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authorDan Williams <dan.j.williams@intel.com>2018-12-28 11:39:46 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-28 23:11:52 +0300
commit063a7d1d3623db31ca5d2309cab6030ebf93b72f (patch)
treedb21d6e0f9a623faa40bc2d9ac2dc1f43f5ba9a5 /include/linux/memremap.h
parentc86aa7bbfd5568ba8a82d3635d8f7b8a8e06fe54 (diff)
downloadlinux-063a7d1d3623db31ca5d2309cab6030ebf93b72f.tar.xz
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
The kbuild robot reported the following on a development branch that used memremap.h in a new path: In file included from arch/m68k/include/asm/pgtable_mm.h:148:0, from arch/m68k/include/asm/pgtable.h:5, from include/linux/memremap.h:7, from drivers//dax/bus.c:3: arch/m68k/include/asm/motorola_pgtable.h: In function 'pgd_offset': >> arch/m68k/include/asm/motorola_pgtable.h:199:11: error: dereferencing pointer to incomplete type 'const struct mm_struct' return mm->pgd + pgd_index(address); ^~ The ->page_fault() callback is specific to HMM. Move it to 'struct hmm_devmem' where the unusual asm/pgtable.h dependency can be contained in include/linux/hmm.h. Longer term refactoring this dependency out of HMM is recommended, but in the meantime memremap.h remains generic. Link: http://lkml.kernel.org/r/154534090899.3120190.6652620807617715272.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 5042db43cc26 ("mm/ZONE_DEVICE: new type of ZONE_DEVICE memory...") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: "Jérôme Glisse" <jglisse@redhat.com> Cc: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/memremap.h')
-rw-r--r--include/linux/memremap.h32
1 files changed, 0 insertions, 32 deletions
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 55db66b3716f..f0628660d541 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -4,8 +4,6 @@
#include <linux/ioport.h>
#include <linux/percpu-refcount.h>
-#include <asm/pgtable.h>
-
struct resource;
struct device;
@@ -66,47 +64,18 @@ enum memory_type {
};
/*
- * For MEMORY_DEVICE_PRIVATE we use ZONE_DEVICE and extend it with two
- * callbacks:
- * page_fault()
- * page_free()
- *
* Additional notes about MEMORY_DEVICE_PRIVATE may be found in
* include/linux/hmm.h and Documentation/vm/hmm.rst. There is also a brief
* explanation in include/linux/memory_hotplug.h.
*
- * The page_fault() callback must migrate page back, from device memory to
- * system memory, so that the CPU can access it. This might fail for various
- * reasons (device issues, device have been unplugged, ...). When such error
- * conditions happen, the page_fault() callback must return VM_FAULT_SIGBUS and
- * set the CPU page table entry to "poisoned".
- *
- * Note that because memory cgroup charges are transferred to the device memory,
- * this should never fail due to memory restrictions. However, allocation
- * of a regular system page might still fail because we are out of memory. If
- * that happens, the page_fault() callback must return VM_FAULT_OOM.
- *
- * The page_fault() callback can also try to migrate back multiple pages in one
- * chunk, as an optimization. It must, however, prioritize the faulting address
- * over all the others.
- *
- *
* The page_free() callback is 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.)
- *
- * For MEMORY_DEVICE_PUBLIC only the page_free() callback matter.
*/
-typedef int (*dev_page_fault_t)(struct vm_area_struct *vma,
- unsigned long addr,
- const struct page *page,
- unsigned int flags,
- pmd_t *pmdp);
typedef void (*dev_page_free_t)(struct page *page, void *data);
/**
* struct dev_pagemap - metadata for ZONE_DEVICE mappings
- * @page_fault: callback when CPU fault on an unaddressable device page
* @page_free: free page callback when page refcount reaches 1
* @altmap: pre-allocated/reserved memory for vmemmap allocations
* @res: physical address range covered by @ref
@@ -117,7 +86,6 @@ typedef void (*dev_page_free_t)(struct page *page, void *data);
* @type: memory type: see MEMORY_* in memory_hotplug.h
*/
struct dev_pagemap {
- dev_page_fault_t page_fault;
dev_page_free_t page_free;
struct vmem_altmap altmap;
bool altmap_valid;