Messages in this thread | | | From | Nathan Rossi <> | Date | Thu, 10 Nov 2016 19:57:11 +1000 | Subject | Re: [PATCH] ARM: zynq: Reserve correct amount of non-DMA RAM |
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On 10 November 2016 at 19:33, Nathan Rossi <nathan@nathanrossi.com> wrote: > On 10 November 2016 at 18:41, Michal Simek <monstr@monstr.eu> wrote: >> + Nathan >> >> 2016-10-31 17:26 GMT+01:00 Kyle Roeschley <kyle.roeschley@ni.com>: >>> >>> On Zynq, we haven't been reserving the correct amount of DMA-incapable >>> RAM to keep DMA away from it (per the Zynq TRM Section 4.1, it should be >>> the first 512k). In older kernels, this was masked by the >>> memblock_reserve call in arm_memblock_init(). Now, reserve the correct >>> amount excplicitly rather than relying on swapper_pg_dir, which is an >>> address and not a size anyway. >>> >>> Fixes: 46f5b96 ("ARM: zynq: Reserve not DMAable space in front of the >>> kernel") >>> >>> Signed-off-by: Kyle Roeschley <kyle.roeschley@ni.com> > > Tested-by: Nathan Rossi <nathan@nathanrossi.com> > > For reference this causes problems with DEBUG_RODATA (which changed to
Sorry typo -> s/causes/caused/, as in "... this [incorrect reserving of the lower 512K] caused ...".
Regards, Nathan
> default yes for CPU_V7 in v4.6) due to padding memory between > .head.text and .text, allowing memory below 0x80000 to be available > for allocation as non-reserved memory. > > Regards, > Nathan > >>> --- >>> Found when migrating from 4.1 to 4.6. >>> >>> arch/arm/mach-zynq/common.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c >>> index 6cefdb8..75885bc 100644 >>> --- a/arch/arm/mach-zynq/common.c >>> +++ b/arch/arm/mach-zynq/common.c >>> @@ -59,7 +59,7 @@ void __iomem *zynq_scu_base; >>> static void __init zynq_memory_init(void) >>> { >>> if (!__pa(PAGE_OFFSET)) >>> - memblock_reserve(__pa(PAGE_OFFSET), __pa(swapper_pg_dir)); >>> + memblock_reserve(__pa(PAGE_OFFSET), 0x80000); >>> } >>> >>> static struct platform_device zynq_cpuidle_device = { >>> -- >>> 2.9.3 >>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@lists.infradead.org >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >> >> >> >> >> -- >> Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91 >> w: www.monstr.eu p: +42-0-721842854 >> Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/ >> Maintainer of Linux kernel - Xilinx Zynq ARM architecture >> Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform
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