Re: [RESEND PATCH 1/1] ArmPlatformPkg/ArmTrustZone: Add support for specifying Subregions to be disabled

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 17 October 2016 at 14:25, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> On Mon, Oct 17, 2016 at 10:18:01AM +0000, Bhupesh Sharma wrote:
>> Hi Ard, Leif,
>>
>> Any comments on this patch ?
>
> You didn't cc me before :)
>
> But more importantly, I don't really have any platform to test this
> on, so I could use a Tested-by: from someone who does. Evan, do you?
>
>> > From: Bhupesh Sharma [mailto:bhupesh.sharma@nxp.com]
>> > Sent: Friday, October 14, 2016 4:40 PM
>> >
>> > ARM TZASC-380 IP provides a mechanism to split memory regions being
>> > protected via it into eight equal-sized sub-regions, with a bit setting
>> > allowing the corresponding subregion to be disabled.
>> >
>> > Several NXP/FSL SoCs support the TZASC-380 IP block and allow the DDR
>> > connected via the TZASC to be partitioned into regions having different
>> > security settings.
>> >
>> > This patch enables this support and can be used for SoCs which support
>> > such partition of DDR regions.
>> >
>> > Details of the 'subregion_disable'
>
> This is not actually what the register is called in the link you're
> providing.
>
>> > register can be viewed here:
>> > http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0431c/CJ
>> > ABCFHB.html
>> >
>> > Contributed-under: TianoCore Contribution Agreement 1.0
>> > Signed-off-by: Bhupesh Sharma <bhupesh.sharma@nxp.com>
>> > Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> > ---
>> >  .../Library/ArmVExpressSecLibCTA9x4/CTA9x4Sec.c     | 21
>> > ++++++++++++++-------
>> >  ArmPlatformPkg/Drivers/ArmTrustZone/ArmTrustZone.c  |  5 +++--
>> >  ArmPlatformPkg/Include/Drivers/ArmTrustzone.h       |  3 ++-
>> >  3 files changed, 19 insertions(+), 10 deletions(-)
>> >
>> > diff --git
>> > a/ArmPlatformPkg/ArmVExpressPkg/Library/ArmVExpressSecLibCTA9x4/CTA9x4S
>> > ec.c
>> > b/ArmPlatformPkg/ArmVExpressPkg/Library/ArmVExpressSecLibCTA9x4/CTA9x4S
>> > ec.c
>> > index 6fa0774..d358d65 100644
>> > ---
>> > a/ArmPlatformPkg/ArmVExpressPkg/Library/ArmVExpressSecLibCTA9x4/CTA9x4S
>> > ec.c
>> > +++
>> > b/ArmPlatformPkg/ArmVExpressPkg/Library/ArmVExpressSecLibCTA9x4/CTA9
>> > +++ x4Sec.c
>> > @@ -72,18 +72,21 @@ ArmPlatformSecTrustzoneInit (
>> >    // NOR Flash 0 non secure (BootMon)
>> >    TZASCSetRegion(ARM_VE_TZASC_BASE,1,TZASC_REGION_ENABLED,
>> >        ARM_VE_SMB_NOR0_BASE,0,
>> > -      TZASC_REGION_SIZE_64MB, TZASC_REGION_SECURITY_NSRW);
>> > +      TZASC_REGION_SIZE_64MB, TZASC_REGION_SECURITY_NSRW,
>> > +      0);
>> >
>> >    // NOR Flash 1. The first half of the NOR Flash1 must be secure for
>> > the secure firmware (sec_uefi.bin)
>> >    if (PcdGetBool (PcdTrustzoneSupport) == TRUE) {
>> >      //Note: Your OS Kernel must be aware of the secure regions before
>> > to enable this region
>> >      TZASCSetRegion(ARM_VE_TZASC_BASE,2,TZASC_REGION_ENABLED,
>> >          ARM_VE_SMB_NOR1_BASE + SIZE_32MB,0,
>> > -        TZASC_REGION_SIZE_32MB, TZASC_REGION_SECURITY_NSRW);
>> > +        TZASC_REGION_SIZE_32MB, TZASC_REGION_SECURITY_NSRW,
>> > +   0);
>
> TAB used (convert to spaces).
>
>> >    } else {
>> >      TZASCSetRegion(ARM_VE_TZASC_BASE,2,TZASC_REGION_ENABLED,
>> >          ARM_VE_SMB_NOR1_BASE,0,
>> > -        TZASC_REGION_SIZE_64MB, TZASC_REGION_SECURITY_NSRW);
>> > +        TZASC_REGION_SIZE_64MB, TZASC_REGION_SECURITY_NSRW,
>> > +   0);
>
> TAB used (convert to spaces).
>
>> >    }
>> >
>> >    // Base of SRAM. Only half of SRAM in Non Secure world @@ -92,22
>> > +95,26 @@ ArmPlatformSecTrustzoneInit (
>> >      //Note: Your OS Kernel must be aware of the secure regions before
>> > to enable this region
>> >      TZASCSetRegion(ARM_VE_TZASC_BASE,3,TZASC_REGION_ENABLED,
>> >          ARM_VE_SMB_SRAM_BASE,0,
>> > -        TZASC_REGION_SIZE_16MB, TZASC_REGION_SECURITY_NSRW);
>> > +        TZASC_REGION_SIZE_16MB, TZASC_REGION_SECURITY_NSRW,
>> > +   0);
>
> TAB used (convert to spaces).
