Re: [igt-dev] [PATCH i-g-t 1/3] lib/xe: Add support to reset all GT's

[Matthew Brost <matthew.brost@intel.com>]

On Fri, Aug 11, 2023 at 03:52:16PM +0200, Maarten Lankhorst wrote:
> Hey,
> 
> Den 2023-08-10 kl. 12:17, skrev Ch, Sai Gowtham:
> > 
> > -----Original Message-----
> > From: Kumar, Janga Rahul <janga.rahul.kumar@intel.com>
> > Sent: Monday, August 7, 2023 9:28 AM
> > To: igt-dev@lists.freedesktop.org; Gandi, Ramadevi <ramadevi.gandi@intel.com>; Kumar, Janga Rahul <janga.rahul.kumar@intel.com>
> > Cc: Ch, Sai Gowtham <sai.gowtham.ch@intel.com>; Joshi, Kunal1 <kunal1.joshi@intel.com>; kamil.konieczny@linux.intel.com; Karas, Anna <anna.karas@intel.com>
> > Subject: [PATCH i-g-t 1/3] lib/xe: Add support to reset all GT's
> > 
> > From: Janga Rahul Kumar <janga.rahul.kumar@intel.com>
> > 
> > Introduce xe gt library.
> > 
> > Add support to check GT reset and force reset all GT's.
> > 
> > Cc: Sai Gowtham Ch <sai.gowtham.ch@intel.com>
> > Cc: Kunal Joshi <kunal1.joshi@intel.com>
> > Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
> > Cc: Anna Karas <anna.karas@intel.com>
> > Signed-off-by: Janga Rahul Kumar <janga.rahul.kumar@intel.com>
> > Tested-by: Kunal Joshi <kunal1.joshi@intel.com>
> > ---
> >   lib/meson.build |  1 +
> >   lib/xe/xe_gt.c  | 62 +++++++++++++++++++++++++++++++++++++++++++++++++
> >   lib/xe/xe_gt.h  | 27 +++++++++++++++++++++
> >   3 files changed, 90 insertions(+)
> >   create mode 100644 lib/xe/xe_gt.c
> >   create mode 100644 lib/xe/xe_gt.h
> > 
> > diff --git a/lib/meson.build b/lib/meson.build index ce11c0715..b7bfcf4f0 100644
> > --- a/lib/meson.build
> > +++ b/lib/meson.build
> > @@ -103,6 +103,7 @@ lib_sources = [
> >   	'igt_dsc.c',
> >   	'xe/xe_compute.c',
> >   	'xe/xe_compute_square_kernels.c',
> > +	'xe/xe_gt.c',
> >   	'xe/xe_ioctl.c',
> >   	'xe/xe_query.c',
> >   	'xe/xe_spin.c',
> > diff --git a/lib/xe/xe_gt.c b/lib/xe/xe_gt.c new file mode 100644 index 000000000..9cad739be
> > --- /dev/null
> > +++ b/lib/xe/xe_gt.c
> > @@ -0,0 +1,62 @@
> > +/* SPDX-License-Identifier: MIT */
> > +/*
> > + * Copyright © 2023 Intel Corporation
> > + *
> > + * Authors:
> > + *    Janga Rahul Kumar <janga.rahul.kumar@intel.com>
> > + */
> > +
> > +#include <fcntl.h>
> > +
> > I don’t think new line is needed here.
> > +#include "xe_gt.h"
> > +
> > +/**
> > + * has_xe_gt_reset:
> > + * @fd: open xe drm file descriptor
> > + *
> > + * Check gt force reset sysfs entry is available or not
> > + *
> > + * Returns: reset sysfs entry available  */ bool has_xe_gt_reset(int
> > +fd) {
> > +	char reset_sysfs_path[100];
> > +	struct stat st;
> > +	int gt;
> > +	int reset_sysfs_fd = -1;
> > +	int sysfs_fd = -1;
> > +
> > +	igt_assert_eq(fstat(fd, &st), 0);
> > +	sysfs_fd = igt_sysfs_open(fd);
> > +
> > +	igt_assert(sysfs_fd != -1);
> > +	xe_for_each_gt(fd, gt) {
> > +		sprintf(reset_sysfs_path, "/sys/kernel/debug/dri/%d/gt%d/force_reset",
> > +				minor(st.st_rdev), gt);
> > +		reset_sysfs_fd = openat(sysfs_fd, reset_sysfs_path, O_RDONLY);
> > +
> > +		if (reset_sysfs_fd == -1) {
> > +			close(sysfs_fd);
> > +			return 0;
> > +		}
> > +
> > +		close(reset_sysfs_fd);
> > +	}
> > +
> > +	close(sysfs_fd);
> > +	return 1;
> > +}
> 
> We can reset a gt by only opening a file in debugfs? That seems like a
> terrible api, we should probably force it to only reset by writing 1 or
> something instead..
> 

Yea this was my lazyness when adding, agree we should fix this in the KMD.

Matt

> Cheers,
> 
> ~Maarten
>