Move code that supports processing the crash'ed kernel's memory
preserved by firmware to platform specific callback functions.

Signed-off-by: Hari Bathini <hbath...@linux.ibm.com>
---
 arch/powerpc/kernel/fadump-common.h          |    6 
 arch/powerpc/kernel/fadump.c                 |  340 +-------------------------
 arch/powerpc/platforms/pseries/rtas-fadump.c |  278 +++++++++++++++++++++
 3 files changed, 299 insertions(+), 325 deletions(-)

diff --git a/arch/powerpc/kernel/fadump-common.h 
b/arch/powerpc/kernel/fadump-common.h
index 273247d..0231a0b 100644
--- a/arch/powerpc/kernel/fadump-common.h
+++ b/arch/powerpc/kernel/fadump-common.h
@@ -100,6 +100,12 @@ struct fw_dump {
        /* cmd line option during boot */
        unsigned long   reserve_bootvar;
 
+       /*
+        * Start address of preserve area. This memory is reserved
+        * permanently (production or capture kernel) for FADump.
+        */
+       unsigned long   preserv_area_start;
+
        unsigned long   cpu_state_data_size;
        unsigned long   hpte_region_size;
        unsigned long   boot_memory_size;
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 650ebf8..e995db1 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -28,15 +28,12 @@
 #include <asm/debugfs.h>
 #include <asm/page.h>
 #include <asm/prom.h>
-#include <asm/rtas.h>
 #include <asm/fadump.h>
 #include <asm/setup.h>
 
 #include "fadump-common.h"
-#include "../platforms/pseries/rtas-fadump.h"
 
 static struct fw_dump fw_dump;
-static const struct rtas_fadump_mem_struct *fdm_active;
 
 static DEFINE_MUTEX(fadump_mutex);
 struct fad_crash_memory_ranges *crash_memory_ranges;
@@ -111,22 +108,13 @@ static int __init fadump_cma_init(void) { return 1; }
 int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
                                      int depth, void *data)
 {
-       int ret;
-
-       if (depth != 1 || strcmp(uname, "rtas") != 0)
+       if (depth != 1)
                return 0;
 
-       ret = rtas_fadump_dt_scan(&fw_dump, node);
+       if (strcmp(uname, "rtas") == 0)
+               return rtas_fadump_dt_scan(&fw_dump, node);
 
-       /*
-        * The 'ibm,kernel-dump' rtas node is present only if there is
-        * dump data waiting for us.
-        */
-       fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
-       if (fdm_active)
-               fw_dump.dump_active = 1;
-
-       return ret;
+       return 0;
 }
 
 /*
@@ -308,9 +296,7 @@ int __init fadump_reserve_mem(void)
         * If dump is active then we have already calculated the size during
         * first kernel.
         */
-       if (fdm_active)
-               fw_dump.boot_memory_size = 
be64_to_cpu(fdm_active->rmr_region.source_len);
-       else {
+       if (!fw_dump.dump_active) {
                fw_dump.boot_memory_size = fadump_calculate_reserve_size();
 #ifdef CONFIG_CMA
                if (!fw_dump.nocma)
@@ -320,6 +306,7 @@ int __init fadump_reserve_mem(void)
 #endif
        }
 
+       size = get_fadump_area_size();
        if (memory_limit)
                memory_boundary = memory_limit;
        else
@@ -346,15 +333,10 @@ int __init fadump_reserve_mem(void)
                size = memory_boundary - base;
                fadump_reserve_crash_area(base, size);
 
-               fw_dump.fadumphdr_addr =
-                               
be64_to_cpu(fdm_active->rmr_region.destination_address) +
-                               be64_to_cpu(fdm_active->rmr_region.source_len);
-               pr_debug("fadumphdr_addr = %pa\n", &fw_dump.fadumphdr_addr);
+               pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
                fw_dump.reserve_dump_area_start = base;
                fw_dump.reserve_dump_area_size = size;
        } else {
-               size = get_fadump_area_size();
-
                /*
                 * Reserve memory at an offset closer to bottom of the RAM to
                 * minimize the impact of memory hot-remove operation. We can't
@@ -469,218 +451,6 @@ void crash_fadump(struct pt_regs *regs, const char *str)
        fw_dump.ops->fadump_trigger(fdh, str);
 }
 
