diff options
| author | Furquan Shaikh <furquan@google.com> | 2014-08-27 15:57:47 -0700 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2015-03-21 13:38:56 +0100 |
| commit | 4c2cb16d8908a4dd229733fc6e49c5662718381a (patch) | |
| tree | ba9163d4e4a415cde0b968394e48a33979515c9d /payloads/libpayload | |
| parent | adabbe5e20705c69e44ee3674ddd78c74ed173b7 (diff) | |
| download | coreboot-4c2cb16d8908a4dd229733fc6e49c5662718381a.tar.xz | |
libpayload arm64: Add support for read and write registers at current EL in assembly
In order to ease the process of reading and writing any register at current EL,
provide read_current and write_current assembly macros. These are included in
arch/lib_helpers.h under the __ASSEMBLY__ macro condition. This is done to allow
the same header file to be included by .c and .S files.
BUG=chrome-os-partner:31634
BRANCH=None
TEST=Compiles successfully for ryu
Change-Id: I79241a944b68ebb24865e745a9835f54ab6d1a8f
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 2b55fbde466126c4de7f5f7bb2d1427196be842f
Original-Change-Id: I678ab89c4aa1b08898166e135b5ab2d6453bb5e8
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/214576
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/8801
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'payloads/libpayload')
| -rw-r--r-- | payloads/libpayload/include/arm64/arch/lib_helpers.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/payloads/libpayload/include/arm64/arch/lib_helpers.h b/payloads/libpayload/include/arm64/arch/lib_helpers.h index 3adba81c88..d98d6f7d6b 100644 --- a/payloads/libpayload/include/arm64/arch/lib_helpers.h +++ b/payloads/libpayload/include/arm64/arch/lib_helpers.h @@ -33,6 +33,61 @@ #ifndef __ARCH_LIB_HELPERS_H__ #define __ARCH_LIB_HELPERS_H__ +#ifdef __ASSEMBLY__ + +/* Macro to switch to label based on current el */ +.macro switch_el xreg label1 label2 label3 + mrs \xreg, CurrentEL + /* Currently at EL1 */ + cmp \xreg, 0x4 + b.eq \label1 + /* Currently at EL2 */ + cmp \xreg, 0x8 + b.eq \label2 + /* Currently at EL3 */ + cmp \xreg, 0xc + b.eq \label3 +.endm + +/* Macro to read sysreg at current EL + xreg - reg in which read value needs to be stored + sysreg - system reg that is to be read +*/ +.macro read_current xreg sysreg + switch_el \xreg, 101f, 102f, 103f +101: + mrs \xreg, \sysreg\()_el1 + b 104f +102: + mrs \xreg, \sysreg\()_el2 + b 104f +103: + mrs \xreg, \sysreg\()_el3 + b 104f +104: +.endm + +/* Macro to write sysreg at current EL + xreg - reg from which value needs to be written + sysreg - system reg that is to be written + temp - temp reg that can be used to read current EL +*/ +.macro write_current sysreg xreg temp + switch_el \temp, 101f, 102f, 103f +101: + msr \sysreg\()_el1, \xreg + b 104f +102: + msr \sysreg\()_el2, \xreg + b 104f +103: + msr \sysreg\()_el3, \xreg + b 104f +104: +.endm + +#else + #define EL0 0 #define EL1 1 #define EL2 2 @@ -318,4 +373,6 @@ void tlbivaa_el1(uint64_t va); /* Clock */ void set_cntfrq(uint32_t freq); +#endif // __ASSEMBLY__ + #endif //__ARCH_LIB_HELPERS_H__ |