[PATCH v5 21/30] arm64: enable POE and PIE to coexist

[Joey Gouly]

Permission Indirection Extension and Permission Overlay Extension can be
enabled independently.

When PIE is disabled and POE is enabled, the permissions set by POR_EL0 will be
applied on top of the permissions set in the PTE.

When both PIE and POE are enabled, the permissions set by POR_EL0 will be
applied on top of the permissions set by the PIRE0_EL1 register.
However PIRE0_EL1 has encodings that specifically enable and disable the
overlay from applying.

For example:
	0001	Read, Overlay applied.
	1000	Read, Overlay not applied.

Switch to using the 'Overlay applied' encodings in PIRE0_EL1, so that PIE and
POE can coexist.

Signed-off-by: Joey Gouly <joey.gouly at arm.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will at kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>
---
 arch/arm64/include/asm/pgtable-prot.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git arch/arm64/include/asm/pgtable-prot.h arch/arm64/include/asm/pgtable-prot.h
index b11cfb9fdd37..2a11d0c10760 100644
--- arch/arm64/include/asm/pgtable-prot.h
+++ arch/arm64/include/asm/pgtable-prot.h
@@ -154,10 +154,10 @@ static inline bool __pure lpa2_is_enabled(void)
 
 #define PIE_E0	( \
 	PIRx_ELx_PERM(pte_pi_index(_PAGE_EXECONLY),      PIE_X_O) | \
-	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY_EXEC), PIE_RX)  | \
-	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED_EXEC),   PIE_RWX) | \
-	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY),      PIE_R)   | \
-	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED),        PIE_RW))
+	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY_EXEC), PIE_RX_O)  | \
+	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED_EXEC),   PIE_RWX_O) | \
+	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY),      PIE_R_O)   | \
+	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED),        PIE_RW_O))
 
 #define PIE_E1	( \
 	PIRx_ELx_PERM(pte_pi_index(_PAGE_EXECONLY),      PIE_NONE_O) | \
-- 
2.25.1