diff options
| -rw-r--r-- | src/arch/arm64/include/armv8/arch/lib_helpers.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/src/arch/arm64/include/armv8/arch/lib_helpers.h b/src/arch/arm64/include/armv8/arch/lib_helpers.h index a80474799d..422b81a56b 100644 --- a/src/arch/arm64/include/armv8/arch/lib_helpers.h +++ b/src/arch/arm64/include/armv8/arch/lib_helpers.h @@ -214,6 +214,31 @@ 104: .endm +/* Macro to read from a register at EL3 only if we are currently at that + level. This is required to ensure that we do not attempt to read registers + from a level lower than el3. e.g. SCR is available for read only at EL3. + IMPORTANT: if EL != EL3, macro silently doesn't perform the read. +*/ +.macro read_el3 xreg sysreg + switch_el \xreg, 402f, 402f, 401f +401: + mrs \xreg, \sysreg\()_el3 +402: +.endm + +/* Macro to write to a register at EL3 only if we are currently at that + level. This is required to ensure that we do not attempt to write to + registers from a level lower than el3. e.g. SCR is available to write only at + EL3. + IMPORTANT: if EL != EL3, macro silently doesn't perform the write. +*/ +.macro write_el3 sysreg xreg temp + switch_el \temp, 402f, 402f, 401f +401: + msr \sysreg\()_el3, \xreg +402: +.endm + #else #include <stdint.h> |