From d0a7e8ca5b996d36219e6fc002907291c8ee677b Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:02 +0200 Subject: [PATCH] mmiotrace: print header using the read hook. Now the header is printed only for `trace_pipe' file. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- kernel/trace/trace_mmiotrace.c | 60 ++++++++++++++++++++++++++++++---- 1 file changed, 53 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 79be4a18ec..6d2edbdde9 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -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, }; -- 2.39.5