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Commit d0a7e8ca authored by Pekka Paalanen's avatar Pekka Paalanen Committed by Thomas Gleixner
Browse files

mmiotrace: print header using the read hook. 



Now the header is printed only for `trace_pipe' file.

Signed-off-by: default avatarPekka Paalanen <pq@iki.fi>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7423d111

kernel/trace/trace_mmiotrace.c

+53 −7
Original line number Diff line number Diff line
@@ -12,6 +12,10 @@ 


#include "trace.h"



struct header_iter {

	struct pci_dev *dev;

};



static struct trace_array *mmio_trace_array;



static void mmio_reset_data(struct trace_array *tr)
@@ -89,17 +93,57 @@ static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) 
	return ret;

}



/* XXX: This is not called for trace_pipe file! */

static void mmio_print_header(struct trace_iterator *iter)

static void destroy_header_iter(struct header_iter *hiter)

{

	if (!hiter)

		return;

	pci_dev_put(hiter->dev);

	kfree(hiter);

}



static void mmio_pipe_open(struct trace_iterator *iter)

{

	struct header_iter *hiter;

	struct trace_seq *s = &iter->seq;

	struct pci_dev *dev = NULL;



	trace_seq_printf(s, "VERSION 20070824\n");



	for_each_pci_dev(dev)

		mmio_print_pcidev(s, dev);

	/* XXX: return value? What if header is very long? */

	hiter = kzalloc(sizeof(*hiter), GFP_KERNEL);

	if (!hiter)

		return;



	hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);

	iter->private = hiter;

}



/* XXX: This is not called when the pipe is closed! */

static void mmio_close(struct trace_iterator *iter)

{

	struct header_iter *hiter = iter->private;

	destroy_header_iter(hiter);

	iter->private = NULL;

}



static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,

				char __user *ubuf, size_t cnt, loff_t *ppos)

{

	ssize_t ret;

	struct header_iter *hiter = iter->private;

	struct trace_seq *s = &iter->seq;



	if (!hiter)

		return 0;



	mmio_print_pcidev(s, hiter->dev);

	hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);



	if (!hiter->dev) {

		destroy_header_iter(hiter);

		iter->private = NULL;

	}



	ret = trace_seq_to_user(s, ubuf, cnt);

	return (ret == -EBUSY) ? 0 : ret;

}



static int mmio_print_rw(struct trace_iterator *iter)
@@ -190,7 +234,9 @@ static struct tracer mmio_tracer __read_mostly = 
	.name		= "mmiotrace",

	.init		= mmio_trace_init,

	.reset		= mmio_trace_reset,

	.open		= mmio_print_header,

	.pipe_open	= mmio_pipe_open,

	.close		= mmio_close,

	.read		= mmio_read,

	.ctrl_update	= mmio_trace_ctrl_update,

	.print_line	= mmio_print_line,

};