[PATCH RESEND 2/5] kexec: Export kexec_in_progress

[Brian King]

A kexec boot for some ipr SAS adapters was seen to take ~20 seconds
just doing ipr adapter initialization. This is due to the fact that
a kexec invokes the driver's shutdown handler which places the adapter
into a state that requires a hard reset and resulting firmware initialization
to be usable again, which takes significant time. By exporting kexec_in_progress,
this process can be optimized significantly in the driver by essentially
placing the adapter into a state where this hardware reset and re-initialization
can be bypassed, eliminating this delay in kexec boot.

Cc: Eric Biederman <ebiederm at xmission.com>
Cc: kexec <kexec at lists.infradead.org>
Signed-off-by: Brian King <brking at linux.vnet.ibm.com>
---

 kernel/kexec.c |    2 ++
 1 file changed, 2 insertions(+)

diff -puN kernel/kexec.c~kexec_export_in_prog kernel/kexec.c
--- scsi-queue/kernel/kexec.c~kexec_export_in_prog	2014-12-02 12:13:22.820325731 -0600
+++ scsi-queue-bjking1/kernel/kexec.c	2014-12-02 12:13:22.825325687 -0600
@@ -2768,3 +2768,5 @@ int kernel_kexec(void)
 	mutex_unlock(&kexec_mutex);
 	return error;
 }
+
+EXPORT_SYMBOL_GPL(kexec_in_progress);
_