From e1bc5d1b8e0547c258e65dd97a03560f4d69e635 Mon Sep 17 00:00:00 2001
From: Robin Murphy <robin.murphy@arm.com>
Date: Tue, 25 Jul 2017 11:55:41 +0100
Subject: [PATCH] arm64: Handle trapped DC CVAP

Cache clean to PoP is subject to the same access controls as to PoC, so
if we are trapping userspace cache maintenance with SCTLR_EL1.UCI, we
need to be prepared to handle it. To avoid getting into complicated
fights with binutils about ARMv8.2 options, we'll just cheat and use the
raw SYS instruction rather than the 'proper' DC alias.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/include/asm/esr.h | 3 ++-
 arch/arm64/kernel/traps.c    | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 130b5343ba6df..66ed8b6b9976c 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -169,9 +169,10 @@
 /*
  * User space cache operations have the following sysreg encoding
  * in System instructions.
- * op0=1, op1=3, op2=1, crn=7, crm={ 5, 10, 11, 14 }, WRITE (L=0)
+ * op0=1, op1=3, op2=1, crn=7, crm={ 5, 10, 11, 12, 14 }, WRITE (L=0)
  */
 #define ESR_ELx_SYS64_ISS_CRM_DC_CIVAC	14
+#define ESR_ELx_SYS64_ISS_CRM_DC_CVAP	12
 #define ESR_ELx_SYS64_ISS_CRM_DC_CVAU	11
 #define ESR_ELx_SYS64_ISS_CRM_DC_CVAC	10
 #define ESR_ELx_SYS64_ISS_CRM_IC_IVAU	5
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 0f047e916cee8..ccb9727d67b2c 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -484,6 +484,9 @@ static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs)
 	case ESR_ELx_SYS64_ISS_CRM_DC_CVAC:	/* DC CVAC, gets promoted */
 		__user_cache_maint("dc civac", address, ret);
 		break;
+	case ESR_ELx_SYS64_ISS_CRM_DC_CVAP:	/* DC CVAP */
+		__user_cache_maint("sys 3, c7, c12, 1", address, ret);
+		break;
 	case ESR_ELx_SYS64_ISS_CRM_DC_CIVAC:	/* DC CIVAC */
 		__user_cache_maint("dc civac", address, ret);
 		break;
-- 
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