[PATCH v5 12/31] powernv/fadump: register kernel metadata address with opal

[Hari Bathini <hbathini@linux.ibm.com>]

OPAL allows registering address with it in the first kernel and
retrieving it after MPIPL. Setup kernel metadata and register its
address with OPAL to use it for processing the crash dump.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
---
 arch/powerpc/kernel/fadump-common.h          |    4 +
 arch/powerpc/kernel/fadump.c                 |   53 +++++++++++-----
 arch/powerpc/platforms/powernv/opal-fadump.c |   86 ++++++++++++++++++++++++++
 arch/powerpc/platforms/powernv/opal-fadump.h |   33 ++++++++++
 arch/powerpc/platforms/pseries/rtas-fadump.c |   18 +++++
 5 files changed, 174 insertions(+), 20 deletions(-)
 create mode 100644 arch/powerpc/platforms/powernv/opal-fadump.h

diff --git a/arch/powerpc/kernel/fadump-common.h b/arch/powerpc/kernel/fadump-common.h
index f6c52d3..0acf412 100644
--- a/arch/powerpc/kernel/fadump-common.h
+++ b/arch/powerpc/kernel/fadump-common.h
@@ -100,6 +100,8 @@ struct fw_dump {
 	unsigned long	cpu_notes_buf;
 	unsigned long	cpu_notes_buf_size;
 
+	u64		kernel_metadata;
+
 	int		ibm_configure_kernel_dump;
 
 	unsigned long	fadump_enabled:1;
@@ -113,6 +115,8 @@ struct fw_dump {
 
 struct fadump_ops {
 	ulong	(*fadump_init_mem_struct)(struct fw_dump *fadump_config);
+	ulong	(*fadump_get_metadata_size)(void);
+	int	(*fadump_setup_metadata)(struct fw_dump *fadump_config);
 	int	(*fadump_register)(struct fw_dump *fadump_config);
 	int	(*fadump_unregister)(struct fw_dump *fadump_config);
 	int	(*fadump_invalidate)(struct fw_dump *fadump_config);
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index b8061fb9..a086a09 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -258,6 +258,9 @@ static unsigned long get_fadump_area_size(void)
 	size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
 
 	size = PAGE_ALIGN(size);
+
+	/* This is to hold kernel metadata on platforms that support it */
+	size += fw_dump.ops->fadump_get_metadata_size();
 	return size;
 }
 
@@ -283,17 +286,17 @@ static void __init fadump_reserve_crash_area(unsigned long base,
 
 int __init fadump_reserve_mem(void)
 {
+	int ret = 1;
 	unsigned long base, size, memory_boundary;
 
 	if (!fw_dump.fadump_enabled)
 		return 0;
 
 	if (!fw_dump.fadump_supported) {
-		printk(KERN_INFO "Firmware-assisted dump is not supported on"
-				" this hardware\n");
-		fw_dump.fadump_enabled = 0;
-		return 0;
+		pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
+		goto error_out;
 	}
+
 	/*
 	 * Initialize boot memory size
 	 * If dump is active then we have already calculated the size during
@@ -330,6 +333,7 @@ int __init fadump_reserve_mem(void)
 	else
 		memory_boundary = memblock_end_of_DRAM();
 
+	base = fw_dump.boot_memory_size;
 	size = get_fadump_area_size();
 	fw_dump.reserve_dump_area_size = size;
 	if (fw_dump.dump_active) {
@@ -349,7 +353,6 @@ int __init fadump_reserve_mem(void)
 		 * dump is written to disk by userspace tool. This memory
 		 * will be released for general use once the dump is saved.
 		 */
-		base = fw_dump.boot_memory_size;
 		size = memory_boundary - base;
 		fadump_reserve_crash_area(base, size);
 
@@ -363,29 +366,43 @@ int __init fadump_reserve_mem(void)
 		 * use memblock_find_in_range() here since it doesn't allocate
 		 * from bottom to top.
 		 */
-		for (base = fw_dump.boot_memory_size;
-		     base <= (memory_boundary - size);
-		     base += size) {
+		while (base <= (memory_boundary - size)) {
 			if (memblock_is_region_memory(base, size) &&
 			    !memblock_is_region_reserved(base, size))
 				break;
+
+			base += size;
 		}
-		if ((base > (memory_boundary - size)) ||
-		    memblock_reserve(base, size)) {
+
+		if (base > (memory_boundary - size)) {
+			pr_err("Failed to find memory chunk for reservation\n");
+			goto error_out;
+		}
+		fw_dump.reserve_dump_area_start = base;
+
+		/*
+		 * Calculate the kernel metadata address and register it with
+		 * f/w if the platform supports.
+		 */
+		if (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0)
+			goto error_out;
+
+		if (memblock_reserve(base, size)) {
 			pr_err("Failed to reserve memory\n");
-			return 0;
+			goto error_out;
 		}
 