-#define GPR_MASK       0xffffff0000000000
-static inline int fadump_gpr_index(u64 id)
-{
-       int i = -1;
-       char str[3];
-
-       if ((id & GPR_MASK) == fadump_str_to_u64("GPR")) {
-               /* get the digits at the end */
-               id &= ~GPR_MASK;
-               id >>= 24;
-               str[2] = '\0';
-               str[1] = id & 0xff;
-               str[0] = (id >> 8) & 0xff;
-               sscanf(str, "%d", &i);
-               if (i > 31)
-                       i = -1;
-       }
-       return i;
-}
-
-static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
-                                                               u64 reg_val)
-{
-       int i;
-
-       i = fadump_gpr_index(reg_id);
-       if (i >= 0)
-               regs->gpr[i] = (unsigned long)reg_val;
-       else if (reg_id == fadump_str_to_u64("NIA"))
-               regs->nip = (unsigned long)reg_val;
-       else if (reg_id == fadump_str_to_u64("MSR"))
-               regs->msr = (unsigned long)reg_val;
-       else if (reg_id == fadump_str_to_u64("CTR"))
-               regs->ctr = (unsigned long)reg_val;
-       else if (reg_id == fadump_str_to_u64("LR"))
-               regs->link = (unsigned long)reg_val;
-       else if (reg_id == fadump_str_to_u64("XER"))
-               regs->xer = (unsigned long)reg_val;
-       else if (reg_id == fadump_str_to_u64("CR"))
-               regs->ccr = (unsigned long)reg_val;
-       else if (reg_id == fadump_str_to_u64("DAR"))
-               regs->dar = (unsigned long)reg_val;
-       else if (reg_id == fadump_str_to_u64("DSISR"))
-               regs->dsisr = (unsigned long)reg_val;
-}
-
-static struct rtas_fadump_reg_entry*
-fadump_read_registers(struct rtas_fadump_reg_entry *reg_entry, struct pt_regs 
*regs)
-{
-       memset(regs, 0, sizeof(struct pt_regs));
-
-       while (be64_to_cpu(reg_entry->reg_id) != fadump_str_to_u64("CPUEND")) {
-               fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
-                                       be64_to_cpu(reg_entry->reg_value));
-               reg_entry++;
-       }
-       reg_entry++;
-       return reg_entry;
-}
-
-/*
- * Read CPU state dump data and convert it into ELF notes.
- * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
- * used to access the data to allow for additional fields to be added without
- * affecting compatibility. Each list of registers for a CPU starts with
- * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
- * 8 Byte ASCII identifier and 8 Byte register value. The register entry
- * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
- * of register value. For more details refer to PAPR document.
- *
- * Only for the crashing cpu we ignore the CPU dump data and get exact
- * state from fadump crash info structure populated by first kernel at the
- * time of crash.
- */
-static int __init fadump_build_cpu_notes(const struct rtas_fadump_mem_struct 
*fdm)
-{
-       struct rtas_fadump_reg_save_area_header *reg_header;
-       struct rtas_fadump_reg_entry *reg_entry;
-       struct fadump_crash_info_header *fdh = NULL;
-       void *vaddr;
-       unsigned long addr;
-       u32 num_cpus, *note_buf;
-       struct pt_regs regs;
-       int i, rc = 0, cpu = 0;
-
-       if (!fdm->cpu_state_data.bytes_dumped)
-               return -EINVAL;
-
-       addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
-       vaddr = __va(addr);
-
-       reg_header = vaddr;
-       if (be64_to_cpu(reg_header->magic_number) !=
-           fadump_str_to_u64("REGSAVE")) {
-               printk(KERN_ERR "Unable to read register save area.\n");
-               return -ENOENT;
-       }
-       pr_debug("--------CPU State Data------------\n");
-       pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
-       pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
-
-       vaddr += be32_to_cpu(reg_header->num_cpu_offset);
-       num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
-       pr_debug("NumCpus     : %u\n", num_cpus);
-       vaddr += sizeof(u32);
-       reg_entry = (struct rtas_fadump_reg_entry *)vaddr;
-
-       /* Allocate buffer to hold cpu crash notes. */
-       fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
-       fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
