diff mbox

clk: don't use __initconst for non-const arrays

Message ID 1410469471-31027-1-git-send-email-u.kleine-koenig@pengutronix.de (mailing list archive)
State New, archived
Headers show

Commit Message

Uwe Kleine-König Sept. 11, 2014, 9:04 p.m. UTC 
The statement

	static const char *name[];

defines a modifiable array of pointers to constant chars. That is

	*name[0] = 'f';

is forbidden, but

	name[0] = "f";

is not. So marking an array that is defined as above with __initconst is
wrong. Either an additional const must be added such that the whole
definition reads:

	static const char *const name[] __initconst;

or where this is not possible __initdata must be used.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/clk/hisilicon/clk-hix5hd2.c |  6 ++--
 drivers/clk/mxs/clk-imx23.c         | 12 ++++----
 drivers/clk/mxs/clk-imx28.c         | 18 ++++++------
 drivers/clk/rockchip/clk.h          |  2 +-
 drivers/clk/samsung/clk-s5pv210.c   | 56 ++++++++++++++++++-------------------
 drivers/clk/ti/composite.c          |  2 +-
 6 files changed, 48 insertions(+), 48 deletions(-)

Comments

Tomasz Figa Sept. 11, 2014, 9:48 p.m. UTC | #1 
[adding Sylwester and removing my samsung.com e-mail which is no longer
valid]

On 11.09.2014 23:04, Uwe Kleine-König wrote:
> The statement
> 
> 	static const char *name[];
> 
> defines a modifiable array of pointers to constant chars. That is
> 
> 	*name[0] = 'f';
> 
> is forbidden, but
> 
> 	name[0] = "f";
> 
> is not. So marking an array that is defined as above with __initconst is
> wrong. Either an additional const must be added such that the whole
> definition reads:
> 
> 	static const char *const name[] __initconst;
> 
> or where this is not possible __initdata must be used.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/clk/hisilicon/clk-hix5hd2.c |  6 ++--
>  drivers/clk/mxs/clk-imx23.c         | 12 ++++----
>  drivers/clk/mxs/clk-imx28.c         | 18 ++++++------
>  drivers/clk/rockchip/clk.h          |  2 +-
>  drivers/clk/samsung/clk-s5pv210.c   | 56 ++++++++++++++++++-------------------

For drivers/clk/samsung/*

Acked-by: Tomasz Figa <tomasz.figa@gmail.com>

Best regards,
Tomasz
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Uwe Kleine-König Sept. 11, 2014, 10:04 p.m. UTC | #2 
Hello,

On Thu, Sep 11, 2014 at 11:04:31PM +0200, Uwe Kleine-König wrote:
>  /* Mux parent lists. */
> -static const char *fin_pll_p[] __initconst = {
> +static const char *fin_pll_p[] __initdata = {
>  	"xxti",
>  	"xusbxti"
>  };
As discussed with Tomasz on irc: The sad thing here is that for this
array only 8 bytes are freed when .init.rodata is thrown away (that is
two pointers). The actual data---5 + 8 bytes + maybe aligning---isn't
freed though.

We wondered if there is a nice and easy way to throw away the
characters, too.

The only way I currently see is:

	const char xxti[] __initconst = "xxti";
	...

	static const char *fin_pll_p[] __initdata = {
		xxti,
		...
	};

but this definitively doesn't qualify as "nice and easy". Is there an
alternative?

Best regards
Uwe
Ard Biesheuvel Sept. 12, 2014, 7:42 a.m. UTC | #3 
On 12 September 2014 00:04, Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
> Hello,
>
> On Thu, Sep 11, 2014 at 11:04:31PM +0200, Uwe Kleine-König wrote:
>>  /* Mux parent lists. */
>> -static const char *fin_pll_p[] __initconst = {
>> +static const char *fin_pll_p[] __initdata = {
>>       "xxti",
>>       "xusbxti"
>>  };
> As discussed with Tomasz on irc: The sad thing here is that for this
> array only 8 bytes are freed when .init.rodata is thrown away (that is
> two pointers). The actual data---5 + 8 bytes + maybe aligning---isn't
> freed though.
>
> We wondered if there is a nice and easy way to throw away the
> characters, too.
>
> The only way I currently see is:
>
>         const char xxti[] __initconst = "xxti";
>         ...
>
>         static const char *fin_pll_p[] __initdata = {
>                 xxti,
>                 ...
>         };
>
> but this definitively doesn't qualify as "nice and easy". Is there an
> alternative?
>

