Re: [PATCH v2 09/16] powernv/fadump: process architected register state data provided by firmware

From: Hari Bathini <redacted>

Firmware provides architected register state data at the time of crash.
Process this data and build CPU notes to append to ELF core.

Signed-off-by: Hari Bathini <redacted>
Signed-off-by: Vasant Hegde <redacted>
---

Changes in v2:
* Updated reg type values according to recent OPAL changes


 arch/powerpc/include/asm/opal-api.h          |   23 +++
 arch/powerpc/kernel/fadump-common.h          |    3 
 arch/powerpc/platforms/powernv/opal-fadump.c |  187 ++++++++++++++++++++++++--
 arch/powerpc/platforms/powernv/opal-fadump.h |    4 +
 4 files changed, 206 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 75471c2..91f2735 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h

@@ -976,6 +976,29 @@ struct opal_sg_list {
  * Firmware-Assisted Dump (FADump)
  */
 
+/* FADump thread header for register entries */
+struct opal_fadump_thread_hdr {
+	__be32  pir;
+	/* 0x00 - 0x0F - The corresponding stop state of the core */
+	u8      core_state;
+	u8      reserved[3];
+
+	__be32	offset;	/* Offset to Register Entries array */
+	__be32	ecnt;	/* Number of entries */
+	__be32	esize;	/* Alloc size of each array entry in bytes */
+	__be32	eactsz;	/* Actual size of each array entry in bytes */
+} __packed;
+
+#define OPAL_REG_TYPE_GPR		0x01
+#define OPAL_REG_TYPE_SPR		0x02
+
+/* FADump register entry. */
+struct opal_fadump_reg_entry {
+	__be32		reg_type;
+	__be32		reg_num;
+	__be64		reg_val;
+};
+
 /* The maximum number of dump sections supported by OPAL */
 #define OPAL_FADUMP_NR_SECTIONS			64
 

diff --git a/arch/powerpc/kernel/fadump-common.h b/arch/powerpc/kernel/fadump-common.h
index ff764d4..8d47382 100644
--- a/arch/powerpc/kernel/fadump-common.h
+++ b/arch/powerpc/kernel/fadump-common.h

@@ -117,6 +117,9 @@ struct fadump_memory_range {
 
 /* Firmware-assisted dump configuration details. */
 struct fw_dump {
+	unsigned long	cpu_state_destination_addr;
+	unsigned long	cpu_state_data_version;
+	unsigned long	cpu_state_entry_size;
 	unsigned long	cpu_state_data_size;
 	unsigned long	hpte_region_size;
 	unsigned long	boot_memory_size;

diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c
index da8480d..853f663 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.c
+++ b/arch/powerpc/platforms/powernv/opal-fadump.c

@@ -94,6 +94,12 @@ static void update_fadump_config(struct fw_dump *fadump_conf,
 
 				last_end = base + size;
 				j++;
+			} else if (fdm->section[i].src_type ==
+				   OPAL_FADUMP_CPU_STATE_DATA) {
+				fadump_conf->cpu_state_destination_addr =
+					be64_to_cpu(fdm->section[i].dest_addr);
+				fadump_conf->cpu_state_data_size =
+					be64_to_cpu(fdm->section[i].dest_size);
 			}
 		}
 		fadump_conf->rmr_regions_cnt = j;

@@ -199,6 +205,75 @@ static int opal_invalidate_fadump(struct fw_dump *fadump_conf)
 	return 0;
 }
 
+static inline void fadump_set_regval_regnum(struct pt_regs *regs, u32 reg_type,
+					    u32 reg_num, u64 reg_val)
+{
+	if (reg_type == OPAL_REG_TYPE_GPR) {
+		if (reg_num < 32)
+			regs->gpr[reg_num] = reg_val;
+		return;
+	}
+
+	switch (reg_num) {
+	case 2000:
+		regs->nip = reg_val;
+		break;
+	case 2001:
+		regs->msr = reg_val;
+		break;
+	case 9:
+		regs->ctr = reg_val;
+		break;
+	case 8:
+		regs->link = reg_val;
+		break;
+	case 1:
+		regs->xer = reg_val;
+		break;
+	case 2002:
+		regs->ccr = reg_val;
+		break;
+	case 19:
+		regs->dar = reg_val;
+		break;
+	case 18:
+		regs->dsisr = reg_val;
+		break;