On Fri, Aug 07, 2015 at 10:33:33AM +0800, Wei Yang wrote:
>On Fri, Aug 07, 2015 at 11:36:56AM +1000, Gavin Shan wrote:
>>On Thu, Aug 06, 2015 at 09:41:41PM +0800, Wei Yang wrote:
>>>On Thu, Aug 06, 2015 at 03:36:01PM +1000, Gavin Shan wrote:
>>>>On Wed, Aug 05, 2015 at 09:25:03AM +0800, Wei Yang wrote:
>>>>>When M64 BAR is set to Single PE mode, the PE# assigned to VF could be
>>>>>discrete.
>>>>>
>>>>>This patch restructures the patch to allocate discrete PE# for VFs when M64
>>>>>BAR is set to Single PE mode.
>>>>>
>>>>>Signed-off-by: Wei Yang <weiy...@linux.vnet.ibm.com>
>>>>>---
>>>>> arch/powerpc/include/asm/pci-bridge.h | 2 +-
>>>>> arch/powerpc/platforms/powernv/pci-ioda.c | 69
>>>>> +++++++++++++++++++++--------
>>>>> 2 files changed, 51 insertions(+), 20 deletions(-)
>>>>>
>>>>>diff --git a/arch/powerpc/include/asm/pci-bridge.h
>>>>>b/arch/powerpc/include/asm/pci-bridge.h
>>>>>index 8aeba4c..72415c7 100644
>>>>>--- a/arch/powerpc/include/asm/pci-bridge.h
>>>>>+++ b/arch/powerpc/include/asm/pci-bridge.h
>>>>>@@ -213,7 +213,7 @@ struct pci_dn {
>>>>> #ifdef CONFIG_PCI_IOV
>>>>> u16 vfs_expanded; /* number of VFs IOV BAR expanded */
>>>>> u16 num_vfs; /* number of VFs enabled*/
>>>>>- int offset; /* PE# for the first VF PE */
>>>>>+ int *offset; /* PE# for the first VF PE or array */
>>>>> bool m64_single_mode; /* Use M64 BAR in Single Mode */
>>>>> #define IODA_INVALID_M64 (-1)
>>>>> int (*m64_map)[PCI_SRIOV_NUM_BARS];
>>>>
>>>>how about renaming "offset" to "pe_num_map", or "pe_map" ? Similar to the
>>>>comments
>>>>I gave to the "m64_bar_map", num_of_max_vfs entries can be allocated.
>>>>Though not
>>>>all of them will be used, not too much memory will be wasted.
>>>>
>>>
>>>Thanks for your comment.
>>>
>>>I have thought about change the name to make it more self explain. While
>>>another fact I want to take in is this field is also used to be reflect the
>>>shift offset when M64 BAR is used in the Shared Mode. So I maintain the name.
>>>
>>>How about use "enum", one maintain the name "offset", and another one rename
>>>to
>>>"pe_num_map". And use the meaningful name at proper place?
>>>
>
>So I suppose you agree with my naming proposal.
>
No, I dislike the "enum" things.
>>
>>Ok. I'm explaining it with more details. There are two cases: single vs shared
>>mode. When PHB M64 BARs run in single mode, you need an array to track the
>>allocated discrete PE#. The VF_index is the index to the array. When PHB M64
>>BARs run in shared mode, you need continuous PE#. No array required for this
>>case. Instead, the starting PE# should be stored to somewhere, which can
>>be pdn->offset[0] simply.
>>
>>So when allocating memory for this array, you just simply allocate
>>(sizeof(*pdn->offset)
>>*max_vf_num) no matter what mode PHB's M64 BARs will run in. The point is
>>nobody
>>can enable (max_vf_num + 1) VFs.
>
>The max_vf_num is 15?
>
I don't understand why you said: the max_vf_num is 15. Since max_vf_num is
variable
on different PFs, how can it be fixed value - 15 ?
>>
>>With above way, the arrays for PE# and M64 BAR remapping needn't be allocated
>>when enabling SRIOV capability and releasing on disabling SRIOV capability.
>>Instead, those two arrays can be allocated during resource fixup time and
>>free'ed
>>when destroying the pdn.
>>
>
>My same point of view like previous, if the memory is not in the concern, how
>about define them static?
>
It's a bad idea from my review. How many entries this array is going to have?
256 * NUM_OF_MAX_VF_BARS ?
>And for the long term, we may support more VFs. Then at that moment, we need
>to restructure the code to meet it.
>
>So I suggest if we want to allocate it dynamically, we allocate the exact
>number of space.
>
Fine... it can be improved when it has to be, as you said.
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