Hi Jan, On lun., août 28 2017, Jan Luebbe <[email protected]> wrote:
> At least the Armada XP SoC supports 4GB on a single DRAM window. Because > the size register values contain the actual size - 1, the MSB is set in > that case. For example, the SDRAM window's control register's value is > 0xffffffe1 for 4GB (bits 31 to 24 contain the size). > > The MBUS driver reads back each window's size from registers and > calculates the actual size as (control_reg | ~DDR_SIZE_MASK) + 1, which > overflows for 32 bit values, resulting in other miscalculations further > on (a bad RAM window for the CESA crypto engine calculated by > mvebu_mbus_setup_cpu_target_nooverlap() in my case). > > This patch changes the type in 'struct mbus_dram_window' from u32 to > u64, which allows us to keep using the same register calculation code in > most MBUS-using drivers (which calculate ->size - 1 again). > Your patch looks good, but as it is a fix we should also apply it on stable, could you provide the commit to fix? Thanks, Gregory > Signed-off-by: Jan Luebbe <[email protected]> > --- > drivers/bus/mvebu-mbus.c | 2 +- > include/linux/mbus.h | 4 ++-- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/bus/mvebu-mbus.c b/drivers/bus/mvebu-mbus.c > index c7f396903184..70db4d5638a6 100644 > --- a/drivers/bus/mvebu-mbus.c > +++ b/drivers/bus/mvebu-mbus.c > @@ -720,7 +720,7 @@ mvebu_mbus_default_setup_cpu_target(struct > mvebu_mbus_state *mbus) > if (mbus->hw_io_coherency) > w->mbus_attr |= ATTR_HW_COHERENCY; > w->base = base & DDR_BASE_CS_LOW_MASK; > - w->size = (size | ~DDR_SIZE_MASK) + 1; > + w->size = (u64)(size | ~DDR_SIZE_MASK) + 1; > } > } > mvebu_mbus_dram_info.num_cs = cs; > diff --git a/include/linux/mbus.h b/include/linux/mbus.h > index 0d3f14fd2621..4773145246ed 100644 > --- a/include/linux/mbus.h > +++ b/include/linux/mbus.h > @@ -31,8 +31,8 @@ struct mbus_dram_target_info > struct mbus_dram_window { > u8 cs_index; > u8 mbus_attr; > - u32 base; > - u32 size; > + u64 base; > + u64 size; > } cs[4]; > }; > > -- > 2.11.0 > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com