-       note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
-       if (!note_buf) {
-               printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
-                       "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
-               return -ENOMEM;
-       }
-       fw_dump.cpu_notes_buf = __pa(note_buf);
-
-       pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
-                       (num_cpus * sizeof(note_buf_t)), note_buf);
-
-       if (fw_dump.fadumphdr_addr)
-               fdh = __va(fw_dump.fadumphdr_addr);
-
-       for (i = 0; i < num_cpus; i++) {
-               if (be64_to_cpu(reg_entry->reg_id) != 
fadump_str_to_u64("CPUSTRT")) {
-                       printk(KERN_ERR "Unable to read CPU state data\n");
-                       rc = -ENOENT;
-                       goto error_out;
-               }
-               /* Lower 4 bytes of reg_value contains logical cpu id */
-               cpu = be64_to_cpu(reg_entry->reg_value) & 
RTAS_FADUMP_CPU_ID_MASK;
-               if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
-                       RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry);
-                       continue;
-               }
-               pr_debug("Reading register data for cpu %d...\n", cpu);
-               if (fdh && fdh->crashing_cpu == cpu) {
-                       regs = fdh->regs;
-                       note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
-                       RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry);
-               } else {
-                       reg_entry++;
-                       reg_entry = fadump_read_registers(reg_entry, &regs);
-                       note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
-               }
-       }
-       final_note(note_buf);
-
-       if (fdh) {
-               addr = fdh->elfcorehdr_addr;
-               pr_debug("Updating elfcore header(%lx) with cpu notes\n", addr);
-               fadump_update_elfcore_header(&fw_dump, (char *)__va(addr));
-       }
-       return 0;
-
-error_out:
-       fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
-                                       fw_dump.cpu_notes_buf_size);
-       fw_dump.cpu_notes_buf = 0;
-       fw_dump.cpu_notes_buf_size = 0;
-       return rc;
-
-}
-
-/*
- * Validate and process the dump data stored by firmware before exporting
- * it through '/proc/vmcore'.
- */
-static int __init process_fadump(const struct rtas_fadump_mem_struct 
*fdm_active)
-{
-       struct fadump_crash_info_header *fdh;
-       int rc = 0;
-
-       if (!fdm_active || !fw_dump.fadumphdr_addr)
-               return -EINVAL;
-
-       /* Check if the dump data is valid. */
-       if ((be16_to_cpu(fdm_active->header.dump_status_flag) == 
RTAS_FADUMP_ERROR_FLAG) ||
-                       (fdm_active->cpu_state_data.error_flags != 0) ||
-                       (fdm_active->rmr_region.error_flags != 0)) {
-               printk(KERN_ERR "Dump taken by platform is not valid\n");
-               return -EINVAL;
-       }
-       if ((fdm_active->rmr_region.bytes_dumped !=
-                       fdm_active->rmr_region.source_len) ||
-                       !fdm_active->cpu_state_data.bytes_dumped) {
-               printk(KERN_ERR "Dump taken by platform is incomplete\n");
-               return -EINVAL;
-       }
-
-       /* Validate the fadump crash info header */
-       fdh = __va(fw_dump.fadumphdr_addr);
-       if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
-               printk(KERN_ERR "Crash info header is not valid.\n");
-               return -EINVAL;
-       }
-
-       rc = fadump_build_cpu_notes(fdm_active);
-       if (rc)
-               return rc;
-
-       /*
-        * We are done validating dump info and elfcore header is now ready
-        * to be exported. set elfcorehdr_addr so that vmcore module will
-        * export the elfcore header through '/proc/vmcore'.
-        */
-       elfcorehdr_addr = fdh->elfcorehdr_addr;
-
-       return 0;
-}
-
 static void free_crash_memory_ranges(void)
 {
        kfree(crash_memory_ranges);
@@ -970,7 +740,6 @@ static unsigned long init_fadump_header(unsigned long addr)
        if (!addr)
                return 0;
 
