Presumably the intent here was that hmm_range_fault() could put the data
into some HW specific format and thus avoid some work. However, nothing
actually does that, and it isn't clear how anything actually could do that
as hmm_range_fault() provides CPU addresses which must be DMA mapped.

Perhaps there is some special HW that does not need DMA mapping, but we
don't have any examples of this, and the theoretical performance win of
avoiding an extra scan over the pfns array doesn't seem worth the
complexity. Plus pfns needs to be scanned anyhow to sort out any
DEVICE_PRIVATE pages.

This version replaces the uint64_t with an usigned long containing a pfn
and fixed flags. On input flags is filled with the HMM_PFN_REQ_* values,
on successful output it is filled with HMM_PFN_* values, describing the
state of the pages.

amdgpu is simple to convert, it doesn't use snapshot and doesn't use
per-page flags.

nouveau uses only 16 hmm_pte entries at most (ie fits in a few cache
lines), and it sweeps over its pfns array a couple of times anyhow. It
also has a nasty call chain before it reaches the dma map and hardware
suggesting performance isn't important:

   nouveau_svm_fault():
     args.i.m.method = NVIF_VMM_V0_PFNMAP
     nouveau_range_fault()
      nvif_object_ioctl()
       client->driver->ioctl()
	  struct nvif_driver nvif_driver_nvkm:
	    .ioctl = nvkm_client_ioctl
	   nvkm_ioctl()
	    nvkm_ioctl_path()
	      nvkm_ioctl_v0[type].func(..)
	      nvkm_ioctl_mthd()
	       nvkm_object_mthd()
		  struct nvkm_object_func nvkm_uvmm:
		    .mthd = nvkm_uvmm_mthd
		   nvkm_uvmm_mthd()
		    nvkm_uvmm_mthd_pfnmap()
		     nvkm_vmm_pfn_map()
		      nvkm_vmm_ptes_get_map()
		       func == gp100_vmm_pgt_pfn
			struct nvkm_vmm_desc_func gp100_vmm_desc_spt:
			  .pfn = gp100_vmm_pgt_pfn
			 nvkm_vmm_iter()
			  REF_PTES == func == gp100_vmm_pgt_pfn()
			    dma_map_page()

Link: https://lore.kernel.org/r/5-v2-b4e84f444c7d+24f57-hmm_no_flags_jgg@mellanox.comAcked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Tested-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

This is just an alias for HMM_PFN_ERROR, nothing cares that the error was
because of a special page vs any other error case.

Link: https://lore.kernel.org/r/4-v2-b4e84f444c7d+24f57-hmm_no_flags_jgg@mellanox.comAcked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohn Hubbard <jhubbard@nvidia.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Since amdgpu does not use the snapshot mode of hmm_range_fault() a
successful return already proves that all entries in the pfns are
HMM_PFN_VALID, there is no need to check the return result of
hmm_device_entry_to_page().

Link: https://lore.kernel.org/r/3-v2-b4e84f444c7d+24f57-hmm_no_flags_jgg@mellanox.comAcked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

hmm_vma_walk->last is supposed to be updated after every write to the
pfns, so that it can be returned by hmm_range_fault(). However, this is
not done consistently. Fortunately nothing checks the return code of
hmm_range_fault() for anything other than error.

More importantly last must be set before returning -EBUSY as it is used to
prevent reading an output pfn as an input flags when the loop restarts.

For clarity and simplicity make hmm_range_fault() return 0 or -ERRNO. Only
set last when returning -EBUSY.

Link: https://lore.kernel.org/r/2-v2-b4e84f444c7d+24f57-hmm_no_flags_jgg@mellanox.comAcked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Tested-by: NRalph Campbell <rcampbell@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Now that flags are handled on a fine-grained per-page basis this global
flag is redundant and has a confusing overlap with the pfn_flags_mask and
default_flags.

Normalize the HMM_FAULT_SNAPSHOT behavior into one place. Callers needing
the SNAPSHOT behavior should set a pfn_flags_mask and default_flags that
always results in a cleared HMM_PFN_VALID. Then no pages will be faulted,
and HMM_FAULT_SNAPSHOT is not a special flow that overrides the masking
mechanism.

As this is the last flag, also remove the flags argument. If future flags
are needed they can be part of the struct hmm_range function arguments.