-		pr_info("Reserved %ldMB of memory at %ldMB for firmware-"
-			"assisted dump (System RAM: %ldMB)\n",
-			(unsigned long)(size >> 20),
-			(unsigned long)(base >> 20),
+		pr_info("Reserved %ldMB of memory at %#016lx (System RAM: %ldMB)\n",
+			(unsigned long)(size >> 20), base,
 			(unsigned long)(memblock_phys_mem_size() >> 20));
 
-		fw_dump.reserve_dump_area_start = base;
-		return fadump_cma_init();
+		ret = fadump_cma_init();
 	}
-	return 1;
+
+	return ret;
+error_out:
+	fw_dump.fadump_enabled = 0;
+	return 0;
 }
 
 unsigned long __init arch_reserved_kernel_pages(void)
diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c
index e330877..e5c4700 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.c
+++ b/arch/powerpc/platforms/powernv/opal-fadump.c
@@ -13,14 +13,86 @@
 #include <linux/seq_file.h>
 #include <linux/of_fdt.h>
 #include <linux/libfdt.h>
+#include <linux/mm.h>
 
+#include <asm/page.h>
 #include <asm/opal.h>
 
 #include "../../kernel/fadump-common.h"
+#include "opal-fadump.h"
+
+static struct opal_fadump_mem_struct *opal_fdm;
+
+/* Initialize kernel metadata */
+static void opal_fadump_init_metadata(struct opal_fadump_mem_struct *fdm)
+{
+	fdm->version = OPAL_FADUMP_VERSION;
+	fdm->region_cnt = 0;
+	fdm->registered_regions = 0;
+	fdm->fadumphdr_addr = 0;
+}
 
 static ulong opal_fadump_init_mem_struct(struct fw_dump *fadump_conf)
 {
-	return fadump_conf->reserve_dump_area_start;
+	ulong addr = fadump_conf->reserve_dump_area_start;
+
+	opal_fdm = __va(fadump_conf->kernel_metadata);
+	opal_fadump_init_metadata(opal_fdm);
+
+	opal_fdm->region_cnt = 1;
+	opal_fdm->rgn[0].src	= RMA_START;
+	opal_fdm->rgn[0].dest	= addr;
+	opal_fdm->rgn[0].size	= fadump_conf->boot_memory_size;
+	addr += fadump_conf->boot_memory_size;
+
+	/*
+	 * Kernel metadata is passed to f/w and retrieved in capture kerenl.
+	 * So, use it to save fadump header address instead of calculating it.
+	 */
+	opal_fdm->fadumphdr_addr = (opal_fdm->rgn[0].dest +
+				    fadump_conf->boot_memory_size);
+
+	return addr;
+}
+
+static ulong opal_fadump_get_metadata_size(void)
+{
+	ulong size = sizeof(struct opal_fadump_mem_struct);
+
+	size = PAGE_ALIGN(size);
+	return size;
+}
+
+static int opal_fadump_setup_metadata(struct fw_dump *fadump_conf)
+{
+	int err = 0;
+	s64 ret;
+
+	/*
+	 * Use the last page(s) in FADump memory reservation for
+	 * kernel metadata.
+	 */
+	fadump_conf->kernel_metadata = (fadump_conf->reserve_dump_area_start +
+					fadump_conf->reserve_dump_area_size -
+					opal_fadump_get_metadata_size());
+	pr_info("Kernel metadata addr: %llx\n", fadump_conf->kernel_metadata);
+
+	/* Initialize kernel metadata before registering the address with f/w */
+	opal_fdm = __va(fadump_conf->kernel_metadata);
+	opal_fadump_init_metadata(opal_fdm);
+
+	/*
+	 * Register metadata address with f/w. Can be retrieved in
+	 * the capture kernel.
+	 */
+	ret = opal_mpipl_register_tag(OPAL_MPIPL_TAG_KERNEL,
+				      fadump_conf->kernel_metadata);
+	if (ret != OPAL_SUCCESS) {
+		pr_err("Failed to set kernel metadata tag!\n");
+		err = -EPERM;
+	}
+
+	return err;
 }
 
