System reset IPI facility and Mambo implementation

Add an opal call OPAL_SIGNAL_SYSTEM_RESET which allows system reset
exceptions to be raised on other CPUs and act as an NMI IPI. There
is an initial simple Mambo implementation, but allowances are made
for a more complex hardware implementation.

This API is based on the POWER8 implementation from Alistair Popple.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[stewart@linux.vnet.ibm.com: minor RST fix]
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/doc/opal-api/opal-signal-system-reset-145.rst b/doc/opal-api/opal-signal-system-reset-145.rst
new file mode 100644
index 0000000..4c1ee93
--- /dev/null
+++ b/doc/opal-api/opal-signal-system-reset-145.rst
@@ -0,0 +1,44 @@
+OPAL_SIGNAL_SYSTEM_RESET
+========================
+::
+
+   int64_t signal_system_reset(int32_t cpu_nr);
+ 
+This OPAL call causes the specified cpu(s) to be reset to the system
+reset exception handler (0x100).
+
+The exact contents of system registers (e.g., SRR1 wakeup causes) may
+vary depending on implementation and should not be relied upon.
+
+Resetting active threads on the same core as this call is run may
+not be supported by some platforms. In that case, OPAL_PARTIAL will be
+returned and NONE of the interrupts will be delivered.
+
+Arguments
+---------
+::
+
+  int32_t cpu_nr
+    cpu_nr >= 0        The cpu server number of the target cpu to reset.
+    SYS_RESET_ALL (-1) All cpus should be reset.
+    SYS_RESET_ALL_OTHERS (-2) All but the current cpu should be reset.
+
+Returns
+-------
+OPAL_SUCCESS
+  The power down was updated successful.
+
+OPAL_PARAMETER
+  A parameter was incorrect.
+
+OPAL_HARDWARE
+  Hardware indicated failure during reset.
+
+OPAL_PARTIAL
+  Platform can not reset all requested CPUs at this time. This requires
+  platform-specific code to work around, otherwise to be treated as
+  failure. No CPUs are reset.
+
+OPAL_UNSUPPORTED
+  This processor/platform is not supported.
+