From: Richard Henderson <richard.henderson@linaro.org>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [PATCH v2 1/2] target/arm: Fix select for aa64_va_parameters_both
Date: Sat, 15 Feb 2020 23:02:22 -0800 [thread overview]
Message-ID: <a7a28b7f-2e7f-19a1-f39a-d3a6074db7c6@linaro.org> (raw)
In-Reply-To: <CAFEAcA8ed6mzXSKVGMKDEVm0zz4VS63RCwCwbedj_c4N4BCpPw@mail.gmail.com>
On 2/13/20 5:25 AM, Peter Maydell wrote:
> On Thu, 13 Feb 2020 at 13:12, Peter Maydell <peter.maydell@linaro.org> wrote:
>>
>> On Tue, 11 Feb 2020 at 19:42, Richard Henderson
>> <richard.henderson@linaro.org> wrote:
>>>
>>> Select should always be 0 for a regime with one range.
>>>
>>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>>
>> This change makes sense, and matches what aa32_va_parameters() does,
>> but I think we need to update some of the callsites.
>>
>> (1) In get_phys_addr_lpae() we have the check:
>>
>> if (-top_bits != param.select || (param.select && !ttbr1_valid)) {
>>
>> where ttbr1_valid is the return value of (effectively)
>> aarch64 ? regime_has_2_ranges() : (el != 2);
>> but I think it's no longer possible to get here with param.select == 1
>> and !ttbr1_valid, so this becomes a dead check.
>
> ...or should the code instead be checking literal pointer bit 55
> against ttbr1_valid now ?
No, I think the first expression now covers everything, as you suggested in the
first reply.
r~
next prev parent reply other threads:[~2020-02-16 7:03 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-11 19:42 [PATCH v2 0/2] target/arm: Reduce aa64_va_parameter overhead Richard Henderson
2020-02-11 19:42 ` [PATCH v2 1/2] target/arm: Fix select for aa64_va_parameters_both Richard Henderson
2020-02-13 13:12 ` Peter Maydell
2020-02-13 13:13 ` Peter Maydell
2020-02-13 13:25 ` Peter Maydell
2020-02-16 7:02 ` Richard Henderson [this message]
2020-02-11 19:42 ` [PATCH v2 2/2] target/arm: Split out aa64_va_parameter_tbi, aa64_va_parameter_tbid Richard Henderson
2020-02-13 13:12 ` Peter Maydell
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