-       fw_dump.fadumphdr_addr = addr;
        fdh = __va(addr);
        addr += sizeof(struct fadump_crash_info_header);
 
@@ -1014,39 +783,12 @@ static int register_fadump(void)
        return fw_dump.ops->register_fadump(&fw_dump);
 }
 
-static int fadump_invalidate_dump(const struct rtas_fadump_mem_struct *fdm)
-{
-       int rc = 0;
-       unsigned int wait_time;
-
-       pr_debug("Invalidating firmware-assisted dump registration\n");
-
-       /* TODO: Add upper time limit for the delay */
-       do {
-               rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
-                       FADUMP_INVALIDATE, fdm,
-                       sizeof(struct rtas_fadump_mem_struct));
-
-               wait_time = rtas_busy_delay_time(rc);
-               if (wait_time)
-                       mdelay(wait_time);
-       } while (wait_time);
-
-       if (rc) {
-               pr_err("Failed to invalidate firmware-assisted dump 
registration. Unexpected error (%d).\n", rc);
-               return rc;
-       }
-       fw_dump.dump_active = 0;
-       fdm_active = NULL;
-       return 0;
-}
-
 void fadump_cleanup(void)
 {
        /* Invalidate the registration only if dump is active. */
        if (fw_dump.dump_active) {
-               /* pass the same memory dump structure provided by platform */
-               fadump_invalidate_dump(fdm_active);
+               pr_debug("Invalidating firmware-assisted dump registration\n");
+               fw_dump.ops->invalidate_fadump(&fw_dump);
        } else if (fw_dump.dump_registered) {
                /* Un-register Firmware-assisted dump if it was registered. */
                fw_dump.ops->unregister_fadump(&fw_dump);
@@ -1132,7 +874,7 @@ static void fadump_invalidate_release_mem(void)
                return;
        }
 
-       destination_address = 
be64_to_cpu(fdm_active->cpu_state_data.destination_address);
+       destination_address = fw_dump.preserv_area_start;
        fadump_cleanup();
        mutex_unlock(&fadump_mutex);
 
@@ -1158,6 +900,7 @@ static void fadump_invalidate_release_mem(void)
                fw_dump.cpu_notes_buf = 0;
                fw_dump.cpu_notes_buf_size = 0;
        }
+
        /* Initialize the kernel dump memory structure for FAD registration. */
        fw_dump.ops->init_fadump_mem_struct(&fw_dump);
 }
@@ -1210,7 +953,7 @@ static ssize_t fadump_register_store(struct kobject *kobj,
        int ret = 0;
        int input = -1;
 
-       if (!fw_dump.fadump_enabled || fdm_active)
+       if (!fw_dump.fadump_enabled || fw_dump.dump_active)
                return -EPERM;
 
        if (kstrtoint(buf, 0, &input))
@@ -1223,7 +966,9 @@ static ssize_t fadump_register_store(struct kobject *kobj,
                if (fw_dump.dump_registered == 0) {
                        goto unlock_out;
                }
+
                /* Un-register Firmware-assisted dump */
+               pr_debug("Un-register firmware-assisted dump\n");
                fw_dump.ops->unregister_fadump(&fw_dump);
                break;
        case 1:
@@ -1246,63 +991,13 @@ static ssize_t fadump_register_store(struct kobject 
*kobj,
 
 static int fadump_region_show(struct seq_file *m, void *private)
 {
-       const struct rtas_fadump_mem_struct *fdm_ptr;
-
        if (!fw_dump.fadump_enabled)
                return 0;
 
        mutex_lock(&fadump_mutex);
-       if (fdm_active)
-               fdm_ptr = fdm_active;
-       else {
-               mutex_unlock(&fadump_mutex);
-               fw_dump.ops->fadump_region_show(&fw_dump, m);
-               return 0;
-       }
+       fw_dump.ops->fadump_region_show(&fw_dump, m);
+       mutex_unlock(&fadump_mutex);
 
