Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-2.6-microblaze.git] / include / linux / memremap.h

diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 8af304f..1901049 100644 (file)
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -2,7 +2,7 @@
 #ifndef _LINUX_MEMREMAP_H_
 #define _LINUX_MEMREMAP_H_
 
-#include <linux/mm.h>
+#include <linux/mmzone.h>
 #include <linux/range.h>
 #include <linux/ioport.h>
 #include <linux/percpu-refcount.h>
@@ -39,7 +39,14 @@ struct vmem_altmap {
  * must be treated as an opaque object, rather than a "normal" struct page.
  *
  * A more complete discussion of unaddressable memory may be found in
- * include/linux/hmm.h and Documentation/vm/hmm.rst.
+ * include/linux/hmm.h and Documentation/mm/hmm.rst.
+ *
+ * MEMORY_DEVICE_COHERENT:
+ * Device memory that is cache coherent from device and CPU point of view. This
+ * is used on platforms that have an advanced system bus (like CAPI or CXL). A
+ * driver can hotplug the device memory using ZONE_DEVICE and with that memory
+ * type. Any page of a process can be migrated to such memory. However no one
+ * should be allowed to pin such memory so that it can always be evicted.
  *
  * MEMORY_DEVICE_FS_DAX:
  * Host memory that has similar access semantics as System RAM i.e. DMA
@@ -61,6 +68,7 @@ struct vmem_altmap {
 enum memory_type {
        /* 0 is reserved to catch uninitialized type fields */
        MEMORY_DEVICE_PRIVATE = 1,
+       MEMORY_DEVICE_COHERENT,
        MEMORY_DEVICE_FS_DAX,
        MEMORY_DEVICE_GENERIC,
        MEMORY_DEVICE_PCI_P2PDMA,
@@ -79,6 +87,18 @@ struct dev_pagemap_ops {
         * the page back to a CPU accessible page.
         */
        vm_fault_t (*migrate_to_ram)(struct vm_fault *vmf);
+
+       /*
+        * Handle the memory failure happens on a range of pfns.  Notify the
+        * processes who are using these pfns, and try to recover the data on
+        * them if necessary.  The mf_flags is finally passed to the recover
+        * function through the whole notify routine.
+        *
+        * When this is not implemented, or it returns -EOPNOTSUPP, the caller
+        * will fall back to a common handler called mf_generic_kill_procs().
+        */
+       int (*memory_failure)(struct dev_pagemap *pgmap, unsigned long pfn,
+                             unsigned long nr_pages, int mf_flags);
 };
 
 #define PGMAP_ALTMAP_VALID     (1 << 0)
@@ -150,6 +170,17 @@ static inline bool is_pci_p2pdma_page(const struct page *page)
                page->pgmap->type == MEMORY_DEVICE_PCI_P2PDMA;
 }
 
+static inline bool is_device_coherent_page(const struct page *page)
+{
+       return is_zone_device_page(page) &&
+               page->pgmap->type == MEMORY_DEVICE_COHERENT;
+}
+
+static inline bool folio_is_device_coherent(const struct folio *folio)
+{
+       return is_device_coherent_page(&folio->page);
+}
+
 #ifdef CONFIG_ZONE_DEVICE
 void *memremap_pages(struct dev_pagemap *pgmap, int nid);
 void memunmap_pages(struct dev_pagemap *pgmap);