4 files changed, 26 insertions, 42 deletions

diff --git a/drivers/infiniband/hw/ipath/Kconfig b/drivers/infiniband/hw/ipath/Kconfig
index 1d9bb115cbf6..8fe54ff00580 100644
--- a/drivers/infiniband/hw/ipath/Kconfig
+++ b/drivers/infiniband/hw/ipath/Kconfig
@@ -9,3 +9,6 @@ config INFINIBAND_IPATH
         as IP-over-InfiniBand as well as with userspace applications
         (in conjunction with InfiniBand userspace access).
         For QLogic PCIe QLE based cards, use the QIB driver instead.
+
+        If you have this hardware you will need to boot with PAT disabled
+        on your x86-64 systems, use the nopat kernel parameter.
diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index bd0caedafe99..2d7e503d13cb 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -42,6 +42,9 @@
 #include <linux/bitmap.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#ifdef CONFIG_X86_64
+#include <asm/pat.h>
+#endif
 
 #include "ipath_kernel.h"
 #include "ipath_verbs.h"
@@ -395,6 +398,14 @@ static int ipath_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
         unsigned long long addr;
         u32 bar0 = 0, bar1 = 0;
 
+#ifdef CONFIG_X86_64
+        if (WARN(pat_enabled(),
+                 "ipath needs PAT disabled, boot with nopat kernel parameter\n")) {
+                ret = -ENODEV;
+                goto bail;
+        }
+#endif
+
         dd = ipath_alloc_devdata(pdev);
         if (IS_ERR(dd)) {
                 ret = PTR_ERR(dd);
@@ -542,6 +553,7 @@ static int ipath_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
         dd->ipath_kregbase = __ioremap(addr, len,
                 (_PAGE_NO_CACHE|_PAGE_WRITETHRU));
 #else
+        /* XXX: split this properly to enable on PAT */
         dd->ipath_kregbase = ioremap_nocache(addr, len);
 #endif
 
@@ -587,12 +599,8 @@ static int ipath_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
         ret = ipath_enable_wc(dd);
 
-        if (ret) {
-                ipath_dev_err(dd, "Write combining not enabled "
-                              "(err %d): performance may be poor\n",
-                              -ret);
+        if (ret)
                 ret = 0;
-        }
 
         ipath_verify_pioperf(dd);
 
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index e08db7020cd4..f0f947122779 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -463,9 +463,7 @@ struct ipath_devdata {
         /* offset in HT config space of slave/primary interface block */
         u8 ipath_ht_slave_off;
         /* for write combining settings */
-        unsigned long ipath_wc_cookie;
-        unsigned long ipath_wc_base;
-        unsigned long ipath_wc_len;
+        int wc_cookie;
         /* ref count for each pkey */
         atomic_t ipath_pkeyrefs[4];
         /* shadow copy of struct page *'s for exp tid pages */
diff --git a/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c b/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
index 4ad0b932df1f..7b6e4c843e19 100644
--- a/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
+++ b/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
@@ -37,7 +37,6 @@
  */
 
 #include <linux/pci.h>
-#include <asm/mtrr.h>
 #include <asm/processor.h>
 
 #include "ipath_kernel.h"
@@ -122,27 +121,14 @@ int ipath_enable_wc(struct ipath_devdata *dd)
         }
 
         if (!ret) {
-                int cookie;
-                ipath_cdbg(VERBOSE, "Setting mtrr for chip to WC "
-                           "(addr %llx, len=0x%llx)\n",
-                           (unsigned long long) pioaddr,
-                           (unsigned long long) piolen);
-                cookie = mtrr_add(pioaddr, piolen, MTRR_TYPE_WRCOMB, 0);
-                if (cookie < 0) {
-                        {
-                                dev_info(&dd->pcidev->dev,
-                                         "mtrr_add()  WC for PIO bufs "
-                                         "failed (%d)\n",
-                                         cookie);
-                                ret = -EINVAL;
-                        }
-                } else {
-                        ipath_cdbg(VERBOSE, "Set mtrr for chip to WC, "
-                                   "cookie is %d\n", cookie);
-                        dd->ipath_wc_cookie = cookie;
-                        dd->ipath_wc_base = (unsigned long) pioaddr;
-                        dd->ipath_wc_len = (unsigned long) piolen;
-                }
+                dd->wc_cookie = arch_phys_wc_add(pioaddr, piolen);
+                if (dd->wc_cookie < 0) {
+                        ipath_dev_err(dd, "Seting mtrr failed on PIO buffers\n");
+                        ret = -ENODEV;
+                } else if (dd->wc_cookie == 0)
+                        ipath_cdbg(VERBOSE, "Set mtrr for chip to WC not needed\n");
+                else
+                        ipath_cdbg(VERBOSE, "Set mtrr for chip to WC\n");
         }
 
         return ret;
@@ -154,16 +140,5 @@ int ipath_enable_wc(struct ipath_devdata *dd)
  */
 void ipath_disable_wc(struct ipath_devdata *dd)
 {
-        if (dd->ipath_wc_cookie) {
-                int r;
-                ipath_cdbg(VERBOSE, "undoing WCCOMB on pio buffers\n");
-                r = mtrr_del(dd->ipath_wc_cookie, dd->ipath_wc_base,
-                             dd->ipath_wc_len);
-                if (r < 0)
-                        dev_info(&dd->pcidev->dev,
-                                 "mtrr_del(%lx, %lx, %lx) failed: %d\n",
-                                 dd->ipath_wc_cookie, dd->ipath_wc_base,
-                                 dd->ipath_wc_len, r);
-                dd->ipath_wc_cookie = 0; /* even on failure */
-        }
+        arch_phys_wc_del(dd->wc_cookie);
 }