powerpc/fadump: remove dependency with CONFIG_KEXEC

Now that crashkernel parameter parsing and vmcoreinfo related code is
moved under CONFIG_CRASH_CORE instead of CONFIG_KEXEC_CORE, remove
dependency with CONFIG_KEXEC for CONFIG_FA_DUMP.  While here, get rid of
definitions of fadump_append_elf_note() & fadump_final_note() functions
to reuse similar functions compiled under CONFIG_CRASH_CORE.

Link: http://lkml.kernel.org/r/149035343956.6881.1536459326017709354.stgit@hbathini.in.ibm.com
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/Kconfig

@@ -571,21 +571,23 @@ config RELOCATABLE_TEST
 	  relocation code.
 
 config CRASH_DUMP
-	bool "Build a kdump crash kernel"
+	bool "Build a dump capture kernel"
 	depends on PPC64 || 6xx || FSL_BOOKE || (44x && !SMP)
 	select RELOCATABLE if PPC64 || 44x || FSL_BOOKE
 	help
-	  Build a kernel suitable for use as a kdump capture kernel.
+	  Build a kernel suitable for use as a dump capture kernel.
 	  The same kernel binary can be used as production kernel and dump
 	  capture kernel.
 
 config FA_DUMP
 	bool "Firmware-assisted dump"
-	depends on PPC64 && PPC_RTAS && CRASH_DUMP && KEXEC_CORE
+	depends on PPC64 && PPC_RTAS
+	select CRASH_CORE
+	select CRASH_DUMP
 	help
 	  A robust mechanism to get reliable kernel crash dump with
 	  assistance from firmware. This approach does not use kexec,
-	  instead firmware assists in booting the kdump kernel
+	  instead firmware assists in booting the capture kernel
 	  while preserving memory contents. Firmware-assisted dump
 	  is meant to be a kdump replacement offering robustness and
 	  speed not possible without system firmware assistance.

arch/powerpc/include/asm/fadump.h

@@ -73,6 +73,8 @@
 	reg_entry++;							\
 })
 
+extern int crashing_cpu;
+
 /* Kernel Dump section info */
 struct fadump_section {
 	__be32	request_flag;

arch/powerpc/kernel/crash.c

@@ -43,8 +43,6 @@
 #define IPI_TIMEOUT		10000
 #define REAL_MODE_TIMEOUT	10000
 
-/* This keeps a track of which one is the crashing cpu. */
-int crashing_cpu = -1;
 static int time_to_dump;
 
 #define CRASH_HANDLER_MAX 3

arch/powerpc/kernel/fadump.c

@@ -527,34 +527,6 @@ fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
 	return reg_entry;
 }
 
-static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
-						void *data, size_t data_len)
-{
-	struct elf_note note;
-
-	note.n_namesz = strlen(name) + 1;
-	note.n_descsz = data_len;
-	note.n_type   = type;
-	memcpy(buf, &note, sizeof(note));
-	buf += (sizeof(note) + 3)/4;
-	memcpy(buf, name, note.n_namesz);
-	buf += (note.n_namesz + 3)/4;
-	memcpy(buf, data, note.n_descsz);
-	buf += (note.n_descsz + 3)/4;
-
-	return buf;
-}
-
-static void fadump_final_note(u32 *buf)
-{
-	struct elf_note note;
-
-	note.n_namesz = 0;
-	note.n_descsz = 0;
-	note.n_type   = 0;
-	memcpy(buf, &note, sizeof(note));
-}
-
 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
 {
 	struct elf_prstatus prstatus;
@@ -565,8 +537,8 @@ static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
 	 * prstatus.pr_pid = ????
 	 */
 	elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
-	buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
-				&prstatus, sizeof(prstatus));
+	buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
+			      &prstatus, sizeof(prstatus));
 	return buf;
 }
 
@@ -707,7 +679,7 @@ static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
 			note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 		}
 	}
-	fadump_final_note(note_buf);
+	final_note(note_buf);
 
 	if (fdh) {
 		pr_debug("Updating elfcore header (%llx) with cpu notes\n",

arch/powerpc/kernel/setup-common.c

@@ -125,6 +125,11 @@ int ppc_do_canonicalize_irqs;
 EXPORT_SYMBOL(ppc_do_canonicalize_irqs);
 #endif
 
+#ifdef CONFIG_CRASH_CORE
+/* This keeps a track of which one is the crashing cpu. */
+int crashing_cpu = -1;
+#endif
+
 /* also used by kexec */
 void machine_shutdown(void)
 {