Herton Ronaldo Krzesinski 596fd46268 mtd: nandsim: don't open code a do_div helper ... We don't need to open code the divide function, just use div_u64 that already exists and do the same job. While this is a straightforward clean up, there is more to that, the real motivation for this. While building on a cross compiling environment in armel, using gcc 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5), I was getting the following build error: ERROR: "__aeabi_uldivmod" [drivers/mtd/nand/nandsim.ko] undefined! After investigating with objdump and hand built assembly version generated with the compiler, I narrowed __aeabi_uldivmod as being generated from the divide function. When nandsim.c is built with -fno-inline-functions-called-once, that happens when CONFIG_DEBUG_SECTION_MISMATCH is enabled, the do_div optimization in arch/arm/include/asm/div64.h doesn't work as expected with the open coded divide function: even if the do_div we are using doesn't have a constant divisor, the compiler still includes the else parts of the optimized do_div macro, and translates the divisions there to use __aeabi_uldivmod, instead of only calling __do_div_asm -> __do_div64 and optimizing/removing everything else out. So to reproduce, gcc 4.6 plus CONFIG_DEBUG_SECTION_MISMATCH=y and CONFIG_MTD_NAND_NANDSIM=m should do it, building on armel. After this change, the compiler does the intended thing even with -fno-inline-functions-called-once, and optimizes out as expected the constant handling in the optimized do_div on arm. As this also avoids a build issue, I'm marking for Stable, as I think is applicable for this case. Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: stable@vger.kernel.org Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>		2012-07-06 16:59:33 +01:00
..
gpmi-nand	mtd: gpmi-nand: fix read page when reading to vmalloced area	2012-07-06 15:06:23 +01:00
alauda.c
ams-delta.c
atmel_nand_ecc.h
atmel_nand.c
au1550nd.c
autcpu12.c
bcm_umi_bch.c
bcm_umi_nand.c
bf5xx_nand.c
cafe_nand.c	mtd: cafe_nand: fix an & vs | mistake	2012-07-06 14:27:13 +01:00
cmx270_nand.c
cs553x_nand.c
davinci_nand.c
denali.c
denali.h
diskonchip.c
docg4.c
fsl_elbc_nand.c
fsl_ifc_nand.c
fsl_upm.c
fsmc_nand.c
gpio.c
h1910.c
jz4740_nand.c
Kconfig
Makefile
mpc5121_nfc.c
mxc_nand.c	mtd: mxc_nand: use 32bit copy functions	2012-07-06 15:06:18 +01:00
nand_base.c
nand_bbt.c
nand_bch.c
nand_bcm_umi.c
nand_bcm_umi.h
nand_ecc.c
nand_ids.c
nandsim.c	mtd: nandsim: don't open code a do_div helper	2012-07-06 16:59:33 +01:00
ndfc.c
nomadik_nand.c
nuc900_nand.c
omap2.c
orion_nand.c
pasemi_nand.c
plat_nand.c
ppchameleonevb.c
pxa3xx_nand.c
r852.c
r852.h
rtc_from4.c
s3c2410.c
sh_flctl.c
sharpsl.c
sm_common.c
sm_common.h
socrates_nand.c
spia.c
tmio_nand.c
txx9ndfmc.c