• Eugeniy Paltsev's avatar
    ARC: IOC: panic if kernel was started with previously enabled IOC · 3624379d
    Eugeniy Paltsev authored
    If IOC was already enabled (due to bootloader) it technically needs to
    be reconfigured with aperture base,size corresponding to Linux memory map
    which will certainly be different than uboot's. But disabling and
    reenabling IOC when DMA might be potentially active is tricky business.
    To avoid random memory issues later, just panic here and ask user to
    upgrade bootloader to one which doesn't enable IOC
    This was actually seen as issue on some of the HSDK board with a version
    of uboot which enabled IOC. There were random issues later with starting
    of X or peripherals etc.
    Also while I'm at it, replace hardcoded bits in ARC_REG_IO_COH_PARTIAL
    and ARC_REG_IO_COH_ENABLE registers by definitions.
    Inspired by: https://lkml.org/lkml/2018/1/19/557Signed-off-by: default avatarEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
    Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
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