The R9A06G032 clock driver uses an array of packed structures to reduce
kernel size. However, this array contains pointers, which are no longer
aligned naturally, and cannot be relocated on PPC64. Hence when
compile-testing this driver on PPC64 with CONFIG_RELOCATABLE=y (e.g.
PowerPC allyesconfig), the following warnings are produced:
WARNING: 136 bad relocations
c000000000616be3 R_PPC64_UADDR64 .rodata+0x00000000000cf338
c000000000616bfe R_PPC64_UADDR64 .rodata+0x00000000000cf370
...
Fix this by dropping the __packed attribute from the r9a06g032_clkdesc
definition, trading a small size increase for portability.
This increases the 156-entry clock table by 1 byte per entry, but due to
the compiler generating more efficient code for unpacked accesses, the
net size increase is only 76 bytes (gcc 9.3.0 on arm32).
Reported-by: Stephen Rothwell <[email protected]>
Fixes: 4c3d88526eba2143 ("clk: renesas: Renesas R9A06G032 clock driver")
Signed-off-by: Geert Uytterhoeven <[email protected]>
---
v2:
- Fix authorship.
---
drivers/clk/renesas/r9a06g032-clocks.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clk/renesas/r9a06g032-clocks.c b/drivers/clk/renesas/r9a06g032-clocks.c
index d900f6bf53d0b944..892e91b92f2c80f5 100644
--- a/drivers/clk/renesas/r9a06g032-clocks.c
+++ b/drivers/clk/renesas/r9a06g032-clocks.c
@@ -55,7 +55,7 @@ struct r9a06g032_clkdesc {
u16 sel, g1, r1, g2, r2;
} dual;
};
-} __packed;
+};
#define I_GATE(_clk, _rst, _rdy, _midle, _scon, _mirack, _mistat) \
{ .gate = _clk, .reset = _rst, \
--
2.25.1
Hi Geert,
On Mon, 30 Nov 2020 09:57:43 +0100 Geert Uytterhoeven <[email protected]> wrote:
>
> The R9A06G032 clock driver uses an array of packed structures to reduce
> kernel size. However, this array contains pointers, which are no longer
> aligned naturally, and cannot be relocated on PPC64. Hence when
> compile-testing this driver on PPC64 with CONFIG_RELOCATABLE=y (e.g.
> PowerPC allyesconfig), the following warnings are produced:
>
> WARNING: 136 bad relocations
> c000000000616be3 R_PPC64_UADDR64 .rodata+0x00000000000cf338
> c000000000616bfe R_PPC64_UADDR64 .rodata+0x00000000000cf370
> ...
>
> Fix this by dropping the __packed attribute from the r9a06g032_clkdesc
> definition, trading a small size increase for portability.
>
> This increases the 156-entry clock table by 1 byte per entry, but due to
> the compiler generating more efficient code for unpacked accesses, the
> net size increase is only 76 bytes (gcc 9.3.0 on arm32).
>
> Reported-by: Stephen Rothwell <[email protected]>
> Fixes: 4c3d88526eba2143 ("clk: renesas: Renesas R9A06G032 clock driver")
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
> v2:
> - Fix authorship.
> ---
> drivers/clk/renesas/r9a06g032-clocks.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Thanks.
I have added that to my fixes tree until it gets picked up elsewhere.
--
Cheers,
Stephen Rothwell
Hi Geert,
On Mon, 30 Nov 2020 09:57:43 +0100 Geert Uytterhoeven <[email protected]> wrote:
>
> The R9A06G032 clock driver uses an array of packed structures to reduce
> kernel size. However, this array contains pointers, which are no longer
> aligned naturally, and cannot be relocated on PPC64. Hence when
> compile-testing this driver on PPC64 with CONFIG_RELOCATABLE=y (e.g.
> PowerPC allyesconfig), the following warnings are produced:
>
> WARNING: 136 bad relocations
> c000000000616be3 R_PPC64_UADDR64 .rodata+0x00000000000cf338
> c000000000616bfe R_PPC64_UADDR64 .rodata+0x00000000000cf370
> ...
>
> Fix this by dropping the __packed attribute from the r9a06g032_clkdesc
> definition, trading a small size increase for portability.
>
> This increases the 156-entry clock table by 1 byte per entry, but due to
> the compiler generating more efficient code for unpacked accesses, the
> net size increase is only 76 bytes (gcc 9.3.0 on arm32).
>
> Reported-by: Stephen Rothwell <[email protected]>
> Fixes: 4c3d88526eba2143 ("clk: renesas: Renesas R9A06G032 clock driver")
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
> v2:
> - Fix authorship.
