[PATCH v2 02/29] mm/migrate: Add migrate_device_prepopulated_range
Matthew Brost
matthew.brost at intel.com
Wed Oct 16 03:24:51 UTC 2024
Add migrate_device_prepoluated_range which prepares an array of
pre-populated device pages for migration.
v2:
- s/migrate_device_vma_range/migrate_device_prepopulated_range
- Drop extra mmu invalidation (Vetter)
Cc: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
---
include/linux/migrate.h | 1 +
mm/migrate_device.c | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 002e49b2ebd9..9146ed39a2a3 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -229,6 +229,7 @@ void migrate_vma_pages(struct migrate_vma *migrate);
void migrate_vma_finalize(struct migrate_vma *migrate);
int migrate_device_range(unsigned long *src_pfns, unsigned long start,
unsigned long npages);
+int migrate_device_prepopulated_range(unsigned long *src_pfns, unsigned long npages);
void migrate_device_pages(unsigned long *src_pfns, unsigned long *dst_pfns,
unsigned long npages);
void migrate_device_finalize(unsigned long *src_pfns,
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index 9cf26592ac93..f163c2131022 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -924,6 +924,41 @@ int migrate_device_range(unsigned long *src_pfns, unsigned long start,
}
EXPORT_SYMBOL(migrate_device_range);
+/**
+ * migrate_device_prepopulated_range() - migrate device private pfns to normal memory.
+ * @src_pfns: pre-popluated array of source device private pfns to migrate.
+ * @npages: number of pages to migrate.
+ *
+ * Similar to migrate_device_range() but supports non-contiguous pre-popluated
+ * array of device pages to migrate.
+ */
+int migrate_device_prepopulated_range(unsigned long *src_pfns, unsigned long npages)
+{
+ unsigned long i;
+
+ for (i = 0; i < npages; i++) {
+ struct page *page = pfn_to_page(src_pfns[i]);
+
+ if (!get_page_unless_zero(page)) {
+ src_pfns[i] = 0;
+ continue;
+ }
+
+ if (!trylock_page(page)) {
+ src_pfns[i] = 0;
+ put_page(page);
+ continue;
+ }
+
+ src_pfns[i] = migrate_pfn(src_pfns[i]) | MIGRATE_PFN_MIGRATE;
+ }
+
+ migrate_device_unmap(src_pfns, npages, NULL);
+
+ return 0;
+}
+EXPORT_SYMBOL(migrate_device_prepopulated_range);
+
/*
* Migrate a device coherent folio back to normal memory. The caller should have
* a reference on folio which will be copied to the new folio if migration is
--
2.34.1
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