>
>> >    } else {
>> >      TZASCSetRegion(ARM_VE_TZASC_BASE,3,TZASC_REGION_ENABLED,
>> >          ARM_VE_SMB_SRAM_BASE,0,
>> > -        TZASC_REGION_SIZE_32MB, TZASC_REGION_SECURITY_NSRW);
>> > +        TZASC_REGION_SIZE_32MB, TZASC_REGION_SECURITY_NSRW,
>> > +   0);
>
> TAB used (convert to spaces).
>
> (These are all found by BaseTools/Scripts/PatchCheck.py, which also
> points out that the subject line is too long.)
>
>> >    }
>> >
>> >    // Memory Mapped Peripherals. All in non secure world
>> >    TZASCSetRegion(ARM_VE_TZASC_BASE,4,TZASC_REGION_ENABLED,
>> >        ARM_VE_SMB_PERIPH_BASE,0,
>> > -      TZASC_REGION_SIZE_64MB, TZASC_REGION_SECURITY_NSRW);
>> > +      TZASC_REGION_SIZE_64MB, TZASC_REGION_SECURITY_NSRW,
>> > +      0);
>> >
>> >    // MotherBoard Peripherals and On-chip peripherals.
>> >    TZASCSetRegion(ARM_VE_TZASC_BASE,5,TZASC_REGION_ENABLED,
>> >        ARM_VE_SMB_MB_ON_CHIP_PERIPH_BASE,0,
>> > -      TZASC_REGION_SIZE_256MB, TZASC_REGION_SECURITY_NSRW);
>> > +      TZASC_REGION_SIZE_256MB, TZASC_REGION_SECURITY_NSRW,
>> > +      0);
>> >  }
>> >
>> >  /**
>> > diff --git a/ArmPlatformPkg/Drivers/ArmTrustZone/ArmTrustZone.c
>> > b/ArmPlatformPkg/Drivers/ArmTrustZone/ArmTrustZone.c
>> > index 070c0dc..5cd41ef 100644
>> > --- a/ArmPlatformPkg/Drivers/ArmTrustZone/ArmTrustZone.c
>> > +++ b/ArmPlatformPkg/Drivers/ArmTrustZone/ArmTrustZone.c
>> > @@ -87,7 +87,8 @@ TZASCSetRegion (
>> >    IN  UINTN LowAddress,
>> >    IN  UINTN HighAddress,
>> >    IN  UINTN Size,
>> > -  IN  UINTN Security
>> > +  IN  UINTN Security,
>> > +  IN  UINTN SubregionDisableMask
>> >    )
>> >  {
>> >    UINT32*     Region;
>> > @@ -100,7 +101,7 @@ TZASCSetRegion (
>> >
>> >    MmioWrite32((UINTN)(Region), LowAddress&0xFFFF8000);
>> >    MmioWrite32((UINTN)(Region+1), HighAddress);
>> > -  MmioWrite32((UINTN)(Region+2), ((Security & 0xF) <<28) | ((Size &
>> > 0x3F) << 1) | (Enabled & 0x1));
>> > +  MmioWrite32((UINTN)(Region+2), ((Security & 0xF) <<28) |
>> > + ((SubregionDisableMask & 0xFF) << 8) | ((Size & 0x3F) << 1) |
>> > (Enabled
>> > + & 0x1));
>
> I think these additions tip the code over to where a temporary
> variable should be used for the register value.
>
>> >
>> >    return EFI_SUCCESS;
>> >  }
>> > diff --git a/ArmPlatformPkg/Include/Drivers/ArmTrustzone.h
>> > b/ArmPlatformPkg/Include/Drivers/ArmTrustzone.h
>> > index 78e98aa..1ba963d 100644
>> > --- a/ArmPlatformPkg/Include/Drivers/ArmTrustzone.h
>> > +++ b/ArmPlatformPkg/Include/Drivers/ArmTrustzone.h
>> > @@ -82,7 +82,8 @@ TZASCSetRegion (
>> >    IN  UINTN LowAddress,
>> >    IN  UINTN HighAddress,
>> >    IN  UINTN Size,
>> > -  IN  UINTN Security
>> > +  IN  UINTN Security,
>> > +  IN  UINTN SubregionDisableMask
>> >    );
>
> This modifies a prototype of a function implemented in:
> ArmPlatformPkg/ArmVExpressPkg/Library/ArmVExpressSecLibCTA9x4/CTA9x4Sec.c
> ArmPlatformPkg/ArmVExpressPkg/Library/ArmVExpressSecLibRTSM/RTSMSec.c
> ArmPlatformPkg/Library/ArmPlatformSecLibNull/ArmPlatformLibNullSec.c
>
> But only modifies the implementation in one of them.
> Arguably, the RTSM one could simply be deleted (probably), but if
> we're keeping this library, then the LibNullSec should at least be
> kept up to date.
>
> Ard: comments on deleting the RTSM one?
>

Nope.