Re: [Qemu-devel] [PATCH v5 19/20] hw/arm/virt-acpi-build: Add PCIe controller in ACPI DSDT table

[Shannon Zhao <shannon.zhao@linaro.org>]

On 2015/4/29 16:47, Igor Mammedov wrote:
> On Wed, 29 Apr 2015 11:12:04 +0800
> Shannon Zhao <zhaoshenglong@huawei.com> wrote:
>
>> On 2015/4/28 23:54, Michael S. Tsirkin wrote:
>>> On Tue, Apr 28, 2015 at 05:13:10PM +0200, Igor Mammedov wrote:
>>>>> Here I need to set the value of buffer to 1 or 0, we could
>>>>> createbitfield, but if we want to set the value to non one or zero and
>>>>> the BufferSize is large, how could we do? CreateByteField? It's a little
>>>>> complex for user.
>>>> that's what one would have to do writing it in ASL if bits
>>>> are flipped on/off dynamically.
>>>>
>>>> In ASL you also can declare buffer with static initializer
>>>>
>>>>     Buffer (0x01) { 0x03 }
>>>>
>>>> and compiler is smart enough to set appropriate bits but it doesn't
>>>> allow you to do so with large values. For example:
>>>>
>>>>     Buffer (0x01) { 0xAABBCCDD }
>>>>
>>>> gives error:
>>>> Error 6139 - Constant out of range ^  (0xAABBCCDD, allowable: 0x0-0xFF)
>>>>
>>>> If one wants to manipulate specific fields in Buffer, ASL has
>>>> a bunch of CreateFOOField operators, so lets follow spec and use
>>>> API consistently to avoid confusion.
>>>>
>>>> BTW:
>>>> packaging value as int (even without prefix) is wrong since
>>>> its LE encoding will shuffle bytes and you won't get bits in
>>>> positions that you expect if value is more than 1 byte.
>>>
>>> I don't care about ASL, we are writing in C
>>> But AML is same:
>>> DefBuffer := BufferOp PkgLength BufferSize ByteList
>>> BufferOp := 0x11
>>> BufferSize := TermArg => Integer
>>>
>>> So really just a bytelist.
>>> We don't have any users for aml_buffer, maybe just add
>>> const uint8_t *bytes, unsigned len as parameters.
>>>
>>
>> Agree. It's consistent with the spec. If want to modify the value, could
>> use CreateFOOField.
>>
>> So use following fuction to initialize Buffer?
>>
>> /* ACPI 1.0b: 16.2.5.4 Type 2 Opcodes Encoding: DefBuffer */
>> Aml *aml_buffer(int buffer_size, uint8_t *byte_list)
>> {
>>      int i;
>>      Aml *var = aml_bundle(0x11 /* BufferOp */, AML_BUFFER);
>>      for (i = 0; i < buffer_size; i++) {
>>          build_append_byte(var->buf, *(byte_list + i));
>>      }
>>      return var;
>> }
> maybe
>
> Aml *aml_buffer_initialized(int buffer_size, uint8_t *byte_list);
> Aml *aml_buffer(int buffer_size);
>
> the second one is needed for implementing code like:
> Name(BUFF, Buffer(4){}) // Create SerialBus data buffer as BUFF
> CreateByteField(BUFF, 0x00, STAT) // STAT = Status (Byte)
> CreateWordField(BUFF, 0x02, DATA) // DATA = Data (Byte)
>
> and could reuse aml_buffer_initialized() to reserve space.
>

maybe we could use only one. For the uninitialized buffer we can pass 
byte_list as NULL and within aml_buffer check byte_list, if byte_list is 
NULL, just reserve space.

/* ACPI 1.0b: 16.2.5.4 Type 2 Opcodes Encoding: DefBuffer */
Aml *aml_buffer(int buffer_size, uint8_t *byte_list)
{
     int i;
     Aml *var = aml_bundle(0x11 /* BufferOp */, AML_BUFFER);

     for (i = 0; i < buffer_size; i++) {
         if (byte_list == NULL)
	    build_append_byte(var->buf, 0);
         else
             build_append_byte(var->buf, *(byte_list + i));
    }

    return var;
}

>>
>>> Would that be enough?
>>>
>>>
>>>>>
>>>>>> ifctx1 = aml_if(aml_equal(aml_arg(2), aml_int(0)));
>>>>>> aml_append(ifctx1, aml_store(aml_name("FNEN", aml_int(1)));
>>>>>> ...
>>>>>> /* create bit field for every supported function if supported */
>>>>>> ...
>>>>>> aml_append(method, aml_return(aml_name("RET")));
>>>>>>
>>>>>>
>>>>>>>
>>>>>>>>>
>>>>>>>>>> +    aml_append(ifctx1, aml_return(buf));
>>>>>>>>>> +    aml_append(ifctx, ifctx1);
>>>>>>>>>> +    aml_append(method, ifctx);
>>>>>>>>>> +
>>>>>>>>>> +    buf = aml_buffer();
>>>>>>>>>> +    build_append_int_noprefix(buf->buf, 0x00, 1);
>>>>>>>>>> +    aml_append(method, aml_return(buf));
>>>>>>>>>> +    aml_append(dev, method);
>>>>>>>>>> +
>>>>>>>>>> +    Aml *dev_rp0 = aml_device("%s", "RP0");
>>>>>>>>>> +    aml_append(dev_rp0, aml_name_decl("_ADR", aml_int(0)));
>>>>>>>>>> +    aml_append(dev, dev_rp0);
>>>>>>>>>> +    aml_append(scope, dev);
>>>>>>>>>> +}
>>>>>>>>>> +
>>>>>>>>>>   /* RSDP */
>>>>>>>>>>   static GArray *
>>>>>>>>>>   build_rsdp(GArray *rsdp_table, GArray *linker, unsigned rsdt)
>>>>>>>>>> @@ -318,6 +468,8 @@ build_dsdt(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info)
>>>>>>>>>>       acpi_dsdt_add_flash(scope, info->flash_memmap);
>>>>>>>>>>       acpi_dsdt_add_virtio(scope, info->virtio_mmio_memmap,
>>>>>>>>>>                info->virtio_mmio_irq, info->virtio_mmio_num);
>>>>>>>>>> +    acpi_dsdt_add_pci(scope, guest_info->pcie_info);
>>>>>>>>>> +
>>>>>>>>>>       aml_append(dsdt, scope);
>>>>>>>>>>
>>>>>>>>>>       /* copy AML table into ACPI tables blob and patch header there */
>>>>>>>>
>>>>>>>> .
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> .
>>>>>>
>>>>>
>>>>>
>>>
>>> .
>>>
>>
>>
>