Hi, On 4/18/2018 1:02 PM, Sven Eckelmann wrote: > The QSEE (trustzone) is started on IPQ4019 before Linux is started. > According to QCA, it is placed in in the the memory region > 0x87e80000-0x88000000 and must not be accessed directly. There is an > additional memory region 0x87e00000-0x87E80000 smem which which can be used > for communication with the TZ. The driver for the latter is not yet ready > but it is still not allowed to use this memory region like any other > memory region. > > Not reserving this memory region either leads to kernel crashes, kernel > hangs (often during the boot) or bus errors for userspace programs. The > latter happens when a program is using a memory region which is mapped to > these physical memory regions. > > [ 571.758058] Unhandled fault: imprecise external abort (0xc06) at 0x01715ff8 > [ 571.758099] pgd = cebec000 > [ 571.763826] [01715ff8] *pgd=8e7fa835, *pte=87e7f75f, *ppte=87e7fc7f > Bus error > > Signed-off-by: Sven Eckelmann <sven.eckelmann@xxxxxxxxxxxx> > --- Acked-by: Sricharan R <sricharan@xxxxxxxxxxxxxx> Regards, Sricharan > Cc: Sricharan Ramabadhran <srichara@xxxxxxxxxxxxxxxx> > Cc: Senthilkumar N L <snlakshm@xxxxxxxxxxxxxxxx> > > There are additional memory regions which have to be initialized first by > Linux. So they are currently not used. We were told by QCA that the > features QSDK uses them for are: > > * crash dump feature > - a couple of regions used when 'qca,scm_restart_reason' dt node has the > value 'dload_status' not set to 1 > + apps_bl <0x87000000 0x400000> > + sbl <0x87400000 0x100000> > + cnss_debug <0x87400000 0x100000> > + cpu_context_dump <0x87b00000 0x080000> > - required driver not available in Linux > - safe to remove > * QSEE app execution > - region tz_apps <0x87b80000 0x280000> > - required driver not available in Linux > - safe to remove > * communication with TZ/QSEE > - region smem <0x87b80000 0x280000> > - driver changes not yet upstreamed > - must not be removed because any access can crash kernel/program > * trustzone (QSEE) private memory > - region tz <0x87e80000 0x180000> > - must not be removed because any access can crash kernel/program > > The problem with the missing regions was reported in 2016 [1]. So maybe > this change qualifies for a stable@xxxxxxxxxxxxxxx submission. > > [1] https://www.spinics.net/lists/linux-arm-msm/msg21536.html > --- > arch/arm/boot/dts/qcom-ipq4019.dtsi | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/arch/arm/boot/dts/qcom-ipq4019.dtsi b/arch/arm/boot/dts/qcom-ipq4019.dtsi > index 10d112a4078e..b25daf368012 100644 > --- a/arch/arm/boot/dts/qcom-ipq4019.dtsi > +++ b/arch/arm/boot/dts/qcom-ipq4019.dtsi > @@ -23,6 +23,22 @@ > compatible = "qcom,ipq4019"; > interrupt-parent = <&intc>; > > + reserved-memory { > + #address-cells = <0x1>; > + #size-cells = <0x1>; > + ranges; > + > + smem_region: smem@87e00000 { > + reg = <0x87e00000 0x080000>; > + no-map; > + }; > + > + tz@87e80000 { > + reg = <0x87e80000 0x180000>; > + no-map; > + }; > + }; > + > aliases { > spi0 = &spi_0; > i2c0 = &i2c_0; > -- "QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
