IB/hfi1: Fix bar0 mapping to use write combining

When the debugpat kernel boot flag is turned on the following
traces are printed:

[ 1884.793168] x86/PAT: Overlap at 0x90000000-0x92000000
[ 1884.803510] x86/PAT: reserve_memtype added [mem 0x91200000-0x9127ffff],
track uncached-minus, req write-combining, ret uncached-minus
[ 1884.818167] hfi1 0000:05:00.0: hfi1_0: WC Remapped RcvArray:
ffffc9000a980000

The ioremap_wc() clearly is not returning a write combining mapping due
to an overlap where the RcvArray is mapped in a uncached mapping prior
to creating the proposed write combining mapping.

The patch replaces the single base register for uncached CSRs that
used to overlap the RcvArray with two mappings.   One, kregbase1, from the
bar0 up to the RcvArray and another, kregbase2, from the end of the
RcvArray to the pio send buffer space.  A new dd field, base2_start,
is used to convert the zero-based offset in the CSR routines to the
correct kregbase1/kregbase2 mapping.  A single direct write of the
RcvArray CSRs is replaced with hfi1_put_tid() to insure correct access
using the new disjoint mapping.

Additionally, the kregend field is deleted since it is only ever written.

patdebug now shows the RcvArray as write combining:
[   35.688990] x86/PAT: reserve_memtype added [mem 0x91200000-0x9127ffff],
track write-combining, req write-combining, ret write-combining

To insulate from any potential issues with write combining, all
writeq are now flushed in hfi1_put_tid() and rcv_array_wc_fill().

Reviewed-by: Mitko Haralanov <mitko.haralanov@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 12 insertions, 8 deletions

diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index 62f843d7b099..2e5137b336ce 100644
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -867,12 +867,15 @@ struct hfi1_devdata {
 	struct device *diag_device;
 	struct device *ui_device;
 
-	/* mem-mapped pointer to base of chip regs */
-	u8 __iomem *kregbase;
-	/* end of mem-mapped chip space excluding sendbuf and user regs */
-	u8 __iomem *kregend;
-	/* physical address of chip for io_remap, etc. */
+	/* first mapping up to RcvArray */
+	u8 __iomem *kregbase1;
 	resource_size_t physaddr;
+
+	/* second uncached mapping from RcvArray to pio send buffers */
+	u8 __iomem *kregbase2;
+	/* for detecting offset above kregbase2 address */
+	u32 base2_start;
+
 	/* Per VL data. Enough for all VLs but not all elements are set/used. */
 	struct per_vl_data vld[PER_VL_SEND_CONTEXTS];
 	/* send context data */
@@ -1236,9 +1239,10 @@ static inline bool hfi1_vnic_is_rsm_full(struct hfi1_devdata *dd, int spare)
 #define dc8051_ver_patch(a) ((a) & 0x0000ff)
 
 /* f_put_tid types */
-#define PT_EXPECTED 0
-#define PT_EAGER    1
-#define PT_INVALID  2
+#define PT_EXPECTED       0
+#define PT_EAGER          1
+#define PT_INVALID_FLUSH  2
+#define PT_INVALID        3
 
 struct tid_rb_node;
 struct mmu_rb_node;