* [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
@ 2015-12-13 1:41 Paul Gortmaker
2015-12-13 1:41 ` [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular Paul Gortmaker
` (2 more replies)
0 siblings, 3 replies; 20+ messages in thread
From: Paul Gortmaker @ 2015-12-13 1:41 UTC (permalink / raw)
To: linux-arm-kernel
This series of commits is a slice of a larger project to ensure
people don't have dead code for module removal in non-modular
drivers. Overall there was roughly 5k lines of dead code in the
kernel due to this. So far we've fixed several areas, like tty,
x86, net, etc. and we continue to work on other areas.
There are several reasons to not use module_init for code that can
never be built as a module, but the big ones are:
(1) it is easy to accidentally code up unused module_exit and remove code
(2) it can be misleading when reading the source, thinking it can be
modular when the Makefile and/or Kconfig prohibit it
(3) it requires the include of the module.h header file which in turn
includes nearly everything else.
Here we convert some module_init() calls into device_initcall() and delete
any module_exit and remove code that gets orphaned in the process, for
an overall net code reduction, which is always welcome.
The use of device_initcall ensures that the init function ordering
remains unchanged, but one could argue that PCI host code might be more
appropriate to be handled under subsys_initcall. Fortunately we can
revisit making this extra change at a later date if desired; it does
not need to happen now, and we reduce the risk of introducing
regressions at this point in time by separating the two changes.
Over half of the drivers changed here already explicitly disallowed any
unbind operations. For the rest we make them the same, since there is
not really any sensible use case to unbind any built-in bus support that
I can think of.
I have more "avoid module usage in non-modular code" cleanups for the
PCI subsystem, but these all have a common theme and it makes for a
more maintainer friendly series size to just ask to digest these 1st.
Testing was done on linux-next, using an ARCH=arm allmodconfig and then
explicitly building the files changed in this series. If desired, I
can provide a v4.4-rc4 based branch for merging vs e-mail processing,
since I don't think the underlying baseline is overly important for
this (largely trivial) series of patches.
Paul.
---
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Murali Karicheri <m-karicheri2@ti.com>
Cc: Pratyush Anand <pratyush.anand@gmail.com>
Cc: Richard Zhu <Richard.Zhu@freescale.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-omap@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: rfi@lists.rocketboards.org
Paul Gortmaker (10):
drivers/pci: make host/pci-imx6.c driver explicitly non-modular
drivers/pci: make host/pcie-spear13xx.c driver explicitly non-modular
drivers/pci: make host/pci-mvebu.c explicitly non-modular
drivers/pci: make host/pci-dra7xx.c explicitly non-modular
drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular
drivers/pci: make host/pci-tegra.c explicitly non-modular
drivers/pci: make host/pcie-rcar.c explicitly non-modular
drivers/pci: make host/pcie-xilinx.c explicitly non-modular
drivers/pci: make host/pci-keystone.c explicitly non-modular
drivers/pci: make host/pcie-altera.c explicitly non-modular
drivers/pci/host/pci-dra7xx.c | 31 +++--------------------
drivers/pci/host/pci-imx6.c | 12 +++------
drivers/pci/host/pci-keystone.c | 21 +++-------------
drivers/pci/host/pci-mvebu.c | 11 +++-----
drivers/pci/host/pci-rcar-gen2.c | 12 +++------
drivers/pci/host/pci-tegra.c | 11 +++-----
drivers/pci/host/pcie-altera.c | 12 ++++-----
drivers/pci/host/pcie-rcar.c | 11 +++-----
drivers/pci/host/pcie-spear13xx.c | 10 +++-----
drivers/pci/host/pcie-xilinx.c | 53 ++-------------------------------------
10 files changed, 35 insertions(+), 149 deletions(-)
--
2.6.1
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular
2015-12-13 1:41 [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Paul Gortmaker
@ 2015-12-13 1:41 ` Paul Gortmaker
2015-12-13 10:59 ` Geert Uytterhoeven
2015-12-14 5:19 ` Simon Horman
2015-12-13 1:41 ` [PATCH 07/10] drivers/pci: make host/pcie-rcar.c " Paul Gortmaker
2015-12-14 8:19 ` [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Geert Uytterhoeven
2 siblings, 2 replies; 20+ messages in thread
From: Paul Gortmaker @ 2015-12-13 1:41 UTC (permalink / raw)
To: linux-kernel
Cc: Paul Gortmaker, Simon Horman, Bjorn Helgaas, linux-pci, linux-sh
The Kconfig currently controlling compilation of this code is:
drivers/pci/host/Kconfig:config PCI_RCAR_GEN2
drivers/pci/host/Kconfig: bool "Renesas R-Car Gen2 Internal PCI controller"
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.
We don't have to disallow a driver unbind, since that is already
done for us in this driver.
Since module_platform_driver() uses the same init level priority as
builtin_platform_driver() the init ordering remains unchanged with
this commit.
We don't replace module.h with init.h since the file already has that.
Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.
Cc: Simon Horman <horms@verge.net.au>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/pci/host/pci-rcar-gen2.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c
index c4f64bfee551..81dda40c7a9f 100644
--- a/drivers/pci/host/pci-rcar-gen2.c
+++ b/drivers/pci/host/pci-rcar-gen2.c
@@ -4,6 +4,8 @@
* Copyright (C) 2013 Renesas Solutions Corp.
* Copyright (C) 2013 Cogent Embedded, Inc.
*
+ * Module Author: Valentine Barshak <valentine.barshak@cogentembedded.com>
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
@@ -14,7 +16,6 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
-#include <linux/module.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
@@ -366,8 +367,6 @@ static struct of_device_id rcar_pci_of_match[] = {
{ },
};
-MODULE_DEVICE_TABLE(of, rcar_pci_of_match);
-
static struct platform_driver rcar_pci_driver = {
.driver = {
.name = "pci-rcar-gen2",
@@ -376,9 +375,4 @@ static struct platform_driver rcar_pci_driver = {
},
.probe = rcar_pci_probe,
};
-
-module_platform_driver(rcar_pci_driver);
-
-MODULE_LICENSE("GPL v2");
-MODULE_DESCRIPTION("Renesas R-Car Gen2 internal PCI");
-MODULE_AUTHOR("Valentine Barshak <valentine.barshak@cogentembedded.com>");
+builtin_platform_driver(rcar_pci_driver);
--
2.6.1
^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH 07/10] drivers/pci: make host/pcie-rcar.c explicitly non-modular
2015-12-13 1:41 [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Paul Gortmaker
2015-12-13 1:41 ` [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular Paul Gortmaker
@ 2015-12-13 1:41 ` Paul Gortmaker
2015-12-13 10:58 ` Geert Uytterhoeven
2015-12-14 5:19 ` Simon Horman
2015-12-14 8:19 ` [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Geert Uytterhoeven
2 siblings, 2 replies; 20+ messages in thread
From: Paul Gortmaker @ 2015-12-13 1:41 UTC (permalink / raw)
To: linux-kernel
Cc: Paul Gortmaker, Simon Horman, Bjorn Helgaas, linux-pci, linux-sh
The Kconfig currently controlling compilation of this code is:
drivers/pci/host/Kconfig:config PCI_RCAR_GEN2_PCIE
drivers/pci/host/Kconfig: bool "Renesas R-Car PCIe controller"
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.
