r8169: MSI support

It is currently limited to the tested 0x8136 and 0x8168. 8169sb/8110sb ought
to handle it as well where they support MSI.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Cc: Edward Hsu <edward_hsu@realtek.com.tw>
Tester-Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>

1 files changed, 44 insertions, 6 deletions

diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index 16ecba15830d..ee1c2743eab4 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -278,6 +278,7 @@ enum rtl_register_content {
         TxDMAShift = 8, /* DMA burst value (0-7) is shift this many bits */
 
         /* Config1 register p.24 */
+        MSIEnable       = (1 << 5),     /* Enable Message Signaled Interrupt */
         PMEnable        = (1 << 0),     /* Power Management Enable */
 
         /* Config2 register p. 25 */
@@ -383,6 +384,7 @@ struct ring_info {
 
 enum features {
         RTL_FEATURE_WOL = (1 << 0),
+        RTL_FEATURE_MSI = (1 << 1),
 };
 
 struct rtl8169_private {
@@ -1465,6 +1467,7 @@ static const struct rtl_cfg_info {
         unsigned int align;
         u16 intr_event;
         u16 napi_event;
+        unsigned msi;
 } rtl_cfg_infos [] = {
         [RTL_CFG_0] = {
                 .hw_start       = rtl_hw_start_8169,
@@ -1472,7 +1475,8 @@ static const struct rtl_cfg_info {
                 .align          = 0,
                 .intr_event     = SYSErr | LinkChg | RxOverflow |
                                   RxFIFOOver | TxErr | TxOK | RxOK | RxErr,
-                .napi_event     = RxFIFOOver | TxErr | TxOK | RxOK | RxOverflow
+                .napi_event     = RxFIFOOver | TxErr | TxOK | RxOK | RxOverflow,
+                .msi            = 0
         },
         [RTL_CFG_1] = {
                 .hw_start       = rtl_hw_start_8168,
@@ -1480,7 +1484,8 @@ static const struct rtl_cfg_info {
                 .align          = 8,
                 .intr_event     = SYSErr | LinkChg | RxOverflow |
                                   TxErr | TxOK | RxOK | RxErr,
-                .napi_event     = TxErr | TxOK | RxOK | RxOverflow
+                .napi_event     = TxErr | TxOK | RxOK | RxOverflow,
+                .msi            = RTL_FEATURE_MSI
         },
         [RTL_CFG_2] = {
                 .hw_start       = rtl_hw_start_8101,
@@ -1488,10 +1493,39 @@ static const struct rtl_cfg_info {
                 .align          = 8,
                 .intr_event     = SYSErr | LinkChg | RxOverflow | PCSTimeout |
                                   RxFIFOOver | TxErr | TxOK | RxOK | RxErr,
-                .napi_event     = RxFIFOOver | TxErr | TxOK | RxOK | RxOverflow
+                .napi_event     = RxFIFOOver | TxErr | TxOK | RxOK | RxOverflow,
+                .msi            = RTL_FEATURE_MSI
         }
 };
 
+/* Cfg9346_Unlock assumed. */
+static unsigned rtl_try_msi(struct pci_dev *pdev, void __iomem *ioaddr,
+                            const struct rtl_cfg_info *cfg)
+{
+        unsigned msi = 0;
+        u8 cfg2;
+
+        cfg2 = RTL_R8(Config2) & ~MSIEnable;
+        if (cfg->msi) {
+                if (pci_enable_msi(pdev)) {
+                        dev_info(&pdev->dev, "no MSI. Back to INTx.\n");
+                } else {
+                        cfg2 |= MSIEnable;
+                        msi = RTL_FEATURE_MSI;
+                }
+        }
+        RTL_W8(Config2, cfg2);
+        return msi;
+}
+
+static void rtl_disable_msi(struct pci_dev *pdev, struct rtl8169_private *tp)
+{
+        if (tp->features & RTL_FEATURE_MSI) {
+                pci_disable_msi(pdev);
+                tp->features &= ~RTL_FEATURE_MSI;
+        }
+}
+
 static int __devinit
 rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
@@ -1627,6 +1661,7 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
         RTL_W8(Cfg9346, Cfg9346_Unlock);
         RTL_W8(Config1, RTL_R8(Config1) | PMEnable);
         RTL_W8(Config5, RTL_R8(Config5) & PMEStatus);
+        tp->features |= rtl_try_msi(pdev, ioaddr, cfg);
         RTL_W8(Cfg9346, Cfg9346_Lock);
 
         if (RTL_R8(PHYstatus) & TBI_Enable) {
@@ -1694,7 +1729,7 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
         rc = register_netdev(dev);
         if (rc < 0)
-                goto err_out_unmap_5;
+                goto err_out_msi_5;
 
         pci_set_drvdata(pdev, dev);
 
@@ -1717,7 +1752,8 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 out:
         return rc;
 
-err_out_unmap_5:
+err_out_msi_5:
+        rtl_disable_msi(pdev, tp);
         iounmap(ioaddr);
 err_out_free_res_4:
         pci_release_regions(pdev);
@@ -1738,6 +1774,7 @@ static void __devexit rtl8169_remove_one(struct pci_dev *pdev)
         flush_scheduled_work();
 
         unregister_netdev(dev);
+        rtl_disable_msi(pdev, tp);
         rtl8169_release_board(pdev, dev, tp->mmio_addr);
         pci_set_drvdata(pdev, NULL);
 }
@@ -1781,7 +1818,8 @@ static int rtl8169_open(struct net_device *dev)
 
         smp_mb();
 
-        retval = request_irq(dev->irq, rtl8169_interrupt, IRQF_SHARED,
+        retval = request_irq(dev->irq, rtl8169_interrupt,
+                             (tp->features & RTL_FEATURE_MSI) ? 0 : IRQF_SHARED,
                              dev->name, dev);
         if (retval < 0)
                 goto err_release_ring_2;