Link: https://lore.kernel.org/r/20200327200021.29372-5-jgg@ziepe.caReviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

Remove the HMM_PFN_DEVICE_PRIVATE flag, no driver has ever set this flag
on input, and the only place that uses it on output can be trivially
changed to use is_device_private_page().

This removes the ability to request that device_private pages are faulted
back into system memory.

Link: https://lore.kernel.org/r/20200316193216.920734-4-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

1) SRIOV guest KMD doesn't care training buffer
2) if we resered training buffer that will overlap with IP discovery
reservation because training buffer is at vram_size - 0x8000 and
IP discovery is at ()vram_size - 0x10000 => vram_size -1)

v2: squash in warning fix from Nirmoy
Signed-off-by: NMonk Liu <Monk.Liu@amd.com>
Reviewed-by: NEmily Deng <Emily.Deng@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Calls to dma_map_sg may return less segments / entries than requested
if they fall on page bounderies. The old implementation did not
support this use case.

Fixes: be62dbf5 ("iommu/amd: Convert AMD iommu driver to the dma-iommu api")
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=206461
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=206895
Bug: https://gitlab.freedesktop.org/drm/amd/issues/1056Signed-off-by: NShane Francis <bigbeeshane@gmail.com>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200325090741.21957-3-bigbeeshane@gmail.com
Cc: stable@vger.kernel.org

Add "CP" to AMDGPU_GEM_CREATE_MQD_GFX9 to indicate it is only for CP MQD
buffer.
Signed-off-by: NYong Zhao <Yong.Zhao@amd.com>
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drm_minor_unregister will invoke drm_debugfs_cleanup
to clean all the child node under primary minor node.
We don't need to invoke amdgpu_debugfs_fini and
amdgpu_debugfs_regs_cleanup to clean agian.
Otherwise, it will raise the NULL pointer like below.
[   45.046029] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
[   45.047256] PGD 0 P4D 0
[   45.047713] Oops: 0002 [#1] SMP PTI
[   45.048198] CPU: 0 PID: 2796 Comm: modprobe Tainted: G        W  OE     4.18.0-15-generic #16~18.04.1-Ubuntu
[   45.049538] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[   45.050651] RIP: 0010:down_write+0x1f/0x40
[   45.051194] Code: 90 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb e8 ce d9 ff ff 48 ba 01 00 00 00 ff ff ff ff 48 89 d8 <f0> 48 0f c1 10 85 d2 74 05 e8 53 1c ff ff 65 48 8b 04 25 00 5c 01
[   45.053702] RSP: 0018:ffffad8f4133fd40 EFLAGS: 00010246
[   45.054384] RAX: 00000000000000a8 RBX: 00000000000000a8 RCX: ffffa011327dd814
[   45.055349] RDX: ffffffff00000001 RSI: 0000000000000001 RDI: 00000000000000a8
[   45.056346] RBP: ffffad8f4133fd48 R08: 0000000000000000 R09: ffffffffc0690a00
[   45.057326] R10: ffffad8f4133fd58 R11: 0000000000000001 R12: ffffa0113cff0300
[   45.058266] R13: ffffa0113c0a0000 R14: ffffffffc0c02a10 R15: ffffa0113e5c7860
[   45.059221] FS:  00007f60d46f9540(0000) GS:ffffa0113fc00000(0000) knlGS:0000000000000000
[   45.060809] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   45.061826] CR2: 00000000000000a8 CR3: 0000000136250004 CR4: 00000000003606f0
[   45.062913] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   45.064404] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   45.065897] Call Trace:
[   45.066426]  debugfs_remove+0x36/0xa0
[   45.067131]  amdgpu_debugfs_ring_fini+0x15/0x20 [amdgpu]
[   45.068019]  amdgpu_debugfs_fini+0x2c/0x50 [amdgpu]
[   45.068756]  amdgpu_pci_remove+0x49/0x70 [amdgpu]
[   45.069439]  pci_device_remove+0x3e/0xc0
[   45.070037]  device_release_driver_internal+0x18a/0x260
[   45.070842]  driver_detach+0x3f/0x80
[   45.071325]  bus_remove_driver+0x59/0xd0
[   45.071850]  driver_unregister+0x2c/0x40
[   45.072377]  pci_unregister_driver+0x22/0xa0
[   45.073043]  amdgpu_exit+0x15/0x57c [amdgpu]
[   45.073683]  __x64_sys_delete_module+0x146/0x280
[   45.074369]  do_syscall_64+0x5a/0x120
[   45.074916]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

v2: remove all debugfs cleanup/fini code at amdgpu
v3: squash in unused variable removal
Signed-off-by: NYintian Tao <yttao@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

In order to remove the load and unload drm callbacks,
we need to reorder the init sequence to move all the drm
debugfs file handling.  Do this for ttm.
Tested-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return a negative error code to the user.