Since module_platform_driver() uses the same init level priority as
builtin_platform_driver() the init ordering remains unchanged with
this commit.
We don't have to disallow a driver unbind, since that is already
done for us in this driver.
Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.
Cc: Simon Horman <horms@verge.net.au>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/pci/host/pcie-rcar.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index f4fa6c537448..2c619277d265 100644
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -7,6 +7,8 @@
* arch/sh/drivers/pci/ops-sh7786.c
* Copyright (C) 2009 - 2011 Paul Mundt
*
+ * Module Author: Phil Edworthy <phil.edworthy@renesas.com>
+ *
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
@@ -18,7 +20,7 @@
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/init.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
@@ -921,7 +923,6 @@ static const struct of_device_id rcar_pcie_of_match[] = {
{ .compatible = "renesas,pcie-r8a7791", .data = rcar_pcie_hw_init },
{},
};
-MODULE_DEVICE_TABLE(of, rcar_pcie_of_match);
static int rcar_pcie_probe(struct platform_device *pdev)
{
@@ -1007,8 +1008,4 @@ static struct platform_driver rcar_pcie_driver = {
},
.probe = rcar_pcie_probe,
};
-module_platform_driver(rcar_pcie_driver);
-
-MODULE_AUTHOR("Phil Edworthy <phil.edworthy@renesas.com>");
-MODULE_DESCRIPTION("Renesas R-Car PCIe driver");
-MODULE_LICENSE("GPL v2");
+builtin_platform_driver(rcar_pcie_driver);
--
2.6.1
^ permalink raw reply related [flat|nested] 20+ messages in thread
* Re: [PATCH 07/10] drivers/pci: make host/pcie-rcar.c explicitly non-modular
2015-12-13 1:41 ` [PATCH 07/10] drivers/pci: make host/pcie-rcar.c " Paul Gortmaker
@ 2015-12-13 10:58 ` Geert Uytterhoeven
2015-12-13 18:20 ` Paul Gortmaker
2015-12-17 11:32 ` Phil Edworthy
2015-12-14 5:19 ` Simon Horman
1 sibling, 2 replies; 20+ messages in thread
From: Geert Uytterhoeven @ 2015-12-13 10:58 UTC (permalink / raw)
To: Paul Gortmaker, Phil Edworthy
Cc: linux-kernel@vger.kernel.org, Simon Horman, Bjorn Helgaas,
linux-pci, Linux-sh list
CC MODULE_AUTHOR
On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
<paul.gortmaker@windriver.com> wrote:
> The Kconfig currently controlling compilation of this code is:
>
> drivers/pci/host/Kconfig:config PCI_RCAR_GEN2_PCIE
> drivers/pci/host/Kconfig: bool "Renesas R-Car PCIe controller"
>
> ...meaning that it currently is not being built as a module by anyone.
>
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
>
> Since module_platform_driver() uses the same init level priority as
> builtin_platform_driver() the init ordering remains unchanged with
> this commit.
>
> We don't have to disallow a driver unbind, since that is already
> done for us in this driver.
>
> Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
>
> We also delete the MODULE_LICENSE tag etc. since all that information
> was (or is now) contained at the top of the file in the comments.
>
> Cc: Simon Horman <horms@verge.net.au>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: linux-pci@vger.kernel.org
> Cc: linux-sh@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
> drivers/pci/host/pcie-rcar.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
> index f4fa6c537448..2c619277d265 100644
> --- a/drivers/pci/host/pcie-rcar.c
> +++ b/drivers/pci/host/pcie-rcar.c
> @@ -7,6 +7,8 @@
> * arch/sh/drivers/pci/ops-sh7786.c
> * Copyright (C) 2009 - 2011 Paul Mundt
> *
> + * Module Author: Phil Edworthy <phil.edworthy@renesas.com>
> + *
> * This file is licensed under the terms of the GNU General Public
> * License version 2. This program is licensed "as is" without any
> * warranty of any kind, whether express or implied.
> @@ -18,7 +20,7 @@
> #include <linux/irq.h>
> #include <linux/irqdomain.h>
> #include <linux/kernel.h>
> -#include <linux/module.h>
> +#include <linux/init.h>
> #include <linux/msi.h>
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> @@ -921,7 +923,6 @@ static const struct of_device_id rcar_pcie_of_match[] = {
> { .compatible = "renesas,pcie-r8a7791", .data = rcar_pcie_hw_init },
> {},
> };
> -MODULE_DEVICE_TABLE(of, rcar_pcie_of_match);
>
> static int rcar_pcie_probe(struct platform_device *pdev)
> {
> @@ -1007,8 +1008,4 @@ static struct platform_driver rcar_pcie_driver = {
> },
> .probe = rcar_pcie_probe,
> };
> -module_platform_driver(rcar_pcie_driver);
> -
> -MODULE_AUTHOR("Phil Edworthy <phil.edworthy@renesas.com>");
> -MODULE_DESCRIPTION("Renesas R-Car PCIe driver");
> -MODULE_LICENSE("GPL v2");
> +builtin_platform_driver(rcar_pcie_driver);
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular
2015-12-13 1:41 ` [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular Paul Gortmaker
@ 2015-12-13 10:59 ` Geert Uytterhoeven
2015-12-13 18:15 ` Paul Gortmaker
2015-12-14 5:19 ` Simon Horman
1 sibling, 1 reply; 20+ messages in thread
From: Geert Uytterhoeven @ 2015-12-13 10:59 UTC (permalink / raw)
To: Paul Gortmaker, Valentine Barshak
Cc: linux-kernel@vger.kernel.org, Simon Horman, Bjorn Helgaas,
linux-pci, Linux-sh list
CC MODULE_AUTHOR
On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
<paul.gortmaker@windriver.com> wrote:
> The Kconfig currently controlling compilation of this code is:
>
> drivers/pci/host/Kconfig:config PCI_RCAR_GEN2
> drivers/pci/host/Kconfig: bool "Renesas R-Car Gen2 Internal PCI controller"
>
> ...meaning that it currently is not being built as a module by anyone.
>
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
>
> We don't have to disallow a driver unbind, since that is already
> done for us in this driver.
>
> Since module_platform_driver() uses the same init level priority as
> builtin_platform_driver() the init ordering remains unchanged with
> this commit.
