Messages in this thread | | | Subject | Re: [PATCH net] page_pool: Revert "page_pool: disable dma mapping support..." | From | Guillaume Tucker <> | Date | Wed, 17 Nov 2021 10:28:04 +0000 |
| |
On 17/11/2021 07:56, Yunsheng Lin wrote: > This reverts commit d00e60ee54b12de945b8493cf18c1ada9e422514. > > As reported by Guillaume in [1]: > Enabling LPAE always enables CONFIG_ARCH_DMA_ADDR_T_64BIT > in 32-bit systems, which breaks the bootup proceess when a > ethernet driver is using page pool with PP_FLAG_DMA_MAP flag. > As we were hoping we had no active consumers for such system > when we removed the dma mapping support, and LPAE seems like > a common feature for 32 bits system, so revert it. > > 1. https://www.spinics.net/lists/netdev/msg779890.html > > Fixes: d00e60ee54b1 ("page_pool: disable dma mapping support for 32-bit arch with 64-bit DMA") > Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Tested-by: "kernelci.org bot" <bot@kernelci.org>
Here's some test results with the revert patch applied on top of mainline, to confirm the platform boots again:
https://staging.kernelci.org/test/plan/id/6194d88fbe0f345a9b1760aa/
Thanks, Guillaume
> --- > include/linux/mm_types.h | 13 ++++++++++++- > include/net/page_pool.h | 12 +++++++++++- > net/core/page_pool.c | 10 ++++------ > 3 files changed, 27 insertions(+), 8 deletions(-) > > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index bb8c6f5f19bc..c3a6e6209600 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -105,7 +105,18 @@ struct page { > struct page_pool *pp; > unsigned long _pp_mapping_pad; > unsigned long dma_addr; > - atomic_long_t pp_frag_count; > + union { > + /** > + * dma_addr_upper: might require a 64-bit > + * value on 32-bit architectures. > + */ > + unsigned long dma_addr_upper; > + /** > + * For frag page support, not supported in > + * 32-bit architectures with 64-bit DMA. > + */ > + atomic_long_t pp_frag_count; > + }; > }; > struct { /* slab, slob and slub */ > union { > diff --git a/include/net/page_pool.h b/include/net/page_pool.h > index 3855f069627f..a4082406a003 100644 > --- a/include/net/page_pool.h > +++ b/include/net/page_pool.h > @@ -216,14 +216,24 @@ static inline void page_pool_recycle_direct(struct page_pool *pool, > page_pool_put_full_page(pool, page, true); > } > > +#define PAGE_POOL_DMA_USE_PP_FRAG_COUNT \ > + (sizeof(dma_addr_t) > sizeof(unsigned long)) > + > static inline dma_addr_t page_pool_get_dma_addr(struct page *page) > { > - return page->dma_addr; > + dma_addr_t ret = page->dma_addr; > + > + if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT) > + ret |= (dma_addr_t)page->dma_addr_upper << 16 << 16; > + > + return ret; > } > > static inline void page_pool_set_dma_addr(struct page *page, dma_addr_t addr) > { > page->dma_addr = addr; > + if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT) > + page->dma_addr_upper = upper_32_bits(addr); > } > > static inline void page_pool_set_frag_count(struct page *page, long nr) > diff --git a/net/core/page_pool.c b/net/core/page_pool.c > index 9b60e4301a44..1a6978427d6c 100644 > --- a/net/core/page_pool.c > +++ b/net/core/page_pool.c > @@ -49,12 +49,6 @@ static int page_pool_init(struct page_pool *pool, > * which is the XDP_TX use-case. > */ > if (pool->p.flags & PP_FLAG_DMA_MAP) { > - /* DMA-mapping is not supported on 32-bit systems with > - * 64-bit DMA mapping. > - */ > - if (sizeof(dma_addr_t) > sizeof(unsigned long)) > - return -EOPNOTSUPP; > - > if ((pool->p.dma_dir != DMA_FROM_DEVICE) && > (pool->p.dma_dir != DMA_BIDIRECTIONAL)) > return -EINVAL; > @@ -75,6 +69,10 @@ static int page_pool_init(struct page_pool *pool, > */ > } > > + if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT && > + pool->p.flags & PP_FLAG_PAGE_FRAG) > + return -EINVAL; > + > if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0) > return -ENOMEM; > >
| |