Christoph Hellwig
2021-Feb-04 07:29 UTC
[Nouveau] [PATCH RFC v1 2/6] swiotlb: convert variables to arrays
On Wed, Feb 03, 2021 at 03:37:05PM -0800, Dongli Zhang wrote:> This patch converts several swiotlb related variables to arrays, in > order to maintain stat/status for different swiotlb buffers. Here are > variables involved: > > - io_tlb_start and io_tlb_end > - io_tlb_nslabs and io_tlb_used > - io_tlb_list > - io_tlb_index > - max_segment > - io_tlb_orig_addr > - no_iotlb_memory > > There is no functional change and this is to prepare to enable 64-bit > swiotlb.Claire Chang (on Cc) already posted a patch like this a month ago, which looks much better because it actually uses a struct instead of all the random variables.
Robin Murphy
2021-Feb-04 11:49 UTC
[Nouveau] [PATCH RFC v1 2/6] swiotlb: convert variables to arrays
On 2021-02-04 07:29, Christoph Hellwig wrote:> On Wed, Feb 03, 2021 at 03:37:05PM -0800, Dongli Zhang wrote: >> This patch converts several swiotlb related variables to arrays, in >> order to maintain stat/status for different swiotlb buffers. Here are >> variables involved: >> >> - io_tlb_start and io_tlb_end >> - io_tlb_nslabs and io_tlb_used >> - io_tlb_list >> - io_tlb_index >> - max_segment >> - io_tlb_orig_addr >> - no_iotlb_memory >> >> There is no functional change and this is to prepare to enable 64-bit >> swiotlb. > > Claire Chang (on Cc) already posted a patch like this a month ago, > which looks much better because it actually uses a struct instead > of all the random variables.Indeed, I skimmed the cover letter and immediately thought that this whole thing is just the restricted DMA pool concept[1] again, only from a slightly different angle. Robin. [1] https://lore.kernel.org/linux-iommu/20210106034124.30560-1-tientzu at chromium.org/