[coreboot-gerrit] New patch to review for coreboot: 8948403 arm64: Add support for read and write registers at current EL in assembly
Patrick Georgi (pgeorgi@google.com)
gerrit at coreboot.org
Fri Mar 27 09:39:45 CET 2015
Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9062
-gerrit
commit 8948403951e9f7dc9ee29898c7767ea367663de7
Author: Furquan Shaikh <furquan at google.com>
Date: Sun Aug 31 12:21:37 2014 -0700
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:30785
BRANCH=None
TEST=Compiles successfully
Change-Id: I51749b6e4ae7b1ffbaae28d915cd100a28959f26
Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
Original-Commit-Id: c11c7287f507fa398cbbee75abc2bd11140ef19b
Original-Change-Id: I1258850438624abfe3b1ed7240df0db0e7905be6
Original-Signed-off-by: Furquan Shaikh <furquan at google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/216373
Original-Reviewed-by: Aaron Durbin <adurbin at chromium.org>
Original-Reviewed-by: Tom Warren <twarren at nvidia.com>
Original-Tested-by: Furquan Shaikh <furquan at chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan at chromium.org>
---
src/arch/arm64/include/armv8/arch/lib_helpers.h | 97 +++++++++++++++++++++++++
1 file changed, 97 insertions(+)
diff --git a/src/arch/arm64/include/armv8/arch/lib_helpers.h b/src/arch/arm64/include/armv8/arch/lib_helpers.h
index 57b63d8..958b8e7 100644
--- a/src/arch/arm64/include/armv8/arch/lib_helpers.h
+++ b/src/arch/arm64/include/armv8/arch/lib_helpers.h
@@ -22,6 +22,9 @@
* file.
*/
+#ifndef __ARCH_LIB_HELPERS_H__
+#define __ARCH_LIB_HELPERS_H__
+
#define EL0 0
#define EL1 1
#define EL2 2
@@ -30,6 +33,96 @@
#define CURRENT_EL_MASK 0x3
#define CURRENT_EL_SHIFT 2
+#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, #(EL1 << CURRENT_EL_SHIFT)
+ b.eq \label1
+ /* Currently at EL2 */
+ cmp \xreg, #(EL2 << CURRENT_EL_SHIFT)
+ b.eq \label2
+ /* Currently at EL3 */
+ cmp \xreg, #(EL3 << CURRENT_EL_SHIFT)
+ 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
+
+/* Macro to read sysreg at current EL - 1
+ xreg - reg in which read value needs to be stored
+ sysreg - system reg that is to be read
+*/
+.macro read_lower xreg sysreg
+ switch_el \xreg, 101f, 102f, 103f
+101:
+ b 104f
+102:
+ mrs \xreg, \sysreg\()_el1
+ b 104f
+103:
+ mrs \xreg, \sysreg\()_el2
+ b 104f
+104:
+.endm
+
+/* Macro to write sysreg at current EL - 1
+ 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_lower sysreg xreg temp
+ switch_el \temp, 101f, 102f, 103f
+101:
+ b 104f
+102:
+ msr \sysreg\()_el1, \xreg
+ b 104f
+103:
+ msr \sysreg\()_el2, \xreg
+ b 104f
+104:
+.endm
+
+#else
+
#define DAIF_DBG_BIT (1<<3)
#define DAIF_ABT_BIT (1<<2)
#define DAIF_IRQ_BIT (1<<1)
@@ -290,3 +383,7 @@ void tlbiallis_el2(void);
void tlbiallis_el3(void);
void tlbiallis_current(void);
void tlbivaa_el1(uint64_t va);
+
+#endif // __ASSEMBLY__
+
+#endif // __ARCH_LIB_HELPERS_H__
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