This is a note to let you know that I've just added the patch titled
powerpc/64: Add macros for annotating the destination of rfid/hrfid
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 50e51c13b3822d14ff6df4279423e4b7b2269bc3 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@xxxxxxxxx>
Date: Wed, 10 Jan 2018 03:07:15 +1100
Subject: powerpc/64: Add macros for annotating the destination of rfid/hrfid
From: Nicholas Piggin <npiggin@xxxxxxxxx>
commit 50e51c13b3822d14ff6df4279423e4b7b2269bc3 upstream.
The rfid/hrfid ((Hypervisor) Return From Interrupt) instruction is
used for switching from the kernel to userspace, and from the
hypervisor to the guest kernel. However it can and is also used for
other transitions, eg. from real mode kernel code to virtual mode
kernel code, and it's not always clear from the code what the
destination context is.
To make it clearer when reading the code, add macros which encode the
expected destination context.
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/exception-64e.h | 6 ++++++
arch/powerpc/include/asm/exception-64s.h | 29 +++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
--- a/arch/powerpc/include/asm/exception-64e.h
+++ b/arch/powerpc/include/asm/exception-64e.h
@@ -209,5 +209,11 @@ exc_##label##_book3e:
ori r3,r3,vector_offset@l; \
mtspr SPRN_IVOR##vector_number,r3;
+#define RFI_TO_KERNEL \
+ rfi
+
+#define RFI_TO_USER \
+ rfi
+
#endif /* _ASM_POWERPC_EXCEPTION_64E_H */
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -51,6 +51,35 @@
#define EX_PPR 88 /* SMT thread status register (priority) */
#define EX_CTR 96
+/* Macros for annotating the expected destination of (h)rfid */
+
+#define RFI_TO_KERNEL \
+ rfid
+
+#define RFI_TO_USER \
+ rfid
+
+#define RFI_TO_USER_OR_KERNEL \
+ rfid
+
+#define RFI_TO_GUEST \
+ rfid
+
+#define HRFI_TO_KERNEL \
+ hrfid
+
+#define HRFI_TO_USER \
+ hrfid
+
+#define HRFI_TO_USER_OR_KERNEL \
+ hrfid
+
+#define HRFI_TO_GUEST \
+ hrfid
+
+#define HRFI_TO_UNKNOWN \
+ hrfid
+
#ifdef CONFIG_RELOCATABLE
#define __EXCEPTION_RELON_PROLOG_PSERIES_1(label, h) \
mfspr r11,SPRN_##h##SRR0; /* save SRR0 */ \
Patches currently in stable-queue which might be from npiggin@xxxxxxxxx are
queue-4.9/powerpc-64-add-macros-for-annotating-the-destination-of-rfid-hrfid.patch
queue-4.9/powerpc-64s-allow-control-of-rfi-flush-via-debugfs.patch
queue-4.9/powerpc-64s-convert-slb_miss_common-to-use-rfi_to_user-kernel.patch
queue-4.9/powerpc-64-convert-the-syscall-exit-path-to-use-rfi_to_user-kernel.patch
queue-4.9/powerpc-64s-add-support-for-rfi-flush-of-l1-d-cache.patch
queue-4.9/powerpc-64-convert-fast_exception_return-to-use-rfi_to_user-kernel.patch