What about doing

static const char fin_pll_p[][8] __initconst = {
     "xxti",
     "xusbxti"
};
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Uwe Kleine-König Sept. 12, 2014, 7:59 a.m. UTC | #4 
Hello Ard,

On Fri, Sep 12, 2014 at 09:42:29AM +0200, Ard Biesheuvel wrote:
> On 12 September 2014 00:04, Uwe Kleine-König
> <u.kleine-koenig@pengutronix.de> wrote:
> > Hello,
> >
> > On Thu, Sep 11, 2014 at 11:04:31PM +0200, Uwe Kleine-König wrote:
> >>  /* Mux parent lists. */
> >> -static const char *fin_pll_p[] __initconst = {
> >> +static const char *fin_pll_p[] __initdata = {
> >>       "xxti",
> >>       "xusbxti"
> >>  };
> > As discussed with Tomasz on irc: The sad thing here is that for this
> > array only 8 bytes are freed when .init.rodata is thrown away (that is
> > two pointers). The actual data---5 + 8 bytes + maybe aligning---isn't
> > freed though.
> >
> > We wondered if there is a nice and easy way to throw away the
> > characters, too.
> >
> > The only way I currently see is:
> >
> >         const char xxti[] __initconst = "xxti";
> >         ...
> >
> >         static const char *fin_pll_p[] __initdata = {
> >                 xxti,
> >                 ...
> >         };
> >
> > but this definitively doesn't qualify as "nice and easy". Is there an
> > alternative?
> >
> 
> What about doing
> 
> static const char fin_pll_p[][8] __initconst = {
>      "xxti",
>      "xusbxti"
> };
This results in the strings being moved to .init.rodata and so they are
discarded. But it also results in:

	drivers/clk/samsung/clk-s5pv210.c:412:2: warning: initialization from incompatible pointer type [enabled by default]
	  MUX_F(FIN_PLL, "fin_pll", fin_pll_p, OM_STAT, 0, 1,
	  ^
	drivers/clk/samsung/clk-s5pv210.c:412:2: warning: (near initialization for 'early_mux_clks[0].parent_names') [enabled by default]

That's because early_mux_clks[0].parent_names is of type const char **
while fin_pll_p as suggested doesn't provide an array of pointers to the
start of the contained strings.
I don't see a way to fix that unless we fix the maximal clock name
length globally and so waste much memory.

Best regards
Uwe
diff mbox

Patch

diff --git a/drivers/clk/hisilicon/clk-hix5hd2.c b/drivers/clk/hisilicon/clk-hix5hd2.c
index e5fcfb4e32ef..7acae2eeb490 100644
--- a/drivers/clk/hisilicon/clk-hix5hd2.c
+++ b/drivers/clk/hisilicon/clk-hix5hd2.c
@@ -44,15 +44,15 @@  static struct hisi_fixed_rate_clock hix5hd2_fixed_rate_clks[] __initdata = {
 	{ HIX5HD2_FIXED_83M, "83m", NULL, CLK_IS_ROOT, 83333333, },
 };
 
-static const char *sfc_mux_p[] __initconst = {
+static const char *sfc_mux_p[] __initdata = {
 		"24m", "150m", "200m", "100m", "75m", };
 static u32 sfc_mux_table[] = {0, 4, 5, 6, 7};
 
-static const char *sdio1_mux_p[] __initconst = {
+static const char *sdio1_mux_p[] __initdata = {
 		"75m", "100m", "50m", "15m", };
 static u32 sdio1_mux_table[] = {0, 1, 2, 3};
 
