diff mbox series

[v2,04/12] mm: add device public vma selection for memory migration

Message ID 20210913161604.31981-5-alex.sierra@amd.com (mailing list archive)
State New
Headers show
Series MEMORY_DEVICE_PUBLIC for CPU-accessible coherent device memory | expand

Commit Message

Sierra Guiza, Alejandro (Alex) Sept. 13, 2021, 4:15 p.m. UTC 
This case is used to migrate pages from device memory, back to system
memory. Device public type memory is cache coherent from device and CPU
point of view.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
---
v2:
condition added when migrations from device public pages.
---
 include/linux/migrate.h | 1 +
 mm/migrate.c            | 9 +++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 4bb4e519e3f5..2fe22596e02c 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -156,6 +156,7 @@  static inline unsigned long migrate_pfn(unsigned long pfn)
 enum migrate_vma_direction {
 	MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
 	MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
+	MIGRATE_VMA_SELECT_DEVICE_PUBLIC = 1 << 2,
 };
 
 struct migrate_vma {
diff --git a/mm/migrate.c b/mm/migrate.c
index 7392648966d2..036baf24b58b 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2406,8 +2406,6 @@  static int migrate_vma_collect_pmd(pmd_t *pmdp,
 			if (is_write_device_private_entry(entry))
 				mpfn |= MIGRATE_PFN_WRITE;
 		} else {
-			if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
-				goto next;
 			pfn = pte_pfn(pte);
 			if (is_zero_pfn(pfn)) {
 				mpfn = MIGRATE_PFN_MIGRATE;
@@ -2415,6 +2413,13 @@  static int migrate_vma_collect_pmd(pmd_t *pmdp,
 				goto next;
 			}
 			page = vm_normal_page(migrate->vma, addr, pte);
+			if (!is_zone_device_page(page) &&
+			    !(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
+				goto next;
+			if (is_zone_device_page(page) &&
+			    (!(migrate->flags & MIGRATE_VMA_SELECT_DEVICE_PUBLIC) ||
+			     page->pgmap->owner != migrate->pgmap_owner))
+				goto next;
 			mpfn = migrate_pfn(pfn) | MIGRATE_PFN_MIGRATE;
 			mpfn |= pte_write(pte) ? MIGRATE_PFN_WRITE : 0;
 		}