+{
+        u8 pos;
+        int ttl;
+        for (pos = pci_find_capability(dev, PCI_CAP_ID_HT), ttl = 48;
+             pos && ttl;
+             pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_HT), ttl--) {
+                u32 cap_hdr;
+                /* MSI mapping section according to Hypertransport spec */
+                if (pci_read_config_dword(dev, pos, &cap_hdr) == 0
+                    && (cap_hdr & 0xf8000000) == 0xa8000000 /* MSI mapping */) {
+                        printk(KERN_INFO "PCI: Found HT MSI mapping on %s with capability %s\n",
+                               pci_name(dev), cap_hdr & 0x10000 ? "enabled" : "disabled");
+                        return (cap_hdr & 0x10000) != 0; /* MSI mapping cap enabled */
+                }
+        }
+        return 0;
+}
+
+/* Check the hypertransport MSI mapping to know whether MSI is enabled or not */
+static void __devinit quirk_msi_ht_cap(struct pci_dev *dev)
+{
+        if (dev->subordinate && !msi_ht_cap_enabled(dev)) {
+                printk(KERN_WARNING "PCI: MSI quirk detected. "
+                       "MSI disabled on chipset %s.\n",
+                       pci_name(dev));
+                dev->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
+        }
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_HT2000_PCIE,
+                        quirk_msi_ht_cap);
+
+/* The nVidia CK804 chipset may have 2 HT MSI mappings.
+ * MSI are supported if the MSI capability set in any of these mappings.
+ */
+static void __devinit quirk_nvidia_ck804_msi_ht_cap(struct pci_dev *dev)
+{
+        struct pci_dev *pdev;
+
+        if (!dev->subordinate)
+                return;
+
+        /* check HT MSI cap on this chipset and the root one.
+         * a single one having MSI is enough to be sure that MSI are supported.
+         */
+        pdev = pci_find_slot(dev->bus->number, 0);
+        if (dev->subordinate && !msi_ht_cap_enabled(dev)
+            && !msi_ht_cap_enabled(pdev)) {
+                printk(KERN_WARNING "PCI: MSI quirk detected. "
+                       "MSI disabled on chipset %s.\n",
+                       pci_name(dev));
+                dev->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
+        }
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_CK804_PCIE,
+                        quirk_nvidia_ck804_msi_ht_cap);
 #endif /* CONFIG_PCI_MSI */
 
 EXPORT_SYMBOL(pcie_mch_quirk);
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 6a1e09834559..b9e263adebab 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -1411,6 +1411,7 @@
 #define PCI_DEVICE_ID_SERVERWORKS_LE      0x0009
 #define PCI_DEVICE_ID_SERVERWORKS_GCNB_LE 0x0017
 #define PCI_DEVICE_ID_SERVERWORKS_EPB     0x0103
+#define PCI_DEVICE_ID_SERVERWORKS_HT2000_PCIE   0x0132
 #define PCI_DEVICE_ID_SERVERWORKS_OSB4    0x0200
 #define PCI_DEVICE_ID_SERVERWORKS_CSB5    0x0201
 #define PCI_DEVICE_ID_SERVERWORKS_CSB6    0x0203