1 files changed, 232 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index eb8f782afade..63857e183de5 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -32,6 +32,7 @@
 #include <linux/delay.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
+#include <linux/crash_dump.h>
 
 #include <asm/page.h>
 #include <asm/prom.h>
@@ -43,6 +44,8 @@ static struct fadump_mem_struct fdm;
 static const struct fadump_mem_struct *fdm_active;
 
 static DEFINE_MUTEX(fadump_mutex);
+struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
+int crash_mem_ranges;
 
 /* Scan the Firmware Assisted dump configuration details. */
 int __init early_init_dt_scan_fw_dump(unsigned long node,
@@ -235,6 +238,10 @@ static unsigned long get_fadump_area_size(void)
         size += fw_dump.cpu_state_data_size;
         size += fw_dump.hpte_region_size;
         size += fw_dump.boot_memory_size;
+        size += sizeof(struct fadump_crash_info_header);
+        size += sizeof(struct elfhdr); /* ELF core header.*/
+        /* Program headers for crash memory regions. */
+        size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
 
         size = PAGE_ALIGN(size);
         return size;
@@ -300,6 +307,12 @@ int __init fadump_reserve_mem(void)
                                 "for saving crash dump\n",
                                 (unsigned long)(size >> 20),
                                 (unsigned long)(base >> 20));
+
+                fw_dump.fadumphdr_addr =
+                                fdm_active->rmr_region.destination_address +
+                                fdm_active->rmr_region.source_len;
+                pr_debug("fadumphdr_addr = %p\n",
+                                (void *) fw_dump.fadumphdr_addr);
         } else {
                 /* Reserve the memory at the top of memory. */
                 size = get_fadump_area_size();
@@ -380,8 +393,210 @@ static void register_fw_dump(struct fadump_mem_struct *fdm)
         }
 }
 
