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target/arm: Remove CP_ACCESS_TRAP_UNCATEGORIZED_{EL2, EL3}

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We added the CPAccessResult values CP_ACCESS_TRAP_UNCATEGORIZED_EL2
and CP_ACCESS_TRAP_UNCATEGORIZED_EL3 purely in order to use them in
the ats_access() function, but doing so was incorrect (a bug fixed in
a previous commit).  There aren't any cases where we want an access
function to be able to request a trap to EL2 or EL3 with a zero
syndrome value, so remove these enum values.

As well as cleaning up dead code, the motivation here is that
we'd like to implement fine-grained-trap handling in
helper_access_check_cp_reg(). Although the fine-grained traps
to EL2 are always lower priority than trap-to-same-EL and
higher priority than trap-to-EL3, they are in the middle of
various other kinds of trap-to-EL2. Knowing that a trap-to-EL2
must always for us have the same syndrome (ie that an access
function will return CP_ACCESS_TRAP_EL2 and there is no other
kind of trap-to-EL2 enum value) means we don't have to try
to choose which of the two syndrome values to report if the
access would trap to EL2 both for the fine-grained-trap and
because the access function requires it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-4-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-4-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2023-01-30 18:24:39 +00:00
parent ce9a8863b2
commit 80ea70f2e5
2 changed files with 4 additions and 2 deletions
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4
target/arm/cpregs.h
View File

@ -224,10 +224,10 @@ typedef enum CPAccessResult {
* Access fails and results in an exception syndrome 0x0 ("uncategorized").
* Note that this is not a catch-all case -- the set of cases which may
* result in this failure is specifically defined by the architecture.
* This trap is always to the usual target EL, never directly to a
* specified target EL.
*/
CP_ACCESS_TRAP_UNCATEGORIZED = (2 << 2),
CP_ACCESS_TRAP_UNCATEGORIZED_EL2 = CP_ACCESS_TRAP_UNCATEGORIZED | 2,
CP_ACCESS_TRAP_UNCATEGORIZED_EL3 = CP_ACCESS_TRAP_UNCATEGORIZED | 3,
} CPAccessResult;
typedef struct ARMCPRegInfo ARMCPRegInfo;

2
target/arm/op_helper.c
View File

@ -673,6 +673,8 @@ const void *HELPER(access_check_cp_reg)(CPUARMState *env, uint32_t key,
case CP_ACCESS_TRAP:
break;
case CP_ACCESS_TRAP_UNCATEGORIZED:
/* Only CP_ACCESS_TRAP traps are direct to a specified EL */
assert((res & CP_ACCESS_EL_MASK) == 0);
if (cpu_isar_feature(aa64_ids, cpu) && isread &&
arm_cpreg_in_idspace(ri)) {
/*