X86: uv: implement a gru_read_gpa kernel function

The BIOS has decided to store a pointer to the partition reserved page in
a scratch MMR.  The GRU is only able to read an MMR using a vload
instruction.  The gru_read_gpa() function will implemented.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/misc/sgi-gru/grukservices.h b/drivers/misc/sgi-gru/grukservices.h
index d60d34bca44d..02aa94d8484a 100644
--- a/drivers/misc/sgi-gru/grukservices.h
+++ b/drivers/misc/sgi-gru/grukservices.h
@@ -131,6 +131,20 @@ extern void *gru_get_next_message(struct gru_message_queue_desc *mqd);
 
 
 /*
+ * Read a GRU global GPA. Source can be located in a remote partition.
+ *
+ *    Input:
+ *      value           memory address where MMR value is returned
+ *      gpa             source numalink physical address of GPA
+ *
+ *    Output:
+ *      0               OK
+ *      >0              error
+ */
+int gru_read_gpa(unsigned long *value, unsigned long gpa);
+
+
+/*
  * Copy data using the GRU. Source or destination can be located in a remote
  * partition.
  *