On Tue, May 19, 2015 at 07:33:28PM +0100, Peter Maydell wrote:
> Some coprocessor access functions will need to indicate that the
> instruction should trap to EL2 or EL3 rather than the default
> target exception level; add corresponding CPAccessResult enum
> entries and handling code.
>
> Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
> ---
> target-arm/cpu.h | 6 +++++-
> target-arm/op_helper.c | 14 +++++++++++++-
> 2 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 9119a94..e431372 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -1252,7 +1252,8 @@ typedef enum CPAccessResult {
> /* Access fails due to a configurable trap or enable which would
> * result in a categorized exception syndrome giving information about
> * the failing instruction (ie syndrome category 0x3, 0x4, 0x5, 0x6,
> - * 0xc or 0x18).
> + * 0xc or 0x18). The exception is taken to the usual target EL (EL1 or
> + * PL1 if in EL0, otherwise to the current EL).
> */
> CP_ACCESS_TRAP = 1,
> /* Access fails and results in an exception syndrome 0x0
> ("uncategorized").
> @@ -1260,6 +1261,9 @@ typedef enum CPAccessResult {
> * result in this failure is specifically defined by the architecture.
> */
> CP_ACCESS_TRAP_UNCATEGORIZED = 2,
> + /* As CP_ACCESS_TRAP, but for traps directly to EL2 or EL3 */
> + CP_ACCESS_TRAP_EL2 = 3,
> + CP_ACCESS_TRAP_EL3 = 4,
> } CPAccessResult;
>
> /* Access functions for coprocessor registers. These cannot fail and
> diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
> index d693b01..5963f3b 100644
> --- a/target-arm/op_helper.c
> +++ b/target-arm/op_helper.c
> @@ -335,6 +335,7 @@ void HELPER(set_user_reg)(CPUARMState *env, uint32_t
> regno, uint32_t val)
> void HELPER(access_check_cp_reg)(CPUARMState *env, void *rip, uint32_t
> syndrome)
> {
> const ARMCPRegInfo *ri = rip;
> + int target_el;
>
> if (arm_feature(env, ARM_FEATURE_XSCALE) && ri->cp < 14
> && extract32(env->cp15.c15_cpar, ri->cp, 1) == 0) {
> @@ -349,6 +350,17 @@ void HELPER(access_check_cp_reg)(CPUARMState *env, void
> *rip, uint32_t syndrome)
> case CP_ACCESS_OK:
> return;
> case CP_ACCESS_TRAP:
> + target_el = exception_target_el(env);
> + break;
> + case CP_ACCESS_TRAP_EL2:
> + /* Requesting a trap to EL2 when we're in EL3 or S-EL0/1 is
> + * a bug in the access function.
> + */
> + assert(!arm_is_secure(env) && !arm_current_el(env) == 3);
> + target_el = 2;
> + break;
> + case CP_ACCESS_TRAP_EL3:
> + target_el = 3;
> break;
> case CP_ACCESS_TRAP_UNCATEGORIZED:
> syndrome = syn_uncategorized();
It looks like you need a:
target_el = exception_target_el(env);
here, no?
> @@ -357,7 +369,7 @@ void HELPER(access_check_cp_reg)(CPUARMState *env, void
> *rip, uint32_t syndrome)
> g_assert_not_reached();
> }
>
> - raise_exception(env, EXCP_UDEF, syndrome, exception_target_el(env));
> + raise_exception(env, EXCP_UDEF, syndrome, target_el);
> }
>
> void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value)
> --
> 1.9.1
>