-       seq_printf(m,
-                       "CPU : [%#016llx-%#016llx] %#llx bytes, "
-                       "Dumped: %#llx\n",
-                       
be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
-                       
be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
-                       be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
-                       be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
-                       be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
-       seq_printf(m,
-                       "HPTE: [%#016llx-%#016llx] %#llx bytes, "
-                       "Dumped: %#llx\n",
-                       be64_to_cpu(fdm_ptr->hpte_region.destination_address),
-                       be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
-                       be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
-                       be64_to_cpu(fdm_ptr->hpte_region.source_len),
-                       be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
-       seq_printf(m,
-                       "DUMP: [%#016llx-%#016llx] %#llx bytes, "
-                       "Dumped: %#llx\n",
-                       be64_to_cpu(fdm_ptr->rmr_region.destination_address),
-                       be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
-                       be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
-                       be64_to_cpu(fdm_ptr->rmr_region.source_len),
-                       be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
-
-       if (!fdm_active ||
-               (fw_dump.reserve_dump_area_start ==
-               be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
-               goto out;
-
-       /* Dump is active. Show reserved memory region. */
-       seq_printf(m,
-                       "    : [%#016llx-%#016llx] %#llx bytes, "
-                       "Dumped: %#llx\n",
-                       (unsigned long long)fw_dump.reserve_dump_area_start,
-                       
be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
-                       
be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
-                       fw_dump.reserve_dump_area_start,
-                       
be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
-                       fw_dump.reserve_dump_area_start);
-out:
-       if (fdm_active)
-               mutex_unlock(&fadump_mutex);
        return 0;
 }
 
@@ -1373,12 +1068,13 @@ int __init setup_fadump(void)
                 * if dump process fails then invalidate the registration
                 * and release memory before proceeding for re-registration.
                 */
-               if (process_fadump(fdm_active) < 0)
+               if (fw_dump.ops->process_fadump(&fw_dump) < 0)
                        fadump_invalidate_release_mem();
        }
        /* Initialize the kernel dump memory structure for FAD registration. */
        else if (fw_dump.reserve_dump_area_size)
                fw_dump.ops->init_fadump_mem_struct(&fw_dump);
+
        fadump_init_files();
 
        return 1;
diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.c 
b/arch/powerpc/platforms/pseries/rtas-fadump.c
index 790a37d..7ce84f8 100644
--- a/arch/powerpc/platforms/pseries/rtas-fadump.c
+++ b/arch/powerpc/platforms/pseries/rtas-fadump.c
@@ -31,6 +31,7 @@
 #include "rtas-fadump.h"
 
 static struct rtas_fadump_mem_struct fdm;
+static const struct rtas_fadump_mem_struct *fdm_active;
 
 static void rtas_fadump_update_config(struct fw_dump *fadump_conf,
                                      const struct rtas_fadump_mem_struct *fdm)
@@ -40,6 +41,23 @@ static void rtas_fadump_update_config(struct fw_dump 
*fadump_conf,
 
        fadump_conf->fadumphdr_addr = (fadump_conf->boot_mem_dest_addr +
                                       fadump_conf->boot_memory_size);
+
+       /* Start address of preserve area (permanent reservation) */
+       fadump_conf->preserv_area_start =
+               be64_to_cpu(fdm->cpu_state_data.destination_address);
+       pr_debug("Preserve area start address: 0x%lx\n",
+                fadump_conf->preserv_area_start);
+}
+
+/*
+ * This function is called in the capture kernel to get configuration details
+ * setup in the first kernel and passed to the f/w.
+ */
+static void rtas_fadump_get_config(struct fw_dump *fadump_conf,
+                                  const struct rtas_fadump_mem_struct *fdm)
+{
+       fadump_conf->boot_memory_size = be64_to_cpu(fdm->rmr_region.source_len);
+       rtas_fadump_update_config(fadump_conf, fdm);
 }
 
