kexec/ppc64: bring up new ppc64le architecture

This patch provides support for the new Power PC litte endian (LE) mode. The
LE mode only differs in the way the instructions and data are stored in memory
thus there is no real need to duplicate the ppc64 code.

However some compilation's options, especially for the purgatory, differ
between little and big endian mode's support. A new "SUBARCH" build variable
is introduced which is currently only used for PPC64 to specify the
endianness.

Another set of changes in this patch is fixing minor endianess issues in the
ppc64 code and fix an alignment issue raised on Power7 little endian mode.
Among these fixes, the check on the kernel binary endianess is removed,
since we can imagine kexecing a LE kernel from a BE environment, as far as
the specified root filesystem and initrd file are containing the right
binaries.

This patch depends on the patch "kexec/ppc64: use common architecture
fs2dt.c file" I sent earlier on the kexec mailing list.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

Makefile.in

@@ -22,6 +22,7 @@ includedir	= @includedir@
 
 # The target architecture
 ARCH		= @ARCH@
+SUBARCH		= @SUBARCH@
 OBJDIR		= @OBJDIR@
 target		= @target@
 host		= @host@

config/config.guess

@@ -4,7 +4,7 @@
 #   2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
 #   2011, 2012 Free Software Foundation, Inc.
 
-timestamp='2012-02-10'
+timestamp='2013-10-21'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -972,6 +972,9 @@ EOF
     ppc64:Linux:*:*)
 	echo powerpc64-unknown-linux-gnu
 	exit ;;
+    ppc64le:Linux:*:*)
+	echo powerpc64le-unknown-linux-gnu
+	exit ;;
     ppc:Linux:*:*)
 	echo powerpc-unknown-linux-gnu
 	exit ;;

configure.ac

@@ -29,6 +29,11 @@ case $target_cpu in
 		;;
 	powerpc64 )
 		ARCH="ppc64"
+		SUBARCH="BE"
+		;;
+	powerpc64le )
+		ARCH="ppc64"
+		SUBARCH="LE"
 		;;
 	arm* )
 		ARCH="arm"
@@ -197,6 +202,7 @@ AC_SUBST([TARGET_CFLAGS])
 AC_SUBST([ASFLAGS])
 
 AC_SUBST([ARCH])
+AC_SUBST([SUBARCH])
 AC_SUBST([OBJDIR])
 AC_SUBST([INSTALL])
 

kexec/arch/ppc64/kexec-elf-ppc64.c

@@ -237,13 +237,13 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,
 	 * entry is before this one
 	 */
 	bb_ptr = (struct bootblock *)(seg_buf);
-	rsvmap_ptr = (uint64_t *)(seg_buf + bb_ptr->off_mem_rsvmap);
+	rsvmap_ptr = (uint64_t *)(seg_buf + be32_to_cpu(bb_ptr->off_mem_rsvmap));
 	while (*rsvmap_ptr || *(rsvmap_ptr+1))
 		rsvmap_ptr += 2;
 	rsvmap_ptr -= 2;
-	*rsvmap_ptr = my_dt_offset;
+	*rsvmap_ptr = cpu_to_be64(my_dt_offset);
 	rsvmap_ptr++;
-	*rsvmap_ptr = bb_ptr->totalsize;
+	*rsvmap_ptr = cpu_to_be64((uint64_t)be32_to_cpu(bb_ptr->totalsize));
 #endif
 
 	/* Set kernel */

kexec/arch/ppc64/kexec-elf-rel-ppc64.c

@@ -7,9 +7,6 @@
 
 int machine_verify_elf_rel(struct mem_ehdr *ehdr)
 {
-	if (ehdr->ei_data != ELFDATA2MSB) {
-		return 0;
-	}
 	if (ehdr->ei_class != ELFCLASS64) {
 		return 0;
 	}

kexec/arch/ppc64/kexec-ppc64.c

@@ -532,6 +532,7 @@ static int get_devtree_details(unsigned long kexec_flags)
 				perror(fname);
 				goto error_openfile;
 			}
+			rtas_base = be32_to_cpu(rtas_base);
 			memset(fname, 0, sizeof(fname));
 			strcpy(fname, device_tree);
 			strcat(fname, dentry->d_name);
@@ -545,6 +546,7 @@ static int get_devtree_details(unsigned long kexec_flags)
 				goto error_openfile;
 			}
 			closedir(cdir);
+			rtas_size = be32_to_cpu(rtas_size);
 			/* Add rtas to exclude_range */
 			exclude_range[i].start = rtas_base;
 			exclude_range[i].end = rtas_base + rtas_size;
@@ -798,6 +800,7 @@ const struct arch_map_entry arches[] = {
 	 * So pass KEXEC_ARCH_PPC64 here
 	 */
 	{ "ppc64", KEXEC_ARCH_PPC64 },
+	{ "ppc64le", KEXEC_ARCH_PPC64 },
 	{ NULL, 0 },
 };
 

purgatory/arch/ppc64/Makefile

@@ -11,7 +11,13 @@ ppc64_PURGATORY_SRCS += purgatory/arch/ppc64/misc.S
 
 ppc64_PURGATORY_EXTRA_CFLAGS += -m64 -mcall-aixdesc -msoft-float
 ppc64_PURGATORY_EXTRA_ASFLAGS += -m64 -mcall-aixdesc
-ppc64_PURGATORY_EXTRA_LDFLAGS += -melf64ppc
+ifeq ($(SUBARCH),BE)
+	ppc64_PURGATORY_EXTRA_LDFLAGS += -melf64ppc
+else
+	ppc64_PURGATORY_EXTRA_LDFLAGS += -melf64lppc
+	ppc64_PURGATORY_EXTRA_CFLAGS += -mlittle-endian
+	ppc64_PURGATORY_EXTRA_ASFLAGS += -mlittle-endian
+endif
 
 dist += purgatory/arch/ppc64/Makefile $(ppc64_PURGATORY_SRCS)		\
 	purgatory/arch/ppc64/hvCall.h					\

purgatory/arch/ppc64/v2wrap.S

@@ -46,6 +46,7 @@
 	ori     rn,rn,name##@l
 
 	.machine ppc64
+	.align 8
 	.globl purgatory_start
 purgatory_start:	b	master
 	.org purgatory_start + 0x5c     # ABI: possible run_at_load flag at 0x5c