Merge branch kvm-arm64/mops into kvmarm/next

* kvm-arm64/mops:
  : KVM support for MOPS, courtesy of Kristina Martsenko
  :
  : MOPS adds new instructions for accelerating memcpy(), memset(), and
  : memmove() operations in hardware. This series brings virtualization
  : support for KVM guests, and allows VMs to run on asymmetrict systems
  : that may have different MOPS implementations.
  KVM: arm64: Expose MOPS instructions to guests
  KVM: arm64: Add handler for MOPS exceptions

Signed-off-by: Oliver Upton <[email protected]>

1 files changed, 52 insertions, 2 deletions

diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index d66dfb3a72dd..eefe766d6161 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -9,10 +9,9 @@
 
 #include <linux/list.h>
 #include <asm/esr.h>
+#include <asm/ptrace.h>
 #include <asm/sections.h>
 
-struct pt_regs;
-
 #ifdef CONFIG_ARMV8_DEPRECATED
 bool try_emulate_armv8_deprecated(struct pt_regs *regs, u32 insn);
 #else
@@ -101,4 +100,55 @@ static inline unsigned long arm64_ras_serror_get_severity(unsigned long esr)
 
 bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned long esr);
 void __noreturn arm64_serror_panic(struct pt_regs *regs, unsigned long esr);
+
+static inline void arm64_mops_reset_regs(struct user_pt_regs *regs, unsigned long esr)
+{
+	bool wrong_option = esr & ESR_ELx_MOPS_ISS_WRONG_OPTION;
+	bool option_a = esr & ESR_ELx_MOPS_ISS_OPTION_A;
+	int dstreg = ESR_ELx_MOPS_ISS_DESTREG(esr);
+	int srcreg = ESR_ELx_MOPS_ISS_SRCREG(esr);
+	int sizereg = ESR_ELx_MOPS_ISS_SIZEREG(esr);
+	unsigned long dst, src, size;
+
+	dst = regs->regs[dstreg];
+	src = regs->regs[srcreg];
+	size = regs->regs[sizereg];
+
+	/*
+	 * Put the registers back in the original format suitable for a
+	 * prologue instruction, using the generic return routine from the
+	 * Arm ARM (DDI 0487I.a) rules CNTMJ and MWFQH.
+	 */
+	if (esr & ESR_ELx_MOPS_ISS_MEM_INST) {
+		/* SET* instruction */
+		if (option_a ^ wrong_option) {
+			/* Format is from Option A; forward set */
+			regs->regs[dstreg] = dst + size;
+			regs->regs[sizereg] = -size;
+		}
+	} else {
+		/* CPY* instruction */
+		if (!(option_a ^ wrong_option)) {
+			/* Format is from Option B */
+			if (regs->pstate & PSR_N_BIT) {
+				/* Backward copy */
+				regs->regs[dstreg] = dst - size;
+				regs->regs[srcreg] = src - size;
+			}
+		} else {
+			/* Format is from Option A */
+			if (size & BIT(63)) {
+				/* Forward copy */
+				regs->regs[dstreg] = dst + size;
+				regs->regs[srcreg] = src + size;
+				regs->regs[sizereg] = -size;
+			}
+		}
+	}
+
+	if (esr & ESR_ELx_MOPS_ISS_FROM_EPILOGUE)
+		regs->pc -= 8;
+	else
+		regs->pc -= 4;
+}
 #endif