-static const char *fephy_mux_p[] __initconst = { "25m", "125m"};
+static const char *fephy_mux_p[] __initdata = { "25m", "125m"};
 static u32 fephy_mux_table[] = {0, 1};
 
 
diff --git a/drivers/clk/mxs/clk-imx23.c b/drivers/clk/mxs/clk-imx23.c
index 9fc9359f5133..22d136aa699f 100644
--- a/drivers/clk/mxs/clk-imx23.c
+++ b/drivers/clk/mxs/clk-imx23.c
@@ -77,12 +77,12 @@  static void __init clk_misc_init(void)
 	writel_relaxed(30 << BP_FRAC_IOFRAC, FRAC + SET);
 }
 
-static const char *sel_pll[]  __initconst = { "pll", "ref_xtal", };
-static const char *sel_cpu[]  __initconst = { "ref_cpu", "ref_xtal", };
-static const char *sel_pix[]  __initconst = { "ref_pix", "ref_xtal", };
-static const char *sel_io[]   __initconst = { "ref_io", "ref_xtal", };
-static const char *cpu_sels[] __initconst = { "cpu_pll", "cpu_xtal", };
-static const char *emi_sels[] __initconst = { "emi_pll", "emi_xtal", };
+static const char *sel_pll[]  __initdata = { "pll", "ref_xtal", };
+static const char *sel_cpu[]  __initdata = { "ref_cpu", "ref_xtal", };
+static const char *sel_pix[]  __initdata = { "ref_pix", "ref_xtal", };
+static const char *sel_io[]   __initdata = { "ref_io", "ref_xtal", };
+static const char *cpu_sels[] __initdata = { "cpu_pll", "cpu_xtal", };
+static const char *emi_sels[] __initdata = { "emi_pll", "emi_xtal", };
 
 enum imx23_clk {
 	ref_xtal, pll, ref_cpu, ref_emi, ref_pix, ref_io, saif_sel,
diff --git a/drivers/clk/mxs/clk-imx28.c b/drivers/clk/mxs/clk-imx28.c
index a6c35010e4e5..b1be3746ce95 100644
--- a/drivers/clk/mxs/clk-imx28.c
+++ b/drivers/clk/mxs/clk-imx28.c
@@ -125,15 +125,15 @@  static void __init clk_misc_init(void)
 	writel_relaxed(val, FRAC0);
 }
 
-static const char *sel_cpu[]  __initconst = { "ref_cpu", "ref_xtal", };
-static const char *sel_io0[]  __initconst = { "ref_io0", "ref_xtal", };
-static const char *sel_io1[]  __initconst = { "ref_io1", "ref_xtal", };
-static const char *sel_pix[]  __initconst = { "ref_pix", "ref_xtal", };
-static const char *sel_gpmi[] __initconst = { "ref_gpmi", "ref_xtal", };
-static const char *sel_pll0[] __initconst = { "pll0", "ref_xtal", };
-static const char *cpu_sels[] __initconst = { "cpu_pll", "cpu_xtal", };
-static const char *emi_sels[] __initconst = { "emi_pll", "emi_xtal", };
-static const char *ptp_sels[] __initconst = { "ref_xtal", "pll0", };
+static const char *sel_cpu[]  __initdata = { "ref_cpu", "ref_xtal", };
+static const char *sel_io0[]  __initdata = { "ref_io0", "ref_xtal", };
+static const char *sel_io1[]  __initdata = { "ref_io1", "ref_xtal", };
+static const char *sel_pix[]  __initdata = { "ref_pix", "ref_xtal", };
+static const char *sel_gpmi[] __initdata = { "ref_gpmi", "ref_xtal", };
+static const char *sel_pll0[] __initdata = { "pll0", "ref_xtal", };
+static const char *cpu_sels[] __initdata = { "cpu_pll", "cpu_xtal", };
+static const char *emi_sels[] __initdata = { "emi_pll", "emi_xtal", };
+static const char *ptp_sels[] __initdata = { "ref_xtal", "pll0", };
 
 enum imx28_clk {
 	ref_xtal, pll0, pll1, pll2, ref_cpu, ref_emi, ref_io0, ref_io1,
diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
index 887cbdeca2aa..74fbb9c4b6de 100644
--- a/drivers/clk/rockchip/clk.h
+++ b/drivers/clk/rockchip/clk.h
@@ -120,7 +120,7 @@  struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type,
 		struct rockchip_pll_rate_table *rate_table,
 		spinlock_t *lock);
 
