kernel: backport page fragment API changes from 4.10+ to 4.9

mt76 now relies on this API

Signed-off-by: Felix Fietkau <[email protected]>

target/linux/generic/backport-4.9/040-mm-add-support-for-releasing-multiple-instances-of-a.patch

@@ -0,0 +1,75 @@
+From: Alexander Duyck <[email protected]>
+Date: Wed, 14 Dec 2016 15:05:26 -0800
+Subject: [PATCH] mm: add support for releasing multiple instances of a page
+
+Add a function that allows us to batch free a page that has multiple
+references outstanding.  Specifically this function can be used to drop
+a page being used in the page frag alloc cache.  With this drivers can
+make use of functionality similar to the page frag alloc cache without
+having to do any workarounds for the fact that there is no function that
+frees multiple references.
+
+Link: http://lkml.kernel.org/r/[email protected]
+Signed-off-by: Alexander Duyck <[email protected]>
+Cc: "David S. Miller" <[email protected]>
+Cc: "James E.J. Bottomley" <[email protected]>
+Cc: Chris Metcalf <[email protected]>
+Cc: David Howells <[email protected]>
+Cc: Geert Uytterhoeven <[email protected]>
+Cc: Hans-Christian Noren Egtvedt <[email protected]>
+Cc: Helge Deller <[email protected]>
+Cc: James Hogan <[email protected]>
+Cc: Jeff Kirsher <[email protected]>
+Cc: Jonas Bonn <[email protected]>
+Cc: Keguang Zhang <[email protected]>
+Cc: Ley Foon Tan <[email protected]>
+Cc: Mark Salter <[email protected]>
+Cc: Max Filippov <[email protected]>
+Cc: Michael Ellerman <[email protected]>
+Cc: Michal Simek <[email protected]>
+Cc: Ralf Baechle <[email protected]>
+Cc: Rich Felker <[email protected]>
+Cc: Richard Kuo <[email protected]>
+Cc: Russell King <[email protected]>
+Cc: Steven Miao <[email protected]>
+Cc: Tobias Klauser <[email protected]>
+Cc: Vineet Gupta <[email protected]>
+Cc: Yoshinori Sato <[email protected]>
+Signed-off-by: Andrew Morton <[email protected]>
+Signed-off-by: Linus Torvalds <[email protected]>
+---
+
+--- a/include/linux/gfp.h
++++ b/include/linux/gfp.h
+@@ -506,6 +506,8 @@ extern void free_hot_cold_page(struct pa
+ extern void free_hot_cold_page_list(struct list_head *list, bool cold);
+ 
+ struct page_frag_cache;
++extern void __page_frag_drain(struct page *page, unsigned int order,
++			      unsigned int count);
+ extern void *__alloc_page_frag(struct page_frag_cache *nc,
+ 			       unsigned int fragsz, gfp_t gfp_mask);
+ extern void __free_page_frag(void *addr);
+--- a/mm/page_alloc.c
++++ b/mm/page_alloc.c
+@@ -3946,6 +3946,20 @@ static struct page *__page_frag_refill(s
+ 	return page;
+ }
+ 
++void __page_frag_drain(struct page *page, unsigned int order,
++		       unsigned int count)
++{
++	VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
++
++	if (page_ref_sub_and_test(page, count)) {
++		if (order == 0)
++			free_hot_cold_page(page, false);
++		else
++			__free_pages_ok(page, order);
++	}
++}
++EXPORT_SYMBOL(__page_frag_drain);
++
+ void *__alloc_page_frag(struct page_frag_cache *nc,
+ 			unsigned int fragsz, gfp_t gfp_mask)
+ {

target/linux/generic/backport-4.9/041-mm-rename-__alloc_page_frag-to-page_frag_alloc-and-_.patch

