hmm_vma_fault is marked as a legacy API to get rid of, but quite suites the current nouvea flow. Move it to the only user in preparation for fixing a locking bug involving caller and callee. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- drivers/gpu/drm/nouveau/nouveau_svm.c | 54 ++++++++++++++++++++++++++- include/linux/hmm.h | 54 --------------------------- 2 files changed, 53 insertions(+), 55 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index 9d40114d7949..e831f4184a17 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -36,6 +36,13 @@ #include <linux/sort.h> #include <linux/hmm.h> +/* + * When waiting for mmu notifiers we need some kind of time out otherwise we + * could potentialy wait for ever, 1000ms ie 1s sounds like a long time to + * wait already. + */ +#define NOUVEAU_RANGE_FAULT_TIMEOUT 1000 + struct nouveau_svm { struct nouveau_drm *drm; struct mutex mutex; @@ -475,6 +482,51 @@ nouveau_svm_fault_cache(struct nouveau_svm *svm, fault->inst, fault->addr, fault->access); } +static int +nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range, + bool block) +{ + long ret; + + /* + * With the old API the driver must set each individual entries with + * the requested flags (valid, write, ...). So here we set the mask to + * keep intact the entries provided by the driver and zero out the + * default_flags. + */ + range->default_flags = 0; + range->pfn_flags_mask = -1UL; + + ret = hmm_range_register(range, mirror, + range->start, range->end, + PAGE_SHIFT); + if (ret) + return (int)ret; + + if (!hmm_range_wait_until_valid(range, NOUVEAU_RANGE_FAULT_TIMEOUT)) { + /* + * The mmap_sem was taken by driver we release it here and + * returns -EAGAIN which correspond to mmap_sem have been + * drop in the old API. + */ + up_read(&range->vma->vm_mm->mmap_sem); + return -EAGAIN; + } + + ret = hmm_range_fault(range, block); + if (ret <= 0) { + if (ret == -EBUSY || !ret) { + /* Same as above, drop mmap_sem to match old API. */ + up_read(&range->vma->vm_mm->mmap_sem); + ret = -EBUSY; + } else if (ret == -EAGAIN) + ret = -EBUSY; + hmm_range_unregister(range); + return ret; + } + return 0; +} + static int nouveau_svm_fault(struct nvif_notify *notify) { @@ -649,7 +701,7 @@ nouveau_svm_fault(struct nvif_notify *notify) range.values = nouveau_svm_pfn_values; range.pfn_shift = NVIF_VMM_PFNMAP_V0_ADDR_SHIFT; again: - ret = hmm_vma_fault(&svmm->mirror, &range, true); + ret = nouveau_range_fault(&svmm->mirror, &range, true); if (ret == 0) { mutex_lock(&svmm->mutex); if (!hmm_range_unregister(&range)) { diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 4b185d286c3b..3457cf9182e5 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -478,60 +478,6 @@ long hmm_range_dma_unmap(struct hmm_range *range, dma_addr_t *daddrs, bool dirty); -/* - * HMM_RANGE_DEFAULT_TIMEOUT - default timeout (ms) when waiting for a range - * - * When waiting for mmu notifiers we need some kind of time out otherwise we - * could potentialy wait for ever, 1000ms ie 1s sounds like a long time to - * wait already. - */ -#define HMM_RANGE_DEFAULT_TIMEOUT 1000 - -/* This is a temporary helper to avoid merge conflict between trees. */ -static inline int hmm_vma_fault(struct hmm_mirror *mirror, - struct hmm_range *range, bool block) -{ - long ret; - - /* - * With the old API the driver must set each individual entries with - * the requested flags (valid, write, ...). So here we set the mask to - * keep intact the entries provided by the driver and zero out the - * default_flags. - */ - range->default_flags = 0; - range->pfn_flags_mask = -1UL; - - ret = hmm_range_register(range, mirror, - range->start, range->end, - PAGE_SHIFT); - if (ret) - return (int)ret; - - if (!hmm_range_wait_until_valid(range, HMM_RANGE_DEFAULT_TIMEOUT)) { - /* - * The mmap_sem was taken by driver we release it here and - * returns -EAGAIN which correspond to mmap_sem have been - * drop in the old API. - */ - up_read(&range->vma->vm_mm->mmap_sem); - return -EAGAIN; - } - - ret = hmm_range_fault(range, block); - if (ret <= 0) { - if (ret == -EBUSY || !ret) { - /* Same as above, drop mmap_sem to match old API. */ - up_read(&range->vma->vm_mm->mmap_sem); - ret = -EBUSY; - } else if (ret == -EAGAIN) - ret = -EBUSY; - hmm_range_unregister(range); - return ret; - } - return 0; -} - /* Below are for HMM internal use only! Not to be used by device driver! */ static inline void hmm_mm_init(struct mm_struct *mm) { -- 2.20.1