mm/hmm: replace the block argument to hmm_range_fault with a flags value

This allows easier expansion to other flags, and also makes the callers a little easier to read.

Christoph Hellwig committed 7 years ago

Commit 9a4903e1 parent d2e8d554 files · +48 −41Browse files

Unified · Split

4 files

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +1 −1
drivers/gpu/drm/nouveau/nouveau_svm.c +1 −1
include/linux/hmm.h +9 −2
mm/hmm.c +37 −37

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c+1−1

@@ -832,7 +832,7 @@ retry: · 831 unmodified lines
832		832
833	down_read(&mm->mmap_sem);	833	down_read(&mm->mmap_sem);
834		834
835	r = hmm_range_fault(range, true);	835	r = hmm_range_fault(range, 0);
836	if (unlikely(r < 0)) {	836	if (unlikely(r < 0)) {
837	if (likely(r == -EAGAIN)) {	837	if (likely(r == -EAGAIN)) {
838	/*	838	/*

drivers/gpu/drm/nouveau/nouveau_svm.c+1−1

@@ -505,7 +505,7 @@ nouveau_range_fault(struct hmm_mirror mirror, struct hmm_range range) · 504 unmodified lines
505	return -EBUSY;	505	return -EBUSY;
506	}	506	}
507		507
508	ret = hmm_range_fault(range, true);	508	ret = hmm_range_fault(range, 0);
509	if (ret <= 0) {	509	if (ret <= 0) {
510	if (ret == 0)	510	if (ret == 0)
511	ret = -EBUSY;	511	ret = -EBUSY;

include/linux/hmm.h+9−2

 		       unsigned long end,
 		       unsigned page_shift);
 void hmm_range_unregister(struct hmm_range *range);
+/*
+ * Retry fault if non-blocking, drop mmap_sem and return -EAGAIN in that case.
+ */
+#define HMM_FAULT_ALLOW_RETRY		(1 << 0)
 long hmm_range_snapshot(struct hmm_range *range);
-long hmm_range_fault(struct hmm_range *range, bool block);
+long hmm_range_fault(struct hmm_range *range, unsigned int flags);
 long hmm_range_dma_map(struct hmm_range *range,
 		       struct device *device,
 		       dma_addr_t *daddrs,
-		       bool block);
+		       unsigned int flags);
 long hmm_range_dma_unmap(struct hmm_range *range,
 			 struct vm_area_struct *vma,
 			 struct device *device,

mm/hmm.c+37−37

 	struct dev_pagemap	*pgmap;
 	unsigned long		last;
 	bool			fault;
-	bool			block;
+	unsigned int		flags;
 };
 static int hmm_vma_do_fault(struct mm_walk *walk, unsigned long addr,
 	struct vm_area_struct *vma = walk->vma;
 	vm_fault_t ret;
-	flags |= hmm_vma_walk->block ? 0 : FAULT_FLAG_ALLOW_RETRY;
+	if (hmm_vma_walk->flags & HMM_FAULT_ALLOW_RETRY)
-	flags |= write_fault ? FAULT_FLAG_WRITE : 0;
+		flags |= FAULT_FLAG_ALLOW_RETRY;
+	if (write_fault)
+		flags |= FAULT_FLAG_WRITE;
 	ret = handle_mm_fault(vma, addr, flags);
 	if (ret & VM_FAULT_RETRY) {
 		/* Note, handle_mm_fault did up_read(&mm->mmap_sem)) */
 }
 EXPORT_SYMBOL(hmm_range_snapshot);
-/*
+/**
- * hmm_range_fault() - try to fault some address in a virtual address range
+ * hmm_range_fault - try to fault some address in a virtual address range
- * @range: range being faulted
+ * @range:	range being faulted
- * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem)
+ * @flags:	HMM_FAULT_* flags
- * Return: number of valid pages in range->pfns[] (from range start
- *          address). This may be zero. If the return value is negative,
- *          then one of the following values may be returned:
  *
- *           -EINVAL  invalid arguments or mm or virtual address are in an
+ * Return: the number of valid pages in range->pfns[] (from range start
- *                    invalid vma (for instance device file vma).
+ * address), which may be zero.  On error one of the following status codes
- *           -ENOMEM: Out of memory.
+ * can be returned:
- *           -EPERM:  Invalid permission (for instance asking for write and
+ *
- *                    range is read only).
+ * -EINVAL:	Invalid arguments or mm or virtual address is in an invalid vma
- *           -EAGAIN: If you need to retry and mmap_sem was drop. This can only
+ *		(e.g., device file vma).
- *                    happens if block argument is false.
+ * -ENOMEM:	Out of memory.
- *           -EBUSY:  If the the range is being invalidated and you should wait
+ * -EPERM:	Invalid permission (e.g., asking for write and range is read
- *                    for invalidation to finish.
+ *		only).
- *           -EFAULT: Invalid (ie either no valid vma or it is illegal to access
+ * -EAGAIN:	A page fault needs to be retried and mmap_sem was dropped.
- *                    that range), number of valid pages in range->pfns[] (from
+ * -EBUSY:	The range has been invalidated and the caller needs to wait for
- *                    range start address).
+ *		the invalidation to finish.
+ * -EFAULT:	Invalid (i.e., either no valid vma or it is illegal to access
+ *		that range) number of valid pages in range->pfns[] (from
+ *              range start address).
  *
  * This is similar to a regular CPU page fault except that it will not trigger
  * any memory migration if the memory being faulted is not accessible by CPUs
  * On error, for one virtual address in the range, the function will mark the
  * corresponding HMM pfn entry with an error flag.
  */
-long hmm_range_fault(struct hmm_range *range, bool block)
+long hmm_range_fault(struct hmm_range *range, unsigned int flags)
 {
 	const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP;
 	unsigned long start = range->start, end;
 		hmm_vma_walk.pgmap = NULL;
 		hmm_vma_walk.last = start;
 		hmm_vma_walk.fault = true;
-		hmm_vma_walk.block = block;
+		hmm_vma_walk.flags = flags;
 		hmm_vma_walk.range = range;
 		mm_walk.private = &hmm_vma_walk;
 		end = min(range->end, vma->vm_end);
 EXPORT_SYMBOL(hmm_range_fault);
 /**
- * hmm_range_dma_map() - hmm_range_fault() and dma map page all in one.
+ * hmm_range_dma_map - hmm_range_fault() and dma map page all in one.
- * @range: range being faulted
+ * @range:	range being faulted
- * @device: device against to dma map page to
+ * @device:	device to map page to
- * @daddrs: dma address of mapped pages
+ * @daddrs:	array of dma addresses for the mapped pages
- * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem)
+ * @flags:	HMM_FAULT_*
- * Return: number of pages mapped on success, -EAGAIN if mmap_sem have been
- *          drop and you need to try again, some other error value otherwise
  *
- * Note same usage pattern as hmm_range_fault().
+ * Return: the number of pages mapped on success (including zero), or any
+ * status return from hmm_range_fault() otherwise.
  */
-long hmm_range_dma_map(struct hmm_range *range,
+long hmm_range_dma_map(struct hmm_range *range, struct device *device,
-		       struct device *device,
+		dma_addr_t *daddrs, unsigned int flags)
-		       dma_addr_t *daddrs,
-		       bool block)
 {
 	unsigned long i, npages, mapped;
 	long ret;
-	ret = hmm_range_fault(range, block);
+	ret = hmm_range_fault(range, flags);
 	if (ret <= 0)
 		return ret ? ret : -EBUSY;

mm/hmm: replace the block argument to hmm_range_fault with a flags value

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