 static ulong rtas_fadump_init_mem_struct(struct fw_dump *fadump_conf)
@@ -180,7 +198,196 @@ static int rtas_fadump_unregister_fadump(struct fw_dump 
*fadump_conf)
 
 static int rtas_fadump_invalidate_fadump(struct fw_dump *fadump_conf)
 {
-       return -EIO;
+       int rc;
+       unsigned int wait_time;
+
+       /* TODO: Add upper time limit for the delay */
+       do {
+               rc =  rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1,
+                               NULL, FADUMP_INVALIDATE, fdm_active,
+                               sizeof(struct rtas_fadump_mem_struct));
+
+               wait_time = rtas_busy_delay_time(rc);
+               if (wait_time)
+                       mdelay(wait_time);
+       } while (wait_time);
+
+       if (rc) {
+               pr_err("Failed to invalidate - unexpected error (%d).\n", rc);
+               return -EIO;
+       }
+
+       fadump_conf->dump_active = 0;
+       fdm_active = NULL;
+       return 0;
+}
+
+#define RTAS_FADUMP_GPR_MASK                   0xffffff0000000000
+static inline int rtas_fadump_gpr_index(u64 id)
+{
+       int i = -1;
+       char str[3];
+
+       if ((id & RTAS_FADUMP_GPR_MASK) == fadump_str_to_u64("GPR")) {
+               /* get the digits at the end */
+               id &= ~RTAS_FADUMP_GPR_MASK;
+               id >>= 24;
+               str[2] = '\0';
+               str[1] = id & 0xff;
+               str[0] = (id >> 8) & 0xff;
+               if (kstrtoint(str, 10, &i))
+                       i = -EINVAL;
+               if (i > 31)
+                       i = -1;
+       }
+       return i;
+}
+
+void rtas_fadump_set_regval(struct pt_regs *regs, u64 reg_id, u64 reg_val)
+{
+       int i;
+
+       i = rtas_fadump_gpr_index(reg_id);
+       if (i >= 0)
+               regs->gpr[i] = (unsigned long)reg_val;
+       else if (reg_id == fadump_str_to_u64("NIA"))
+               regs->nip = (unsigned long)reg_val;
+       else if (reg_id == fadump_str_to_u64("MSR"))
+               regs->msr = (unsigned long)reg_val;
+       else if (reg_id == fadump_str_to_u64("CTR"))
+               regs->ctr = (unsigned long)reg_val;
+       else if (reg_id == fadump_str_to_u64("LR"))
+               regs->link = (unsigned long)reg_val;
+       else if (reg_id == fadump_str_to_u64("XER"))
+               regs->xer = (unsigned long)reg_val;
+       else if (reg_id == fadump_str_to_u64("CR"))
+               regs->ccr = (unsigned long)reg_val;
+       else if (reg_id == fadump_str_to_u64("DAR"))
+               regs->dar = (unsigned long)reg_val;
+       else if (reg_id == fadump_str_to_u64("DSISR"))
+               regs->dsisr = (unsigned long)reg_val;
+}
+
+static struct rtas_fadump_reg_entry*
+rtas_fadump_read_regs(struct rtas_fadump_reg_entry *reg_entry,
+                     struct pt_regs *regs)
+{
+       memset(regs, 0, sizeof(struct pt_regs));
+
+       while (be64_to_cpu(reg_entry->reg_id) != fadump_str_to_u64("CPUEND")) {
+               rtas_fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
+                                      be64_to_cpu(reg_entry->reg_value));
+               reg_entry++;
+       }
+       reg_entry++;
+       return reg_entry;
+}
+
+/*
+ * Read CPU state dump data and convert it into ELF notes.
+ * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
+ * used to access the data to allow for additional fields to be added without
+ * affecting compatibility. Each list of registers for a CPU starts with
+ * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
+ * 8 Byte ASCII identifier and 8 Byte register value. The register entry
+ * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
+ * of register value. For more details refer to PAPR document.
+ *
+ * Only for the crashing cpu we ignore the CPU dump data and get exact
+ * state from fadump crash info structure populated by first kernel at the
+ * time of crash.
+ */
+static int __init rtas_fadump_build_cpu_notes(struct fw_dump *fadump_conf)
+{
+       struct rtas_fadump_reg_save_area_header *reg_header;
+       struct rtas_fadump_reg_entry *reg_entry;
+       struct fadump_crash_info_header *fdh = NULL;
+       void *vaddr;
+       unsigned long addr;
+       u32 num_cpus, *note_buf;
+       struct pt_regs regs;
+       int i, rc = 0, cpu = 0;
+
+       addr = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
+       vaddr = __va(addr);
+
+       reg_header = vaddr;
+       if (be64_to_cpu(reg_header->magic_number) !=
+           fadump_str_to_u64("REGSAVE")) {
+               pr_err("Unable to read register save area.\n");
+               return -ENOENT;
+       }
+
+       pr_debug("--------CPU State Data------------\n");
+       pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
+       pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
+
+       vaddr += be32_to_cpu(reg_header->num_cpu_offset);
+       num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
+       pr_debug("NumCpus     : %u\n", num_cpus);
+       vaddr += sizeof(u32);
+       reg_entry = (struct rtas_fadump_reg_entry *)vaddr;
+
+       /* Allocate buffer to hold cpu crash notes. */
+       fadump_conf->cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
+       fadump_conf->cpu_notes_buf_size =
+               PAGE_ALIGN(fadump_conf->cpu_notes_buf_size);
+       note_buf = fadump_cpu_notes_buf_alloc(fadump_conf->cpu_notes_buf_size);
+       if (!note_buf) {
+               pr_err("Failed to allocate 0x%lx bytes for cpu notes buffer\n",
+                      fadump_conf->cpu_notes_buf_size);
+               return -ENOMEM;
+       }
+       fadump_conf->cpu_notes_buf = __pa(note_buf);
+
+       pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
+                       (num_cpus * sizeof(note_buf_t)), note_buf);
+
+       if (fadump_conf->fadumphdr_addr)
+               fdh = __va(fadump_conf->fadumphdr_addr);
+
+       for (i = 0; i < num_cpus; i++) {
+               if (be64_to_cpu(reg_entry->reg_id) !=
+                   fadump_str_to_u64("CPUSTRT")) {
+                       pr_err("Unable to read CPU state data\n");
+                       rc = -ENOENT;
+                       goto error_out;
+               }
+               /* Lower 4 bytes of reg_value contains logical cpu id */
+               cpu = (be64_to_cpu(reg_entry->reg_value) &
+                      RTAS_FADUMP_CPU_ID_MASK);
+               if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
+                       RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry);
+                       continue;
+               }
+               pr_debug("Reading register data for cpu %d...\n", cpu);
+               if (fdh && fdh->crashing_cpu == cpu) {
+                       regs = fdh->regs;
+                       note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
+                       RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry);
+               } else {
+                       reg_entry++;
+                       reg_entry = rtas_fadump_read_regs(reg_entry, &regs);
+                       note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
+               }
+       }
+       final_note(note_buf);
+
+       if (fdh) {
+               pr_debug("Updating elfcore header (%llx) with cpu notes\n",
+                        fdh->elfcorehdr_addr);
+               fadump_update_elfcore_header(fadump_conf,
+                                            __va(fdh->elfcorehdr_addr));
+       }
+       return 0;
+
+error_out:
+       fadump_cpu_notes_buf_free((ulong)__va(fadump_conf->cpu_notes_buf),
+                                 fadump_conf->cpu_notes_buf_size);
+       fadump_conf->cpu_notes_buf = 0;
+       fadump_conf->cpu_notes_buf_size = 0;
+       return rc;
+
 }
 
