Commit 16daf3d9 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'wwan-debugfs-tweaks' 

Sergey Ryazanov says:

====================
WWAN debugfs tweaks

This is a follow-up series to just applied IOSM (and WWAN) debugfs
interface support [1]. The series has two main goals:
1. move the driver-specific debugfs knobs to a subdirectory;
2. make the debugfs interface optional for both IOSM and for the WWAN
   core.

As for the first part, I must say that it was my mistake. I suggested to
place debugfs entries under a common per WWAN device directory. But I
missed the driver subdirectory in the example, so it become:

/sys/kernel/debugfs/wwan/wwan0/trace

Since the traces collection is a driver-specific feature, it is better
to keep it under the driver-specific subdirectory:

/sys/kernel/debugfs/wwan/wwan0/iosm/trace

It is desirable to be able to entirely disable the debugfs interface. It
can be disabled for several reasons, including security and consumed
storage space. See detailed rationale with usage example in the 4th
patch.

The changes themselves are relatively simple, but require a code
rearrangement. So to make changes clear, I chose to split them into
preparatory and main changes and properly describe each of them.

IOSM part is compile-tested only since I do not have IOSM supported
device, so it needs Ack from the driver developers.

I would like to thank Johannes Berg and Leon Romanovsky. Their
suggestions and comments helped a lot to rework the initial
over-engineered solution to something less confusing and much more
simple. Thanks!

1. https://lore.kernel.org/netdev/20211120162155.1216081-1-m.chetan.kumar@linux.intel.com
2. https://patchwork.kernel.org/project/netdevbpf/patch/20211204174033.950528-1-arnd@kernel.org/
====================

Link: https://lore.kernel.org/r/20211207092140.19142-1-ryazanov.s.a@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents a43a0720 283e6f5a

drivers/net/wwan/Kconfig

+12 −1
Original line number Diff line number Diff line
@@ -16,6 +16,17 @@ config WWAN 


if WWAN



config WWAN_DEBUGFS

	bool "WWAN devices debugfs interface" if EXPERT

	depends on DEBUG_FS

	default y

	help

	  Enables debugfs infrastructure for the WWAN core and device drivers.



	  If this option is selected, then you can find the debug interface

	  elements for each WWAN device in a directory that is corresponding to

	  the device name: debugfs/wwan/wwanX.



config WWAN_HWSIM

	tristate "Simulated WWAN device"

	help
@@ -85,7 +96,7 @@ config IOSM 
	tristate "IOSM Driver for Intel M.2 WWAN Device"

	depends on INTEL_IOMMU

	select NET_DEVLINK

	select RELAY

	select RELAY if WWAN_DEBUGFS

	help

	  This driver enables Intel M.2 WWAN Device communication.

drivers/net/wwan/iosm/Makefile

+4 −1
Original line number Diff line number Diff line
@@ -21,7 +21,10 @@ iosm-y = \ 
	iosm_ipc_mux_codec.o		\

	iosm_ipc_devlink.o		\

	iosm_ipc_flash.o		\

	iosm_ipc_coredump.o		\

	iosm_ipc_coredump.o



iosm-$(CONFIG_WWAN_DEBUGFS) += \

	iosm_ipc_debugfs.o		\

	iosm_ipc_trace.o



obj-$(CONFIG_IOSM) := iosm.o

drivers/net/wwan/iosm/iosm_ipc_debugfs.c

0 → 100644
+29 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2020-2021 Intel Corporation.

 */



#include <linux/debugfs.h>

#include <linux/wwan.h>



#include "iosm_ipc_imem.h"

#include "iosm_ipc_trace.h"

#include "iosm_ipc_debugfs.h"



void ipc_debugfs_init(struct iosm_imem *ipc_imem)

{

	struct dentry *debugfs_pdev = wwan_get_debugfs_dir(ipc_imem->dev);



	ipc_imem->debugfs_dir = debugfs_create_dir(KBUILD_MODNAME,

						   debugfs_pdev);



	ipc_imem->trace = ipc_trace_init(ipc_imem);

	if (!ipc_imem->trace)

		dev_warn(ipc_imem->dev, "trace channel init failed");

}



void ipc_debugfs_deinit(struct iosm_imem *ipc_imem)

{

	ipc_trace_deinit(ipc_imem->trace);

	debugfs_remove_recursive(ipc_imem->debugfs_dir);

}

drivers/net/wwan/iosm/iosm_ipc_debugfs.h

0 → 100644
+17 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only

 *

 * Copyright (C) 2020-2021 Intel Corporation.

 */



#ifndef IOSM_IPC_DEBUGFS_H

#define IOSM_IPC_DEBUGFS_H



#ifdef CONFIG_WWAN_DEBUGFS

void ipc_debugfs_init(struct iosm_imem *ipc_imem);

void ipc_debugfs_deinit(struct iosm_imem *ipc_imem);

#else

static inline void ipc_debugfs_init(struct iosm_imem *ipc_imem) {}

static inline void ipc_debugfs_deinit(struct iosm_imem *ipc_imem) {}

#endif



#endif

drivers/net/wwan/iosm/iosm_ipc_imem.c

+5 −8
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include "iosm_ipc_imem.h"

#include "iosm_ipc_port.h"

#include "iosm_ipc_trace.h"

#include "iosm_ipc_debugfs.h"



/* Check the wwan ips if it is valid with Channel as input. */

static int ipc_imem_check_wwan_ips(struct ipc_mem_channel *chnl)
@@ -272,8 +273,8 @@ static void ipc_imem_dl_skb_process(struct iosm_imem *ipc_imem, 
		if (port_id == IPC_MEM_CTRL_CHL_ID_7)

			ipc_imem_sys_devlink_notify_rx(ipc_imem->ipc_devlink,

						       skb);

		else if (port_id == ipc_imem->trace->chl_id)

			ipc_trace_port_rx(ipc_imem->trace, skb);

		else if (ipc_is_trace_channel(ipc_imem, port_id))

			ipc_trace_port_rx(ipc_imem, skb);

		else

			wwan_port_rx(ipc_imem->ipc_port[port_id]->iosm_port,

				     skb);
@@ -554,11 +555,7 @@ static void ipc_imem_run_state_worker(struct work_struct *instance) 
		ctrl_chl_idx++;

	}



	ipc_imem->trace = ipc_imem_trace_channel_init(ipc_imem);

	if (!ipc_imem->trace) {

		dev_err(ipc_imem->dev, "trace channel init failed");

		return;

	}

	ipc_debugfs_init(ipc_imem);



	ipc_task_queue_send_task(ipc_imem, ipc_imem_send_mdm_rdy_cb, 0, NULL, 0,

				 false);
@@ -1175,7 +1172,7 @@ void ipc_imem_cleanup(struct iosm_imem *ipc_imem) 


	if (test_and_clear_bit(FULLY_FUNCTIONAL, &ipc_imem->flag)) {

		ipc_mux_deinit(ipc_imem->mux);

		ipc_trace_deinit(ipc_imem->trace);

		ipc_debugfs_deinit(ipc_imem);

		ipc_wwan_deinit(ipc_imem->wwan);

		ipc_port_deinit(ipc_imem->ipc_port);

	}