@@ -0,0 +1,137 @@
+From: Alexander Duyck <[email protected]>
+Date: Tue, 10 Jan 2017 16:58:06 -0800
+Subject: [PATCH] mm: rename __alloc_page_frag to page_frag_alloc and
+ __free_page_frag to page_frag_free
+
+Patch series "Page fragment updates", v4.
+
+This patch series takes care of a few cleanups for the page fragments
+API.
+
+First we do some renames so that things are much more consistent.  First
+we move the page_frag_ portion of the name to the front of the functions
+names.  Secondly we split out the cache specific functions from the
+other page fragment functions by adding the word "cache" to the name.
+
+Finally I added a bit of documentation that will hopefully help to
+explain some of this.  I plan to revisit this later as we get things
+more ironed out in the near future with the changes planned for the DMA
+setup to support eXpress Data Path.
+
+This patch (of 3):
+
+This patch renames the page frag functions to be more consistent with
+other APIs.  Specifically we place the name page_frag first in the name
+and then have either an alloc or free call name that we append as the
+suffix.  This makes it a bit clearer in terms of naming.
+
+In addition we drop the leading double underscores since we are
+technically no longer a backing interface and instead the front end that
+is called from the networking APIs.
+
+Link: http://lkml.kernel.org/r/[email protected]
+Signed-off-by: Alexander Duyck <[email protected]>
+Signed-off-by: Andrew Morton <[email protected]>
+Signed-off-by: Linus Torvalds <[email protected]>
+---
+
+--- a/include/linux/gfp.h
++++ b/include/linux/gfp.h
+@@ -508,9 +508,9 @@ extern void free_hot_cold_page_list(stru
+ struct page_frag_cache;
+ extern void __page_frag_drain(struct page *page, unsigned int order,
+ 			      unsigned int count);
+-extern void *__alloc_page_frag(struct page_frag_cache *nc,
+-			       unsigned int fragsz, gfp_t gfp_mask);
+-extern void __free_page_frag(void *addr);
++extern void *page_frag_alloc(struct page_frag_cache *nc,
++			     unsigned int fragsz, gfp_t gfp_mask);
++extern void page_frag_free(void *addr);
+ 
+ #define __free_page(page) __free_pages((page), 0)
+ #define free_page(addr) free_pages((addr), 0)
+--- a/include/linux/skbuff.h
++++ b/include/linux/skbuff.h
+@@ -2471,7 +2471,7 @@ static inline struct sk_buff *netdev_all
+ 
+ static inline void skb_free_frag(void *addr)
+ {
+-	__free_page_frag(addr);
++	page_frag_free(addr);
+ }
+ 
+ void *napi_alloc_frag(unsigned int fragsz);
+--- a/mm/page_alloc.c
++++ b/mm/page_alloc.c
+@@ -3960,8 +3960,8 @@ void __page_frag_drain(struct page *page
+ }
+ EXPORT_SYMBOL(__page_frag_drain);
+ 
+-void *__alloc_page_frag(struct page_frag_cache *nc,
+-			unsigned int fragsz, gfp_t gfp_mask)
++void *page_frag_alloc(struct page_frag_cache *nc,
++		      unsigned int fragsz, gfp_t gfp_mask)
+ {
+ 	unsigned int size = PAGE_SIZE;
+ 	struct page *page;
+@@ -4012,19 +4012,19 @@ refill:
+ 
+ 	return nc->va + offset;
+ }
+-EXPORT_SYMBOL(__alloc_page_frag);
++EXPORT_SYMBOL(page_frag_alloc);
+ 
+ /*
+  * Frees a page fragment allocated out of either a compound or order 0 page.
+  */
+-void __free_page_frag(void *addr)
++void page_frag_free(void *addr)
+ {
+ 	struct page *page = virt_to_head_page(addr);
+ 
+ 	if (unlikely(put_page_testzero(page)))
+ 		__free_pages_ok(page, compound_order(page));
+ }
+-EXPORT_SYMBOL(__free_page_frag);
++EXPORT_SYMBOL(page_frag_free);
+ 
+ static void *make_alloc_exact(unsigned long addr, unsigned int order,
+ 		size_t size)
+--- a/net/core/skbuff.c
++++ b/net/core/skbuff.c
+@@ -369,7 +369,7 @@ static void *__netdev_alloc_frag(unsigne
+ 
+ 	local_irq_save(flags);
+ 	nc = this_cpu_ptr(&netdev_alloc_cache);
+-	data = __alloc_page_frag(nc, fragsz, gfp_mask);
++	data = page_frag_alloc(nc, fragsz, gfp_mask);
+ 	local_irq_restore(flags);
+ 	return data;
+ }
+@@ -391,7 +391,7 @@ static void *__napi_alloc_frag(unsigned
+ {
+ 	struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache);
+ 
+-	return __alloc_page_frag(&nc->page, fragsz, gfp_mask);
++	return page_frag_alloc(&nc->page, fragsz, gfp_mask);
+ }
+ 
+ void *napi_alloc_frag(unsigned int fragsz)
+@@ -441,7 +441,7 @@ struct sk_buff *__netdev_alloc_skb(struc
+ 	local_irq_save(flags);
+ 
+ 	nc = this_cpu_ptr(&netdev_alloc_cache);
+-	data = __alloc_page_frag(nc, len, gfp_mask);
++	data = page_frag_alloc(nc, len, gfp_mask);
+ 	pfmemalloc = nc->pfmemalloc;
+ 
+ 	local_irq_restore(flags);
+@@ -505,7 +505,7 @@ struct sk_buff *__napi_alloc_skb(struct
+ 	if (sk_memalloc_socks())
+ 		gfp_mask |= __GFP_MEMALLOC;
+ 
+-	data = __alloc_page_frag(&nc->page, len, gfp_mask);
++	data = page_frag_alloc(&nc->page, len, gfp_mask);
+ 	if (unlikely(!data))
+ 		return NULL;
+ 

