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 | 17 +++++++++++++++++ ArmPkg/Library/ArmLib/AArch64/ArmLibSupport.S | 16 ++++++++++++++++ ArmPkg/Library/ArmLib/Arm/ArmLibSupport.S | 8 ++++++++ 3 files changed, 41 insertions(+) diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h index ffda50e9d767..b22879fe6e94 100644 --- a/ArmPkg/Include/Library/ArmLib.h +++ b/ArmPkg/Include/Library/ArmLib.h @@ -29,6 +29,17 @@ #define EFI_MEMORY_CACHETYPE_MASK (EFI_MEMORY_UC | EFI_MEMORY_WC | \ EFI_MEMORY_WT | EFI_MEMORY_WB | \ EFI_MEMORY_UCE) +// +// ARM_MMU_IDMAP_RANGE defines the maximum size of the identity mapping +// that covers the entire address space when running in UEFI. This is +// limited to what can architecturally be mapped using a 4 KB granule, +// even if the hardware is capable of mapping more using larger pages. +// +#ifdef MDE_CPU_ARM +#define ARM_MMU_IDMAP_RANGE (1ULL << 32) +#else +#define ARM_MMU_IDMAP_RANGE (1ULL << 48) +#endif /** * The UEFI firmware must not use the ARM_MEMORY_REGION_ATTRIBUTE_NONSECURE_* attributes. @@ -733,4 +744,10 @@ 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..7332601241aa 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, 52, -1 + 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 -- 2.19.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
