[RFC PATCH v4 03/30] acpi-dsdt: Implement functions for memory hotplug

[Vasilis Liaskovitis]

Extend the DSDT to include methods for handling memory hot-add and hot-remove
notifications and memory device status requests. These functions are called
from the memory device SSDT methods.
---
 src/acpi-dsdt-mem-hotplug.dsl |   57 +++++++++++++++++++++++++++++++++++++++++
 src/acpi-dsdt.dsl             |    5 +++-
 2 files changed, 61 insertions(+), 1 deletions(-)
 create mode 100644 src/acpi-dsdt-mem-hotplug.dsl

diff --git a/src/acpi-dsdt-mem-hotplug.dsl b/src/acpi-dsdt-mem-hotplug.dsl
new file mode 100644
index 0000000..0e7ced3
--- /dev/null
+++ b/src/acpi-dsdt-mem-hotplug.dsl
@@ -0,0 +1,57 @@
+/****************************************************************
+ * Memory hotplug
+ ****************************************************************/
+
+Scope(_SB) {
+        /* Objects filled in by run-time generated SSDT */
+        External(MTFY, MethodObj)
+        External(MEON, PkgObj)
+
+        Method (CMST, 1, NotSerialized) {
+            // _STA method - return ON status of memdevice
+            // Local0 = MEON flag for this cpu
+            Store(DerefOf(Index(MEON, Arg0)), Local0)
+            If (Local0) { Return(0xF) } Else { Return(0x0) }
+        }
+
+        /* Memory hotplug notify array */
+        OperationRegion(MEST, SystemIO, 0xaf80, 32)
+        Field (MEST, ByteAcc, NoLock, Preserve)
+        {
+            MES, 256
+        }
+ 
+        Method(MESC, 0) {
+            // Local5 = active memdevice bitmap
+            Store (MES, Local5)
+            // Local2 = last read byte from bitmap
+            Store (Zero, Local2)
+            // Local0 = memory device iterator
+            Store (Zero, Local0)
+            While (LLess(Local0, SizeOf(MEON))) {
+                // Local1 = MEON flag for this memory device
+                Store(DerefOf(Index(MEON, Local0)), Local1)
+                If (And(Local0, 0x07)) {
+                    // Shift down previously read bitmap byte
+                    ShiftRight(Local2, 1, Local2)
+                } Else {
+                    // Read next byte from memdevice bitmap
+                    Store(DerefOf(Index(Local5, ShiftRight(Local0, 3))), Local2)
+                }
+                // Local3 = active state for this memory device
+                Store(And(Local2, 1), Local3)
+
+                If (LNotEqual(Local1, Local3)) {
+                    // State change - update MEON with new state
+                    Store(Local3, Index(MEON, Local0))
+                    // Do MEM notify
+                    If (LEqual(Local3, 1)) {
+                        MTFY(Local0, 1)
+                    }
+                }
+                Increment(Local0)
+            }
+            Return(One)
+        }
+
+}
diff --git a/src/acpi-dsdt.dsl b/src/acpi-dsdt.dsl
index 158f6b4..98c9413 100644
--- a/src/acpi-dsdt.dsl
+++ b/src/acpi-dsdt.dsl
@@ -294,6 +294,7 @@ DefinitionBlock (
     }

#include "acpi-dsdt-cpu-hotplug.dsl"
+#include "acpi-dsdt-mem-hotplug.dsl"

/****************************************************************
@@ -313,7 +314,9 @@ DefinitionBlock (
             // CPU hotplug event
             _SB.PRSC()
         }
-        Method(_L03) {
+        Method(_E03) {
+            // Memory hotplug event
+            _SB.MESC()
         }
         Method(_L04) {
         }