On 26/11/18 12:46, Ard Biesheuvel wrote: > 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)
Using index 6 == 52 and updating the comment: Reviewed-by: Philippe Mathieu-Daudé <[email protected]> > >> 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
