ANDROID: vendor_hooks: add vendor hook in cma_alloc()

By this vh, so that we can reimplement the function cma_alloc()

Bug: 299425220
Change-Id: I7068915c3c38784dba25d130434abe595b06b996
Signed-off-by: Wanwei Jiang <wanwei.jiang@amlogic.com>

drivers/android/vendor_hooks.c

@@ -102,3 +102,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_sched_show_task);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ftrace_format_check);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mem_cgroup_free);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mem_cgroup_alloc);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_cma_alloc_bypass);

include/trace/hooks/mm.h

@@ -19,7 +19,6 @@ DECLARE_RESTRICTED_HOOK(android_rvh_set_gfp_zone_flags,
 DECLARE_RESTRICTED_HOOK(android_rvh_set_readahead_gfp_mask,
 			TP_PROTO(gfp_t *flags),
 			TP_ARGS(flags), 1);
-
 */
 struct mem_cgroup;
 DECLARE_HOOK(android_vh_mem_cgroup_alloc,
@@ -29,6 +28,10 @@ DECLARE_HOOK(android_vh_mem_cgroup_free,
 	TP_PROTO(struct mem_cgroup *memcg),
 	TP_ARGS(memcg));
 
+DECLARE_HOOK(android_vh_cma_alloc_bypass,
+	TP_PROTO(struct cma *cma, unsigned long count, unsigned int align,
+		gfp_t gfp_mask, struct page **page, bool *bypass),
+	TP_ARGS(cma, count, align, gfp_mask, page, bypass));
 #endif /* _TRACE_HOOK_MM_H */
 
 /* This part must be outside protection */

mm/cma.c

@@ -30,6 +30,8 @@
 #include <linux/sched.h>
 #include <linux/jiffies.h>
 #include <trace/events/cma.h>
+#undef CREATE_TRACE_POINTS
+#include <trace/hooks/mm.h>
 
 #include "internal.h"
 #include "cma.h"
@@ -420,11 +422,17 @@ struct page *__cma_alloc(struct cma *cma, unsigned long count,
 	const char *name = cma ? cma->name : NULL;
 	int num_attempts = 0;
 	int max_retries = 5;
+	bool bypass = false;
 
 	if (WARN_ON_ONCE((gfp & GFP_KERNEL) == 0 ||
 		(gfp & ~(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY)) != 0))
 		return page;
 
+	trace_android_vh_cma_alloc_bypass(cma, count, align, gfp,
+				&page, &bypass);
+	if (bypass)
+		return page;
+
 	trace_cma_alloc_start(name, count, align);
 
 	if (!cma || !cma->count || !cma->bitmap)