Fixes: 030d5b97 ("drm/amdgpu: use amdgpu_device_vram_access in amdgpu_ttm_vram_read")
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Make use of the better performance here as well.

This patch is only compile tested!

v2: fix calculation bug pointed out by Felix
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Acked-by: NJonathan Kim <Jonathan.Kim@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

This speeds up the access quite a bit from 2.2 MB/s to
2.9 MB/s on 32bit and 12,8 MB/s on 64bit.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Acked-by: NJonathan Kim <Jonathan.Kim@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

For unlocked page table updates we need to be able
to sync to fences of a specific VM.

v2: use SYNC_ALWAYS in the UVD code
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Another completely unused feature.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NHuang Rui <ray.huang@amd.com>
Link: https://patchwork.freedesktop.org/patch/348265/

Fixes: 4dee6e4c ("drm/amdgpu: use linux size macro to simplify ONE_Kib & One_Mib")
Signed-off-by: NFlora Cui <flora.cui@amd.com>
Reviewed-by: NKevin Wang <kevin1.wang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

replace internal size macro with linux size macro
Signed-off-by: NKevin Wang <kevin1.wang@amd.com>
Reviewed-by: NTianci Yin <tianci.yin@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

IP discovery TMR(occupied the top VRAM with size DISCOVERY_TMR_SIZE)
has been reserved, and the p2c buffer is in the range of this TMR, so
the p2c buffer reservation is unnecessary.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NKevin Wang <kevin1.wang@amd.com>
Reviewed-by: NXiaojie Yuan <xiaojie.yuan@amd.com>
Signed-off-by: NTianci.Yin <tianci.yin@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

The method of getting fb_loc changed from parsing VBIOS to
taking certain offset from top of VRAM
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NTianci.Yin <tianci.yin@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Entity currently keeps a copy of run_queue list and modify it in
drm_sched_entity_set_priority(). Entities shouldn't modify run_queue
list. Use drm_gpu_scheduler list instead of drm_sched_rq list
in drm_sched_entity struct. In this way we can select a runqueue based
on entity/ctx's priority for a  drm scheduler.
Signed-off-by: NNirmoy Das <nirmoy.das@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

When a page tables needs to be evicted the VM code should
decide if that is possible or not.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Convert the collision-retry lock around hmm_range_fault to use the one now
provided by the mmu_interval notifier.

Although this driver does not seem to use the collision retry lock that
hmm provides correctly, it can still be converted over to use the
mmu_interval_notifier api instead of hmm_mirror without too much trouble.

This also deletes another place where a driver is associating additional
data (struct amdgpu_mn) with a mmu_struct.

Link: https://lore.kernel.org/r/20191112202231.3856-13-jgg@ziepe.caSigned-off-by: NPhilip Yang <Philip.Yang@amd.com>
Reviewed-by: NPhilip Yang <Philip.Yang@amd.com>
Tested-by: NPhilip Yang <Philip.Yang@amd.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

find_vma() must be called under the mmap_sem, reorganize this code to
do the vma check after entering the lock.

Further, fix the unlocked use of struct task_struct's mm, instead use
the mm from hmm_mirror which has an active mm_grab. Also the mm_grab
must be converted to a mm_get before acquiring mmap_sem or calling
find_vma().

