[POWERPC] coredump: Add SPU elf notes to coredump.

This patch adds SPU elf notes to the coredump. It creates a separate note
for each of /regs, /fpcr, /lslr, /decr, /decr_status, /mem, /signal1,
/signal1_type, /signal2, /signal2_type, /event_mask, /event_status,
/mbox_info, /ibox_info, /wbox_info, /dma_info, /proxydma_info, /object-id.

A new macro, ARCH_HAVE_EXTRA_NOTES, was created for architectures to
specify they have extra elf core notes.

A new macro, ELF_CORE_EXTRA_NOTES_SIZE, was created so the size of the
additional notes could be calculated and added to the notes phdr entry.

A new macro, ELF_CORE_WRITE_EXTRA_NOTES, was created so the new notes
would be written after the existing notes.

The SPU coredump code resides in spufs. Stub functions are provided in the
kernel which are hooked into the spufs code which does the actual work via
register_arch_coredump_calls().

A new set of __spufs_<file>_read/get() functions was provided to allow the
coredump code to read from the spufs files without having to lock the
SPU context for each file read from.

Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Dwayne Grant McConnell <decimal@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

include/asm-powerpc/elf.h

@@ -411,4 +411,17 @@ do {									\
 /* Keep this the last entry.  */
 #define R_PPC64_NUM		107
 
+#ifdef CONFIG_PPC_CELL
+/* Notes used in ET_CORE. Note name is "SPU/<fd>/<filename>". */
+#define NT_SPU		1
+
+extern int arch_notes_size(void);
+extern void arch_write_notes(struct file *file);
+
+#define ELF_CORE_EXTRA_NOTES_SIZE arch_notes_size()
+#define ELF_CORE_WRITE_EXTRA_NOTES arch_write_notes(file)
+
+#define ARCH_HAVE_EXTRA_ELF_NOTES
+#endif /* CONFIG_PPC_CELL */
+
 #endif /* _ASM_POWERPC_ELF_H */