>
> We don't replace module.h with init.h since the file already has that.
>
> Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
>
> We also delete the MODULE_LICENSE tag etc. since all that information
> was (or is now) contained at the top of the file in the comments.
>
> Cc: Simon Horman <horms@verge.net.au>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: linux-pci@vger.kernel.org
> Cc: linux-sh@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
> drivers/pci/host/pci-rcar-gen2.c | 12 +++---------
> 1 file changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c
> index c4f64bfee551..81dda40c7a9f 100644
> --- a/drivers/pci/host/pci-rcar-gen2.c
> +++ b/drivers/pci/host/pci-rcar-gen2.c
> @@ -4,6 +4,8 @@
> * Copyright (C) 2013 Renesas Solutions Corp.
> * Copyright (C) 2013 Cogent Embedded, Inc.
> *
> + * Module Author: Valentine Barshak <valentine.barshak@cogentembedded.com>
> + *
> * This program is free software; you can redistribute it and/or modify
> * it under the terms of the GNU General Public License version 2 as
> * published by the Free Software Foundation.
> @@ -14,7 +16,6 @@
> #include <linux/interrupt.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> -#include <linux/module.h>
> #include <linux/of_pci.h>
> #include <linux/pci.h>
> #include <linux/platform_device.h>
> @@ -366,8 +367,6 @@ static struct of_device_id rcar_pci_of_match[] = {
> { },
> };
>
> -MODULE_DEVICE_TABLE(of, rcar_pci_of_match);
> -
> static struct platform_driver rcar_pci_driver = {
> .driver = {
> .name = "pci-rcar-gen2",
> @@ -376,9 +375,4 @@ static struct platform_driver rcar_pci_driver = {
> },
> .probe = rcar_pci_probe,
> };
> -
> -module_platform_driver(rcar_pci_driver);
> -
> -MODULE_LICENSE("GPL v2");
> -MODULE_DESCRIPTION("Renesas R-Car Gen2 internal PCI");
> -MODULE_AUTHOR("Valentine Barshak <valentine.barshak@cogentembedded.com>");
> +builtin_platform_driver(rcar_pci_driver);
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular
2015-12-13 10:59 ` Geert Uytterhoeven
@ 2015-12-13 18:15 ` Paul Gortmaker
2015-12-13 20:37 ` Joe Perches
0 siblings, 1 reply; 20+ messages in thread
From: Paul Gortmaker @ 2015-12-13 18:15 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Valentine Barshak, linux-kernel@vger.kernel.org, Simon Horman,
Bjorn Helgaas, linux-pci, Linux-sh list, Joe Perches
[Re: [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular] On 13/12/2015 (Sun 11:59) Geert Uytterhoeven wrote:
> CC MODULE_AUTHOR
Thanks, I just assumed get-maintainer.pl would have automatically
collected that up with the other names it emits. Apparently not.
Joe: is there a reason it doesn't use the module author field?
Paul.
--
>
> On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
> > The Kconfig currently controlling compilation of this code is:
> >
> > drivers/pci/host/Kconfig:config PCI_RCAR_GEN2
> > drivers/pci/host/Kconfig: bool "Renesas R-Car Gen2 Internal PCI controller"
> >
> > ...meaning that it currently is not being built as a module by anyone.
> >
> > Lets remove the modular code that is essentially orphaned, so that
> > when reading the driver there is no doubt it is builtin-only.
> >
> > We don't have to disallow a driver unbind, since that is already
> > done for us in this driver.
> >
> > Since module_platform_driver() uses the same init level priority as
> > builtin_platform_driver() the init ordering remains unchanged with
> > this commit.
> >
> > We don't replace module.h with init.h since the file already has that.
> >
> > Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
> >
> > We also delete the MODULE_LICENSE tag etc. since all that information
> > was (or is now) contained at the top of the file in the comments.
> >
> > Cc: Simon Horman <horms@verge.net.au>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: linux-pci@vger.kernel.org
> > Cc: linux-sh@vger.kernel.org
> > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> > ---
> > drivers/pci/host/pci-rcar-gen2.c | 12 +++---------
> > 1 file changed, 3 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c
> > index c4f64bfee551..81dda40c7a9f 100644
> > --- a/drivers/pci/host/pci-rcar-gen2.c
> > +++ b/drivers/pci/host/pci-rcar-gen2.c
> > @@ -4,6 +4,8 @@
> > * Copyright (C) 2013 Renesas Solutions Corp.
> > * Copyright (C) 2013 Cogent Embedded, Inc.
> > *
> > + * Module Author: Valentine Barshak <valentine.barshak@cogentembedded.com>
> > + *
> > * This program is free software; you can redistribute it and/or modify
> > * it under the terms of the GNU General Public License version 2 as
> > * published by the Free Software Foundation.
> > @@ -14,7 +16,6 @@
> > #include <linux/interrupt.h>
> > #include <linux/io.h>
> > #include <linux/kernel.h>
> > -#include <linux/module.h>
> > #include <linux/of_pci.h>
> > #include <linux/pci.h>
> > #include <linux/platform_device.h>
> > @@ -366,8 +367,6 @@ static struct of_device_id rcar_pci_of_match[] = {
> > { },
> > };
> >
> > -MODULE_DEVICE_TABLE(of, rcar_pci_of_match);
> > -
> > static struct platform_driver rcar_pci_driver = {
> > .driver = {
> > .name = "pci-rcar-gen2",
> > @@ -376,9 +375,4 @@ static struct platform_driver rcar_pci_driver = {
> > },
> > .probe = rcar_pci_probe,
> > };
> > -
> > -module_platform_driver(rcar_pci_driver);
> > -
> > -MODULE_LICENSE("GPL v2");
> > -MODULE_DESCRIPTION("Renesas R-Car Gen2 internal PCI");
> > -MODULE_AUTHOR("Valentine Barshak <valentine.barshak@cogentembedded.com>");
> > +builtin_platform_driver(rcar_pci_driver);
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 07/10] drivers/pci: make host/pcie-rcar.c explicitly non-modular
2015-12-13 10:58 ` Geert Uytterhoeven
@ 2015-12-13 18:20 ` Paul Gortmaker
2015-12-17 11:32 ` Phil Edworthy
1 sibling, 0 replies; 20+ messages in thread
From: Paul Gortmaker @ 2015-12-13 18:20 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Phil Edworthy, linux-kernel@vger.kernel.org, Simon Horman,
Bjorn Helgaas, linux-pci, Linux-sh list
[Re: [PATCH 07/10] drivers/pci: make host/pcie-rcar.c explicitly non-modular] On 13/12/2015 (Sun 11:58) Geert Uytterhoeven wrote:
> CC MODULE_AUTHOR
Yep, thanks -- I'll check for future sends to ensure get_maintainer.pl
hasn't omitted the module author. Looks like it may emit the module
author if they have been actively committing, but that won't work in the
authored and then largely left it alone case.