-#define PNAME(x) static const char *x[] __initconst
+#define PNAME(x) static const char *x[] __initdata
 
 enum rockchip_clk_branch_type {
 	branch_composite,
diff --git a/drivers/clk/samsung/clk-s5pv210.c b/drivers/clk/samsung/clk-s5pv210.c
index d270a2084644..e668e479a697 100644
--- a/drivers/clk/samsung/clk-s5pv210.c
+++ b/drivers/clk/samsung/clk-s5pv210.c
@@ -169,44 +169,44 @@  static inline void s5pv210_clk_sleep_init(void) { }
 #endif
 
 /* Mux parent lists. */
-static const char *fin_pll_p[] __initconst = {
+static const char *fin_pll_p[] __initdata = {
 	"xxti",
 	"xusbxti"
 };
 
-static const char *mout_apll_p[] __initconst = {
+static const char *mout_apll_p[] __initdata = {
 	"fin_pll",
 	"fout_apll"
 };
 
-static const char *mout_mpll_p[] __initconst = {
+static const char *mout_mpll_p[] __initdata = {
 	"fin_pll",
 	"fout_mpll"
 };
 
-static const char *mout_epll_p[] __initconst = {
+static const char *mout_epll_p[] __initdata = {
 	"fin_pll",
 	"fout_epll"
 };
 
-static const char *mout_vpllsrc_p[] __initconst = {
+static const char *mout_vpllsrc_p[] __initdata = {
 	"fin_pll",
 	"sclk_hdmi27m"
 };
 
-static const char *mout_vpll_p[] __initconst = {
+static const char *mout_vpll_p[] __initdata = {
 	"mout_vpllsrc",
 	"fout_vpll"
 };
 
-static const char *mout_group1_p[] __initconst = {
+static const char *mout_group1_p[] __initdata = {
 	"dout_a2m",
 	"mout_mpll",
 	"mout_epll",
 	"mout_vpll"
 };
 
-static const char *mout_group2_p[] __initconst = {
+static const char *mout_group2_p[] __initdata = {
 	"xxti",
 	"xusbxti",
 	"sclk_hdmi27m",
@@ -218,7 +218,7 @@  static const char *mout_group2_p[] __initconst = {
 	"mout_vpll",
 };
 
-static const char *mout_audio0_p[] __initconst = {
+static const char *mout_audio0_p[] __initdata = {
 	"xxti",
 	"pcmcdclk0",
 	"sclk_hdmi27m",
@@ -230,7 +230,7 @@  static const char *mout_audio0_p[] __initconst = {
 	"mout_vpll",
 };
 
-static const char *mout_audio1_p[] __initconst = {
+static const char *mout_audio1_p[] __initdata = {
 	"i2scdclk1",
 	"pcmcdclk1",
 	"sclk_hdmi27m",
@@ -242,7 +242,7 @@  static const char *mout_audio1_p[] __initconst = {
 	"mout_vpll",
 };
 
-static const char *mout_audio2_p[] __initconst = {
+static const char *mout_audio2_p[] __initdata = {
 	"i2scdclk2",
 	"pcmcdclk2",
 	"sclk_hdmi27m",
@@ -254,63 +254,63 @@  static const char *mout_audio2_p[] __initconst = {
 	"mout_vpll",
 };
 
-static const char *mout_spdif_p[] __initconst = {
+static const char *mout_spdif_p[] __initdata = {
 	"dout_audio0",
 	"dout_audio1",
 	"dout_audio3",
 };
 
-static const char *mout_group3_p[] __initconst = {
+static const char *mout_group3_p[] __initdata = {
 	"mout_apll",
 	"mout_mpll"
 };
 
