[PATCH 00/17] mark const init data with __initconst instead of __initdata

[PATCH 00/17] mark const init data with __initconst instead of __initdata

[Uwe Kleine-König]

Hello,

this series fixes a common error to use __initdata to mark const
variables. Most of the time this works well enough to go unnoticed
(though I wonder why the linker doesn't warn about that).
Just try adding something like

	int something __initdata;

to one of the patched files and compile to see the error.

While touching these annotations I also corrected the position where it
was wrong to go between the variable name and the =.

Note this series is not compile tested.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[PATCH 11/17] powerpc: mark const init data with __initconst instead of __initdata

[Uwe Kleine-König]

As long as there is no other non-const variable marked __initdata in the
same compilation unit it doesn't hurt. If there were one however
compilation would fail with

	error: $variablename causes a section type conflict

because a section containing const variables is marked read only and so
cannot contain non-const variables.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: cbe-oss-dev@lists.ozlabs.org
---
 arch/powerpc/platforms/40x/ppc40x_simple.c    |    2 +-
 arch/powerpc/platforms/512x/mpc5121_generic.c |    2 +-
 arch/powerpc/platforms/52xx/lite5200.c        |    2 +-
 arch/powerpc/platforms/52xx/media5200.c       |    2 +-
 arch/powerpc/platforms/52xx/mpc5200_simple.c  |    2 +-
 arch/powerpc/platforms/52xx/mpc52xx_pci.c     |    2 +-
 arch/powerpc/platforms/83xx/mpc830x_rdb.c     |    2 +-
 arch/powerpc/platforms/83xx/mpc831x_rdb.c     |    2 +-
 arch/powerpc/platforms/83xx/mpc837x_rdb.c     |    2 +-
 arch/powerpc/platforms/85xx/tqm85xx.c         |    2 +-
 arch/powerpc/platforms/cell/qpace_setup.c     |    2 +-
 arch/powerpc/platforms/cell/setup.c           |    2 +-
 12 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/platforms/40x/ppc40x_simple.c b/arch/powerpc/platforms/40x/ppc40x_simple.c
index 9761206..2efba25 100644
--- a/arch/powerpc/platforms/40x/ppc40x_simple.c
+++ b/arch/powerpc/platforms/40x/ppc40x_simple.c
@@ -50,7 +50,7 @@ machine_device_initcall(ppc40x_simple, ppc40x_device_probe);
  * Again, if your board needs to do things differently then create a
  * board.c file for it rather than adding it to this list.
  */
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"amcc,acadia",
 	"amcc,haleakala",
 	"amcc,kilauea",
diff --git a/arch/powerpc/platforms/512x/mpc5121_generic.c b/arch/powerpc/platforms/512x/mpc5121_generic.c
index 926731f..b1b558c 100644
--- a/arch/powerpc/platforms/512x/mpc5121_generic.c
+++ b/arch/powerpc/platforms/512x/mpc5121_generic.c
@@ -26,7 +26,7 @@
 /*
  * list of supported boards
  */
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"prt,prtlvt",
 	NULL
 };
diff --git a/arch/powerpc/platforms/52xx/lite5200.c b/arch/powerpc/platforms/52xx/lite5200.c
index 01ffa64..86bd6f2 100644
--- a/arch/powerpc/platforms/52xx/lite5200.c
+++ b/arch/powerpc/platforms/52xx/lite5200.c
@@ -172,7 +172,7 @@ static void __init lite5200_setup_arch(void)
 	mpc52xx_setup_pci();
 }
 
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"fsl,lite5200",
 	"fsl,lite5200b",
 	NULL,
diff --git a/arch/powerpc/platforms/52xx/media5200.c b/arch/powerpc/platforms/52xx/media5200.c
index 17d91b7..df4d53a 100644
--- a/arch/powerpc/platforms/52xx/media5200.c
+++ b/arch/powerpc/platforms/52xx/media5200.c
@@ -232,7 +232,7 @@ static void __init media5200_setup_arch(void)
 }
 
 /* list of the supported boards */
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"fsl,media5200",
 	NULL
 };
diff --git a/arch/powerpc/platforms/52xx/mpc5200_simple.c b/arch/powerpc/platforms/52xx/mpc5200_simple.c
index c0aa040..2622361 100644
--- a/arch/powerpc/platforms/52xx/mpc5200_simple.c
+++ b/arch/powerpc/platforms/52xx/mpc5200_simple.c
@@ -49,7 +49,7 @@ static void __init mpc5200_simple_setup_arch(void)
 }
 
 /* list of the supported boards */
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"anonymous,a4m072",
 	"anon,charon",
 	"intercontrol,digsy-mtc",
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pci.c b/arch/powerpc/platforms/52xx/mpc52xx_pci.c
index bfb11e0..e2d401a 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pci.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pci.c
@@ -93,7 +93,7 @@ struct mpc52xx_pci {
 };
 
