Commit 107e8998 authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

mm/hmm: define the pre-processor related parts of hmm.h even if disabled 

Only the function calls are stubbed out with static inlines that always
fail. This is the standard way to write a header for an optional component
and makes it easier for drivers that only optionally need HMM_MIRROR.

Link: https://lore.kernel.org/r/20191112202231.3856-5-jgg@ziepe.ca


Reviewed-by: default avatarJérôme Glisse <jglisse@redhat.com>
Tested-by: default avatarRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 04ec32fb

include/linux/hmm.h

+47 −12
Original line number Diff line number Diff line
@@ -62,8 +62,6 @@ 
#include <linux/kconfig.h>

#include <asm/pgtable.h>



#ifdef CONFIG_HMM_MIRROR



#include <linux/device.h>

#include <linux/migrate.h>

#include <linux/memremap.h>
@@ -374,6 +372,15 @@ struct hmm_mirror { 
	struct list_head		list;

};



/*

 * Retry fault if non-blocking, drop mmap_sem and return -EAGAIN in that case.

 */

#define HMM_FAULT_ALLOW_RETRY		(1 << 0)



/* Don't fault in missing PTEs, just snapshot the current state. */

#define HMM_FAULT_SNAPSHOT		(1 << 1)



#ifdef CONFIG_HMM_MIRROR

int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm);

void hmm_mirror_unregister(struct hmm_mirror *mirror);
@@ -383,14 +390,6 @@ void hmm_mirror_unregister(struct hmm_mirror *mirror); 
int hmm_range_register(struct hmm_range *range, struct hmm_mirror *mirror);

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)



/* Don't fault in missing PTEs, just snapshot the current state. */

#define HMM_FAULT_SNAPSHOT		(1 << 1)



long hmm_range_fault(struct hmm_range *range, unsigned int flags);



long hmm_range_dma_map(struct hmm_range *range,
@@ -401,6 +400,44 @@ long hmm_range_dma_unmap(struct hmm_range *range, 
			 struct device *device,

			 dma_addr_t *daddrs,

			 bool dirty);

#else

int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm)

{

	return -EOPNOTSUPP;

}



void hmm_mirror_unregister(struct hmm_mirror *mirror)

{

}



int hmm_range_register(struct hmm_range *range, struct hmm_mirror *mirror)

{

	return -EOPNOTSUPP;

}



void hmm_range_unregister(struct hmm_range *range)

{

}



static inline long hmm_range_fault(struct hmm_range *range, unsigned int flags)

{

	return -EOPNOTSUPP;

}



static inline long hmm_range_dma_map(struct hmm_range *range,

				     struct device *device, dma_addr_t *daddrs,

				     unsigned int flags)

{

	return -EOPNOTSUPP;

}



static inline long hmm_range_dma_unmap(struct hmm_range *range,

				       struct device *device,

				       dma_addr_t *daddrs, bool dirty)

{

	return -EOPNOTSUPP;

}

#endif



/*

 * HMM_RANGE_DEFAULT_TIMEOUT - default timeout (ms) when waiting for a range
@@ -411,6 +448,4 @@ long hmm_range_dma_unmap(struct hmm_range *range, 
 */

#define HMM_RANGE_DEFAULT_TIMEOUT 1000



#endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */



#endif /* LINUX_HMM_H */

kernel/fork.c

+0 −1
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 
#include <linux/binfmts.h>

#include <linux/mman.h>

#include <linux/mmu_notifier.h>

#include <linux/hmm.h>

#include <linux/fs.h>

#include <linux/mm.h>

#include <linux/vmacache.h>

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