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Commit 03dc6107 authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk
Browse files

Merge branch 'stable/frontswap-tmemonly' of...

Merge branch 'stable/frontswap-tmemonly' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem into stable/drivers

* 'stable/frontswap-tmemonly' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem:
  xen: prepare tmem shim to handle frontswap
parents 56299378 afec6e04
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+7 −0
Original line number Diff line number Diff line
@@ -105,4 +105,11 @@ config SWIOTLB_XEN
	depends on PCI
	select SWIOTLB

config XEN_TMEM
	bool
	default y if (CLEANCACHE || FRONTSWAP)
	help
	  Shim to interface in-kernel Transcendent Memory hooks
	  (e.g. cleancache and frontswap) to Xen tmem hypercalls.

endmenu
+1 −1
Original line number Diff line number Diff line
obj-y	+= grant-table.o features.o events.o manage.o balloon.o
obj-y	+= xenbus/
obj-y	+= tmem.o

nostackp := $(call cc-option, -fno-stack-protector)
CFLAGS_features.o			:= $(nostackp)
@@ -15,6 +14,7 @@ obj-$(CONFIG_XEN_GRANT_DEV_ALLOC) += xen-gntalloc.o
obj-$(CONFIG_XENFS)			+= xenfs/
obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
obj-$(CONFIG_XEN_PLATFORM_PCI)		+= xen-platform-pci.o
obj-$(CONFIG_XEN_TMEM)			+= tmem.o
obj-$(CONFIG_SWIOTLB_XEN)		+= swiotlb-xen.o
obj-$(CONFIG_XEN_DOM0)			+= pci.o

+158 −12
Original line number Diff line number Diff line
/*
 * Xen implementation for transcendent memory (tmem)
 *
 * Copyright (C) 2009-2010 Oracle Corp.  All rights reserved.
 * Copyright (C) 2009-2011 Oracle Corp.  All rights reserved.
 * Author: Dan Magenheimer
 */

@@ -9,8 +9,14 @@
#include <linux/types.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/module.h>
#include <linux/cleancache.h>

/* temporary ifdef until include/linux/frontswap.h is upstream */
#ifdef CONFIG_FRONTSWAP
#include <linux/frontswap.h>
#endif

#include <xen/xen.h>
#include <xen/interface/xen.h>
#include <asm/xen/hypercall.h>
@@ -122,14 +128,8 @@ static int xen_tmem_flush_object(u32 pool_id, struct tmem_oid oid)
	return xen_tmem_op(TMEM_FLUSH_OBJECT, pool_id, oid, 0, 0, 0, 0, 0);
}

static int xen_tmem_destroy_pool(u32 pool_id)
{
	struct tmem_oid oid = { { 0 } };

	return xen_tmem_op(TMEM_DESTROY_POOL, pool_id, oid, 0, 0, 0, 0, 0);
}

int tmem_enabled;
int tmem_enabled __read_mostly;
EXPORT_SYMBOL(tmem_enabled);

static int __init enable_tmem(char *s)
{
@@ -139,6 +139,14 @@ static int __init enable_tmem(char *s)

__setup("tmem", enable_tmem);

#ifdef CONFIG_CLEANCACHE
static int xen_tmem_destroy_pool(u32 pool_id)
{
	struct tmem_oid oid = { { 0 } };

	return xen_tmem_op(TMEM_DESTROY_POOL, pool_id, oid, 0, 0, 0, 0, 0);
}

/* cleancache ops */

static void tmem_cleancache_put_page(int pool, struct cleancache_filekey key,
@@ -240,18 +248,156 @@ static struct cleancache_ops tmem_cleancache_ops = {
	.init_shared_fs = tmem_cleancache_init_shared_fs,
	.init_fs = tmem_cleancache_init_fs
};
#endif

static int __init xen_tmem_init(void)
#ifdef CONFIG_FRONTSWAP
/* frontswap tmem operations */

/* a single tmem poolid is used for all frontswap "types" (swapfiles) */
static int tmem_frontswap_poolid;

/*
 * Swizzling increases objects per swaptype, increasing tmem concurrency
 * for heavy swaploads.  Later, larger nr_cpus -> larger SWIZ_BITS
 */
#define SWIZ_BITS		4
#define SWIZ_MASK		((1 << SWIZ_BITS) - 1)
#define _oswiz(_type, _ind)	((_type << SWIZ_BITS) | (_ind & SWIZ_MASK))
#define iswiz(_ind)		(_ind >> SWIZ_BITS)

static inline struct tmem_oid oswiz(unsigned type, u32 ind)
{
	struct cleancache_ops old_ops;
	struct tmem_oid oid = { .oid = { 0 } };
	oid.oid[0] = _oswiz(type, ind);
	return oid;
}

