core/cpu.c: Add OPAL call to setup Nest MMU

POWER9 has an off core MMU called the Nest MMU which allows other
units within a chip to perform address translations. The context and
setup for translations is handled by the requesting agents, however
the Nest MMU does need to know where in system memory the page tables
are located.

This patch adds a call to setup the Nest MMU page table pointer on a
per-chip basis.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/doc/opal-api/opal-nmmu-set-ptcr-127.txt b/doc/opal-api/opal-nmmu-set-ptcr-127.txt
new file mode 100644
index 0000000..eac13f3
--- /dev/null
+++ b/doc/opal-api/opal-nmmu-set-ptcr-127.txt
@@ -0,0 +1,22 @@
+OPAL_NMMU_SET_PTCR
+-------------------
+
+#define OPAL_NMMU_SET_PTCR			127
+
+int64 opal_nmmu_set_ptcr(uint64 chip_id, uint64_t ptcr)
+
+Arguments:
+
+  uint64 chip_id
+    either the chip id containing the nest mmu who's ptcr should be set
+    or alternatively -1ULL to indicate all nest mmu ptcr's should be set to
+    the same value.
+  uint64 ptcr
+    ptcr value pointing to either the radix tables or hash tables.
+
+This OPAL call sets up the Nest MMU by pointing it at the radix page
+table base or the hash page table base (HTABORG).
+
+Return Values:
+OPAL_SUCCESS: the power down was updated successful
+OPAL_PARAMETER: a parameter was incorrect