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authorSteven Price <steven.price@arm.com>2020-04-22 15:25:27 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2020-09-04 12:46:06 +0100
commit4beba9486abd2f86d125271d6946f7c38ed0fe77 (patch)
treeb6077490a328fe217ca4f359ceea847872f3f4cd
parent637ec831ea4f09c7529ac4078399ce4e25b46341 (diff)
mm: Add PG_arch_2 page flag
For arm64 MTE support it is necessary to be able to mark pages that contain user space visible tags that will need to be saved/restored e.g. when swapped out. To support this add a new arch specific flag (PG_arch_2). This flag is only available on 64-bit architectures due to the limited number of spare page flags on the 32-bit ones. Signed-off-by: Steven Price <steven.price@arm.com> [catalin.marinas@arm.com: use CONFIG_64BIT for guarding this new flag] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--fs/proc/page.c3
-rw-r--r--include/linux/kernel-page-flags.h1
-rw-r--r--include/linux/page-flags.h3
-rw-r--r--include/trace/events/mmflags.h9
-rw-r--r--tools/vm/page-types.c2
5 files changed, 17 insertions, 1 deletions
diff --git a/fs/proc/page.c b/fs/proc/page.c
index f909243d4a66..9f1077d94cde 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -217,6 +217,9 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
+#ifdef CONFIG_64BIT
+ u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
+#endif
return u;
};
diff --git a/include/linux/kernel-page-flags.h b/include/linux/kernel-page-flags.h
index abd20ef93c98..eee1877a354e 100644
--- a/include/linux/kernel-page-flags.h
+++ b/include/linux/kernel-page-flags.h
@@ -17,5 +17,6 @@
#define KPF_ARCH 38
#define KPF_UNCACHED 39
#define KPF_SOFTDIRTY 40
+#define KPF_ARCH_2 41
#endif /* LINUX_KERNEL_PAGE_FLAGS_H */
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 6be1aa559b1e..276140c94f4a 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -136,6 +136,9 @@ enum pageflags {
PG_young,
PG_idle,
#endif
+#ifdef CONFIG_64BIT
+ PG_arch_2,
+#endif
__NR_PAGEFLAGS,
/* Filesystems */
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 5fb752034386..67018d367b9f 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -79,6 +79,12 @@
#define IF_HAVE_PG_IDLE(flag,string)
#endif
+#ifdef CONFIG_64BIT
+#define IF_HAVE_PG_ARCH_2(flag,string) ,{1UL << flag, string}
+#else
+#define IF_HAVE_PG_ARCH_2(flag,string)
+#endif
+
#define __def_pageflag_names \
{1UL << PG_locked, "locked" }, \
{1UL << PG_waiters, "waiters" }, \
@@ -105,7 +111,8 @@ IF_HAVE_PG_MLOCK(PG_mlocked, "mlocked" ) \
IF_HAVE_PG_UNCACHED(PG_uncached, "uncached" ) \
IF_HAVE_PG_HWPOISON(PG_hwpoison, "hwpoison" ) \
IF_HAVE_PG_IDLE(PG_young, "young" ) \
-IF_HAVE_PG_IDLE(PG_idle, "idle" )
+IF_HAVE_PG_IDLE(PG_idle, "idle" ) \
+IF_HAVE_PG_ARCH_2(PG_arch_2, "arch_2" )
#define show_page_flags(flags) \
(flags) ? __print_flags(flags, "|", \
diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
index 58c0eab71bca..0517c744b04e 100644
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c
@@ -78,6 +78,7 @@
#define KPF_ARCH 38
#define KPF_UNCACHED 39
#define KPF_SOFTDIRTY 40
+#define KPF_ARCH_2 41
/* [48-] take some arbitrary free slots for expanding overloaded flags
* not part of kernel API
@@ -135,6 +136,7 @@ static const char * const page_flag_names[] = {
[KPF_ARCH] = "h:arch",
[KPF_UNCACHED] = "c:uncached",
[KPF_SOFTDIRTY] = "f:softdirty",
+ [KPF_ARCH_2] = "H:arch_2",
[KPF_READAHEAD] = "I:readahead",
[KPF_SLOB_FREE] = "P:slob_free",