[Skiboot] [PATCH v8 11/24] MPIPL: Define OPAL metadata area

[Vasant Hegde]

We want to save some information (like crashing CPU PIR, kernel tags,
etc) before triggering MPIPL. Post MPIPL we will use this information
to retrieve dump metadata and create dump.

MDRT table doesn't need 64K. Hence split MDRT table to accommodate
metadata area.

Finally define metadata structure.

Signed-off-by: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>
---
 core/opal-dump.c    | 13 +++++++++++++
 include/mem-map.h   |  8 +++++++-
 include/opal-dump.h |  8 ++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/core/opal-dump.c b/core/opal-dump.c
index dc364fab1..ea9d00ead 100644
--- a/core/opal-dump.c
+++ b/core/opal-dump.c
@@ -37,6 +37,8 @@ static struct spira_ntuple *ntuple_mdst;
 static struct spira_ntuple *ntuple_mddt;
 static struct spira_ntuple *ntuple_mdrt;
 
+static struct mpipl_metadata    *mpipl_metadata;
+
 static int opal_mpipl_add_entry(u8 region, u64 src, u64 dest, u64 size)
 {
 	int i, max_cnt;
@@ -133,6 +135,17 @@ void opal_mpipl_init(void)
 	ntuple_mddt = &(spirah.ntuples.mdump_dst);
 	ntuple_mdrt = &(spirah.ntuples.mdump_res);
 
+	/* Get metadata area pointer */
+	mpipl_metadata = (void *)(DUMP_METADATA_AREA_BASE);
+
+	/* Clear OPAL metadata area */
+	if (sizeof(struct mpipl_metadata) > DUMP_METADATA_AREA_SIZE) {
+		prlog(PR_ERR, "INSUFFICIENT OPAL METADATA AREA\n");
+		prlog(PR_ERR, "INCREASE OPAL MEDTADATA AREA SIZE\n");
+		assert(false);
+	}
+	memset(mpipl_metadata, 0, sizeof(struct mpipl_metadata));
+
 	/* Clear MDST and MDDT table */
 	memset(mdst_base, 0, MDST_TABLE_SIZE);
 	ntuple_mdst->act_cnt = 0;
diff --git a/include/mem-map.h b/include/mem-map.h
index 0e03932a1..a29b8fb3e 100644
--- a/include/mem-map.h
+++ b/include/mem-map.h
@@ -106,7 +106,13 @@
  * memory after moving memory content from source to destination memory.
  */
 #define MDRT_TABLE_BASE		(SKIBOOT_BASE + 0x01c00000)
-#define MDRT_TABLE_SIZE		0x00010000
+#define MDRT_TABLE_SIZE		0x00008000
+
+/* This is our dump metadata area. We will use this memory to save metadata
+ * (like crashing CPU details, payload tags) before triggering MPIPL.
+ */
+#define DUMP_METADATA_AREA_BASE	(SKIBOOT_BASE + 0x01c08000)
+#define DUMP_METADATA_AREA_SIZE	0x8000
 
 /* Total size of the above area
  *
diff --git a/include/opal-dump.h b/include/opal-dump.h
index 0a86dcb1b..0838ee124 100644
--- a/include/opal-dump.h
+++ b/include/opal-dump.h
@@ -121,6 +121,14 @@ struct proc_reg_data {
 	uint64_t reg_val;
 } __packed;
 
+/* Metadata to capture before triggering MPIPL */
+struct mpipl_metadata {
+	/* Crashing PIR is required to create OPAL dump */
+	uint32_t	crashing_pir;
+	/* Kernel expects OPAL to presrve tag and pass it back via OPAL API */
+	uint64_t	kernel_tag;
+} __packed;
+
 /* init opal dump */
 extern void opal_mpipl_init(void);
 
-- 
2.14.3