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[v3,01/70] IB/qib: Use cache inhibitted and guarded mapping on powerpc

Message ID 1461936393-10131-1-git-send-email-mpe@ellerman.id.au (mailing list archive)
State Accepted
Headers show

Commit Message

Michael Ellerman April 29, 2016, 1:25 p.m. UTC 
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

The driver was requesting for a writethrough mapping. But with those
flags we will end up with an SAO mapping because we now have memory
conherence always enabled. ie, the existing mapping will end up with a
WIMG value 0b1110 which is Strong Access Order.

Update this to use cache inhibitted guarded mapping.

Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 drivers/infiniband/hw/qib/qib_file_ops.c | 5 +----
 drivers/infiniband/hw/qib/qib_pcie.c     | 6 ------
 2 files changed, 1 insertion(+), 10 deletions(-)

Comments

Michael Ellerman May 1, 2016, 1:02 p.m. UTC | #1 
On Fri, 2016-29-04 at 13:25:24 UTC, Michael Ellerman wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> 
> The driver was requesting for a writethrough mapping. But with those
> flags we will end up with an SAO mapping because we now have memory
> conherence always enabled. ie, the existing mapping will end up with a
> WIMG value 0b1110 which is Strong Access Order.
> 
> Update this to use cache inhibitted guarded mapping.
> 
> Cc: Doug Ledford <dledford@redhat.com>
> Cc: Sean Hefty <sean.hefty@intel.com>
> Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
> Cc: linux-rdma@vger.kernel.org
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Acked-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Applied to powerpc next.

https://git.kernel.org/powerpc/c/8ffb4103f5e28d7e7890ed4774

cheers
diff mbox

Patch

diff --git a/drivers/infiniband/hw/qib/qib_file_ops.c b/drivers/infiniband/hw/qib/qib_file_ops.c
index e449e394963f..a3d593f546ec 100644
--- a/drivers/infiniband/hw/qib/qib_file_ops.c
+++ b/drivers/infiniband/hw/qib/qib_file_ops.c
@@ -822,10 +822,7 @@  static int mmap_piobufs(struct vm_area_struct *vma,
 	phys = dd->physaddr + piobufs;
 
 #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;
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 #endif
 
 	/*
diff --git a/drivers/infiniband/hw/qib/qib_pcie.c b/drivers/infiniband/hw/qib/qib_pcie.c
index 4758a3801ae8..6abe1c621aa4 100644
--- a/drivers/infiniband/hw/qib/qib_pcie.c
+++ b/drivers/infiniband/hw/qib/qib_pcie.c
@@ -144,13 +144,7 @@  int qib_pcie_ddinit(struct qib_devdata *dd, struct pci_dev *pdev,
 	addr = pci_resource_start(pdev, 0);
 	len = pci_resource_len(pdev, 0);
 
-#if defined(__powerpc__)
-	/* There isn't a generic way to specify writethrough mappings */
-	dd->kregbase = __ioremap(addr, len, _PAGE_NO_CACHE | _PAGE_WRITETHRU);
-#else
 	dd->kregbase = ioremap_nocache(addr, len);
-#endif
-
 	if (!dd->kregbase)
 		return -ENOMEM;