From c37583942c14d3574efbb42e39798bd21e65cfc3 Mon Sep 17 00:00:00 2001

From: Dmitry Safonov <dima@arista.com>

Date: Thu, 10 May 2018 19:14:48 +0100

Subject: [PATCH 8/8] ppc64/aarch64: Dynamically define PAGE_SIZE

On ppc64/aarch64 Linux can be set to use Large pages, so the PAGE_SIZE

isn't build-time constant anymore. Define it through _SC_PAGESIZE.

There are different sizes for a page on ppc64:

: #if defined(CONFIG_PPC_256K_PAGES)

: #define PAGE_SHIFT              18

: #elif defined(CONFIG_PPC_64K_PAGES)

: #define PAGE_SHIFT              16

: #elif defined(CONFIG_PPC_16K_PAGES)

: #define PAGE_SHIFT              14

: #else

: #define PAGE_SHIFT              12

: #endif

And on aarch64 there are default sizes and possibly someone can set his

own PAGE_SHIFT:

: config ARM64_PAGE_SHIFT

:         int

:         default 16 if ARM64_64K_PAGES

:         default 14 if ARM64_16K_PAGES

:         default 12

On the downside - each time we need PAGE_SIZE, we're doing libc

function call on aarch64/ppc64.

Fixes: #415

Tested-by: Adrian Reber <areber@redhat.com>

Signed-off-by: Dmitry Safonov <dima@arista.com>

Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

---

 criu/arch/aarch64/crtools.c            |  3 ++

 criu/arch/ppc64/crtools.c              |  3 ++

 include/common/arch/aarch64/asm/page.h | 42 +++++++++++++++++---------

 include/common/arch/ppc64/asm/page.h   | 40 +++++++++++++++---------

 4 files changed, 59 insertions(+), 29 deletions(-)

diff --git a/criu/arch/aarch64/crtools.c b/criu/arch/aarch64/crtools.c

index f98743a23..b2ef1c312 100644

--- a/criu/arch/aarch64/crtools.c

+++ b/criu/arch/aarch64/crtools.c

@@ -21,6 +21,9 @@

 #include "restorer.h"

 #include <compel/compel.h>

+unsigned __page_size = 0;

+unsigned __page_shift = 0;

+

 #define assign_reg(dst, src, e)		dst->e = (__typeof__(dst->e))(src)->e

 int save_task_regs(void *x, user_regs_struct_t *regs, user_fpregs_struct_t *fpsimd)

diff --git a/criu/arch/ppc64/crtools.c b/criu/arch/ppc64/crtools.c

index 5a5966ad4..077c243b2 100644

--- a/criu/arch/ppc64/crtools.c

+++ b/criu/arch/ppc64/crtools.c

@@ -23,6 +23,9 @@

 #include "images/core.pb-c.h"

 #include "images/creds.pb-c.h"

+unsigned __page_size = 0;

+unsigned __page_shift = 0;

+

 static UserPpc64FpstateEntry *copy_fp_regs(uint64_t *fpregs)

 {

 	UserPpc64FpstateEntry *fpe;

diff --git a/include/common/arch/aarch64/asm/page.h b/include/common/arch/aarch64/asm/page.h

index 4126c8474..bd8fe8f71 100644

--- a/include/common/arch/aarch64/asm/page.h

+++ b/include/common/arch/aarch64/asm/page.h

@@ -4,22 +4,36 @@

 #define ARCH_HAS_LONG_PAGES

 #ifndef CR_NOGLIBC

-#include <unistd.h>

-

-#ifndef PAGE_SHIFT

-# define PAGE_SHIFT	12

-#endif

-

-#ifndef PAGE_SIZE

-# define PAGE_SIZE	(1UL << PAGE_SHIFT)

-#endif

-

-#ifndef PAGE_MASK

-# define PAGE_MASK	(~(PAGE_SIZE - 1))

-#endif

+#include <string.h> /* ffsl() */

+#include <unistd.h> /* _SC_PAGESIZE */

+

+extern unsigned __page_size;

+extern unsigned __page_shift;

+

+static inline unsigned page_size(void)

+{

+	if (!__page_size)

+		__page_size = sysconf(_SC_PAGESIZE);

+	return __page_size;

+}

+

+static inline unsigned page_shift(void)

+{

+	if (!__page_shift)

+		__page_shift = (ffsl(page_size()) - 1);

+	return __page_shift;

+}

+

+/*

+ * Don't add ifdefs for PAGE_SIZE: if any header defines it as a constant

+ * on aarch64, then we need refrain using PAGE_SIZE in criu and use

+ * page_size() across sources (as it may differ on aarch64).

+ */

+#define PAGE_SIZE	page_size()

+#define PAGE_MASK	(~(PAGE_SIZE - 1))

+#define PAGE_SHIFT	page_shift()

 #define PAGE_PFN(addr)	((addr) / PAGE_SIZE)

-#define page_size()	sysconf(_SC_PAGESIZE)

 #else /* CR_NOGLIBC */

diff --git a/include/common/arch/ppc64/asm/page.h b/include/common/arch/ppc64/asm/page.h

index a95af55ef..5107cb8e0 100644

--- a/include/common/arch/ppc64/asm/page.h

+++ b/include/common/arch/ppc64/asm/page.h

@@ -4,26 +4,36 @@

 #define ARCH_HAS_LONG_PAGES

 #ifndef CR_NOGLIBC

-#include <unistd.h>

+#include <string.h> /* ffsl() */

+#include <unistd.h> /* _SC_PAGESIZE */

+

+extern unsigned __page_size;

+extern unsigned __page_shift;

+

+static inline unsigned page_size(void)

+{

+	if (!__page_size)

+		__page_size = sysconf(_SC_PAGESIZE);

+	return __page_size;

+}

+

+static inline unsigned page_shift(void)

+{

+	if (!__page_shift)

+		__page_shift = (ffsl(page_size()) - 1);

+	return __page_shift;

+}

 /*

- * Default config for Pseries is to use 64K pages.

- * See kernel file arch/powerpc/configs/pseries_*defconfig

+ * Don't add ifdefs for PAGE_SIZE: if any header defines it as a constant

+ * on ppc64, then we need refrain using PAGE_SIZE in criu and use

+ * page_size() across sources (as it may differ on ppc64).

  */

-#ifndef PAGE_SHIFT

-# define PAGE_SHIFT	16

-#endif

-

-#ifndef PAGE_SIZE

-# define PAGE_SIZE	(1UL << PAGE_SHIFT)

-#endif

-

-#ifndef PAGE_MASK

-# define PAGE_MASK	(~(PAGE_SIZE - 1))

-#endif

+#define PAGE_SIZE	page_size()

+#define PAGE_MASK	(~(PAGE_SIZE - 1))

+#define PAGE_SHIFT	page_shift()

 #define PAGE_PFN(addr)	((addr) / PAGE_SIZE)

-#define page_size()	sysconf(_SC_PAGESIZE)

 #else /* CR_NOGLIBC */

-- 

2.17.0