 /* MPC5200 device tree match tables */
-const struct of_device_id mpc52xx_pci_ids[] __initdata = {
+const struct of_device_id mpc52xx_pci_ids[] __initconst = {
 	{ .type = "pci", .compatible = "fsl,mpc5200-pci", },
 	{ .type = "pci", .compatible = "mpc5200-pci", },
 	{}
diff --git a/arch/powerpc/platforms/83xx/mpc830x_rdb.c b/arch/powerpc/platforms/83xx/mpc830x_rdb.c
index 4f2d9fe..3327ab9 100644
--- a/arch/powerpc/platforms/83xx/mpc830x_rdb.c
+++ b/arch/powerpc/platforms/83xx/mpc830x_rdb.c
@@ -34,7 +34,7 @@ static void __init mpc830x_rdb_setup_arch(void)
 	mpc831x_usb_cfg();
 }
 
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"MPC8308RDB",
 	"fsl,mpc8308rdb",
 	"denx,mpc8308_p1m",
diff --git a/arch/powerpc/platforms/83xx/mpc831x_rdb.c b/arch/powerpc/platforms/83xx/mpc831x_rdb.c
index fa25977..067d3f0 100644
--- a/arch/powerpc/platforms/83xx/mpc831x_rdb.c
+++ b/arch/powerpc/platforms/83xx/mpc831x_rdb.c
@@ -35,7 +35,7 @@ static void __init mpc831x_rdb_setup_arch(void)
 	mpc831x_usb_cfg();
 }
 
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"MPC8313ERDB",
 	"fsl,mpc8315erdb",
 	NULL
diff --git a/arch/powerpc/platforms/83xx/mpc837x_rdb.c b/arch/powerpc/platforms/83xx/mpc837x_rdb.c
index 16c9c9c..a9a15bb 100644
--- a/arch/powerpc/platforms/83xx/mpc837x_rdb.c
+++ b/arch/powerpc/platforms/83xx/mpc837x_rdb.c
@@ -60,7 +60,7 @@ static void __init mpc837x_rdb_setup_arch(void)
 
 machine_device_initcall(mpc837x_rdb, mpc83xx_declare_of_platform_devices);
 
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"fsl,mpc8377rdb",
 	"fsl,mpc8378rdb",
 	"fsl,mpc8379rdb",
diff --git a/arch/powerpc/platforms/85xx/tqm85xx.c b/arch/powerpc/platforms/85xx/tqm85xx.c
index 4d786c2..c182de0 100644
--- a/arch/powerpc/platforms/85xx/tqm85xx.c
+++ b/arch/powerpc/platforms/85xx/tqm85xx.c
@@ -125,7 +125,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_1520,
 
 machine_device_initcall(tqm85xx, mpc85xx_common_publish_devices);
 
-static const char *board[] __initdata = {
+static const char *board[] __initconst = {
 	"tqc,tqm8540",
 	"tqc,tqm8541",
 	"tqc,tqm8548",
diff --git a/arch/powerpc/platforms/cell/qpace_setup.c b/arch/powerpc/platforms/cell/qpace_setup.c
index 7f9b674..6e3409d 100644
--- a/arch/powerpc/platforms/cell/qpace_setup.c
+++ b/arch/powerpc/platforms/cell/qpace_setup.c
@@ -61,7 +61,7 @@ static void qpace_progress(char *s, unsigned short hex)
 	printk("*** %04x : %s\n", hex, s ? s : "");
 }
 
-static const struct of_device_id qpace_bus_ids[] __initdata = {
+static const struct of_device_id qpace_bus_ids[] __initconst = {
 	{ .type = "soc", },
 	{ .compatible = "soc", },
 	{ .type = "spider", },
diff --git a/arch/powerpc/platforms/cell/setup.c b/arch/powerpc/platforms/cell/setup.c
index fa3e294..4ab0876 100644
--- a/arch/powerpc/platforms/cell/setup.c
+++ b/arch/powerpc/platforms/cell/setup.c
@@ -140,7 +140,7 @@ static int __devinit cell_setup_phb(struct pci_controller *phb)
 	return 0;
 }
 
-static const struct of_device_id cell_bus_ids[] __initdata = {
+static const struct of_device_id cell_bus_ids[] __initconst = {
 	{ .type = "soc", },
 	{ .compatible = "soc", },
 	{ .type = "spider", },
-- 
1.7.9.1

Re: [PATCH 00/17] mark const init data with __initconst instead of __initdata

[Uwe Kleine-König]

On Thu, Mar 29, 2012 at 11:11:31PM +0200, Uwe Kleine-König wrote:
> Hello,
> 
> this series fixes a common error to use __initdata to mark const
> variables. Most of the time this works well enough to go unnoticed
> (though I wonder why the linker doesn't warn about that).
> Just try adding something like
> 
> 	int something __initdata;
> 
> to one of the patched files and compile to see the error.
> 
> While touching these annotations I also corrected the position where it
> was wrong to go between the variable name and the =.
> 
> Note this series is not compile tested.
After a question by Shawn Guo I noticed that my command to do the changes
was to lax and changed things that must not be changed (at least not
with further care). Affected are lines like:

	static const char *at91_dt_board_compat[] __initconst = {

While at91_dt_board_compat[0] is const, at91_dt_board_compat is not.