P.
--
>
> On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
> > The Kconfig currently controlling compilation of this code is:
> >
> > drivers/pci/host/Kconfig:config PCI_RCAR_GEN2_PCIE
> > drivers/pci/host/Kconfig: bool "Renesas R-Car PCIe controller"
> >
> > ...meaning that it currently is not being built as a module by anyone.
> >
> > Lets remove the modular code that is essentially orphaned, so that
> > when reading the driver there is no doubt it is builtin-only.
> >
> > Since module_platform_driver() uses the same init level priority as
> > builtin_platform_driver() the init ordering remains unchanged with
> > this commit.
> >
> > We don't have to disallow a driver unbind, since that is already
> > done for us in this driver.
> >
> > Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
> >
> > We also delete the MODULE_LICENSE tag etc. since all that information
> > was (or is now) contained at the top of the file in the comments.
> >
> > Cc: Simon Horman <horms@verge.net.au>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: linux-pci@vger.kernel.org
> > Cc: linux-sh@vger.kernel.org
> > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> > ---
> > drivers/pci/host/pcie-rcar.c | 11 ++++-------
> > 1 file changed, 4 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
> > index f4fa6c537448..2c619277d265 100644
> > --- a/drivers/pci/host/pcie-rcar.c
> > +++ b/drivers/pci/host/pcie-rcar.c
> > @@ -7,6 +7,8 @@
> > * arch/sh/drivers/pci/ops-sh7786.c
> > * Copyright (C) 2009 - 2011 Paul Mundt
> > *
> > + * Module Author: Phil Edworthy <phil.edworthy@renesas.com>
> > + *
> > * This file is licensed under the terms of the GNU General Public
> > * License version 2. This program is licensed "as is" without any
> > * warranty of any kind, whether express or implied.
> > @@ -18,7 +20,7 @@
> > #include <linux/irq.h>
> > #include <linux/irqdomain.h>
> > #include <linux/kernel.h>
> > -#include <linux/module.h>
> > +#include <linux/init.h>
> > #include <linux/msi.h>
> > #include <linux/of_address.h>
> > #include <linux/of_irq.h>
> > @@ -921,7 +923,6 @@ static const struct of_device_id rcar_pcie_of_match[] = {
> > { .compatible = "renesas,pcie-r8a7791", .data = rcar_pcie_hw_init },
> > {},
> > };
> > -MODULE_DEVICE_TABLE(of, rcar_pcie_of_match);
> >
> > static int rcar_pcie_probe(struct platform_device *pdev)
> > {
> > @@ -1007,8 +1008,4 @@ static struct platform_driver rcar_pcie_driver = {
> > },
> > .probe = rcar_pcie_probe,
> > };
> > -module_platform_driver(rcar_pcie_driver);
> > -
> > -MODULE_AUTHOR("Phil Edworthy <phil.edworthy@renesas.com>");
> > -MODULE_DESCRIPTION("Renesas R-Car PCIe driver");
> > -MODULE_LICENSE("GPL v2");
> > +builtin_platform_driver(rcar_pcie_driver);
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular
2015-12-13 18:15 ` Paul Gortmaker
@ 2015-12-13 20:37 ` Joe Perches
0 siblings, 0 replies; 20+ messages in thread
From: Joe Perches @ 2015-12-13 20:37 UTC (permalink / raw)
To: Paul Gortmaker, Geert Uytterhoeven
Cc: Valentine Barshak, linux-kernel@vger.kernel.org, Simon Horman,
Bjorn Helgaas, linux-pci, Linux-sh list
On Sun, 2015-12-13 at 13:15 -0500, Paul Gortmaker wrote:
> [Re: [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly
> non-modular] On 13/12/2015 (Sun 11:59) Geert Uytterhoeven wrote:
>
> > CC MODULE_AUTHOR
>
> Thanks, I just assumed get-maintainer.pl would have automatically
> collected that up with the other names it emits. Apparently not.
>
> Joe: is there a reason it doesn't use the module author field?
Because it's frequently out-of-date and the
MAINTAINERS entry is generally enough.
If you want to add it, there's an option for it
--file-emails
> Paul
cheers, Joe
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 07/10] drivers/pci: make host/pcie-rcar.c explicitly non-modular
2015-12-13 1:41 ` [PATCH 07/10] drivers/pci: make host/pcie-rcar.c " Paul Gortmaker
2015-12-13 10:58 ` Geert Uytterhoeven
@ 2015-12-14 5:19 ` Simon Horman
1 sibling, 0 replies; 20+ messages in thread
From: Simon Horman @ 2015-12-14 5:19 UTC (permalink / raw)
To: Paul Gortmaker; +Cc: linux-kernel, Bjorn Helgaas, linux-pci, linux-sh
On Sat, Dec 12, 2015 at 08:41:54PM -0500, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
>
> drivers/pci/host/Kconfig:config PCI_RCAR_GEN2_PCIE
> drivers/pci/host/Kconfig: bool "Renesas R-Car PCIe controller"
>
> ...meaning that it currently is not being built as a module by anyone.
>
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
>
> Since module_platform_driver() uses the same init level priority as
> builtin_platform_driver() the init ordering remains unchanged with
> this commit.
>
> We don't have to disallow a driver unbind, since that is already
> done for us in this driver.
>
> Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
>
> We also delete the MODULE_LICENSE tag etc. since all that information
> was (or is now) contained at the top of the file in the comments.
>
> Cc: Simon Horman <horms@verge.net.au>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: linux-pci@vger.kernel.org
> Cc: linux-sh@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular
2015-12-13 1:41 ` [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular Paul Gortmaker
2015-12-13 10:59 ` Geert Uytterhoeven
@ 2015-12-14 5:19 ` Simon Horman
1 sibling, 0 replies; 20+ messages in thread
From: Simon Horman @ 2015-12-14 5:19 UTC (permalink / raw)
To: Paul Gortmaker; +Cc: linux-kernel, Bjorn Helgaas, linux-pci, linux-sh
On Sat, Dec 12, 2015 at 08:41:52PM -0500, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
>
> drivers/pci/host/Kconfig:config PCI_RCAR_GEN2
> drivers/pci/host/Kconfig: bool "Renesas R-Car Gen2 Internal PCI controller"
>
> ...meaning that it currently is not being built as a module by anyone.
>
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
>
> We don't have to disallow a driver unbind, since that is already
> done for us in this driver.
>
> Since module_platform_driver() uses the same init level priority as
> builtin_platform_driver() the init ordering remains unchanged with
> this commit.
>
> We don't replace module.h with init.h since the file already has that.
>
> Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
>
> We also delete the MODULE_LICENSE tag etc. since all that information
> was (or is now) contained at the top of the file in the comments.
