Re: [Qemu-devel] [PATCH v2 03/16] register: Add Memory API glue

[Alistair Francis]

On Wed, Jan 27, 2016 at 6:51 AM, KONRAD Frederic
<address@hidden> wrote:
>
>
> Le 19/01/2016 23:35, Alistair Francis a écrit :
>>
>> From: Peter Crosthwaite <address@hidden>
>>
>> Add memory io handlers that glue the register API to the memory API.
>> Just translation functions at this stage. Although it does allow for
>> devices to be created without all-in-one mmio r/w handlers.
>>
>> Signed-off-by: Peter Crosthwaite <address@hidden>
>> Signed-off-by: Alistair Francis <address@hidden>
>> ---
>> changed from v2:
>> Added fast path to register_write_memory to skip endianness bitbashing
>>
>>   hw/core/register.c    | 48
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>   include/hw/register.h | 30 ++++++++++++++++++++++++++++++
>>   2 files changed, 78 insertions(+)
>>
>> diff --git a/hw/core/register.c b/hw/core/register.c
>> index 02a4376..ca10cff 100644
>> --- a/hw/core/register.c
>> +++ b/hw/core/register.c
>> @@ -184,3 +184,51 @@ void register_reset(RegisterInfo *reg)
>>         register_write_val(reg, reg->access->reset);
>>   }
>> +
>> +static inline void register_write_memory(void *opaque, hwaddr addr,
>> +                                         uint64_t value, unsigned size,
>> bool be)
>> +{
>> +    RegisterInfo *reg = opaque;
>
> Doesn't that need the QOM REGISTER(obj) conversion defined in patch 6?

It shouldn't. Looking at other devices they don't use the cast macro
for the opaque data to read/write functions.

Thanks,

Alistair

>
> Fred
>
>> +    uint64_t we = ~0;
>> +    int shift = 0;
>> +
>> +    if (reg->data_size != size) {
>> +        we = (size == 8) ? ~0ull : (1ull << size * 8) - 1;
>> +        shift = 8 * (be ? reg->data_size - size - addr : addr);
>> +    }
>> +
>> +    assert(size + addr <= reg->data_size);
>> +    register_write(reg, value << shift, we << shift);
>> +}
>> +
>> +void register_write_memory_be(void *opaque, hwaddr addr, uint64_t value,
>> +                              unsigned size)
>> +{
>> +    register_write_memory(opaque, addr, value, size, true);
>> +}
>> +
>> +
>> +void register_write_memory_le(void *opaque, hwaddr addr, uint64_t value,
>> +                              unsigned size)
>> +{
>> +    register_write_memory(opaque, addr, value, size, false);
>> +}
>> +
>> +static inline uint64_t register_read_memory(void *opaque, hwaddr addr,
>> +                                            unsigned size, bool be)
>> +{
>> +    RegisterInfo *reg = opaque;
>> +    int shift = 8 * (be ? reg->data_size - size - addr : addr);
>> +
>> +    return register_read(reg) >> shift;
>> +}
>> +
>> +uint64_t register_read_memory_be(void *opaque, hwaddr addr, unsigned
>> size)
>> +{
>> +    return register_read_memory(opaque, addr, size, true);
>> +}
>> +
>> +uint64_t register_read_memory_le(void *opaque, hwaddr addr, unsigned
>> size)
>> +{
>> +    return register_read_memory(opaque, addr, size, false);
>> +}
>> diff --git a/include/hw/register.h b/include/hw/register.h
>> index 249f458..a3c41db 100644
>> --- a/include/hw/register.h
>> +++ b/include/hw/register.h
>> @@ -86,6 +86,8 @@ struct RegisterAccessInfo {
>>    * @prefix: String prefix for log and debug messages
>>    *
>>    * @opaque: Opaque data for the register
>> + *
>> + * @mem: optional Memory region for the register
>>    */
>>     struct RegisterInfo {
>> @@ -103,6 +105,8 @@ struct RegisterInfo {
>>         bool read_lite;
>>       bool write_lite;
>> +
>> +    MemoryRegion mem;
>>   };
>>     /**
>> @@ -129,4 +133,30 @@ uint64_t register_read(RegisterInfo *reg);
>>     void register_reset(RegisterInfo *reg);
>>   +/**
>> + * Memory API MMIO write handler that will write to a Register API
>> register.
>> + *  _be for big endian variant and _le for little endian.
>> + * @opaque: RegisterInfo to write to
>> + * @addr: Address to write
>> + * @value: Value to write
>> + * @size: Number of bytes to write
>> + */
>> +
>> +void register_write_memory_be(void *opaque, hwaddr addr, uint64_t value,
>> +                              unsigned size);
>> +void register_write_memory_le(void *opaque, hwaddr addr, uint64_t value,
>> +                              unsigned size);
>> +
>> +/**
>> + * Memory API MMIO read handler that will read from a Register API
>> register.
>> + *  _be for big endian variant and _le for little endian.
>> + * @opaque: RegisterInfo to read from
>> + * @addr: Address to read
>> + * @size: Number of bytes to read
>> + * returns: Value read from register
>> + */
>> +
>> +uint64_t register_read_memory_be(void *opaque, hwaddr addr, unsigned
>> size);
>> +uint64_t register_read_memory_le(void *opaque, hwaddr addr, unsigned
>> size);
>> +
>>   #endif
>
>
>