[ARM] S3C: Do not kmalloc/kfree during inner suspend code.

The PM CRC checking code kmallocs an area to save a set of
CRC values during suspend. This triggers a warning due to the
call of a function that might sleep whilst the system is not
in a valid state to do so.

Move the allocation and free to points in the suspend and resume
process where they can call a function that might-sleep.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c/include/plat/pm.h

@@ -129,10 +129,12 @@ extern void s3c_pm_dbg(const char *msg, ...);
 #ifdef CONFIG_S3C2410_PM_CHECK
 extern void s3c_pm_check_prepare(void);
 extern void s3c_pm_check_restore(void);
+extern void s3c_pm_check_cleanup(void);
 extern void s3c_pm_check_store(void);
 #else
 #define s3c_pm_check_prepare() do { } while(0)
 #define s3c_pm_check_restore() do { } while(0)
+#define s3c_pm_check_cleanup() do { } while(0)
 #define s3c_pm_check_store()   do { } while(0)
 #endif
 

arch/arm/plat-s3c/pm-check.c

@@ -222,9 +222,21 @@ static u32 *s3c_pm_runcheck(struct resource *res, u32 *val)
 */
 void s3c_pm_check_restore(void)
 {
-	if (crcs != NULL) {
+	if (crcs != NULL)
 		s3c_pm_run_sysram(s3c_pm_runcheck, crcs);
-		kfree(crcs);
-		crcs = NULL;
-	}
 }
+
+/**
+ * s3c_pm_check_cleanup() - free memory resources
+ *
+ * Free the resources that where allocated by the suspend
+ * memory check code. We do this separately from the
+ * s3c_pm_check_restore() function as we cannot call any
+ * functions that might sleep during that resume.
+ */
+void s3c_pm_check_cleanup(void)
+{
+	kfree(crcs);
+	crcs = NULL;
+}
+

arch/arm/plat-s3c/pm.c

@@ -254,10 +254,6 @@ static int s3c_pm_enter(suspend_state_t state)
 		return -EINVAL;
 	}
 
-	/* prepare check area if configured */
-
-	s3c_pm_check_prepare();
-
 	/* store the physical address of the register recovery block */
 
 	s3c_sleep_save_phys = virt_to_phys(regs_save);
@@ -329,8 +325,23 @@ static int s3c_pm_enter(suspend_state_t state)
 	return 0;
 }
 
+static int s3c_pm_prepare(void)
+{
+	/* prepare check area if configured */
+
+	s3c_pm_check_prepare();
+	return 0;
+}
+
+static void s3c_pm_finish(void)
+{
+	s3c_pm_check_cleanup();
+}
+
 static struct platform_suspend_ops s3c_pm_ops = {
 	.enter		= s3c_pm_enter,
+	.prepare	= s3c_pm_prepare,
+	.finish		= s3c_pm_finish,
 	.valid		= suspend_valid_only_mem,
 };