perf/x86/intel/pt: Clean up ToPA allocation path

Some of the allocation parameters are passed as function arguments,
while the CPU number for per-cpu allocation is passed via the buffer
object. There's no reason for this.

Pass the CPU as a function argument instead.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20190821124727.73310-2-alexander.shishkin@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/events/intel/pt.c

@@ -670,7 +670,7 @@ static bool topa_table_full(struct topa *topa)
  *
  * Return:	0 on success or error code.
  */
-static int topa_insert_pages(struct pt_buffer *buf, gfp_t gfp)
+static int topa_insert_pages(struct pt_buffer *buf, int cpu, gfp_t gfp)
 {
 	struct topa *topa = buf->last;
 	int order = 0;
@@ -681,7 +681,7 @@ static int topa_insert_pages(struct pt_buffer *buf, gfp_t gfp)
 		order = page_private(p);
 
 	if (topa_table_full(topa)) {
-		topa = topa_alloc(buf->cpu, gfp);
+		topa = topa_alloc(cpu, gfp);
 		if (!topa)
 			return -ENOMEM;
 
@@ -1061,20 +1061,20 @@ static void pt_buffer_fini_topa(struct pt_buffer *buf)
  * @size:	Total size of all regions within this ToPA.
  * @gfp:	Allocation flags.
  */
-static int pt_buffer_init_topa(struct pt_buffer *buf, unsigned long nr_pages,
-			       gfp_t gfp)
+static int pt_buffer_init_topa(struct pt_buffer *buf, int cpu,
+			       unsigned long nr_pages, gfp_t gfp)
 {
 	struct topa *topa;
 	int err;
 
-	topa = topa_alloc(buf->cpu, gfp);
+	topa = topa_alloc(cpu, gfp);
 	if (!topa)
 		return -ENOMEM;
 
 	topa_insert_table(buf, topa);
 
 	while (buf->nr_pages < nr_pages) {
-		err = topa_insert_pages(buf, gfp);
+		err = topa_insert_pages(buf, cpu, gfp);
 		if (err) {
 			pt_buffer_fini_topa(buf);
 			return -ENOMEM;
@@ -1124,13 +1124,12 @@ pt_buffer_setup_aux(struct perf_event *event, void **pages,
 	if (!buf)
 		return NULL;
 
-	buf->cpu = cpu;
 	buf->snapshot = snapshot;
 	buf->data_pages = pages;
 
 	INIT_LIST_HEAD(&buf->tables);
 
-	ret = pt_buffer_init_topa(buf, nr_pages, GFP_KERNEL);
+	ret = pt_buffer_init_topa(buf, cpu, nr_pages, GFP_KERNEL);
 	if (ret) {
 		kfree(buf);
 		return NULL;

arch/x86/events/intel/pt.h

@@ -53,7 +53,6 @@ struct pt_pmu {
 /**
  * struct pt_buffer - buffer configuration; one buffer per task_struct or
  *		cpu, depending on perf event configuration
- * @cpu:	cpu for per-cpu allocation
  * @tables:	list of ToPA tables in this buffer
  * @first:	shorthand for first topa table
  * @last:	shorthand for last topa table
@@ -71,7 +70,6 @@ struct pt_pmu {
  * @topa_index:	table of topa entries indexed by page offset
  */
 struct pt_buffer {
-	int			cpu;
 	struct list_head	tables;
 	struct topa		*first, *last, *cur;
 	unsigned int		cur_idx;