target/linux/generic/backport-4.9/042-mm-rename-__page_frag-functions-to-__page_frag_cache.patch

@@ -0,0 +1,79 @@
+From: Alexander Duyck <[email protected]>
+Date: Tue, 10 Jan 2017 16:58:09 -0800
+Subject: [PATCH] mm: rename __page_frag functions to __page_frag_cache, drop
+ order from drain
+
+This patch does two things.
+
+First it goes through and renames the __page_frag prefixed functions to
+__page_frag_cache so that we can be clear that we are draining or
+refilling the cache, not the frags themselves.
+
+Second we drop the order parameter from __page_frag_cache_drain since we
+don't actually need to pass it since all fragments are either order 0 or
+must be a compound page.
+
+Link: http://lkml.kernel.org/r/[email protected]
+Signed-off-by: Alexander Duyck <[email protected]>
+Signed-off-by: Andrew Morton <[email protected]>
+Signed-off-by: Linus Torvalds <[email protected]>
+---
+
+--- a/include/linux/gfp.h
++++ b/include/linux/gfp.h
+@@ -506,8 +506,7 @@ extern void free_hot_cold_page(struct pa
+ extern void free_hot_cold_page_list(struct list_head *list, bool cold);
+ 
+ struct page_frag_cache;
+-extern void __page_frag_drain(struct page *page, unsigned int order,
+-			      unsigned int count);
++extern void __page_frag_cache_drain(struct page *page, unsigned int count);
+ extern void *page_frag_alloc(struct page_frag_cache *nc,
+ 			     unsigned int fragsz, gfp_t gfp_mask);
+ extern void page_frag_free(void *addr);
+--- a/mm/page_alloc.c
++++ b/mm/page_alloc.c
+@@ -3925,8 +3925,8 @@ EXPORT_SYMBOL(free_pages);
+  * drivers to provide a backing region of memory for use as either an
+  * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
+  */
+-static struct page *__page_frag_refill(struct page_frag_cache *nc,
+-				       gfp_t gfp_mask)
++static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
++					     gfp_t gfp_mask)
+ {
+ 	struct page *page = NULL;
+ 	gfp_t gfp = gfp_mask;
+@@ -3946,19 +3946,20 @@ static struct page *__page_frag_refill(s
+ 	return page;
+ }
+ 
+-void __page_frag_drain(struct page *page, unsigned int order,
+-		       unsigned int count)
++void __page_frag_cache_drain(struct page *page, unsigned int count)
+ {
+ 	VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
+ 
+ 	if (page_ref_sub_and_test(page, count)) {
++		unsigned int order = compound_order(page);
++
+ 		if (order == 0)
+ 			free_hot_cold_page(page, false);
+ 		else
+ 			__free_pages_ok(page, order);
+ 	}
+ }
+-EXPORT_SYMBOL(__page_frag_drain);
++EXPORT_SYMBOL(__page_frag_cache_drain);
+ 
+ void *page_frag_alloc(struct page_frag_cache *nc,
+ 		      unsigned int fragsz, gfp_t gfp_mask)
+@@ -3969,7 +3970,7 @@ void *page_frag_alloc(struct page_frag_c
+ 
+ 	if (unlikely(!nc->va)) {
+ refill:
+-		page = __page_frag_refill(nc, gfp_mask);
++		page = __page_frag_cache_refill(nc, gfp_mask);
+ 		if (!page)
+ 			return NULL;
+