Fixes: 66c45500 ("drm/amdgpu: use new HMM APIs and helpers")
Fixes: 0919195f ("drm/amdgpu: Enable amdgpu_ttm_tt_get_user_pages in worker threads")
Link: https://lore.kernel.org/r/20191112202231.3856-11-jgg@ziepe.caAcked-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: NPhilip Yang <Philip.Yang@amd.com>
Tested-by: NPhilip Yang <Philip.Yang@amd.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

When unloading driver, need to free discovery memory.
Signed-off-by: NEmily Deng <Emily.Deng@amd.com>
Reviewed-by: NXiaojie Yuan <xiaojie.yuan@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c:1221:24: warning: variable adev set but not used [-Wunused-but-set-variable]
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c:488:24: warning: variable adev set but not used [-Wunused-but-set-variable]
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c:547:24: warning: variable adev set but not used [-Wunused-but-set-variable]

It is never used, so can removed it.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Instead of relying on the DRM functions just implement our own import
functions. This prepares support for taking care of unpinned DMA-buf.

v2: enable for all exporters, not just amdgpu, fix invalidation
    handling, lock reservation object while setting callback
v3: change to new dma_buf attach interface
v4: split out from unpinned DMA-buf work
v5: rebased and cleanup on new DMA-buf interface
v6: squash with invalidation callback change,
    stop using _(map|unmap)_locked
v7: drop invalidations when the BO is already in system domain
v8: rebase on new DMA-buf patch and drop move notification
v9: cleanup comments
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/337948/

For Arcturus the I2C traffic is done through SMU tables and so
we must postpone RAS recovery init to after they are ready
which is in amdgpu_device_ip_hw_init_phase2.
Signed-off-by: NAndrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NEvan Quan <evan.quan@amd.com>
Reviewed-by: NGuchun Chen <guchun.chen@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

memory training using specific fixed vram segment, reserve these
segments before anyone may allocate it.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NLuben Tuikov <luben.tuikov@amd.com>
Signed-off-by: NTianci.Yin <tianci.yin@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

IP Discovery data is TMR fenced by the latest PSP BL,
so we need to reserve this region.

Tested on navi10/12/14 with VBIOS integrated with latest PSP BL.

v2: use DISCOVERY_TMR_SIZE macro as bo size
    use amdgpu_bo_create_kernel_at() to allocate bo
Signed-off-by: NXiaojie Yuan <xiaojie.yuan@amd.com>
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Use the ALIGN() macro to set "num_dw" to a
multiple of 8, i.e. lower 3 bits cleared.
Signed-off-by: NLuben Tuikov <luben.tuikov@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

There is a return statement that is not reachable and a variable that
is not used.  Remove them.

Addresses-Coverity: ("Structurally dead code")
Fixes: de7b45ba ("drm/amdgpu: cleanup creating BOs at fixed location (v2)")
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

The placement is something TTM/BO internal and the RAS code should
avoid touching that directly.

Add a helper to create a BO at a fixed location and use that instead.

v2: squash in fixes (Alex)
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NGuchun Chen <guchun.chen@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

ras recovery_init should be called after ttm init,
bad page reserve should be put in front of gpu reset since i2c
may be unstable during gpu reset.
add cleanup for recovery_init and recovery_fini

v2: add more comment and print.
    remove cancel_work_sync in recovery_init.
Signed-off-by: NTao Zhou <tao.zhou1@amd.com>
Reviewed-by: NGuchun Chen <guchun.chen@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Pass gem vma_offset_manager to ttm_bo_device_init(), so ttm uses it
instead of its own embedded struct.  This makes some gem functions
(specifically drm_gem_object_lookup) work on ttm objects.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190905070509.22407-6-kraxel@redhat.com

Rename the embedded struct vma_offset_manager, new name is _vma_manager.
ttm_bo_device.vma_manager changed to a pointer.

The ttm_bo_device_init() function gets an additional vma_manager
argument which allows to initialize ttm with a different vma manager.
When passing NULL the embedded _vma_manager is used.

All callers are updated to pass NULL, so the behavior doesn't change.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190905070509.22407-2-kraxel@redhat.com

stolen memory should be fixed in visible region.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NTianci.Yin <tianci.yin@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

amdgpu uses a need_dma32 flag to indicate to the drm core that some
allocations need to be done using GFP_DMA32, but it only checks the
device addressing capabilities to make that decision.  Unfortunately
PCIe root ports that have limited addressing exist as well.  Use the
dma_addressing_limited instead to also take those into account.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Be more consistent with the naming of the other DMA-buf objects.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/323401/

All users pass PAGE_SIZE here, and if we wanted to support single entries
for huge pages we should really just add a HMM_FAULT_HUGEPAGE flag instead
that uses the huge page size instead of having the caller calculate that
size once, just for the hmm code to verify it.

Link: https://lore.kernel.org/r/20190806160554.14046-8-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: NJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>