 /*
@@ -189,15 +396,62 @@ static int rtas_fadump_invalidate_fadump(struct fw_dump 
*fadump_conf)
  */
 static int __init rtas_fadump_process_fadump(struct fw_dump *fadump_conf)
 {
-       return -EINVAL;
+       struct fadump_crash_info_header *fdh;
+       int rc = 0;
+
+       if (!fdm_active || !fadump_conf->fadumphdr_addr)
+               return -EINVAL;
+
+       /* Check if the dump data is valid. */
+       if ((be16_to_cpu(fdm_active->header.dump_status_flag) ==
+                       RTAS_FADUMP_ERROR_FLAG) ||
+                       (fdm_active->cpu_state_data.error_flags != 0) ||
+                       (fdm_active->rmr_region.error_flags != 0)) {
+               pr_err("Dump taken by platform is not valid\n");
+               return -EINVAL;
+       }
+       if ((fdm_active->rmr_region.bytes_dumped !=
+                       fdm_active->rmr_region.source_len) ||
+                       !fdm_active->cpu_state_data.bytes_dumped) {
+               pr_err("Dump taken by platform is incomplete\n");
+               return -EINVAL;
+       }
+
+       /* Validate the fadump crash info header */
+       fdh = __va(fadump_conf->fadumphdr_addr);
+       if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
+               pr_err("Crash info header is not valid.\n");
+               return -EINVAL;
+       }
+
+       if (!fdm_active->cpu_state_data.bytes_dumped)
+               return -EINVAL;
+
+       rc = rtas_fadump_build_cpu_notes(fadump_conf);
+       if (rc)
+               return rc;
+
+       /*
+        * We are done validating dump info and elfcore header is now ready
+        * to be exported. set elfcorehdr_addr so that vmcore module will
+        * export the elfcore header through '/proc/vmcore'.
+        */
+       elfcorehdr_addr = fdh->elfcorehdr_addr;
+
+       return 0;
 }
 
