IB/ipath: More changes to support InfiniPath on PowerPC 970 systems

Ordering of writethrough store buffers needs to be forced, and we need
to use ifdef to get writethrough behavior to InfiniPath buffers, because
there is no generic way to specify that at this time (similar to code
in char/drm/drm_vm.c and block/z2ram.c).

Signed-off-by: John Gregor <john.gregor@qlogic.com>
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

4 files changed, 66 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ipath/Makefile b/drivers/infiniband/hw/ipath/Makefile
index 6bb43474d10..075e313941f 100644
--- a/drivers/infiniband/hw/ipath/Makefile
+++ b/drivers/infiniband/hw/ipath/Makefile
@@ -20,6 +20,7 @@ ipath_core-y := \
         ipath_user_pages.o
 
 ipath_core-$(CONFIG_X86_64) += ipath_wc_x86_64.o
+ipath_core-$(CONFIG_PPC64) += ipath_wc_ppc64.o
 
 ib_ipath-y := \
         ipath_cq.o \
diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index f98518d912b..6ded914f9eb 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -440,7 +440,13 @@ static int __devinit ipath_init_one(struct pci_dev *pdev,
         }
         dd->ipath_pcirev = rev;
 
+#if defined(__powerpc__)
+        /* There isn't a generic way to specify writethrough mappings */
+        dd->ipath_kregbase = __ioremap(addr, len,
+                (_PAGE_NO_CACHE|_PAGE_WRITETHRU));
+#else
         dd->ipath_kregbase = ioremap_nocache(addr, len);
+#endif
 
         if (!dd->ipath_kregbase) {
                 ipath_dbg("Unable to map io addr %llx to kvirt, failing\n",
diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index bbaa70e57db..0b6e7679eef 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -985,6 +985,13 @@ static int mmap_piobufs(struct vm_area_struct *vma,
          * write combining behavior we want on the PIO buffers!
          */
 
+#if defined(__powerpc__)
+        /* There isn't a generic way to specify writethrough mappings */
+        pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
+        pgprot_val(vma->vm_page_prot) |= _PAGE_WRITETHRU;
+        pgprot_val(vma->vm_page_prot) &= ~_PAGE_GUARDED;
+#endif
+
         if (vma->vm_flags & VM_READ) {
                 dev_info(&dd->pcidev->dev,
                          "Can't map piobufs as readable (flags=%lx)\n",
diff --git a/drivers/infiniband/hw/ipath/ipath_wc_ppc64.c b/drivers/infiniband/hw/ipath/ipath_wc_ppc64.c
new file mode 100644
index 00000000000..036fde662aa
--- /dev/null
+++ b/drivers/infiniband/hw/ipath/ipath_wc_ppc64.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2006 QLogic, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * This file is conditionally built on PowerPC only.  Otherwise weak symbol
+ * versions of the functions exported from here are used.
+ */
+
+#include "ipath_kernel.h"
+
+/**
+ * ipath_unordered_wc - indicate whether write combining is ordered
+ *
+ * PowerPC systems (at least those in the 970 processor family)
+ * write partially filled store buffers in address order, but will write
+ * completely filled store buffers in "random" order, and therefore must
+ * have serialization for correctness with current InfiniPath chips.
+ *
+ */
+int ipath_unordered_wc(void)
+{
+        return 1;
+}