[RFC PATCH v2 03/21][SeaBIOS] acpi-dsdt: Implement functions for memory hotplug

[Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>]

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.

Signed-off-by: Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>
---
 src/acpi-dsdt.dsl |   70 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/src/acpi-dsdt.dsl b/src/acpi-dsdt.dsl
index 2060686..5d3e92b 100644
--- a/src/acpi-dsdt.dsl
+++ b/src/acpi-dsdt.dsl
@@ -737,6 +737,71 @@ DefinitionBlock (
             }
             Return(One)
         }
+        /* 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
+        }
+ 
+        /* Memory eject byte */
+        OperationRegion(MEMJ, SystemIO, 0xafa0, 1)
+        Field (MEMJ, ByteAcc, NoLock, Preserve)
+        {
+            MPE, 8
+        }
+        
+        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)
+                    } Else {
+                        MTFY(Local0, 3)
+                    }
+                }
+                Increment(Local0)
+            }
+            Return(One)
+        }
+
+        Method (MPEJ, 2, NotSerialized) {
+            // _EJ0 method - eject callback
+            Store(Arg0, MPE)
+            Sleep(200)
+        }
     }
 
 
@@ -759,8 +824,9 @@ DefinitionBlock (
             // CPU hotplug event
             Return(\_SB.PRSC())
         }
-        Method(_L03) {
-            Return(0x01)
+        Method(_E03) {
+            // Memory hotplug event
+            Return(\_SB.MESC())
         }
         Method(_L04) {
             Return(0x01)
-- 
1.7.9