>
> Cc: Simon Horman <horms@verge.net.au>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: linux-pci@vger.kernel.org
> Cc: linux-sh@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
2015-12-13 1:41 [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Paul Gortmaker
2015-12-13 1:41 ` [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular Paul Gortmaker
2015-12-13 1:41 ` [PATCH 07/10] drivers/pci: make host/pcie-rcar.c " Paul Gortmaker
@ 2015-12-14 8:19 ` Geert Uytterhoeven
2015-12-14 8:24 ` Thierry Reding
2 siblings, 1 reply; 20+ messages in thread
From: Geert Uytterhoeven @ 2015-12-14 8:19 UTC (permalink / raw)
To: linux-arm-kernel
Hi Paul,
On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
<paul.gortmaker@windriver.com> wrote:
> This series of commits is a slice of a larger project to ensure
> people don't have dead code for module removal in non-modular
> drivers. Overall there was roughly 5k lines of dead code in the
> kernel due to this. So far we've fixed several areas, like tty,
> x86, net, etc. and we continue to work on other areas.
>
> There are several reasons to not use module_init for code that can
> never be built as a module, but the big ones are:
>
> (1) it is easy to accidentally code up unused module_exit and remove code
> (2) it can be misleading when reading the source, thinking it can be
> modular when the Makefile and/or Kconfig prohibit it
> (3) it requires the include of the module.h header file which in turn
> includes nearly everything else.
>
> Here we convert some module_init() calls into device_initcall() and delete
> any module_exit and remove code that gets orphaned in the process, for
> an overall net code reduction, which is always welcome.
>
> The use of device_initcall ensures that the init function ordering
> remains unchanged, but one could argue that PCI host code might be more
> appropriate to be handled under subsys_initcall. Fortunately we can
> revisit making this extra change at a later date if desired; it does
> not need to happen now, and we reduce the risk of introducing
> regressions at this point in time by separating the two changes.
>
> Over half of the drivers changed here already explicitly disallowed any
> unbind operations. For the rest we make them the same, since there is
> not really any sensible use case to unbind any built-in bus support that
> I can think of.
Personally, I think all of these should become tristate, so distro kernels
don't have to build in PCI(e) support for all SoCs. multi_v7_defconfig kernels
are becoming too big.
That does not preclude making these modules un-unloadable, though.
> Paul Gortmaker (10):
> drivers/pci: make host/pci-imx6.c driver explicitly non-modular
> drivers/pci: make host/pcie-spear13xx.c driver explicitly non-modular
> drivers/pci: make host/pci-mvebu.c explicitly non-modular
> drivers/pci: make host/pci-dra7xx.c explicitly non-modular
> drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular
> drivers/pci: make host/pci-tegra.c explicitly non-modular
> drivers/pci: make host/pcie-rcar.c explicitly non-modular
> drivers/pci: make host/pcie-xilinx.c explicitly non-modular
> drivers/pci: make host/pci-keystone.c explicitly non-modular
> drivers/pci: make host/pcie-altera.c explicitly non-modular
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
2015-12-14 8:19 ` [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Geert Uytterhoeven
@ 2015-12-14 8:24 ` Thierry Reding
2015-12-14 8:26 ` Michal Simek
2015-12-14 8:33 ` Ley Foon Tan
0 siblings, 2 replies; 20+ messages in thread
From: Thierry Reding @ 2015-12-14 8:24 UTC (permalink / raw)
To: linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 2553 bytes --]
On Mon, Dec 14, 2015 at 09:19:30AM +0100, Geert Uytterhoeven wrote:
> Hi Paul,
>
> On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
> <paul.gortmaker@windriver.com> wrote:
> > This series of commits is a slice of a larger project to ensure
> > people don't have dead code for module removal in non-modular
> > drivers. Overall there was roughly 5k lines of dead code in the
> > kernel due to this. So far we've fixed several areas, like tty,
> > x86, net, etc. and we continue to work on other areas.
> >
> > There are several reasons to not use module_init for code that can
> > never be built as a module, but the big ones are:
> >
> > (1) it is easy to accidentally code up unused module_exit and remove code
> > (2) it can be misleading when reading the source, thinking it can be
> > modular when the Makefile and/or Kconfig prohibit it
> > (3) it requires the include of the module.h header file which in turn
> > includes nearly everything else.
> >
> > Here we convert some module_init() calls into device_initcall() and delete
> > any module_exit and remove code that gets orphaned in the process, for
> > an overall net code reduction, which is always welcome.
> >
> > The use of device_initcall ensures that the init function ordering
> > remains unchanged, but one could argue that PCI host code might be more
> > appropriate to be handled under subsys_initcall. Fortunately we can
> > revisit making this extra change at a later date if desired; it does
> > not need to happen now, and we reduce the risk of introducing
> > regressions at this point in time by separating the two changes.
> >
> > Over half of the drivers changed here already explicitly disallowed any
> > unbind operations. For the rest we make them the same, since there is
> > not really any sensible use case to unbind any built-in bus support that
> > I can think of.
>
> Personally, I think all of these should become tristate, so distro kernels
> don't have to build in PCI(e) support for all SoCs. multi_v7_defconfig kernels
> are becoming too big.
>
> That does not preclude making these modules un-unloadable, though.
Most of these can't be made tristate as-is, because they use symbols
that aren't exported. Many of those symbols can easily be exported, so
its just a matter of getting the respective patches merged. I disagree
with making the modules non-unloadable, though. I have a local branch
with changes necessary to unload the host controller driver and it
works just fine.
Thierry
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
2015-12-14 8:24 ` Thierry Reding
@ 2015-12-14 8:26 ` Michal Simek
2015-12-14 8:33 ` Ley Foon Tan
1 sibling, 0 replies; 20+ messages in thread
From: Michal Simek @ 2015-12-14 8:26 UTC (permalink / raw)
To: linux-arm-kernel
On 14.12.2015 09:24, Thierry Reding wrote:
> On Mon, Dec 14, 2015 at 09:19:30AM +0100, Geert Uytterhoeven wrote:
>> Hi Paul,
>>
>> On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
>> <paul.gortmaker@windriver.com> wrote:
>>> This series of commits is a slice of a larger project to ensure
>>> people don't have dead code for module removal in non-modular
>>> drivers. Overall there was roughly 5k lines of dead code in the
>>> kernel due to this. So far we've fixed several areas, like tty,
>>> x86, net, etc. and we continue to work on other areas.
>>>
>>> There are several reasons to not use module_init for code that can
>>> never be built as a module, but the big ones are:
>>>
>>> (1) it is easy to accidentally code up unused module_exit and remove code
>>> (2) it can be misleading when reading the source, thinking it can be
>>> modular when the Makefile and/or Kconfig prohibit it
>>> (3) it requires the include of the module.h header file which in turn
>>> includes nearly everything else.
