[PATCH 2/3] drm/xe/pf: Expose SR-IOV VF control commands over debugfs

[Piotr Piórkowski]

Michal Wajdeczko <michal.wajdeczko at intel.com> wrote on czw [2024-kwi-18 22:34:41 +0200]:
> We already have functions to control the VF.
> Allow to control the VF using debugfs.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c | 79 +++++++++++++++++++++
>  1 file changed, 79 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> index 32ce98698690..8909bb950a8b 100644
> --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c
> @@ -14,6 +14,7 @@
>  #include "xe_gt.h"
>  #include "xe_gt_debugfs.h"
>  #include "xe_gt_sriov_pf_config.h"
> +#include "xe_gt_sriov_pf_control.h"
>  #include "xe_gt_sriov_pf_debugfs.h"
>  #include "xe_gt_sriov_pf_helpers.h"
>  #include "xe_pm.h"
> @@ -153,6 +154,83 @@ static void pf_add_config_attrs(struct xe_gt *gt, struct dentry *parent, unsigne
>  				   &preempt_timeout_fops);
>  }
>  
> +/*
> + *      /sys/kernel/debug/dri/0/
> + *      ├── gt0
> + *      │   ├── vf1
> + *      │   │   ├── control { stop, pause, resume }
> + */
> +
> +static const struct {
> +	const char *cmd;
> +	int (*fn)(struct xe_gt *gt, unsigned int vfid);
> +} control_cmds[] = {
> +	{ "stop", xe_gt_sriov_pf_control_stop_vf },
> +	{ "pause", xe_gt_sriov_pf_control_pause_vf },
> +	{ "resume", xe_gt_sriov_pf_control_resume_vf },
> +};
> +
> +static ssize_t control_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
> +{
> +	struct dentry *dent = file_dentry(file);
> +	struct dentry *parent = dent->d_parent;
> +	struct xe_gt *gt = extract_gt(parent);
> +	struct xe_device *xe = gt_to_xe(gt);
> +	unsigned int vfid = extract_vfid(parent);
> +	int ret = -EINVAL;
> +	char cmd[32];
> +	size_t n;
> +
> +	xe_gt_assert(gt, vfid);
> +	xe_gt_sriov_pf_assert_vfid(gt, vfid);
> +
> +	if (*pos)
> +		return -ESPIPE;
> +
> +	if (count > sizeof(cmd) - 1)
> +		return -EINVAL;
> +
> +	ret = simple_write_to_buffer(cmd, sizeof(cmd) - 1, pos, buf, count);
> +	if (ret < 0)
> +		return ret;
> +	cmd[ret] = '\0';
> +
> +	for (n = 0; n < ARRAY_SIZE(control_cmds); n++) {
> +		xe_gt_assert(gt, sizeof(cmd) > strlen(control_cmds[n].cmd));
> +
> +		if (sysfs_streq(cmd, control_cmds[n].cmd)) {
> +			xe_pm_runtime_get(xe);
> +			ret = control_cmds[n].fn ? (*control_cmds[n].fn)(gt, vfid) : 0;
> +			xe_pm_runtime_put(xe);
> +			break;
> +		}
> +	}
> +
> +	return (ret < 0) ? ret : count;
> +}
> +
> +static ssize_t control_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
> +{
> +	char help[128];
> +	size_t n;
> +
> +	help[0] = '\0';
> +	for (n = 0; n < ARRAY_SIZE(control_cmds); n++) {
> +		strlcat(help, control_cmds[n].cmd, sizeof(help));
> +		strlcat(help, "\n", sizeof(help));
> +	}
> +
> +	return simple_read_from_buffer(buf, count, ppos, help, strlen(help));
> +}
> +
> +static const struct file_operations control_ops = {
> +	.owner		= THIS_MODULE,
> +	.open		= simple_open,
> +	.write		= control_write,
> +	.read		= control_read,
> +	.llseek		= default_llseek,
> +};
> +
>  /**
>   * xe_gt_sriov_pf_debugfs_register - Register SR-IOV PF specific entries in GT debugfs.
>   * @gt: the &xe_gt to register
> @@ -199,5 +277,6 @@ void xe_gt_sriov_pf_debugfs_register(struct xe_gt *gt, struct dentry *root)
>  		vfdentry->d_inode->i_private = (void *)(uintptr_t)n;
>  
>  		pf_add_config_attrs(gt, vfdentry, VFID(n));
> +		debugfs_create_file("control", 0600, vfdentry, NULL, &control_ops);
>  	}
>  }


LGTM:
Reviewed-by: Piotr Piórkowski <piotr.piorkowski at intel.com>

> -- 
> 2.43.0
> 

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