Re: [PATCH 3/3] MdeModulePkg/PciHostBridge: Add RESOURCE_VALID() to simplify code

["Zeng, Star" <star.zeng@intel.com>]

On 2018/9/21 19:12, Laszlo Ersek wrote:
> On 09/21/18 09:25, Ruiyu Ni wrote:
>> Contributed-under: TianoCore Contribution Agreement 1.1
>> Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
>> Cc: Star Zeng <star.zeng@intel.com>
>> ---
>>   .../Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c     | 26 ++++++++++------------
>>   1 file changed, 12 insertions(+), 14 deletions(-)
>>
>> diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
>> index f6234b5d11..916709e276 100644
>> --- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
>> +++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
>> @@ -21,6 +21,8 @@ extern EDKII_IOMMU_PROTOCOL        *mIoMmuProtocol;
>>   
>>   #define NO_MAPPING  (VOID *) (UINTN) -1
>>   
>> +#define RESOURCE_VALID(R) ((R).Base <= (R).Limit)
>> +
>>   //
>>   // Lookup table for increment values based on transfer widths
>>   //
>> @@ -122,25 +124,25 @@ CreateRootBridge (
>>     //
>>     // Make sure Mem and MemAbove4G apertures are valid
>>     //
>> -  if (Bridge->Mem.Base <= Bridge->Mem.Limit) {
>> +  if (RESOURCE_VALID (Bridge->Mem)) {
>>       ASSERT (Bridge->Mem.Limit < SIZE_4GB);
>>       if (Bridge->Mem.Limit >= SIZE_4GB) {
>>         return NULL;
>>       }
>>     }
>> -  if (Bridge->MemAbove4G.Base <= Bridge->MemAbove4G.Limit) {
>> +  if (RESOURCE_VALID (Bridge->MemAbove4G)) {
>>       ASSERT (Bridge->MemAbove4G.Base >= SIZE_4GB);
>>       if (Bridge->MemAbove4G.Base < SIZE_4GB) {
>>         return NULL;
>>       }
>>     }
>> -  if (Bridge->PMem.Base <= Bridge->PMem.Limit) {
>> +  if (RESOURCE_VALID (Bridge->PMem)) {
>>       ASSERT (Bridge->PMem.Limit < SIZE_4GB);
>>       if (Bridge->PMem.Limit >= SIZE_4GB) {
>>         return NULL;
>>       }
>>     }
>> -  if (Bridge->PMemAbove4G.Base <= Bridge->PMemAbove4G.Limit) {
>> +  if (RESOURCE_VALID (Bridge->PMemAbove4G)) {
>>       ASSERT (Bridge->PMemAbove4G.Base >= SIZE_4GB);
>>       if (Bridge->PMemAbove4G.Base < SIZE_4GB) {
>>         return NULL;
>> @@ -157,11 +159,9 @@ CreateRootBridge (
>>         // support separate windows for Non-prefetchable and Prefetchable
>>         // memory.
>>         //
>> -      ASSERT (Bridge->PMem.Base > Bridge->PMem.Limit);
>> -      ASSERT (Bridge->PMemAbove4G.Base > Bridge->PMemAbove4G.Limit);
>> -      if ((Bridge->PMem.Base <= Bridge->PMem.Limit) ||
>> -          (Bridge->PMemAbove4G.Base <= Bridge->PMemAbove4G.Limit)
>> -          ) {
>> +      ASSERT (!RESOURCE_VALID (Bridge->PMem));
>> +      ASSERT (!RESOURCE_VALID (Bridge->PMemAbove4G));
>> +      if (RESOURCE_VALID (Bridge->PMem) || RESOURCE_VALID (Bridge->PMemAbove4G)) {
>>           return NULL;
>>         }
>>       }
>> @@ -171,11 +171,9 @@ CreateRootBridge (
>>         // If this bit is not set, then the PCI Root Bridge does not support
>>         // 64 bit memory windows.
>>         //
>> -      ASSERT (Bridge->MemAbove4G.Base > Bridge->MemAbove4G.Limit);
>> -      ASSERT (Bridge->PMemAbove4G.Base > Bridge->PMemAbove4G.Limit);
>> -      if ((Bridge->MemAbove4G.Base <= Bridge->MemAbove4G.Limit) ||
>> -          (Bridge->PMemAbove4G.Base <= Bridge->PMemAbove4G.Limit)
>> -          ) {
>> +      ASSERT (!RESOURCE_VALID (Bridge->MemAbove4G));
>> +      ASSERT (!RESOURCE_VALID (Bridge->PMemAbove4G));
>> +      if (RESOURCE_VALID (Bridge->MemAbove4G) || RESOURCE_VALID (Bridge->PMemAbove4G)) {
>>           return NULL;
>>         }
>>       }
>>
> 
> Two superficial comments:
> 
> - edk2 prefers long parameter names, so I suggest replacing "R" in the
> macro definition with "Resource"
> 
> - taking the parameter as a pointer is frequently considered more flexible.
> 
> #define RESOURCE_VALID(Resource) ((Resource)->Base <= (Resource)->Limit)
> ....
> if (RESOURCE_VALID (&Bridge->Mem)) {
> ....
> 
> Up to you -- if you like these, feel free to update the patch before
> pushing it (from my side anyway; you do need MdeModulePkg maintainer
> review as well).

I have no strong preference here. Let Ray to make the choice.
I have another very small comment.
Is it better to add "#define RESOURCE_VALID(R) ((R).Base <= (R).Limit)" 
in PciRootBridge.h?
Also move "#define NO_MAPPING  (VOID *) (UINTN) -1" into PciRootBridge.h?
And also move "extern EDKII_IOMMU_PROTOCOL        *mIoMmuProtocol;" into 
PciHostBridge.h?

Thanks,
Star

> 
> With or without changes:
> 
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> 
> Thanks
> Laszlo
>