[PATCH 15/15] drm/xe: Add xe_client_debugfs and introduce debug_data file

[Christian König]

On 08.08.25 12:43, Mika Kuoppala wrote:
> From: Christoph Manszewski <christoph.manszewski at intel.com>
> 
> Create a debug_data file for each xe file/client which is supposed to
> list all mapped debug data and attempts to mimic '/proc/pid/maps'.
> Each line represents a single mapping and has the following format:
> 
>   <vm id> <begin>-<end> <flags> <offset> <pathname>
> 
> Signed-off-by: Christoph Manszewski <christoph.manszewski at intel.com>

Please make sure to CC Sunil on that stuff as well since he created the per client debugfs stuff.

The patch itself looks completely sane to me.

Regards,
Christian.

> ---
>  drivers/gpu/drm/xe/Makefile            |   3 +-
>  drivers/gpu/drm/xe/xe_client_debugfs.c | 118 +++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_client_debugfs.h |  19 ++++
>  drivers/gpu/drm/xe/xe_device.c         |   3 +
>  4 files changed, 142 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/xe/xe_client_debugfs.c
>  create mode 100644 drivers/gpu/drm/xe/xe_client_debugfs.h
> 
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index b932a9e70284..c1d8068d2a97 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -319,7 +319,8 @@ ifeq ($(CONFIG_DRM_FBDEV_EMULATION),y)
>  endif
>  
>  ifeq ($(CONFIG_DEBUG_FS),y)
> -	xe-y += xe_debugfs.o \
> +	xe-y += xe_client_debugfs.o \
> +		xe_debugfs.o \
>  		xe_gt_debugfs.o \
>  		xe_gt_sriov_vf_debugfs.o \
>  		xe_gt_stats.o \
> diff --git a/drivers/gpu/drm/xe/xe_client_debugfs.c b/drivers/gpu/drm/xe/xe_client_debugfs.c
> new file mode 100644
> index 000000000000..0b952038e698
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_client_debugfs.c
> @@ -0,0 +1,118 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#include "xe_client_debugfs.h"
> +
> +#include <linux/debugfs.h>
> +
> +#include "xe_debug_data.h"
> +#include "xe_debug_data_types.h"
> +#include "xe_device_types.h"
> +#include "xe_vm_types.h"
> +
> +#define MAX_LINE_LEN (64 + PATH_MAX)
> +
> +static ssize_t debug_data_read(struct file *file, char __user *buf, size_t count,
> +			       loff_t *ppos)
> +{
> +	struct xe_debug_data *dd;
> +	unsigned long vm_index;
> +	const char *path;
> +	char *kbuf;
> +	struct xe_vm *vm;
> +
> +	struct xe_file *xef = file->private_data;
> +	ssize_t total = 0;
> +	loff_t pos = 0;
> +
> +	if (!xef || !buf)
> +		return -EINVAL;
> +
> +	kbuf = kmalloc(MAX_LINE_LEN, GFP_KERNEL);
> +	if (!kbuf)
> +		return -ENOMEM;
> +
> +	mutex_lock(&xef->vm.lock);
> +
> +	xa_for_each(&xef->vm.xa, vm_index, vm) {
> +		mutex_lock(&vm->debug_data.lock);
> +		list_for_each_entry(dd, &vm->debug_data.list, link) {
> +			int len;
> +
> +			path = dd->flags & DRM_XE_VM_BIND_DEBUG_DATA_FLAG_PSEUDO ?
> +				xe_debug_data_pseudo_path_to_string(dd->pseudopath) :
> +				dd->pathname;
> +
> +			/* Format: <vm id> <begin>-<end> <flags> <offset> <pathname> */
> +			len = snprintf(kbuf, MAX_LINE_LEN, "%lu 0x%llx-0x%llx 0x%llx 0x%x\t%s\n",
> +				vm_index,
> +				dd->addr,
> +				dd->addr + dd->range,
> +				dd->flags,
> +				dd->offset,
> +				path);
> +
> +			if (pos + len <= *ppos) {
> +				pos += len;
> +				continue;
> +			}
> +
> +			if (pos < *ppos) {
> +				const int skip = *ppos - pos;
> +
> +				len -= skip;
> +				memmove(kbuf, kbuf + skip, len);
> +				pos = *ppos;
> +			}
> +
> +			if (total + len > count)
> +				len = count - total;
> +
> +			if (copy_to_user(buf + total, kbuf, len)) {
> +				mutex_unlock(&vm->debug_data.lock);
> +				mutex_unlock(&xef->vm.lock);
> +				kfree(kbuf);
> +				return -EFAULT;
> +			}
> +
> +			total += len;
> +			pos += len;
> +
> +			if (total >= count) {
> +				mutex_unlock(&vm->debug_data.lock);
> +				mutex_unlock(&xef->vm.lock);
> +				kfree(kbuf);
> +				*ppos = pos;
> +				return total;
> +			}
> +		}
> +		mutex_unlock(&vm->debug_data.lock);
> +	}
> +
> +	mutex_unlock(&xef->vm.lock);
> +	kfree(kbuf);
> +	*ppos = pos;
> +	return total;
> +}
> +
> +static int debug_data_open(struct inode *inode, struct file *file)
> +{
> +	struct xe_file *xef = inode->i_private;
> +
> +	file->private_data = xef;
> +	return 0;
> +}
> +
> +static const struct file_operations maps_fops = {
> +	.owner = THIS_MODULE,
> +	.open = debug_data_open,
> +	.read = debug_data_read,
> +	.llseek = default_llseek,
> +};
> +
> +void xe_client_debugfs_register(struct xe_file *xef)
> +{
> +	debugfs_create_file("debug_data", 0444, xef->drm->debugfs_client, xef, &maps_fops);
> +}
> diff --git a/drivers/gpu/drm/xe/xe_client_debugfs.h b/drivers/gpu/drm/xe/xe_client_debugfs.h
> new file mode 100644
> index 000000000000..9eace15c0a49
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_client_debugfs.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#ifndef _XE_CLIENT_DEBUGFS_H_
> +#define _XE_CLIENT_DEBUGFS_H_
> +
> +#include <linux/debugfs.h>
> +
> +struct xe_file;
> +
> +#ifdef CONFIG_DEBUG_FS
> +void xe_client_debugfs_register(struct xe_file *xef);
> +#else
> +static inline void xe_client_debugfs_register(struct xe_file *xef) { }
> +#endif
> +
> +#endif // _XE_CLIENT_DEBUGFS_H_
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 0249fb4aa966..af9c98a4f3a3 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -24,6 +24,7 @@
>  #include "regs/xe_regs.h"
>  #include "xe_bo.h"
>  #include "xe_bo_evict.h"
> +#include "xe_client_debugfs.h"
>  #include "xe_debugfs.h"
>  #include "xe_devcoredump.h"
>  #include "xe_device_sysfs.h"
> @@ -117,6 +118,8 @@ static int xe_file_open(struct drm_device *dev, struct drm_file *file)
>  		put_task_struct(task);
>  	}
>  
> +	xe_client_debugfs_register(xef);
> +
>  	return 0;
>  }
>