[Skiboot] [PATCH 2/2] core: Implement non-FSP dump region opal call

[Joel Stanley]

This provides an implementation of the OPAL_REGISTER_DUMP_REGION and
OPAL_UNREGISTER_DUMP_REGION calls that can be used by non-FSP systems,
and performs that registration for all astbmc platforms.

This pointer will be used by eg. pdbg to fetch the host kernel's log
buffer over FSI.

We unconditionally clear the value on a reboot (both fast-reboot and
reliable reboot) to reduce the chance of debug tools getting the wrong
buffer.

Signed-off-by: Joel Stanley <joel at jms.id.au>
---
 core/Makefile.inc         |  2 +-
 core/dump-region.c        | 61 +++++++++++++++++++++++++++++++++++++++
 core/init.c               |  2 ++
 include/dump.h            | 26 +++++++++++++++++
 platforms/astbmc/common.c |  4 +++
 5 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 core/dump-region.c
 create mode 100644 include/dump.h

diff --git a/core/Makefile.inc b/core/Makefile.inc
index d36350590edb..2d2f74778f4c 100644
--- a/core/Makefile.inc
+++ b/core/Makefile.inc
@@ -9,7 +9,7 @@ CORE_OBJS += vpd.o hostservices.o platform.o nvram.o nvram-format.o hmi.o
 CORE_OBJS += console-log.o ipmi.o time-utils.o pel.o pool.o errorlog.o
 CORE_OBJS += timer.o i2c.o rtc.o flash.o sensor.o ipmi-opal.o
 CORE_OBJS += flash-subpartition.o bitmap.o buddy.o pci-quirk.o powercap.o psr.o
-CORE_OBJS += pci-dt-slot.o direct-controls.o cpufeatures.o
+CORE_OBJS += pci-dt-slot.o direct-controls.o cpufeatures.o dump-region.o
 
 ifeq ($(SKIBOOT_GCOV),1)
 CORE_OBJS += gcov-profiling.o
diff --git a/core/dump-region.c b/core/dump-region.c
new file mode 100644
index 000000000000..6337e8bf0728
--- /dev/null
+++ b/core/dump-region.c
@@ -0,0 +1,61 @@
+/* Copyright 2018 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define pr_fmt(fmt) "DUMP: " fmt
+
+#include <opal.h>
+#include <skiboot.h>
+
+#include <dump.h>
+
+static int64_t bmc_opal_register_dump_region(uint32_t id,
+					     uint64_t addr, uint64_t size)
+{
+	if (id != OPAL_DUMP_REGION_LOG_BUF) {
+		prerror("Unsupported log region id %02x\n", id);
+		return OPAL_UNSUPPORTED;
+	}
+
+	if (size <= 0) {
+		prerror("Invalid log size %lld\n", size);
+		return OPAL_PARAMETER;
+	}
+
+	prlog(PR_INFO, "Registered log buf at 0x%016llx\n", addr);
+	debug_descriptor.log_buf_phys = addr;
+
+	return OPAL_SUCCESS;
+}
+
+static int64_t bmc_opal_unregister_dump_region(uint32_t id)
+{
+	if (id != OPAL_DUMP_REGION_LOG_BUF) {
+		prlog(PR_DEBUG, "Unsupported log region id %02x\n", id);
+		return OPAL_UNSUPPORTED;
+	}
+	prlog(PR_INFO, "Unregistered log buf\n");
+	debug_descriptor.log_buf_phys = 0;
+
+	return OPAL_SUCCESS;
+}
+
+void bmc_dump_region_init(void)
+{
+	opal_register(OPAL_REGISTER_DUMP_REGION,
+		      bmc_opal_register_dump_region, 3);
+	opal_register(OPAL_UNREGISTER_DUMP_REGION,
+		      bmc_opal_unregister_dump_region, 1);
+};
diff --git a/core/init.c b/core/init.c
index 3b887a24d11c..1ef7d800ae9a 100644
--- a/core/init.c
+++ b/core/init.c
@@ -563,6 +563,8 @@ void __noreturn load_and_boot_kernel(bool is_reboot)
 
 	mem_dump_free();
 
+	debug_descriptor.log_buf_phys = 0;
+
 	/* Take processours out of nap */
 	cpu_set_sreset_enable(false);
 	cpu_set_ipi_enable(false);
diff --git a/include/dump.h b/include/dump.h
new file mode 100644
index 000000000000..b629e66a85e6
--- /dev/null
+++ b/include/dump.h
@@ -0,0 +1,26 @@
+/* Copyright 2018 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __DUMP_H
+#define __DUMP_H
+
+/*
+ * Initialise dump region registration OPAL calls for bmc systems.
+ */
+void bmc_dump_region_init(void);
+
+#endif
+
diff --git a/platforms/astbmc/common.c b/platforms/astbmc/common.c
index eaebfde5f38e..82069c841cf4 100644
--- a/platforms/astbmc/common.c
+++ b/platforms/astbmc/common.c
@@ -26,6 +26,7 @@
 #include <bt.h>
 #include <errorlog.h>
 #include <lpc.h>
+#include <dump.h>
 
 #include "astbmc.h"
 
@@ -156,6 +157,9 @@ void astbmc_init(void)
 
 	/* Add BMC firmware info to device tree */
 	ipmi_dt_add_bmc_info();
+
+	/* Enable dump region OPAL calls */
+	bmc_dump_region_init();
 }
 
 int64_t astbmc_ipmi_power_down(uint64_t request)
-- 
2.17.0