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>
diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c
index 766e21e..d2b149f 100644
--- a/drivers/misc/sgi-gru/grukservices.c
+++ b/drivers/misc/sgi-gru/grukservices.c
@@ -858,6 +858,29 @@
/* ---------------------- GRU DATA COPY FUNCTIONS ---------------------------*/
/*
+ * Load a DW from a global GPA. The GPA can be a memory or MMR address.
+ */
+int gru_read_gpa(unsigned long *value, unsigned long gpa)
+{
+ void *cb;
+ void *dsr;
+ int ret, iaa;
+
+ STAT(read_gpa);
+ if (gru_get_cpu_resources(GRU_NUM_KERNEL_DSR_BYTES, &cb, &dsr))
+ return MQE_BUG_NO_RESOURCES;
+ iaa = gpa >> 62;
+ gru_vload_phys(cb, gpa, gru_get_tri(dsr), iaa, IMA);
+ ret = gru_wait(cb);
+ if (ret == CBS_IDLE)
+ *value = *(unsigned long *)dsr;
+ gru_free_cpu_resources(cb, dsr);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gru_read_gpa);
+
+
+/*
* Copy a block of data using the GRU resources
*/
int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,