Re: [Qemu-devel] [PATCH] target-arm: Add MDCR_EL2

[Peter Maydell]

On 29 September 2015 at 07:00, Alex Bennée <address@hidden> wrote:
>
> Sergey Fedorov <address@hidden> writes:
>
>> Signed-off-by: Sergey Fedorov <address@hidden>
>> ---
>>
>> This patch is a prerequisite for a debug exception routing patch:
>> https://lists.gnu.org/archive/html/qemu-devel/2015-09/msg03542.html
>>
>>  target-arm/cpu-qom.h |  1 +
>>  target-arm/cpu.c     |  1 +
>>  target-arm/cpu.h     |  1 +
>>  target-arm/cpu64.c   |  1 +
>>  target-arm/helper.c  | 13 +++++++++++++
>>  5 files changed, 17 insertions(+)
>>
>> diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
>> index 25fb1ce..d2b0769 100644
>> --- a/target-arm/cpu-qom.h
>> +++ b/target-arm/cpu-qom.h
>> @@ -167,6 +167,7 @@ typedef struct ARMCPU {
>>      uint64_t id_aa64mmfr0;
>>      uint64_t id_aa64mmfr1;
>>      uint32_t dbgdidr;
>> +    uint32_t mdcr;
>>      uint32_t clidr;
>>      uint64_t mp_affinity; /* MP ID without feature bits */
>>      /* The elements of this array are the CCSIDR values for each cache,
>> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
>> index d7b4445..6474c0d 100644
>> --- a/target-arm/cpu.c
>> +++ b/target-arm/cpu.c
>> @@ -1125,6 +1125,7 @@ static void cortex_a15_initfn(Object *obj)
>>      cpu->id_isar3 = 0x11112131;
>>      cpu->id_isar4 = 0x10011142;
>>      cpu->dbgdidr = 0x3515f021;
>> +    cpu->mdcr = 0x00000006;
>>      cpu->clidr = 0x0a200023;
>>      cpu->ccsidr[0] = 0x701fe00a; /* 32K L1 dcache */
>>      cpu->ccsidr[1] = 0x201fe00a; /* 32K L1 icache */
>> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
>> index 1b80516..d57ed20 100644
>> --- a/target-arm/cpu.h
>> +++ b/target-arm/cpu.h
>> @@ -380,6 +380,7 @@ typedef struct CPUARMState {
>>          uint64_t dbgwvr[16]; /* watchpoint value registers */
>>          uint64_t dbgwcr[16]; /* watchpoint control registers */
>>          uint64_t mdscr_el1;
>> +        uint64_t mdcr_el2;
>
> Given we already have banked el3 regs shouldn't this be:
>
>            uint64_6 mdcr_el[4]
>
> ?

You could argue either way, but since there's only an
MDCR_EL2 and an MDCR_EL3 and they're not really the same
field format there won't be any code that wants to do
mdcr_el[x], so I think calling the field mdcr_el2 is ok.

-- PMM