[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>

1 files changed, 81 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/cell/spu_coredump.c b/arch/powerpc/platforms/cell/spu_coredump.c
new file mode 100644
index 00000000000..6915b418ee7
--- /dev/null
+++ b/arch/powerpc/platforms/cell/spu_coredump.c
@@ -0,0 +1,81 @@
+/*
+ * SPU core dump code
+ *
+ * (C) Copyright 2006 IBM Corp.
+ *
+ * Author: Dwayne Grant McConnell <decimal@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/file.h>
+#include <linux/module.h>
+#include <linux/syscalls.h>
+
+#include <asm/spu.h>
+
+static struct spu_coredump_calls spu_coredump_calls;
+static DEFINE_MUTEX(spu_coredump_mutex);
+
+int arch_notes_size(void)
+{
+	long ret;
+	struct module *owner = spu_coredump_calls.owner;
+
+	ret = -ENOSYS;
+	mutex_lock(&spu_coredump_mutex);
+	if (owner && try_module_get(owner)) {
+		ret = spu_coredump_calls.arch_notes_size();
+		module_put(owner);
+	}
+	mutex_unlock(&spu_coredump_mutex);
+	return ret;
+}
+
+void arch_write_notes(struct file *file)
+{
+	struct module *owner = spu_coredump_calls.owner;
+
+	mutex_lock(&spu_coredump_mutex);
+	if (owner && try_module_get(owner)) {
+		spu_coredump_calls.arch_write_notes(file);
+		module_put(owner);
+	}
+	mutex_unlock(&spu_coredump_mutex);
+}
+
+int register_arch_coredump_calls(struct spu_coredump_calls *calls)
+{
+	if (spu_coredump_calls.owner)
+		return -EBUSY;
+
+	mutex_lock(&spu_coredump_mutex);
+	spu_coredump_calls.arch_notes_size = calls->arch_notes_size;
+	spu_coredump_calls.arch_write_notes = calls->arch_write_notes;
+	spu_coredump_calls.owner = calls->owner;
+	mutex_unlock(&spu_coredump_mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(register_arch_coredump_calls);
+
+void unregister_arch_coredump_calls(struct spu_coredump_calls *calls)
+{
+	BUG_ON(spu_coredump_calls.owner != calls->owner);
+
+	mutex_lock(&spu_coredump_mutex);
+	spu_coredump_calls.owner = NULL;
+	mutex_unlock(&spu_coredump_mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_arch_coredump_calls);