[PATCH] arm64: mm: use macro instead of if judgement of ZONE_DMA
Yifan Zhang
yifan.zhangm at gmail.com
Fri Oct 17 04:23:42 PDT 2014
Hi Uwe,
Yes, the first patch is broken. So I sent a v2 which is in correct format.
I understand IS_ENABLED is better, but in this case, we can't use "if"
since "ZONE_DMA" is defined under "#ifdef CONFIG_ZONE_DMA". In current
code, once we disable CONFIG_ZONE_DMA, "zone_size[ZONE_DMA]" will
report compiling error as below:
# configuration written to .config
#
making android
scripts/kconfig/conf --silentoldconfig Kconfig
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
CALL scripts/checksyscalls.sh
CC scripts/mod/devicetable-offsets.s
GEN scripts/mod/devicetable-offsets.h
HOSTCC scripts/mod/file2alias.o
HOSTLD scripts/mod/modpost
CHK include/generated/compile.h
CC arch/arm64/mm/init.o
make[1]: Nothing to be done for `dtbs'.
CGIT kernel/gitinfo.S
arch/arm64/mm/init.c: In function 'zone_sizes_init':
arch/arm64/mm/init.c:85:13: error: 'ZONE_DMA' undeclared (first use in
this function)
zone_size[ZONE_DMA] = max_dma - min;
^
arch/arm64/mm/init.c:85:13: note: each undeclared identifier is
reported only once for each function it appears in
make[1]: *** [arch/arm64/mm/init.o] Error 1
make: *** [arch/arm64/mm] Error 2
make: *** Waiting for unfinished jobs....
AS kernel/gitinfo.o
LD kernel/built-in.o
BR,
Yifan
On Fri, Oct 17, 2014 at 6:51 PM, Uwe Kleine-König
<u.kleine-koenig at pengutronix.de> wrote:
> Hello,
>
> On Thu, Oct 16, 2014 at 05:19:43PM +0800, Yifan Zhang wrote:
>> @@ -82,10 +82,10 @@ static void __init zone_sizes_init(unsigned long
>> min, unsigned long max)
>>
>> memset(zone_size, 0, sizeof(zone_size));
>>
>>
>>
>> /* 4GB maximum for 32-bit only capable devices */
>>
>> - if (IS_ENABLED(CONFIG_ZONE_DMA)) {
>>
>> - max_dma = PFN_DOWN(max_zone_dma_phys());
>>
>> - zone_size[ZONE_DMA] = max_dma - min;
>>
>> - }
>>
>> +#ifdef CONFIG_ZONE_DMA
>>
>> + max_dma = PFN_DOWN(max_zone_dma_phys());
>>
>> + zone_size[ZONE_DMA] = max_dma - min;
>>
>> +#endif
> Apart from your patch being broken (probably by your MUA or MTA) usually
> if (IS_ENABLED(...)) is preferred over #ifdef because it doesn't stand
> out over the other program source.
>
> Best regards
> Uwe
>
> --
> Pengutronix e.K. | Uwe Kleine-König |
> Industrial Linux Solutions | http://www.pengutronix.de/ |
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