/* returns 0 if the page was successfully put into frontswap, -1 if not */
static int tmem_frontswap_put_page(unsigned type, pgoff_t offset,
				   struct page *page)
{
	u64 ind64 = (u64)offset;
	u32 ind = (u32)offset;
	unsigned long pfn = page_to_pfn(page);
	int pool = tmem_frontswap_poolid;
	int ret;

	if (pool < 0)
		return -1;
	if (ind64 != ind)
		return -1;
	mb(); /* ensure page is quiescent; tmem may address it with an alias */
	ret = xen_tmem_put_page(pool, oswiz(type, ind), iswiz(ind), pfn);
	/* translate Xen tmem return values to linux semantics */
	if (ret == 1)
		return 0;
	else
		return -1;
}

/*
 * returns 0 if the page was successfully gotten from frontswap, -1 if
 * was not present (should never happen!)
 */
static int tmem_frontswap_get_page(unsigned type, pgoff_t offset,
				   struct page *page)
{
	u64 ind64 = (u64)offset;
	u32 ind = (u32)offset;
	unsigned long pfn = page_to_pfn(page);
	int pool = tmem_frontswap_poolid;
	int ret;

	if (pool < 0)
		return -1;
	if (ind64 != ind)
		return -1;
	ret = xen_tmem_get_page(pool, oswiz(type, ind), iswiz(ind), pfn);
	/* translate Xen tmem return values to linux semantics */
	if (ret == 1)
		return 0;
	else
		return -1;
}

/* flush a single page from frontswap */
static void tmem_frontswap_flush_page(unsigned type, pgoff_t offset)
{
	u64 ind64 = (u64)offset;
	u32 ind = (u32)offset;
	int pool = tmem_frontswap_poolid;

	if (pool < 0)
		return;
	if (ind64 != ind)
		return;
	(void) xen_tmem_flush_page(pool, oswiz(type, ind), iswiz(ind));
}

/* flush all pages from the passed swaptype */
static void tmem_frontswap_flush_area(unsigned type)
{
	int pool = tmem_frontswap_poolid;
	int ind;

	if (pool < 0)
		return;
	for (ind = SWIZ_MASK; ind >= 0; ind--)
		(void)xen_tmem_flush_object(pool, oswiz(type, ind));
}

static void tmem_frontswap_init(unsigned ignored)
{
	struct tmem_pool_uuid private = TMEM_POOL_PRIVATE_UUID;

	/* a single tmem poolid is used for all frontswap "types" (swapfiles) */
	if (tmem_frontswap_poolid < 0)
		tmem_frontswap_poolid =
		    xen_tmem_new_pool(private, TMEM_POOL_PERSIST, PAGE_SIZE);
}

static int __initdata use_frontswap = 1;

static int __init no_frontswap(char *s)
{
	use_frontswap = 0;
	return 1;
}

__setup("nofrontswap", no_frontswap);

static struct frontswap_ops tmem_frontswap_ops = {
	.put_page = tmem_frontswap_put_page,
	.get_page = tmem_frontswap_get_page,
	.flush_page = tmem_frontswap_flush_page,
	.flush_area = tmem_frontswap_flush_area,
	.init = tmem_frontswap_init
};
#endif

static int __init xen_tmem_init(void)
{
	if (!xen_domain())
		return 0;
#ifdef CONFIG_FRONTSWAP
	if (tmem_enabled && use_frontswap) {
		char *s = "";
		struct frontswap_ops old_ops =
			frontswap_register_ops(&tmem_frontswap_ops);

		tmem_frontswap_poolid = -1;
		if (old_ops.init != NULL)
			s = " (WARNING: frontswap_ops overridden)";
		printk(KERN_INFO "frontswap enabled, RAM provided by "
				 "Xen Transcendent Memory\n");
	}
#endif
#ifdef CONFIG_CLEANCACHE
	BUG_ON(sizeof(struct cleancache_filekey) != sizeof(struct tmem_oid));
	if (tmem_enabled && use_cleancache) {
		char *s = "";
		old_ops = cleancache_register_ops(&tmem_cleancache_ops);
		struct cleancache_ops old_ops =
			cleancache_register_ops(&tmem_cleancache_ops);
		if (old_ops.init_fs != NULL)
			s = " (WARNING: cleancache_ops overridden)";
		printk(KERN_INFO "cleancache enabled, RAM provided by "