| Message ID | 20191211025318.457113-21-jhubbard@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/gup: track dma-pinned pages: FOLL_PIN | expand |
On Tue 10-12-19 18:53:13, John Hubbard wrote: > 1. Convert from get_user_pages() to pin_user_pages(). > > 2. As required by pin_user_pages(), release these pages via > put_user_page(). > > Cc: Jan Kara <jack@suse.cz> > Signed-off-by: John Hubbard <jhubbard@nvidia.com> The patch looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> I'd just note that mm_iommu_do_alloc() has a pre-existing bug that the last jump to 'free_exit' (at line 157) happens already after converting page pointers to physical addresses so put_page() calls there will just crash. But that's completely unrelated to your change. I'll send a fix separately. Honza > --- > arch/powerpc/mm/book3s64/iommu_api.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c > index 56cc84520577..a86547822034 100644 > --- a/arch/powerpc/mm/book3s64/iommu_api.c > +++ b/arch/powerpc/mm/book3s64/iommu_api.c > @@ -103,7 +103,7 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, > for (entry = 0; entry < entries; entry += chunk) { > unsigned long n = min(entries - entry, chunk); > > - ret = get_user_pages(ua + (entry << PAGE_SHIFT), n, > + ret = pin_user_pages(ua + (entry << PAGE_SHIFT), n, > FOLL_WRITE | FOLL_LONGTERM, > mem->hpages + entry, NULL); > if (ret == n) { > @@ -167,9 +167,8 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, > return 0; > > free_exit: > - /* free the reference taken */ > - for (i = 0; i < pinned; i++) > - put_page(mem->hpages[i]); > + /* free the references taken */ > + put_user_pages(mem->hpages, pinned); > > vfree(mem->hpas); > kfree(mem); > @@ -215,7 +214,8 @@ static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem) > if (mem->hpas[i] & MM_IOMMU_TABLE_GROUP_PAGE_DIRTY) > SetPageDirty(page); > > - put_page(page); > + put_user_page(page); > + > mem->hpas[i] = 0; > } > } > -- > 2.24.0 >
diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c index 56cc84520577..a86547822034 100644 --- a/arch/powerpc/mm/book3s64/iommu_api.c +++ b/arch/powerpc/mm/book3s64/iommu_api.c @@ -103,7 +103,7 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, for (entry = 0; entry < entries; entry += chunk) { unsigned long n = min(entries - entry, chunk); - ret = get_user_pages(ua + (entry << PAGE_SHIFT), n, + ret = pin_user_pages(ua + (entry << PAGE_SHIFT), n, FOLL_WRITE | FOLL_LONGTERM, mem->hpages + entry, NULL); if (ret == n) { @@ -167,9 +167,8 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, return 0; free_exit: - /* free the reference taken */ - for (i = 0; i < pinned; i++) - put_page(mem->hpages[i]); + /* free the references taken */ + put_user_pages(mem->hpages, pinned); vfree(mem->hpas); kfree(mem); @@ -215,7 +214,8 @@ static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem) if (mem->hpas[i] & MM_IOMMU_TABLE_GROUP_PAGE_DIRTY) SetPageDirty(page); - put_page(page); + put_user_page(page); + mem->hpas[i] = 0; } }
1. Convert from get_user_pages() to pin_user_pages(). 2. As required by pin_user_pages(), release these pages via put_user_page(). Cc: Jan Kara <jack@suse.cz> Signed-off-by: John Hubbard <jhubbard@nvidia.com> --- arch/powerpc/mm/book3s64/iommu_api.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)