>>>
>>> Here we convert some module_init() calls into device_initcall() and delete
>>> any module_exit and remove code that gets orphaned in the process, for
>>> an overall net code reduction, which is always welcome.
>>>
>>> The use of device_initcall ensures that the init function ordering
>>> remains unchanged, but one could argue that PCI host code might be more
>>> appropriate to be handled under subsys_initcall. Fortunately we can
>>> revisit making this extra change at a later date if desired; it does
>>> not need to happen now, and we reduce the risk of introducing
>>> regressions at this point in time by separating the two changes.
>>>
>>> Over half of the drivers changed here already explicitly disallowed any
>>> unbind operations. For the rest we make them the same, since there is
>>> not really any sensible use case to unbind any built-in bus support that
>>> I can think of.
>>
>> Personally, I think all of these should become tristate, so distro kernels
>> don't have to build in PCI(e) support for all SoCs. multi_v7_defconfig kernels
>> are becoming too big.
>>
>> That does not preclude making these modules un-unloadable, though.
>
> Most of these can't be made tristate as-is, because they use symbols
> that aren't exported. Many of those symbols can easily be exported, so
> its just a matter of getting the respective patches merged. I disagree
> with making the modules non-unloadable, though. I have a local branch
> with changes necessary to unload the host controller driver and it
> works just fine.
Great.
Send them out.
Thanks,
Michal
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
2015-12-14 8:24 ` Thierry Reding
2015-12-14 8:26 ` Michal Simek
@ 2015-12-14 8:33 ` Ley Foon Tan
2015-12-14 9:19 ` Thierry Reding
1 sibling, 1 reply; 20+ messages in thread
From: Ley Foon Tan @ 2015-12-14 8:33 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Dec 14, 2015 at 4:24 PM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Mon, Dec 14, 2015 at 09:19:30AM +0100, Geert Uytterhoeven wrote:
>> Hi Paul,
>>
>> On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
>> <paul.gortmaker@windriver.com> wrote:
>> > This series of commits is a slice of a larger project to ensure
>> > people don't have dead code for module removal in non-modular
>> > drivers. Overall there was roughly 5k lines of dead code in the
>> > kernel due to this. So far we've fixed several areas, like tty,
>> > x86, net, etc. and we continue to work on other areas.
>> >
>> > There are several reasons to not use module_init for code that can
>> > never be built as a module, but the big ones are:
>> >
>> > (1) it is easy to accidentally code up unused module_exit and remove code
>> > (2) it can be misleading when reading the source, thinking it can be
>> > modular when the Makefile and/or Kconfig prohibit it
>> > (3) it requires the include of the module.h header file which in turn
>> > includes nearly everything else.
>> >
>> > Here we convert some module_init() calls into device_initcall() and delete
>> > any module_exit and remove code that gets orphaned in the process, for
>> > an overall net code reduction, which is always welcome.
>> >
>> > The use of device_initcall ensures that the init function ordering
>> > remains unchanged, but one could argue that PCI host code might be more
>> > appropriate to be handled under subsys_initcall. Fortunately we can
>> > revisit making this extra change at a later date if desired; it does
>> > not need to happen now, and we reduce the risk of introducing
>> > regressions at this point in time by separating the two changes.
>> >
>> > Over half of the drivers changed here already explicitly disallowed any
>> > unbind operations. For the rest we make them the same, since there is
>> > not really any sensible use case to unbind any built-in bus support that
>> > I can think of.
>>
>> Personally, I think all of these should become tristate, so distro kernels
>> don't have to build in PCI(e) support for all SoCs. multi_v7_defconfig kernels
>> are becoming too big.
>>
>> That does not preclude making these modules un-unloadable, though.
>
> Most of these can't be made tristate as-is, because they use symbols
> that aren't exported. Many of those symbols can easily be exported, so
> its just a matter of getting the respective patches merged. I disagree
> with making the modules non-unloadable, though. I have a local branch
> with changes necessary to unload the host controller driver and it
> works just fine.
>
PCIe host driver that use fixup (DECLARE_PCI_FIXUP_*) can't use tristate.
Fixup region is in kernel region and this region if not updated when
loading a module.
Regards
Ley Foon
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
2015-12-14 8:33 ` Ley Foon Tan
@ 2015-12-14 9:19 ` Thierry Reding
2015-12-14 10:27 ` Arnd Bergmann
0 siblings, 1 reply; 20+ messages in thread
From: Thierry Reding @ 2015-12-14 9:19 UTC (permalink / raw)
To: linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 3428 bytes --]
On Mon, Dec 14, 2015 at 04:33:51PM +0800, Ley Foon Tan wrote:
> On Mon, Dec 14, 2015 at 4:24 PM, Thierry Reding
> <thierry.reding@gmail.com> wrote:
> > On Mon, Dec 14, 2015 at 09:19:30AM +0100, Geert Uytterhoeven wrote:
> >> Hi Paul,
> >>
> >> On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
> >> <paul.gortmaker@windriver.com> wrote:
> >> > This series of commits is a slice of a larger project to ensure
> >> > people don't have dead code for module removal in non-modular
> >> > drivers. Overall there was roughly 5k lines of dead code in the
> >> > kernel due to this. So far we've fixed several areas, like tty,
> >> > x86, net, etc. and we continue to work on other areas.
> >> >
> >> > There are several reasons to not use module_init for code that can
> >> > never be built as a module, but the big ones are:
> >> >
> >> > (1) it is easy to accidentally code up unused module_exit and remove code
> >> > (2) it can be misleading when reading the source, thinking it can be
> >> > modular when the Makefile and/or Kconfig prohibit it
> >> > (3) it requires the include of the module.h header file which in turn
> >> > includes nearly everything else.
> >> >
> >> > Here we convert some module_init() calls into device_initcall() and delete
> >> > any module_exit and remove code that gets orphaned in the process, for
> >> > an overall net code reduction, which is always welcome.
> >> >
> >> > The use of device_initcall ensures that the init function ordering
> >> > remains unchanged, but one could argue that PCI host code might be more
> >> > appropriate to be handled under subsys_initcall. Fortunately we can
> >> > revisit making this extra change at a later date if desired; it does
> >> > not need to happen now, and we reduce the risk of introducing
> >> > regressions at this point in time by separating the two changes.
> >> >
> >> > Over half of the drivers changed here already explicitly disallowed any
> >> > unbind operations. For the rest we make them the same, since there is
> >> > not really any sensible use case to unbind any built-in bus support that
> >> > I can think of.
> >>
> >> Personally, I think all of these should become tristate, so distro kernels
> >> don't have to build in PCI(e) support for all SoCs. multi_v7_defconfig kernels
> >> are becoming too big.
> >>
> >> That does not preclude making these modules un-unloadable, though.
