On Fri, 23 Nov 2018 at 13:14, Ard Biesheuvel <[email protected]> wrote: > > Add a helper function that returns the maximum physical address space > size as supported by the current CPU. > > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Ard Biesheuvel <[email protected]> > --- > ArmPkg/Include/Library/ArmLib.h | 6 ++++++ > ArmPkg/Library/ArmLib/AArch64/ArmLibSupport.S | 16 ++++++++++++++++ > ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S | 8 ++++++++ > 3 files changed, 30 insertions(+) > > diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h > index ffda50e9d767..9a804c15fdb6 100644 > --- a/ArmPkg/Include/Library/ArmLib.h > +++ b/ArmPkg/Include/Library/ArmLib.h > @@ -733,4 +733,10 @@ ArmWriteCntvOff ( > UINT64 Val > ); > > +UINTN > +EFIAPI > +ArmGetPhysicalAddressBits ( > + VOID > + ); > + > #endif // __ARM_LIB__ > diff --git a/ArmPkg/Library/ArmLib/AArch64/ArmLibSupport.S > b/ArmPkg/Library/ArmLib/AArch64/ArmLibSupport.S > index 1ef2f61f5979..75ab8dade485 100644 > --- a/ArmPkg/Library/ArmLib/AArch64/ArmLibSupport.S > +++ b/ArmPkg/Library/ArmLib/AArch64/ArmLibSupport.S > @@ -196,4 +196,20 @@ ASM_FUNC(ArmWriteSctlr) > 3:msr sctlr_el3, x0 > 4:ret > > +ASM_FUNC(ArmGetPhysicalAddressBits) > + mrs x0, id_aa64mmfr0_el1 > + adr x1, .LPARanges > + and x0, x0, #7 > + ldrb w0, [x1, x0] > + ret > + > +// > +// Bits 0..2 of the AA64MFR0_EL1 system register encode the size of the > +// physical address space support on this CPU: > +// 0 == 32 bits, 1 == 36 bits, etc etc > +// 6 and 7 are reserved > +// > +.LPARanges: > + .byte 32, 36, 40, 42, 44, 48, -1, -1 > +
Note: as Drew pointed out, we want 52 bits included as well in this enumeration. I will fix that up when applying (unless anyone objects) > ASM_FUNCTION_REMOVE_IF_UNREFERENCED > diff --git a/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S > b/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S > index f2a517671f0a..f2f3c9a25991 100644 > --- a/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S > +++ b/ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S > @@ -165,4 +165,12 @@ ASM_FUNC(ArmWriteCpuActlr) > isb > bx lr > > +ASM_FUNC (ArmGetPhysicalAddressBits) > + mrc p15, 0, r0, c0, c1, 4 // MMFR0 > + and r0, r0, #0xf // VMSA [3:0] > + cmp r0, #5 // >5 implies LPAE support > + movlt r0, #32 // 32 bits if no LPAE > + movge r0, #40 // 40 bits if LPAE > + bx lr > + > ASM_FUNCTION_REMOVE_IF_UNREFERENCED > -- > 2.17.1 > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