 static void rtas_fadump_region_show(struct fw_dump *fadump_conf,
                                    struct seq_file *m)
 {
-       const struct rtas_fadump_mem_struct *fdm_ptr = &fdm;
+       const struct rtas_fadump_mem_struct *fdm_ptr;
        const struct rtas_fadump_section *cpu_data_section;
 
+       if (fdm_active)
+               fdm_ptr = fdm_active;
+       else
+               fdm_ptr = &fdm;
+
        cpu_data_section = &(fdm_ptr->cpu_state_data);
        seq_printf(m, "CPU :[%#016llx-%#016llx] %#llx bytes, Dumped: %#llx\n",
                   be64_to_cpu(cpu_data_section->destination_address),
@@ -219,6 +473,12 @@ static void rtas_fadump_region_show(struct fw_dump 
*fadump_conf,
        seq_printf(m, "Size: %#llx, Dumped: %#llx bytes\n",
                   be64_to_cpu(fdm_ptr->rmr_region.source_len),
                   be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
+
+       /* Dump is active. Show reserved area start address. */
+       if (fdm_active) {
+               seq_printf(m, "\nMemory above %#016lx is reserved for saving 
crash dump\n",
+                          fadump_conf->reserve_dump_area_start);
+       }
 }
 
 static void rtas_fadump_trigger(struct fadump_crash_info_header *fdh,
@@ -228,6 +488,7 @@ static void rtas_fadump_trigger(struct 
fadump_crash_info_header *fdh,
        rtas_os_term((char *)msg);
 }
 
+
 static struct fadump_ops rtas_fadump_ops = {
        .init_fadump_mem_struct = rtas_fadump_init_mem_struct,
        .register_fadump        = rtas_fadump_register_fadump,
@@ -258,6 +519,17 @@ int __init rtas_fadump_dt_scan(struct fw_dump 
*fadump_conf, ulong node)
        fadump_conf->fadump_platform    = FADUMP_PLATFORM_PSERIES;
        fadump_conf->fadump_supported   = 1;
 
+       /*
+        * The 'ibm,kernel-dump' rtas node is present only if there is
+        * dump data waiting for us.
+        */
+       fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
+       if (fdm_active) {
+               pr_info("Firmware-assisted dump is active.\n");
+               fadump_conf->dump_active = 1;
+               rtas_fadump_get_config(fadump_conf, (void *)__pa(fdm_active));
+       }
+
        /* Get the sizes required to store dump data for the firmware provided
         * dump sections.
         * For each dump section type supported, a 32bit cell which defines

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