[3.16.y-ckt stable] Patch "arm64: Move cpu_resume into the text section" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    arm64: Move cpu_resume into the text section

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt4.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 6f6967544fe08c9244d50767fa8d76aa485ad2db Mon Sep 17 00:00:00 2001
From: Laura Abbott <lauraa at codeaurora.org>
Date: Fri, 21 Nov 2014 21:50:40 +0000
Subject: arm64: Move cpu_resume into the text section

commit c3684fbb446501b48dec6677a6a9f61c215053de upstream.

The function cpu_resume currently lives in the .data section.
There's no reason for it to be there since we can use relative
instructions without a problem. Move a few cpu_resume data
structures out of the assembly file so the .data annotation
can be dropped completely and cpu_resume ends up in the read
only text section.

Reviewed-by: Kees Cook <keescook at chromium.org>
Reviewed-by: Mark Rutland <mark.rutland at arm.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
Tested-by: Mark Rutland <mark.rutland at arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
Tested-by: Kees Cook <keescook at chromium.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
Signed-off-by: Laura Abbott <lauraa at codeaurora.org>
Signed-off-by: Will Deacon <will.deacon at arm.com>
[ luis: 3.16-stable prereq for
  f43c27188a49 "arm64: kernel: fix __cpu_suspend mm switch on warm-boot" ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/arm64/kernel/sleep.S   | 36 ++++++------------------------------
 arch/arm64/kernel/suspend.c |  4 ++--
 2 files changed, 8 insertions(+), 32 deletions(-)

diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
index a564b440416a..ede186cdd452 100644
--- a/arch/arm64/kernel/sleep.S
+++ b/arch/arm64/kernel/sleep.S
@@ -147,14 +147,12 @@ cpu_resume_after_mmu:
 	ret
 ENDPROC(cpu_resume_after_mmu)

-	.data
 ENTRY(cpu_resume)
 	bl	el2_setup		// if in EL2 drop to EL1 cleanly
 #ifdef CONFIG_SMP
 	mrs	x1, mpidr_el1
-	adr	x4, mpidr_hash_ptr
-	ldr	x5, [x4]
-	add	x8, x4, x5		// x8 = struct mpidr_hash phys address
+	adrp	x8, mpidr_hash
+	add x8, x8, #:lo12:mpidr_hash // x8 = struct mpidr_hash phys address
         /* retrieve mpidr_hash members to compute the hash */
 	ldr	x2, [x8, #MPIDR_HASH_MASK]
 	ldp	w3, w4, [x8, #MPIDR_HASH_SHIFTS]
@@ -164,14 +162,15 @@ ENTRY(cpu_resume)
 #else
 	mov	x7, xzr
 #endif
-	adr	x0, sleep_save_sp
+	adrp	x0, sleep_save_sp
+	add	x0, x0, #:lo12:sleep_save_sp
 	ldr	x0, [x0, #SLEEP_SAVE_SP_PHYS]
 	ldr	x0, [x0, x7, lsl #3]
 	/* load sp from context */
 	ldr	x2, [x0, #CPU_CTX_SP]
-	adr	x1, sleep_idmap_phys
+	adrp	x1, sleep_idmap_phys
 	/* load physical address of identity map page table in x1 */
-	ldr	x1, [x1]
+	ldr	x1, [x1, #:lo12:sleep_idmap_phys]
 	mov	sp, x2
 	/*
 	 * cpu_do_resume expects x0 to contain context physical address
@@ -180,26 +179,3 @@ ENTRY(cpu_resume)
 	bl	cpu_do_resume		// PC relative jump, MMU off
 	b	cpu_resume_mmu		// Resume MMU, never returns
 ENDPROC(cpu_resume)
-
-	.align 3
-mpidr_hash_ptr:
-	/*
-	 * offset of mpidr_hash symbol from current location
-	 * used to obtain run-time mpidr_hash address with MMU off
-         */
-	.quad	mpidr_hash - .
-/*
- * physical address of identity mapped page tables
- */
-	.type	sleep_idmap_phys, #object
-ENTRY(sleep_idmap_phys)
-	.quad	0
-/*
- * struct sleep_save_sp {
- *	phys_addr_t *save_ptr_stash;
- *	phys_addr_t save_ptr_stash_phys;
- * };
- */
-	.type	sleep_save_sp, #object
-ENTRY(sleep_save_sp)
-	.space	SLEEP_SAVE_SP_SZ	// struct sleep_save_sp
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index 13ad4dbb1615..3771b72b6569 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -126,8 +126,8 @@ int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
 	return ret;
 }

-extern struct sleep_save_sp sleep_save_sp;
-extern phys_addr_t sleep_idmap_phys;
+struct sleep_save_sp sleep_save_sp;
+phys_addr_t sleep_idmap_phys;

 static int __init cpu_suspend_init(void)
 {
--
2.1.4