> >
> > Most of these can't be made tristate as-is, because they use symbols
> > that aren't exported. Many of those symbols can easily be exported, so
> > its just a matter of getting the respective patches merged. I disagree
> > with making the modules non-unloadable, though. I have a local branch
> > with changes necessary to unload the host controller driver and it
> > works just fine.
> >
> PCIe host driver that use fixup (DECLARE_PCI_FIXUP_*) can't use tristate.
> Fixup region is in kernel region and this region if not updated when
> loading a module.
Interesting, I hadn't thought about that. I suppose this means that the
module will end up containing an unused section with the fixup code. It
might be useful to add a way for that to trigger a warning at build
time.
Perhaps to fix this a mechanism could be introduced to add a table of
fixups to a host controller driver and that will get applied to all
children of the bridge. It could be problematic to cover all of the
different fixup stages, though.
Thierry
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
2015-12-14 9:19 ` Thierry Reding
@ 2015-12-14 10:27 ` Arnd Bergmann
2015-12-15 15:16 ` Paul Gortmaker
0 siblings, 1 reply; 20+ messages in thread
From: Arnd Bergmann @ 2015-12-14 10:27 UTC (permalink / raw)
To: linux-arm-kernel
On Monday 14 December 2015 10:19:40 Thierry Reding wrote:
> > PCIe host driver that use fixup (DECLARE_PCI_FIXUP_*) can't use tristate.
> > Fixup region is in kernel region and this region if not updated when
> > loading a module.
>
> Interesting, I hadn't thought about that. I suppose this means that the
> module will end up containing an unused section with the fixup code. It
> might be useful to add a way for that to trigger a warning at build
> time.
>
> Perhaps to fix this a mechanism could be introduced to add a table of
> fixups to a host controller driver and that will get applied to all
> children of the bridge. It could be problematic to cover all of the
> different fixup stages, though.
>
I think a lot of the fixups shouldn't really be there in the first place,
they are about stuff that we can fix up in the probe function, or that should
be fixed up in the probe function with some appropriate core support added.
Arnd
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
2015-12-14 10:27 ` Arnd Bergmann
@ 2015-12-15 15:16 ` Paul Gortmaker
2016-01-08 20:31 ` Bjorn Helgaas
0 siblings, 1 reply; 20+ messages in thread
From: Paul Gortmaker @ 2015-12-15 15:16 UTC (permalink / raw)
To: linux-arm-kernel
[Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*] On 14/12/2015 (Mon 11:27) Arnd Bergmann wrote:
> On Monday 14 December 2015 10:19:40 Thierry Reding wrote:
> > > PCIe host driver that use fixup (DECLARE_PCI_FIXUP_*) can't use tristate.
> > > Fixup region is in kernel region and this region if not updated when
> > > loading a module.
> >
> > Interesting, I hadn't thought about that. I suppose this means that the
> > module will end up containing an unused section with the fixup code. It
> > might be useful to add a way for that to trigger a warning at build
> > time.
> >
> > Perhaps to fix this a mechanism could be introduced to add a table of
> > fixups to a host controller driver and that will get applied to all
> > children of the bridge. It could be problematic to cover all of the
> > different fixup stages, though.
> >
>
>
> I think a lot of the fixups shouldn't really be there in the first place,
> they are about stuff that we can fix up in the probe function, or that should
> be fixed up in the probe function with some appropriate core support added.
So, the feedback on this is a bit all over the map, leaving me unsure
what to do next. And is the choice we make on a per board/bsp basis or
ideally across all platforms? I see the choices as:
1) do nothing; which IMHO is least desirable as it leaves the code
misrepresenting itself as modular; one of the key issues I wanted to fix
2) use the patches I've sent ; then as they are genuinely made modular,
the person doing so essentially "patch -R" or reverts the change as
step one. This has the advantage of solving the "we'll get to it
someday" issue if someday never comes.
3) make them all tristate; beat it with a stick until it compiles [M]
and modposts -- leaving the fixups and functional testing to people with
the boards and low level knowledge to make it _work_ as a module. The
downside here is the code is still kind of misrepresenting itself as
modularly functional -- a ban of unloading might mitigate that some.
Paul.
--
>
> Arnd
^ permalink raw reply [flat|nested] 20+ messages in thread
* RE: [PATCH 07/10] drivers/pci: make host/pcie-rcar.c explicitly non-modular
2015-12-13 10:58 ` Geert Uytterhoeven
2015-12-13 18:20 ` Paul Gortmaker
@ 2015-12-17 11:32 ` Phil Edworthy
2015-12-17 16:06 ` Paul Gortmaker
1 sibling, 1 reply; 20+ messages in thread
From: Phil Edworthy @ 2015-12-17 11:32 UTC (permalink / raw)
To: Paul Gortmaker
Cc: linux-kernel@vger.kernel.org, Simon Horman, Bjorn Helgaas,
linux-pci, Linux-sh list, Geert Uytterhoeven
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^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 07/10] drivers/pci: make host/pcie-rcar.c explicitly non-modular
2015-12-17 11:32 ` Phil Edworthy
@ 2015-12-17 16:06 ` Paul Gortmaker
0 siblings, 0 replies; 20+ messages in thread
From: Paul Gortmaker @ 2015-12-17 16:06 UTC (permalink / raw)
To: Phil Edworthy
Cc: linux-kernel@vger.kernel.org, Simon Horman, Bjorn Helgaas,
linux-pci, Linux-sh list, Geert Uytterhoeven
[RE: [PATCH 07/10] drivers/pci: make host/pcie-rcar.c explicitly non-modular] On 17/12/2015 (Thu 11:32) Phil Edworthy wrote:
> Hi Paul,
>
> On 13 December 2015 10:59, Geert Uytterhoeven wrote:
> >
> > CC MODULE_AUTHOR
> >
> > On Sun, Dec 13, 2015 at 2:41 AM, Paul Gortmaker
> > <paul.gortmaker@windriver.com> wrote:
> > > The Kconfig currently controlling compilation of this code is:
> > >
> > > drivers/pci/host/Kconfig:config PCI_RCAR_GEN2_PCIE
> > > drivers/pci/host/Kconfig: bool "Renesas R-Car PCIe controller"
> > >
> > > ...meaning that it currently is not being built as a module by anyone.
> > >
> > > Lets remove the modular code that is essentially orphaned, so that
> > > when reading the driver there is no doubt it is builtin-only.
> > >
> > > Since module_platform_driver() uses the same init level priority as
> > > builtin_platform_driver() the init ordering remains unchanged with
> > > this commit.
> > >
> > > We don't have to disallow a driver unbind, since that is already
> > > done for us in this driver.
> > >
> > > Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
> > >
> > > We also delete the MODULE_LICENSE tag etc. since all that information
> > > was (or is now) contained at the top of the file in the comments.
