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-rw-r--r--include/linux/memremap.h95
1 files changed, 76 insertions, 19 deletions
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index c0e9d35889e8..7fcaf3180a5b 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -1,6 +1,8 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MEMREMAP_H_
#define _LINUX_MEMREMAP_H_
+
+#include <linux/mmzone.h>
#include <linux/range.h>
#include <linux/ioport.h>
#include <linux/percpu-refcount.h>
@@ -37,7 +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
@@ -59,6 +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,
@@ -66,27 +76,29 @@ enum memory_type {
struct dev_pagemap_ops {
/*
- * Called once the page refcount reaches 1. (ZONE_DEVICE pages never
- * reach 0 refcount unless there is a refcount bug. This allows the
- * device driver to implement its own memory management.)
+ * Called once the page refcount reaches 0. The reference count will be
+ * reset to one by the core code after the method is called to prepare
+ * for handing out the page again.
*/
void (*page_free)(struct page *page);
/*
- * Transition the refcount in struct dev_pagemap to the dead state.
- */
- void (*kill)(struct dev_pagemap *pgmap);
-
- /*
- * Wait for refcount in struct dev_pagemap to be idle and reap it.
- */
- void (*cleanup)(struct dev_pagemap *pgmap);
-
- /*
* Used for private (un-addressable) device memory only. Must migrate
* 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)
@@ -95,10 +107,14 @@ struct dev_pagemap_ops {
* struct dev_pagemap - metadata for ZONE_DEVICE mappings
* @altmap: pre-allocated/reserved memory for vmemmap allocations
* @ref: reference count that pins the devm_memremap_pages() mapping
- * @internal_ref: internal reference if @ref is not provided by the caller
- * @done: completion for @internal_ref
+ * @done: completion for @ref
* @type: memory type: see MEMORY_* in memory_hotplug.h
* @flags: PGMAP_* flags to specify defailed behavior
+ * @vmemmap_shift: structural definition of how the vmemmap page metadata
+ * is populated, specifically the metadata page order.
+ * A zero value (default) uses base pages as the vmemmap metadata
+ * representation. A bigger value will set up compound struct pages
+ * of the requested order value.
* @ops: method table
* @owner: an opaque pointer identifying the entity that manages this
* instance. Used by various helpers to make sure that no
@@ -109,11 +125,11 @@ struct dev_pagemap_ops {
*/
struct dev_pagemap {
struct vmem_altmap altmap;
- struct percpu_ref *ref;
- struct percpu_ref internal_ref;
+ struct percpu_ref ref;
struct completion done;
enum memory_type type;
unsigned int flags;
+ unsigned long vmemmap_shift;
const struct dev_pagemap_ops *ops;
void *owner;
int nr_range;
@@ -123,6 +139,11 @@ struct dev_pagemap {
};
};
+static inline bool pgmap_has_memory_failure(struct dev_pagemap *pgmap)
+{
+ return pgmap->ops && pgmap->ops->memory_failure;
+}
+
static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap)
{
if (pgmap->flags & PGMAP_ALTMAP_VALID)
@@ -130,7 +151,43 @@ static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap)
return NULL;
}
+static inline unsigned long pgmap_vmemmap_nr(struct dev_pagemap *pgmap)
+{
+ return 1 << pgmap->vmemmap_shift;
+}
+
+static inline bool is_device_private_page(const struct page *page)
+{
+ return IS_ENABLED(CONFIG_DEVICE_PRIVATE) &&
+ is_zone_device_page(page) &&
+ page->pgmap->type == MEMORY_DEVICE_PRIVATE;
+}
+
+static inline bool folio_is_device_private(const struct folio *folio)
+{
+ return is_device_private_page(&folio->page);
+}
+
+static inline bool is_pci_p2pdma_page(const struct page *page)
+{
+ return IS_ENABLED(CONFIG_PCI_P2PDMA) &&
+ is_zone_device_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 zone_device_page_init(struct page *page);
void *memremap_pages(struct dev_pagemap *pgmap, int nid);
void memunmap_pages(struct dev_pagemap *pgmap);
void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap);
@@ -191,7 +248,7 @@ static inline unsigned long memremap_compat_align(void)
static inline void put_dev_pagemap(struct dev_pagemap *pgmap)
{
if (pgmap)
- percpu_ref_put(pgmap->ref);
+ percpu_ref_put(&pgmap->ref);
}
#endif /* _LINUX_MEMREMAP_H_ */