[20/22] mm: move hmm_vma_fault to nouveau

Submitted by Christoph Hellwig on July 1, 2019, 6:20 a.m.

Details

Message ID 20190701062020.19239-21-hch@lst.de
State New
Headers show
Series "Series without cover letter" ( rev: 1 ) in Nouveau

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Commit Message

Christoph Hellwig July 1, 2019, 6:20 a.m.
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@lst.de>
---
 drivers/gpu/drm/nouveau/nouveau_svm.c | 54 ++++++++++++++++++++++++++-
 include/linux/hmm.h                   | 54 ---------------------------
 2 files changed, 53 insertions(+), 55 deletions(-)

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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)
 {

Comments

On 6/30/19 11:20 PM, Christoph Hellwig wrote:
> 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

I didn't quite parse the phrase "quite suites the current nouvea flow."
s/nouvea/nouveau/

> fixing a locking bug involving caller and callee.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

I see where you are going with this and it
looks like straightforward code movement so,

Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>

> ---
>   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)
>   {
>
On Wed, Jul 3, 2019 at 1:49 PM Ralph Campbell <rcampbell@nvidia.com> wrote:
> On 6/30/19 11:20 PM, Christoph Hellwig wrote:
> > 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
>
> I didn't quite parse the phrase "quite suites the current nouvea flow."
> s/nouvea/nouveau/

As long as you're fixing typos, suites -> suits.
On Mon, Jul 01, 2019 at 08:20:18AM +0200, Christoph Hellwig wrote:
> 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@lst.de>
>  drivers/gpu/drm/nouveau/nouveau_svm.c | 54 ++++++++++++++++++++++++++-
>  include/linux/hmm.h                   | 54 ---------------------------
>  2 files changed, 53 insertions(+), 55 deletions(-)

I was thinking about doing exactly this too, but amdgpu started using
this already obsolete API in their latest driver :(

So, we now need to get both drivers to move to the modern API.

Jason
On Wed, Jul 03, 2019 at 03:03:56PM -0300, Jason Gunthorpe wrote:
> I was thinking about doing exactly this too, but amdgpu started using
> this already obsolete API in their latest driver :(
> 
> So, we now need to get both drivers to move to the modern API.

Actually the AMD folks fixed this up after we pointed it out to them,
so even in linux-next it just is nouveau that needs fixing.
On Wed, Jul 03, 2019 at 08:05:25PM +0200, Christoph Hellwig wrote:
> On Wed, Jul 03, 2019 at 03:03:56PM -0300, Jason Gunthorpe wrote:
> > I was thinking about doing exactly this too, but amdgpu started using
> > this already obsolete API in their latest driver :(
> > 
> > So, we now need to get both drivers to move to the modern API.
> 
> Actually the AMD folks fixed this up after we pointed it out to them,
> so even in linux-next it just is nouveau that needs fixing.

Oh, I looked at an older -next, my mistake. Lets do it then.

Jason