On 10 November 2016 at 18:41, Michal Simek <[email protected]> wrote: > + Nathan > > 2016-10-31 17:26 GMT+01:00 Kyle Roeschley <[email protected]>: >> >> 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 <[email protected]>
Tested-by: Nathan Rossi <[email protected]> For reference this causes problems with DEBUG_RODATA (which changed to 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 >> [email protected] >> 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
