HMM patches for 5.3

Improvements and bug fixes for the hmm interface in the kernel:
 
 - Improve clarity, locking and APIs related to the 'hmm mirror' feature
   merged last cycle. In linux-next we now see AMDGPU and nouveau to be
   using this API.
 
 - Remove old or transitional hmm APIs. These are hold overs from the past
   with no users, or APIs that existed only to manage cross tree conflicts.
   There are still a few more of these cleanups that didn't make the merge
   window cut off.
 
 - Improve some core mm APIs:
   * export alloc_pages_vma() for driver use
   * refactor into devm_request_free_mem_region() to manage
     DEVICE_PRIVATE resource reservations
   * refactor duplicative driver code into the core dev_pagemap
     struct
 
 - Remove hmm wrappers of improved core mm APIs, instead have drivers use
   the simplified API directly
 
 - Remove DEVICE_PUBLIC
 
 - Simplify the kconfig flow for the hmm users and core code
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull HMM updates from Jason Gunthorpe:
 "Improvements and bug fixes for the hmm interface in the kernel:

   - Improve clarity, locking and APIs related to the 'hmm mirror'
     feature merged last cycle. In linux-next we now see AMDGPU and
     nouveau to be using this API.

   - Remove old or transitional hmm APIs. These are hold overs from the
     past with no users, or APIs that existed only to manage cross tree
     conflicts. There are still a few more of these cleanups that didn't
     make the merge window cut off.

   - Improve some core mm APIs:
       - export alloc_pages_vma() for driver use
       - refactor into devm_request_free_mem_region() to manage
         DEVICE_PRIVATE resource reservations
       - refactor duplicative driver code into the core dev_pagemap
         struct

   - Remove hmm wrappers of improved core mm APIs, instead have drivers
     use the simplified API directly

   - Remove DEVICE_PUBLIC

   - Simplify the kconfig flow for the hmm users and core code"

* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits)
  mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR
  mm: remove the HMM config option
  mm: sort out the DEVICE_PRIVATE Kconfig mess
  mm: simplify ZONE_DEVICE page private data
  mm: remove hmm_devmem_add
  mm: remove hmm_vma_alloc_locked_page
  nouveau: use devm_memremap_pages directly
  nouveau: use alloc_page_vma directly
  PCI/P2PDMA: use the dev_pagemap internal refcount
  device-dax: use the dev_pagemap internal refcount
  memremap: provide an optional internal refcount in struct dev_pagemap
  memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
  memremap: remove the data field in struct dev_pagemap
  memremap: add a migrate_to_ram method to struct dev_pagemap_ops
  memremap: lift the devmap_enable manipulation into devm_memremap_pages
  memremap: pass a struct dev_pagemap to ->kill and ->cleanup
  memremap: move dev_pagemap callbacks into a separate structure
  memremap: validate the pagemap type passed to devm_memremap_pages
  mm: factor out a devm_request_free_mem_region helper
  mm: export alloc_pages_vma
  ...
This commit is contained in:
Linus Torvalds 2019-07-14 19:42:11 -07:00
commit fec88ab0af
36 changed files with 620 additions and 1327 deletions

View file

@ -246,8 +246,6 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
if (is_device_private_page(new)) {
entry = make_device_private_entry(new, pte_write(pte));
pte = swp_entry_to_pte(entry);
} else if (is_device_public_page(new)) {
pte = pte_mkdevmap(pte);
}
}
@ -381,7 +379,6 @@ static int expected_page_refs(struct address_space *mapping, struct page *page)
* ZONE_DEVICE pages.
*/
expected_count += is_device_private_page(page);
expected_count += is_device_public_page(page);
if (mapping)
expected_count += hpage_nr_pages(page) + page_has_private(page);
@ -994,10 +991,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
if (!PageMappingFlags(page))
page->mapping = NULL;
if (unlikely(is_zone_device_page(newpage))) {
if (is_device_public_page(newpage))
flush_dcache_page(newpage);
} else
if (likely(!is_zone_device_page(newpage)))
flush_dcache_page(newpage);
}
@ -2265,7 +2259,7 @@ again:
pfn = 0;
goto next;
}
page = _vm_normal_page(migrate->vma, addr, pte, true);
page = vm_normal_page(migrate->vma, addr, pte);
mpfn = migrate_pfn(pfn) | MIGRATE_PFN_MIGRATE;
mpfn |= pte_write(pte) ? MIGRATE_PFN_WRITE : 0;
}
@ -2406,16 +2400,7 @@ static bool migrate_vma_check_page(struct page *page)
* FIXME proper solution is to rework migration_entry_wait() so
* it does not need to take a reference on page.
*/
if (is_device_private_page(page))
return true;
/*
* Only allow device public page to be migrated and account for
* the extra reference count imply by ZONE_DEVICE pages.
*/
if (!is_device_public_page(page))
return false;
extra++;
return is_device_private_page(page);
}
/* For file back page */
@ -2665,11 +2650,6 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
swp_entry = make_device_private_entry(page, vma->vm_flags & VM_WRITE);
entry = swp_entry_to_pte(swp_entry);
} else if (is_device_public_page(page)) {
entry = pte_mkold(mk_pte(page, READ_ONCE(vma->vm_page_prot)));
if (vma->vm_flags & VM_WRITE)
entry = pte_mkwrite(pte_mkdirty(entry));
entry = pte_mkdevmap(entry);
}
} else {
entry = mk_pte(page, vma->vm_page_prot);
@ -2789,7 +2769,7 @@ static void migrate_vma_pages(struct migrate_vma *migrate)
migrate->src[i] &= ~MIGRATE_PFN_MIGRATE;
continue;
}
} else if (!is_device_public_page(newpage)) {
} else {
/*
* Other types of ZONE_DEVICE page are not
* supported.