+/*
+ * Validate and process the dump data stored by firmware before exporting
+ * it through '/proc/vmcore'.
+ */
+static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
+{
+        struct fadump_crash_info_header *fdh;
+
+        if (!fdm_active || !fw_dump.fadumphdr_addr)
+                return -EINVAL;
+
+        /* Check if the dump data is valid. */
+        if ((fdm_active->header.dump_status_flag == FADUMP_ERROR_FLAG) ||
+                        (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) {
+                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;
+        }
+
+        /*
+         * 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 inline void fadump_add_crash_memory(unsigned long long base,
+                                        unsigned long long end)
+{
+        if (base == end)
+                return;
+
+        pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
+                crash_mem_ranges, base, end - 1, (end - base));
+        crash_memory_ranges[crash_mem_ranges].base = base;
+        crash_memory_ranges[crash_mem_ranges].size = end - base;
+        crash_mem_ranges++;
+}
+
+static void fadump_exclude_reserved_area(unsigned long long start,
+                                        unsigned long long end)
+{
+        unsigned long long ra_start, ra_end;
+
+        ra_start = fw_dump.reserve_dump_area_start;
+        ra_end = ra_start + fw_dump.reserve_dump_area_size;
+
+        if ((ra_start < end) && (ra_end > start)) {
+                if ((start < ra_start) && (end > ra_end)) {
+                        fadump_add_crash_memory(start, ra_start);
+                        fadump_add_crash_memory(ra_end, end);
+                } else if (start < ra_start) {
+                        fadump_add_crash_memory(start, ra_start);
+                } else if (ra_end < end) {
+                        fadump_add_crash_memory(ra_end, end);
+                }
+        } else
+                fadump_add_crash_memory(start, end);
+}
+
+static int fadump_init_elfcore_header(char *bufp)
+{
+        struct elfhdr *elf;
+
+        elf = (struct elfhdr *) bufp;
+        bufp += sizeof(struct elfhdr);
+        memcpy(elf->e_ident, ELFMAG, SELFMAG);
+        elf->e_ident[EI_CLASS] = ELF_CLASS;
+        elf->e_ident[EI_DATA] = ELF_DATA;
+        elf->e_ident[EI_VERSION] = EV_CURRENT;
+        elf->e_ident[EI_OSABI] = ELF_OSABI;
+        memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
+        elf->e_type = ET_CORE;
+        elf->e_machine = ELF_ARCH;
+        elf->e_version = EV_CURRENT;
+        elf->e_entry = 0;
+        elf->e_phoff = sizeof(struct elfhdr);
+        elf->e_shoff = 0;
+        elf->e_flags = ELF_CORE_EFLAGS;
+        elf->e_ehsize = sizeof(struct elfhdr);
+        elf->e_phentsize = sizeof(struct elf_phdr);
+        elf->e_phnum = 0;
+        elf->e_shentsize = 0;
+        elf->e_shnum = 0;
+        elf->e_shstrndx = 0;
+
+        return 0;
+}
+
+/*
+ * Traverse through memblock structure and setup crash memory ranges. These
+ * ranges will be used create PT_LOAD program headers in elfcore header.
+ */
+static void fadump_setup_crash_memory_ranges(void)
+{
+        struct memblock_region *reg;
+        unsigned long long start, end;
+
+        pr_debug("Setup crash memory ranges.\n");
+        crash_mem_ranges = 0;
+        /*
+         * add the first memory chunk (RMA_START through boot_memory_size) as
+         * a separate memory chunk. The reason is, at the time crash firmware
+         * will move the content of this memory chunk to different location
+         * specified during fadump registration. We need to create a separate
+         * program header for this chunk with the correct offset.
+         */
+        fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
+
+        for_each_memblock(memory, reg) {
+                start = (unsigned long long)reg->base;
+                end = start + (unsigned long long)reg->size;
+                if (start == RMA_START && end >= fw_dump.boot_memory_size)
+                        start = fw_dump.boot_memory_size;
+
+                /* add this range excluding the reserved dump area. */
+                fadump_exclude_reserved_area(start, end);
+        }
+}
+
+static int fadump_create_elfcore_headers(char *bufp)
+{
+        struct elfhdr *elf;
+        struct elf_phdr *phdr;
+        int i;
+
+        fadump_init_elfcore_header(bufp);
+        elf = (struct elfhdr *)bufp;
+        bufp += sizeof(struct elfhdr);
+
+        /* setup PT_LOAD sections. */
+
+        for (i = 0; i < crash_mem_ranges; i++) {
+                unsigned long long mbase, msize;
+                mbase = crash_memory_ranges[i].base;
+                msize = crash_memory_ranges[i].size;
+
+                if (!msize)
+                        continue;
+
+                phdr = (struct elf_phdr *)bufp;
+                bufp += sizeof(struct elf_phdr);
+                phdr->p_type    = PT_LOAD;
+                phdr->p_flags   = PF_R|PF_W|PF_X;
+                phdr->p_offset  = mbase;
+
+                if (mbase == RMA_START) {
+                        /*
+                         * The entire RMA region will be moved by firmware
+                         * to the specified destination_address. Hence set
+                         * the correct offset.
+                         */
+                        phdr->p_offset = fdm.rmr_region.destination_address;
+                }
+
+                phdr->p_paddr = mbase;
+                phdr->p_vaddr = (unsigned long)__va(mbase);
+                phdr->p_filesz = msize;
+                phdr->p_memsz = msize;
+                phdr->p_align = 0;
+
+                /* Increment number of program headers. */
+                (elf->e_phnum)++;
+        }
+        return 0;
+}
+
+static unsigned long init_fadump_header(unsigned long addr)
+{
+        struct fadump_crash_info_header *fdh;
+
+        if (!addr)
+                return 0;
+
+        fw_dump.fadumphdr_addr = addr;
+        fdh = __va(addr);
+        addr += sizeof(struct fadump_crash_info_header);
+
+        memset(fdh, 0, sizeof(struct fadump_crash_info_header));
+        fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
+        fdh->elfcorehdr_addr = addr;
+
+        return addr;
+}
+
 static void register_fadump(void)
 {
+        unsigned long addr;
+        void *vaddr;
+
         /*
          * If no memory is reserved then we can not register for firmware-
          * assisted dump.
@@ -389,6 +604,16 @@ static void register_fadump(void)
         if (!fw_dump.reserve_dump_area_size)
                 return;
 
+        fadump_setup_crash_memory_ranges();
+
+        addr = fdm.rmr_region.destination_address + fdm.rmr_region.source_len;
+        /* Initialize fadump crash info header. */
+        addr = init_fadump_header(addr);
+        vaddr = __va(addr);
+
+        pr_debug("Creating ELF core headers at %#016lx\n", addr);
+        fadump_create_elfcore_headers(vaddr);
+
         /* register the future kernel dump with firmware. */
         register_fw_dump(&fdm);
 }
@@ -585,8 +810,14 @@ int __init setup_fadump(void)
         }
 
         fadump_show_config();
+        /*
+         * If dump data is available then see if it is valid and prepare for
+         * saving it to the disk.
+         */
+        if (fw_dump.dump_active)
+                process_fadump(fdm_active);
         /* Initialize the kernel dump memory structure for FAD registration. */
-        if (fw_dump.reserve_dump_area_size)
+        else if (fw_dump.reserve_dump_area_size)
                 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
         fadump_init_files();