[S390] zfcpdump support.

s390 machines provide hardware support for creating Linux dumps on SCSI
disks. For creating a dump a special purpose dump Linux is used. The first
32 MB of memory are saved by the hardware before the dump Linux is
booted. Via an SCLP interface, the saved memory can be accessed from
Linux. This patch exports memory and registers of the crashed Linux to
userspace via a debugfs file. For more information refer to
Documentation/s390/zfcpdump.txt, which is included in this patch.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 35 insertions, 3 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 863c8d08c026..3dfd0985861c 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -285,6 +285,26 @@ static void __init conmode_default(void)
         }
 }
 
+#if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
+static void __init setup_zfcpdump(unsigned int console_devno)
+{
+        static char str[64];
+
+        if (ipl_info.type != IPL_TYPE_FCP_DUMP)
+                return;
+        if (console_devno != -1)
+                sprintf(str, "cio_ignore=all,!0.0.%04x,!0.0.%04x",
+                        ipl_info.data.fcp.dev_id.devno, console_devno);
+        else
+                sprintf(str, "cio_ignore=all,!0.0.%04x",
+                        ipl_info.data.fcp.dev_id.devno);
+        strcat(COMMAND_LINE, str);
+        console_loglevel = 2;
+}
+#else
+static inline void setup_zfcpdump(unsigned int console_devno) {}
+#endif /* CONFIG_ZFCPDUMP */
+
 #ifdef CONFIG_SMP
 void (*_machine_restart)(char *command) = machine_restart_smp;
 void (*_machine_halt)(void) = machine_halt_smp;
@@ -586,13 +606,20 @@ setup_resources(void)
         }
 }
 
+unsigned long real_memory_size;
+EXPORT_SYMBOL_GPL(real_memory_size);
+
 static void __init setup_memory_end(void)
 {
-        unsigned long real_size, memory_size;
+        unsigned long memory_size;
         unsigned long max_mem, max_phys;
         int i;
 
-        memory_size = real_size = 0;
+#if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
+        if (ipl_info.type == IPL_TYPE_FCP_DUMP)
+                memory_end = ZFCPDUMP_HSA_SIZE;
+#endif
+        memory_size = 0;
         max_phys = VMALLOC_END_INIT - VMALLOC_MIN_SIZE;
         memory_end &= PAGE_MASK;
 
@@ -601,7 +628,8 @@ static void __init setup_memory_end(void)
         for (i = 0; i < MEMORY_CHUNKS; i++) {
                 struct mem_chunk *chunk = &memory_chunk[i];
 
-                real_size = max(real_size, chunk->addr + chunk->size);
+                real_memory_size = max(real_memory_size,
+                                       chunk->addr + chunk->size);
                 if (chunk->addr >= max_mem) {
                         memset(chunk, 0, sizeof(*chunk));
                         continue;
@@ -765,6 +793,7 @@ setup_arch(char **cmdline_p)
 
         parse_early_param();
 
+        setup_ipl_info();
         setup_memory_end();
         setup_addressing_mode();
         setup_memory();
@@ -782,6 +811,9 @@ setup_arch(char **cmdline_p)
 
         /* Setup default console */
         conmode_default();
+
+        /* Setup zfcpdump support */
+        setup_zfcpdump(console_devno);
 }
 
 void print_cpu_info(struct cpuinfo_S390 *cpuinfo)