Fixes several missing-prototype warnings.

Makefile

@@ -70,5 +70,21 @@ install-spank: spank
 	$(INSTALL) -d $(DESTDIR)/$(libdir)/slurm
 	$(INSTALL) msrsave/libspank_msrsafe.so $(DESTDIR)/$(libdir)/slurm/libspank_msrsafe.so
 
+# The current spack package ignore this Makefile for building the
+# msr-safe.ko kernel module, as it is building against an arbitrary
+# version of the linux kernel and thus $(shell uname -r) is not useful.
+#
+# Installation relies on the spack package setting DESTDIR to the
+# msr-safe package prefix spec variable.
+#
+# Later iterations of the spack package might also build and install
+# msrsave.  That will likely require a reworking of this Makefile.
+# Prefer single-source-of-truth in that case.
+spack-install:
+	$(INSTALL) -d $(DESTDIR)/lib/modules
+	$(INSTALL) msr-safe.ko $(DESTDIR)/lib/modules
+	$(INSTALL) -d $(DESTDIR)/include
+	$(INSTALL) msr_safe.h $(DESTDIR)/include
+
 .SUFFIXES: .c .o
 .PHONY: all clean install spank install-spank

msr-smp.c

@@ -18,6 +18,7 @@
 #include <linux/smp.h>
 
 #include "msr_safe.h"
+#include "msr-smp.h"
 
 static void __msr_safe_batch(void *info)
 {

msr-smp.h

@@ -0,0 +1,6 @@
+#ifndef MSR_SMP_INCLUDE
+#define MSR_SMP_INCLUDE
+
+int msr_safe_batch(struct msr_batch_array *oa);
+
+#endif

msr_allowlist.c

@@ -16,6 +16,8 @@
 #include <linux/uaccess.h>
 #include <linux/version.h>
 
+#include "msr_allowlist.h"
+
 #define MAX_WLIST_BSIZE ((128 * 1024) + 1) // "+1" for null character
 
 struct allowlist_entry

msr_allowlist.h

@@ -20,7 +20,7 @@
 
 int msr_allowlist_init(int *majordev);
 
-int msr_allowlist_cleanup(int majordev);
+void msr_allowlist_cleanup(int majordev);
 
 int msr_allowlist_exists(void);
 

msr_batch.c

@@ -31,6 +31,7 @@
 
 #include "msr_batch.h"
 #include "msr_safe.h"
+#include "msr-smp.h"
 #include "msr_allowlist.h"
 
 static struct class *cdev_class;
@@ -73,7 +74,6 @@ static int msrbatch_apply_allowlist(struct msr_batch_array *oa)
     return err;
 }
 
-extern int msr_safe_batch(struct msr_batch_array *oa);
 
 static long msrbatch_ioctl(struct file *f, unsigned int ioc, unsigned long arg)
 {

msr_version.c

@@ -12,6 +12,8 @@
 #include <linux/module.h>
 #include <linux/uaccess.h>
 
+#include "msr_version.h"
+
 static struct class *cdev_class;
 static char cdev_created;
 static char cdev_registered;

msr_version.h

@@ -20,6 +20,6 @@
 
 int msr_version_init(int *majordev);
 
-int msr_version_cleanup(int majordev);
+void msr_version_cleanup(int majordev);
 
 #endif