> ---
> drivers/clk/renesas/r9a06g032-clocks.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clk/renesas/r9a06g032-clocks.c b/drivers/clk/renesas/r9a06g032-clocks.c
> index d900f6bf53d0b944..892e91b92f2c80f5 100644
> --- a/drivers/clk/renesas/r9a06g032-clocks.c
> +++ b/drivers/clk/renesas/r9a06g032-clocks.c
> @@ -55,7 +55,7 @@ struct r9a06g032_clkdesc {
> u16 sel, g1, r1, g2, r2;
> } dual;
> };
> -} __packed;
> +};
>
> #define I_GATE(_clk, _rst, _rdy, _midle, _scon, _mirack, _mistat) \
> { .gate = _clk, .reset = _rst, \
> --
> 2.25.1
>
Tested-by: Stephen Rothwell <[email protected]> # PowerPC allyesconfig build
--
Cheers,
Stephen Rothwell
Quoting Geert Uytterhoeven (2020-11-30 00:57:43)
> The R9A06G032 clock driver uses an array of packed structures to reduce
> kernel size. However, this array contains pointers, which are no longer
> aligned naturally, and cannot be relocated on PPC64. Hence when
> compile-testing this driver on PPC64 with CONFIG_RELOCATABLE=y (e.g.
> PowerPC allyesconfig), the following warnings are produced:
>
> WARNING: 136 bad relocations
> c000000000616be3 R_PPC64_UADDR64 .rodata+0x00000000000cf338
> c000000000616bfe R_PPC64_UADDR64 .rodata+0x00000000000cf370
> ...
>
> Fix this by dropping the __packed attribute from the r9a06g032_clkdesc
> definition, trading a small size increase for portability.
>
> This increases the 156-entry clock table by 1 byte per entry, but due to
> the compiler generating more efficient code for unpacked accesses, the
> net size increase is only 76 bytes (gcc 9.3.0 on arm32).
>
> Reported-by: Stephen Rothwell <[email protected]>
> Fixes: 4c3d88526eba2143 ("clk: renesas: Renesas R9A06G032 clock driver")
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
Acked-by: Stephen Boyd <[email protected]>
Unless you want me to pick this up for clk-fixes?
Hi Stephen,
On Sat, Dec 5, 2020 at 7:24 AM Stephen Boyd <[email protected]> wrote:
> Quoting Geert Uytterhoeven (2020-11-30 00:57:43)
> > The R9A06G032 clock driver uses an array of packed structures to reduce
> > kernel size. However, this array contains pointers, which are no longer
> > aligned naturally, and cannot be relocated on PPC64. Hence when
> > compile-testing this driver on PPC64 with CONFIG_RELOCATABLE=y (e.g.
> > PowerPC allyesconfig), the following warnings are produced:
> >
> > WARNING: 136 bad relocations
> > c000000000616be3 R_PPC64_UADDR64 .rodata+0x00000000000cf338
> > c000000000616bfe R_PPC64_UADDR64 .rodata+0x00000000000cf370
> > ...
> >
> > Fix this by dropping the __packed attribute from the r9a06g032_clkdesc
> > definition, trading a small size increase for portability.
> >
> > This increases the 156-entry clock table by 1 byte per entry, but due to
> > the compiler generating more efficient code for unpacked accesses, the
> > net size increase is only 76 bytes (gcc 9.3.0 on arm32).
> >
> > Reported-by: Stephen Rothwell <[email protected]>
> > Fixes: 4c3d88526eba2143 ("clk: renesas: Renesas R9A06G032 clock driver")
> > Signed-off-by: Geert Uytterhoeven <[email protected]>
> > ---
>
> Acked-by: Stephen Boyd <[email protected]>
>
> Unless you want me to pick this up for clk-fixes?
Yes please. Forgot to retain this comment for v2:
"Please take directly (ppc or clk), as this is a build fix.
https://lore.kernel.org/linux-clk/[email protected]/"
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
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
Quoting Geert Uytterhoeven (2020-11-30 00:57:43)
> The R9A06G032 clock driver uses an array of packed structures to reduce
> kernel size. However, this array contains pointers, which are no longer
> aligned naturally, and cannot be relocated on PPC64. Hence when
> compile-testing this driver on PPC64 with CONFIG_RELOCATABLE=y (e.g.
> PowerPC allyesconfig), the following warnings are produced:
>
> WARNING: 136 bad relocations
> c000000000616be3 R_PPC64_UADDR64 .rodata+0x00000000000cf338
> c000000000616bfe R_PPC64_UADDR64 .rodata+0x00000000000cf370
> ...
>
> Fix this by dropping the __packed attribute from the r9a06g032_clkdesc
> definition, trading a small size increase for portability.
>
> This increases the 156-entry clock table by 1 byte per entry, but due to
> the compiler generating more efficient code for unpacked accesses, the
> net size increase is only 76 bytes (gcc 9.3.0 on arm32).
>
> Reported-by: Stephen Rothwell <[email protected]>
> Fixes: 4c3d88526eba2143 ("clk: renesas: Renesas R9A06G032 clock driver")
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
Applied to clk-fixes