Implement hcall based RTAS for pSeries machines

On pSeries machines, operating systems can instantiate "RTAS" (Run-Time
Abstraction Services), a runtime component of the firmware which implements
a number of low-level, infrequently used operations.  On logical partitions
under a hypervisor, many of the RTAS functions require hypervisor
privilege.  For simplicity, therefore, hypervisor systems typically
implement the in-partition RTAS as just a tiny wrapper around a hypercall
which actually implements the various RTAS functions.

This patch implements such a hypercall based RTAS for our emulated pSeries
machine.  A tiny in-partition "firmware" calls a new hypercall, which
looks up available RTAS services in a table.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

3 files changed, 61 insertions, 0 deletions

diff --git a/pc-bios/spapr-rtas.bin b/pc-bios/spapr-rtas.bin
new file mode 100755
index 0000000..fc24c8e
--- /dev/null
+++ b/pc-bios/spapr-rtas.bin
diff --git a/pc-bios/spapr-rtas/Makefile b/pc-bios/spapr-rtas/Makefile
new file mode 100644
index 0000000..dc8b23e
--- /dev/null
+++ b/pc-bios/spapr-rtas/Makefile
@@ -0,0 +1,24 @@
+all: build-all
+# Dummy command so that make thinks it has done something
+	@true
+
+include ../../config-host.mak
+include $(SRC_PATH)/rules.mak
+
+$(call set-vpath, $(SRC_PATH)/pc-bios/spapr-rtas)
+
+.PHONY : all clean build-all
+
+#CFLAGS += -I$(SRC_PATH)
+#QEMU_CFLAGS = $(CFLAGS)
+
+build-all: spapr-rtas.bin
+
+%.img: %.o
+	$(call quiet-command,$(CC) -nostdlib -o $@ $<,"  Building $(TARGET_DIR)$@")
+
+%.bin: %.img
+	$(call quiet-command,$(OBJCOPY) -O binary -j .text $< $@,"  Building $(TARGET_DIR)$@")
+
+clean:
+	rm -f *.o *.d *.img *.bin *~
diff --git a/pc-bios/spapr-rtas/spapr-rtas.S b/pc-bios/spapr-rtas/spapr-rtas.S
new file mode 100644
index 0000000..903bec2
--- /dev/null
+++ b/pc-bios/spapr-rtas/spapr-rtas.S
@@ -0,0 +1,37 @@
+/*
+ * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
+ *
+ * Trivial in-partition RTAS implementation, based on a hypercall
+ *
+ * Copyright (c) 2010,2011 David Gibson, IBM Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#define KVMPPC_HCALL_BASE       0xf000
+#define KVMPPC_H_RTAS           (KVMPPC_HCALL_BASE + 0x0)
+
+.globl	_start
+_start:
+	mr	4,3
+	lis	3,KVMPPC_H_RTAS@h
+	ori	3,3,KVMPPC_H_RTAS@l
+	sc	1
+	blr