> > >
> > > Cc: Simon Horman <horms@verge.net.au>
> > > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > > Cc: linux-pci@vger.kernel.org
> > > Cc: linux-sh@vger.kernel.org
> > > Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
>
> It doesn't apply, would you mind rebasing onto:
> https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=next
>
Sure I can do that and just resend the 2 renesas commits if there is no
interest in tristate conversions for them. As for the others, I'm still
awaiting feedback on what approach people want to take; I listed what I
figured our possible options are.
Paul.
--
> As for the changes themselves,
> Acked-by: Phil Edworthy <phil.edworthy@renesas.com>
>
> Thanks
> Phil
>
> > > ---
> > > drivers/pci/host/pcie-rcar.c | 11 ++++-------
> > > 1 file changed, 4 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
> > > index f4fa6c537448..2c619277d265 100644
> > > --- a/drivers/pci/host/pcie-rcar.c
> > > +++ b/drivers/pci/host/pcie-rcar.c
> > > @@ -7,6 +7,8 @@
> > > * arch/sh/drivers/pci/ops-sh7786.c
> > > * Copyright (C) 2009 - 2011 Paul Mundt
> > > *
> > > + * Module Author: Phil Edworthy <phil.edworthy@renesas.com>
> > > + *
> > > * This file is licensed under the terms of the GNU General Public
> > > * License version 2. This program is licensed "as is" without any
> > > * warranty of any kind, whether express or implied.
> > > @@ -18,7 +20,7 @@
> > > #include <linux/irq.h>
> > > #include <linux/irqdomain.h>
> > > #include <linux/kernel.h>
> > > -#include <linux/module.h>
> > > +#include <linux/init.h>
> > > #include <linux/msi.h>
> > > #include <linux/of_address.h>
> > > #include <linux/of_irq.h>
> > > @@ -921,7 +923,6 @@ static const struct of_device_id rcar_pcie_of_match[] = {
> > > { .compatible = "renesas,pcie-r8a7791", .data = rcar_pcie_hw_init },
> > > {},
> > > };
> > > -MODULE_DEVICE_TABLE(of, rcar_pcie_of_match);
> > >
> > > static int rcar_pcie_probe(struct platform_device *pdev)
> > > {
> > > @@ -1007,8 +1008,4 @@ static struct platform_driver rcar_pcie_driver = {
> > > },
> > > .probe = rcar_pcie_probe,
> > > };
> > > -module_platform_driver(rcar_pcie_driver);
> > > -
> > > -MODULE_AUTHOR("Phil Edworthy <phil.edworthy@renesas.com>");
> > > -MODULE_DESCRIPTION("Renesas R-Car PCIe driver");
> > > -MODULE_LICENSE("GPL v2");
> > > +builtin_platform_driver(rcar_pcie_driver);
> >
> > Gr{oetje,eeting}s,
> >
> > Geert
> >
> > --
> > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> >
> > In personal conversations with technical people, I call myself a hacker. But
> > when I'm talking to journalists I just say "programmer" or something like that.
> > -- Linus Torvalds
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*
2015-12-15 15:16 ` Paul Gortmaker
@ 2016-01-08 20:31 ` Bjorn Helgaas
0 siblings, 0 replies; 20+ messages in thread
From: Bjorn Helgaas @ 2016-01-08 20:31 UTC (permalink / raw)
To: linux-arm-kernel
On Tue, Dec 15, 2015 at 10:16:24AM -0500, Paul Gortmaker wrote:
> [Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*] On 14/12/2015 (Mon 11:27) Arnd Bergmann wrote:
>
> > On Monday 14 December 2015 10:19:40 Thierry Reding wrote:
> > > > PCIe host driver that use fixup (DECLARE_PCI_FIXUP_*) can't use tristate.
> > > > Fixup region is in kernel region and this region if not updated when
> > > > loading a module.
> > >
> > > Interesting, I hadn't thought about that. I suppose this means that the
> > > module will end up containing an unused section with the fixup code. It
> > > might be useful to add a way for that to trigger a warning at build
> > > time.
> > >
> > > Perhaps to fix this a mechanism could be introduced to add a table of
> > > fixups to a host controller driver and that will get applied to all
> > > children of the bridge. It could be problematic to cover all of the
> > > different fixup stages, though.
> >
> > I think a lot of the fixups shouldn't really be there in the first place,
> > they are about stuff that we can fix up in the probe function, or that should
> > be fixed up in the probe function with some appropriate core support added.
>
> So, the feedback on this is a bit all over the map, leaving me unsure
> what to do next. And is the choice we make on a per board/bsp basis or
> ideally across all platforms? I see the choices as:
>
> 1) do nothing; which IMHO is least desirable as it leaves the code
> misrepresenting itself as modular; one of the key issues I wanted to fix
>
> 2) use the patches I've sent ; then as they are genuinely made modular,
> the person doing so essentially "patch -R" or reverts the change as
> step one. This has the advantage of solving the "we'll get to it
> someday" issue if someday never comes.
>
> 3) make them all tristate; beat it with a stick until it compiles [M]
> and modposts -- leaving the fixups and functional testing to people with
> the boards and low level knowledge to make it _work_ as a module. The
> downside here is the code is still kind of misrepresenting itself as
> modularly functional -- a ban of unloading might mitigate that some.
I'd like to preserve the mind-set that host controller drivers are
*expected* to be modular, even if we aren't there yet. I guess that
means I'm in favor of option 3, at least for drivers that don't use
fixups.
Bjorn
^ permalink raw reply [flat|nested] 20+ messages in thread
end of thread, other threads:[~2016-01-08 20:31 UTC | newest]
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2015-12-13 1:41 [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Paul Gortmaker
2015-12-13 1:41 ` [PATCH 05/10] drivers/pci: make host/pci-rcar-gen2.c explicitly non-modular Paul Gortmaker
2015-12-13 10:59 ` Geert Uytterhoeven
2015-12-13 18:15 ` Paul Gortmaker
2015-12-13 20:37 ` Joe Perches
2015-12-14 5:19 ` Simon Horman
2015-12-13 1:41 ` [PATCH 07/10] drivers/pci: make host/pcie-rcar.c " Paul Gortmaker
2015-12-13 10:58 ` Geert Uytterhoeven
2015-12-13 18:20 ` Paul Gortmaker
2015-12-17 11:32 ` Phil Edworthy
2015-12-17 16:06 ` Paul Gortmaker
2015-12-14 5:19 ` Simon Horman
2015-12-14 8:19 ` [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Geert Uytterhoeven
2015-12-14 8:24 ` Thierry Reding
2015-12-14 8:26 ` Michal Simek
2015-12-14 8:33 ` Ley Foon Tan
2015-12-14 9:19 ` Thierry Reding
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2016-01-08 20:31 ` Bjorn Helgaas
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