ARM: OMAP2+: Fix l2dis_3630 for rodata

[ Upstream commit eeaf9646 ]

We don't want to write to .text section. Let's move l2dis_3630
to .data and access it via a pointer.

For calculating the offset, let's optimize out the add and do it
in ldr/str as suggested by Nicolas Pitre <nicolas.pitre@linaro.org>.

Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: stable@vger.kernel.org # v4.0+
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org # v4.0+
Fixes: 1e6b4811 ("ARM: mm: allow non-text sections to be
non-executable")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

arch/arm/mach-omap2/sleep34xx.S

@@ -86,8 +86,9 @@ ENTRY(enable_omap3630_toggle_l2_on_restore)
 	stmfd	sp!, {lr}	@ save registers on stack
 	/* Setup so that we will disable and enable l2 */
 	mov	r1, #0x1
-	adrl	r2, l2dis_3630	@ may be too distant for plain adr
-	str	r1, [r2]
+	adrl	r3, l2dis_3630_offset	@ may be too distant for plain adr
+	ldr	r2, [r3]		@ value for offset
+	str	r1, [r2, r3]		@ write to l2dis_3630
 	ldmfd	sp!, {pc}	@ restore regs and return
 ENDPROC(enable_omap3630_toggle_l2_on_restore)
 
@@ -415,7 +416,9 @@ ENTRY(omap3_restore)
 	cmp	r2, #0x0	@ Check if target power state was OFF or RET
 	bne	logic_l1_restore
 
-	ldr	r0, l2dis_3630
+	adr	r1, l2dis_3630_offset	@ address for offset
+	ldr	r0, [r1]		@ value for offset
+	ldr	r0, [r1, r0]		@ value at l2dis_3630
 	cmp	r0, #0x1	@ should we disable L2 on 3630?
 	bne	skipl2dis
 	mrc	p15, 0, r0, c1, c0, 1
@@ -484,7 +487,9 @@ l2_inv_gp:
 	mov	r12, #0x2
 	smc	#0			@ Call SMI monitor (smieq)
 logic_l1_restore:
-	ldr	r1, l2dis_3630
+	adr	r0, l2dis_3630_offset	@ adress for offset
+	ldr	r1, [r0]		@ value for offset
+	ldr	r1, [r0, r1]		@ value at l2dis_3630
 	cmp	r1, #0x1		@ Test if L2 re-enable needed on 3630
 	bne	skipl2reen
 	mrc	p15, 0, r1, c1, c0, 1
@@ -513,6 +518,10 @@ control_stat:
 	.word	CONTROL_STAT
 control_mem_rta:
 	.word	CONTROL_MEM_RTA_CTRL
+l2dis_3630_offset:
+	.long	l2dis_3630 - .
+
+	.data
 l2dis_3630:
 	.word	0