Implement the kpkeys interface if CONFIG_ARM64_POE is enabled.
The permissions for KPKEYS_PKEY_DEFAULT (pkey 0) are set to RWX as
this pkey is also used for code mappings.
Signed-off-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
---
arch/arm64/include/asm/kpkeys.h | 43 +++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
create mode 100644 arch/arm64/include/asm/kpkeys.h
diff --git a/arch/arm64/include/asm/kpkeys.h b/arch/arm64/include/asm/kpkeys.h
new file mode 100644
index 000000000000..e17f6df41873
--- /dev/null
+++ b/arch/arm64/include/asm/kpkeys.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_KPKEYS_H
+#define __ASM_KPKEYS_H
+
+#include <asm/barrier.h>
+#include <asm/cpufeature.h>
+#include <asm/por.h>
+
+#include <asm-generic/kpkeys.h>
+
+static inline bool arch_kpkeys_enabled(void)
+{
+ return system_supports_poe();
+}
+
+#ifdef CONFIG_ARM64_POE
+
+static inline u64 por_set_kpkeys_level(u64 por, int level)
+{
+ por = por_set_pkey_perms(por, KPKEYS_PKEY_DEFAULT, POE_RXW);
+
+ return por;
+}
+
+static inline int arch_kpkeys_set_level(int level)
+{
+ u64 prev_por = read_sysreg_s(SYS_POR_EL1);
+
+ write_sysreg_s(por_set_kpkeys_level(prev_por, level), SYS_POR_EL1);
+ isb();
+
+ return prev_por;
+}
+
+static inline void arch_kpkeys_restore_pkey_reg(u64 pkey_reg)
+{
+ write_sysreg_s(pkey_reg, SYS_POR_EL1);
+ isb();
+}
+
+#endif /* CONFIG_ARM64_POE */
+
+#endif /* __ASM_KPKEYS_H */
--
2.47.0