I will send a fixed series later today.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[PATCH v2 00/15] mark const init data with __initconst instead of __initdata

[Uwe Kleine-König]

Hello,

On Thu, Mar 29, 2012 at 11:11:31PM +0200, Uwe Kleine-König wrote:
> this series fixes a common error to use __initdata to mark const
> variables. Most of the time this works well enough to go unnoticed
> (though I wonder why the linker doesn't warn about that).
> Just try adding something like
> 
> 	int something __initdata;
> 
> to one of the patched files and compile to see the error.
> 
> While touching these annotations I also corrected the position where it
> was wrong to go between the variable name and the =.
> 
> Note this series is not compile tested.
I now dropped the wrong annotations. So two patches became obsolete
(mtd and percpu). Note that I also dropped fixing the position of
__initdata if changing it to __initconst was wrong. (I think if
__initdata is placed before the variable name it doesn't have any
effect.)

I didn't promote the Acks I got because all acked changes changed in v2.

For the details changed in each patch see the changelogs in the
respective patch mails that I follow up to this mail.

Thanks
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[PATCH v2 10/15] powerpc: mark const init data with __initconst instead of __initdata

[Uwe Kleine-König]

As long as there is no other non-const variable marked __initdata in the
same compilation unit it doesn't hurt. If there were one however
compilation would fail with

	error: $variablename causes a section type conflict

because a section containing const variables is marked read only and so
cannot contain non-const variables.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: cbe-oss-dev@lists.ozlabs.org
---
changes since (implicit) v1:
 - drop wrong changes to several files:
   - arch/powerpc/platforms/40x/ppc40x_simple.c
   - arch/powerpc/platforms/512x/mpc5121_generic.c
   - arch/powerpc/platforms/52xx/lite5200.c
   - arch/powerpc/platforms/52xx/media5200.c
   - arch/powerpc/platforms/52xx/mpc5200_simple.c
   - arch/powerpc/platforms/83xx/mpc830x_rdb.c
   - arch/powerpc/platforms/83xx/mpc831x_rdb.c
   - arch/powerpc/platforms/83xx/mpc837x_rdb.c
   - arch/powerpc/platforms/85xx/tqm85xx.c

 arch/powerpc/platforms/52xx/mpc52xx_pci.c |    2 +-
 arch/powerpc/platforms/cell/qpace_setup.c |    2 +-
 arch/powerpc/platforms/cell/setup.c       |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pci.c b/arch/powerpc/platforms/52xx/mpc52xx_pci.c
index bfb11e0..e2d401a 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pci.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pci.c
@@ -93,7 +93,7 @@ struct mpc52xx_pci {
 };
 
 /* MPC5200 device tree match tables */
-const struct of_device_id mpc52xx_pci_ids[] __initdata = {
+const struct of_device_id mpc52xx_pci_ids[] __initconst = {
 	{ .type = "pci", .compatible = "fsl,mpc5200-pci", },
 	{ .type = "pci", .compatible = "mpc5200-pci", },
 	{}
diff --git a/arch/powerpc/platforms/cell/qpace_setup.c b/arch/powerpc/platforms/cell/qpace_setup.c
index 7f9b674..6e3409d 100644
--- a/arch/powerpc/platforms/cell/qpace_setup.c
+++ b/arch/powerpc/platforms/cell/qpace_setup.c
@@ -61,7 +61,7 @@ static void qpace_progress(char *s, unsigned short hex)
 	printk("*** %04x : %s\n", hex, s ? s : "");
 }
 
-static const struct of_device_id qpace_bus_ids[] __initdata = {
+static const struct of_device_id qpace_bus_ids[] __initconst = {
 	{ .type = "soc", },
 	{ .compatible = "soc", },
 	{ .type = "spider", },
diff --git a/arch/powerpc/platforms/cell/setup.c b/arch/powerpc/platforms/cell/setup.c
index fa3e294..4ab0876 100644
--- a/arch/powerpc/platforms/cell/setup.c
+++ b/arch/powerpc/platforms/cell/setup.c
@@ -140,7 +140,7 @@ static int __devinit cell_setup_phb(struct pci_controller *phb)
 	return 0;
 }
 
-static const struct of_device_id cell_bus_ids[] __initdata = {
+static const struct of_device_id cell_bus_ids[] __initconst = {
 	{ .type = "soc", },
 	{ .compatible = "soc", },
 	{ .type = "spider", },
-- 
1.7.9.5