 static int opal_fadump_register(struct fw_dump *fadump_conf)
@@ -46,6 +118,16 @@ static int __init opal_fadump_process(struct fw_dump *fadump_conf)
 static void opal_fadump_region_show(struct fw_dump *fadump_conf,
 				    struct seq_file *m)
 {
+	int i;
+	const struct opal_fadump_mem_struct *fdm_ptr = opal_fdm;
+	u64 dumped_bytes = 0;
+
+	for (i = 0; i < fdm_ptr->region_cnt; i++) {
+		seq_printf(m, "DUMP: Src: %#016llx, Dest: %#016llx, ",
+			   fdm_ptr->rgn[i].src, fdm_ptr->rgn[i].dest);
+		seq_printf(m, "Size: %#llx, Dumped: %#llx bytes\n",
+			   fdm_ptr->rgn[i].size, dumped_bytes);
+	}
 }
 
 static void opal_fadump_trigger(struct fadump_crash_info_header *fdh,
@@ -63,6 +145,8 @@ static void opal_fadump_trigger(struct fadump_crash_info_header *fdh,
 
 static struct fadump_ops opal_fadump_ops = {
 	.fadump_init_mem_struct		= opal_fadump_init_mem_struct,
+	.fadump_get_metadata_size	= opal_fadump_get_metadata_size,
+	.fadump_setup_metadata		= opal_fadump_setup_metadata,
 	.fadump_register		= opal_fadump_register,
 	.fadump_unregister		= opal_fadump_unregister,
 	.fadump_invalidate		= opal_fadump_invalidate,
diff --git a/arch/powerpc/platforms/powernv/opal-fadump.h b/arch/powerpc/platforms/powernv/opal-fadump.h
new file mode 100644
index 0000000..19cac1f
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-fadump.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Firmware-Assisted Dump support on POWER platform (OPAL).
+ *
+ * Copyright 2019, IBM Corp.
+ * Author: Hari Bathini <hbathini@linux.ibm.com>
+ */
+
+#ifndef __PPC64_OPAL_FA_DUMP_H__
+#define __PPC64_OPAL_FA_DUMP_H__
+
+/* OPAL FADump structure format version */
+#define OPAL_FADUMP_VERSION			0x1
+
+/* Maximum number of memory regions kernel supports */
+#define OPAL_FADUMP_MAX_MEM_REGS		128
+
+/*
+ * FADump memory structure for storing kernel metadata needed to
+ * register-for/process crash dump. The address of this structure will
+ * be registered with f/w for retrieving during crash dump.
+ */
+struct opal_fadump_mem_struct {
+
+	u8	version;
+	u8	reserved[3];
+	u16	region_cnt;		/* number of regions */
+	u16	registered_regions;	/* Regions registered for MPIPL */
+	u64	fadumphdr_addr;
+	struct opal_mpipl_region	rgn[OPAL_FADUMP_MAX_MEM_REGS];
+} __attribute__((packed));
+
+#endif /* __PPC64_OPAL_FA_DUMP_H__ */
diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.c b/arch/powerpc/platforms/pseries/rtas-fadump.c
index 2b94392..4111ee9 100644
--- a/arch/powerpc/platforms/pseries/rtas-fadump.c
+++ b/arch/powerpc/platforms/pseries/rtas-fadump.c
@@ -121,6 +121,21 @@ static ulong rtas_fadump_init_mem_struct(struct fw_dump *fadump_conf)
 	return addr;
 }
 
+/*
+ * On this platform, the metadata struture is passed while registering
+ * for FADump and the same is returned by f/w in capture kernel.
+ * No additional provision to setup kernel metadata separately.
+ */
+static ulong rtas_fadump_get_metadata_size(void)
+{
+	return 0;
+}
+
+static int rtas_fadump_setup_metadata(struct fw_dump *fadump_conf)
+{
+	return 0;
+}
+
 static int rtas_fadump_register(struct fw_dump *fadump_conf)
 {
 	int rc, err = -EIO;
@@ -486,9 +501,10 @@ static void rtas_fadump_trigger(struct fadump_crash_info_header *fdh,
 	rtas_os_term((char *)msg);
 }
 
-
 static struct fadump_ops rtas_fadump_ops = {
 	.fadump_init_mem_struct		= rtas_fadump_init_mem_struct,
+	.fadump_get_metadata_size	= rtas_fadump_get_metadata_size,
+	.fadump_setup_metadata		= rtas_fadump_setup_metadata,
 	.fadump_register		= rtas_fadump_register,
 	.fadump_unregister		= rtas_fadump_unregister,
 	.fadump_invalidate		= rtas_fadump_invalidate,