-static const char *mout_group4_p[] __initconst = {
+static const char *mout_group4_p[] __initdata = {
 	"mout_mpll",
 	"dout_a2m"
 };
 
-static const char *mout_flash_p[] __initconst = {
+static const char *mout_flash_p[] __initdata = {
 	"dout_hclkd",
 	"dout_hclkp"
 };
 
-static const char *mout_dac_p[] __initconst = {
+static const char *mout_dac_p[] __initdata = {
 	"mout_vpll",
 	"sclk_hdmiphy"
 };
 
-static const char *mout_hdmi_p[] __initconst = {
+static const char *mout_hdmi_p[] __initdata = {
 	"sclk_hdmiphy",
 	"dout_tblk"
 };
 
-static const char *mout_mixer_p[] __initconst = {
+static const char *mout_mixer_p[] __initdata = {
 	"mout_dac",
 	"mout_hdmi"
 };
 
-static const char *mout_vpll_6442_p[] __initconst = {
+static const char *mout_vpll_6442_p[] __initdata = {
 	"fin_pll",
 	"fout_vpll"
 };
 
-static const char *mout_mixer_6442_p[] __initconst = {
+static const char *mout_mixer_6442_p[] __initdata = {
 	"mout_vpll",
 	"dout_mixer"
 };
 
-static const char *mout_d0sync_6442_p[] __initconst = {
+static const char *mout_d0sync_6442_p[] __initdata = {
 	"mout_dsys",
 	"div_apll"
 };
 
-static const char *mout_d1sync_6442_p[] __initconst = {
+static const char *mout_d1sync_6442_p[] __initdata = {
 	"mout_psys",
 	"div_apll"
 };
 
-static const char *mout_group2_6442_p[] __initconst = {
+static const char *mout_group2_6442_p[] __initdata = {
 	"fin_pll",
 	"none",
 	"none",
@@ -322,7 +322,7 @@  static const char *mout_group2_6442_p[] __initconst = {
 	"mout_vpll",
 };
 
-static const char *mout_audio0_6442_p[] __initconst = {
+static const char *mout_audio0_6442_p[] __initdata = {
 	"fin_pll",
 	"pcmcdclk0",
 	"none",
@@ -334,7 +334,7 @@  static const char *mout_audio0_6442_p[] __initconst = {
 	"mout_vpll",
 };
 
-static const char *mout_audio1_6442_p[] __initconst = {
+static const char *mout_audio1_6442_p[] __initdata = {
 	"i2scdclk1",
 	"pcmcdclk1",
 	"none",
@@ -347,7 +347,7 @@  static const char *mout_audio1_6442_p[] __initconst = {
 	"fin_pll",
 };
 
-static const char *mout_clksel_p[] __initconst = {
+static const char *mout_clksel_p[] __initdata = {
 	"fout_apll_clkout",
 	"fout_mpll_clkout",
 	"fout_epll",
@@ -370,7 +370,7 @@  static const char *mout_clksel_p[] __initconst = {
 	"div_dclk"
 };
 
-static const char *mout_clksel_6442_p[] __initconst = {
+static const char *mout_clksel_6442_p[] __initdata = {
 	"fout_apll_clkout",
 	"fout_mpll_clkout",
 	"fout_epll",
@@ -393,7 +393,7 @@  static const char *mout_clksel_6442_p[] __initconst = {
 	"div_dclk"
 };
 
-static const char *mout_clkout_p[] __initconst = {
+static const char *mout_clkout_p[] __initdata = {
 	"dout_clkout",
 	"none",
 	"xxti",
diff --git a/drivers/clk/ti/composite.c b/drivers/clk/ti/composite.c
index 19d8980ba458..c429c65b5b21 100644
--- a/drivers/clk/ti/composite.c
+++ b/drivers/clk/ti/composite.c
@@ -67,7 +67,7 @@  struct component_clk {
 	struct list_head link;
 };
 
-static const char * __initconst component_clk_types[] = {
+static const char * const component_clk_types[] __initconst = {
 	"gate", "divider", "mux"
 };