[PATCH] staging: vchiq_arm: mark vchiq_platform_init() static

[Arnd Bergmann]

From: Arnd Bergmann <arnd at arndb.de>

This function has no callers from other files, and the declaration
was removed a while ago, causing a W=1 warning:

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:465:5: error: no previous prototype for 'vchiq_platform_init'

Marking it static solves this problem but introduces a new warning
since gcc determines that 'g_fragments_base' is never initialized
in some kernel configurations:

In file included from include/linux/string.h:254,
                 from include/linux/bitmap.h:11,
                 from include/linux/cpumask.h:12,
                 from include/linux/mm_types_task.h:14,
                 from include/linux/mm_types.h:5,
                 from include/linux/buildid.h:5,
                 from include/linux/module.h:14,
                 from drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:8:
In function 'memcpy_to_page',
    inlined from 'free_pagelist' at drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:433:4:
include/linux/fortify-string.h:57:33: error: argument 2 null where non-null expected [-Werror=nonnull]
include/linux/highmem.h:427:9: note: in expansion of macro 'memcpy'
  427 |         memcpy(to + offset, from, len);
      |         ^~~~~~

Add a NULL pointer check for this in addition to the static annotation
to avoid both.

Fixes: 89cc4218f640 ("staging: vchiq_arm: drop unnecessary declarations")
Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---
 drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index 90a3958d1f29..aa2313f3bcab 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -415,7 +415,7 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
 	pagelistinfo->scatterlist_mapped = 0;
 
 	/* Deal with any partial cache lines (fragments) */
-	if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
+	if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS && g_fragments_base) {
 		char *fragments = g_fragments_base +
 			(pagelist->type - PAGELIST_READ_WITH_FRAGMENTS) *
 			g_fragments_size;
@@ -462,7 +462,7 @@ free_pagelist(struct vchiq_instance *instance, struct vchiq_pagelist_info *pagel
 	cleanup_pagelistinfo(instance, pagelistinfo);
 }
 
-int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state *state)
+static int vchiq_platform_init(struct platform_device *pdev, struct vchiq_state *state)
 {
 	struct device *dev = &pdev->dev;
 	struct vchiq_drvdata *drvdata = platform_get_drvdata(pdev);
-- 
2.39.2