Commit 9a4903e4 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jason Gunthorpe
Browse files

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.

Link: https://lore.kernel.org/r/20190726005650.2566-4-rcampbell@nvidia.com


Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent d2e8d551

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

+1 −1
Original line number Diff line number Diff line
@@ -832,7 +832,7 @@ retry: 


	down_read(&mm->mmap_sem);



	r = hmm_range_fault(range, true);

	r = hmm_range_fault(range, 0);

	if (unlikely(r < 0)) {

		if (likely(r == -EAGAIN)) {

			/*

drivers/gpu/drm/nouveau/nouveau_svm.c

+1 −1
Original line number Diff line number Diff line
@@ -505,7 +505,7 @@ nouveau_range_fault(struct hmm_mirror *mirror, struct hmm_range *range) 
		return -EBUSY;

	}



	ret = hmm_range_fault(range, true);

	ret = hmm_range_fault(range, 0);

	if (ret <= 0) {

		if (ret == 0)

			ret = -EBUSY;

include/linux/hmm.h

+9 −2
Original line number Diff line number Diff line
@@ -407,12 +407,19 @@ int hmm_range_register(struct hmm_range *range, 
		       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
Original line number Diff line number Diff line
@@ -281,7 +281,7 @@ struct hmm_vma_walk { 
	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,
@@ -293,8 +293,11 @@ 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;

	flags |= write_fault ? FAULT_FLAG_WRITE : 0;

	if (hmm_vma_walk->flags & HMM_FAULT_ALLOW_RETRY)

		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)) */
@@ -1012,25 +1015,25 @@ long hmm_range_snapshot(struct hmm_range *range) 
}

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

 * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem)

 * 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:

 * @flags:	HMM_FAULT_* flags

 *

 * Return: the number of valid pages in range->pfns[] (from range start

 * address), which may be zero.  On error one of the following status codes

 * can be returned:

 *

 *           -EINVAL  invalid arguments or mm or virtual address are in an

 *                    invalid vma (for instance device file vma).

 * -EINVAL:	Invalid arguments or mm or virtual address is in an invalid vma

 *		(e.g., device file vma).

 * -ENOMEM:	Out of memory.

 *           -EPERM:  Invalid permission (for instance asking for write and

 *                    range is read only).

 *           -EAGAIN: If you need to retry and mmap_sem was drop. This can only

 *                    happens if block argument is false.

 *           -EBUSY:  If the the range is being invalidated and you should wait

 *                    for invalidation to finish.

 *           -EFAULT: Invalid (ie either no valid vma or it is illegal to access

 *                    that range), number of valid pages in range->pfns[] (from

 * -EPERM:	Invalid permission (e.g., asking for write and range is read

 *		only).

 * -EAGAIN:	A page fault needs to be retried and mmap_sem was dropped.

 * -EBUSY:	The range has been invalidated and the caller needs to wait for

 *		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
@@ -1040,7 +1043,7 @@ EXPORT_SYMBOL(hmm_range_snapshot); 
 * 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;
@@ -1086,7 +1089,7 @@ long hmm_range_fault(struct hmm_range *range, bool block) 
		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);
@@ -1125,25 +1128,22 @@ long hmm_range_fault(struct hmm_range *range, bool block) 
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

 * @device: device against to dma map page to

 * @daddrs: dma address of mapped pages

 * @block: allow blocking on fault (if true it sleeps and do not drop mmap_sem)

 * 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

 * @device:	device to map page to

 * @daddrs:	array of dma addresses for the mapped pages

 * @flags:	HMM_FAULT_*

 *

 * 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,

		       struct device *device,

		       dma_addr_t *daddrs,

		       bool block)

long hmm_range_dma_map(struct hmm_range *range, struct device *device,

		dma_addr_t *daddrs, unsigned int flags)

{

	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;

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